I have a stock B20 engine. What would an "S" cam do for the performance of the engine? How much of an effort is it to replace the cam?

Thanks for your help.

Jerry
1969 123GT

When you say stock, is it an A, B, E or F?

Assuming it's a B20B the S cam would hurt your bottom end torque & not give you much extra top end in return. If you have twin SU's, a cam with 220 degrees at .050" is the maximum you want, use a K if you're staying with stock springs, D or modern equivalent if you are upgrading your valve springs to dual or beehive.

Here's what Ian Rankin's website http://www.geocities.com/iadr1/superlist_grinds.html
says:
GRIND
NAME
.050
Duration
Advertised
Duration
Overlap
lift
w/1.5
lift
w/1.6
lobe centers
intk / exh valve events @ .050
intake / exhaust
btdc . abdc . bbdc . atdc . valve events @ .020
intake / exhaust
btdc abdc bbdc atdc

R-Sport 's' 254 300 98 .510 .544 101 / 101 26 48 48 26 49 71 71 49

Suggest you go to the site and see it for yourself - formatting is a pain here!
--
George Downs, Bartlesville, Heart of the USA!

Heck of a lot of erroneous info at IADR's. I wish he'd fix it because a lot of people take it as gospel.

Since he hasn't maintained it in over 5 years I suspect he will not fix it.
It only stays up because there is no charge for it.
If you want a job done right........
BTW I have not found a better source for all that info and it IS worth more than I pay for it!
--
George Downs, Bartlesville, Heart of the USA!

Have you got Excel or something else that opens .xls? Send me your email addy to B20Paul@yahoo.com.au & I'll send you a copy of my cam spreadsheet.

I think what George was suggesting is that we create an updated list that is correct and post it on this site. I've noticed a distinct lack of FAQ's related to 122's. I'm going to be dropping in the VPD cam in a couple of weeks and will take lift and duration measurements if there is interest. It's not on Ian's list.

Craig

I put this up a while a go.



Which VPD cam are you installing?

Could you take measurements at valve clearance/1.5, .013", .015", .020", .050", .100", .150", etc. that would fit in well with what I do + Phil has measured an Enem grind in a similar fashion.

Drop me an email if you(or anyone else) want my spreadsheet.

I'm using the street performance grind. I've got some time while I sort out some machinging trouble, so I'll see what I can do.

Craig

That would be great, it look like a cam that would go very well with a stock head.

So... in your opinion, is the 'S' cam info on that website accurate, or not?
--

Gary L - 1971 142E ITB racer, 73 1800ES, 02 S60 T5

No. According to measurements from Ben Flierman, an S cam is 287 degrees @ .020" , 256 degrees @ .050" with .325 lift.

The C,K,D and Enem 18 are wrong too. The VV61&71 are close.

Ian's mistake is believing that advertised duration is .020". That is what the SAE would like it to be, but manufacturers make advertised duration what ever they like. Example, Isky's VV71 advertised duration of 268 degrees is taken at .017"!

I still monitor some of these boards.

Updates have not been done, *partly* due to the info being rehosted by 1800philes, which make it harder for me to maintain or adjust (ie having to work by e-mail), but *primarily* due to not being especially required, as I will try to point out.
Mainly, though, the information in the charts I complied is intended to aid informed choice, and to correctly "sequence" or group the cams in order of resultant rev range, and I doubt there's concern that the charts have any real weakness for that purpose.

***

IMO, one of the issues Paul and Ben have is that many of their samples are either lightly used, or are "jobber" copies. Use often takes very little off, but it worth mentioning in passing. The bigger issue is the jobber copies. When offering a product, volume cam grinding companies do not usually develop a new "Master" lobe to work from, instead choosing one from their existing "library" after precision measuring the sample they aquired. For instance, I know Melling and the US import parts distributor Impact sold the same A, C & D copies that IPD sold or sell. These are close copies based off design mathematics for Chevy Small Block lobes. In the same way, Wolverine/Blue Racer (absorbed by the Crane Cam group) sold very nice R-grind copies (p/n wg1171, obsolete) based off SBC lobe designs. I believe these, or an independently manufactured equivalent, were also available from Melling. I've seen on EBay, a Crane b20 cam that was essentially a D-grind, though in their case they made no claim to that nomenclature. I am not sure where Ben's "S" cam was sourced from. Being that the cores are made solely in the US, what you get when you order, say, a D cam from KG Trimning in Sweden or from Scandcar in Holland may well be an American copy of a used D-cam supplied to a US manufacturer during the 1970's... in fact, I believe this to be so.
There is also some desire to have somewhat generous dimensions accepted, for SCCA ITB use. In no way has this influenced my stats, but it bears noting that is is possible to buy a D cam that very slightly exceeds my duration specs, which in turn exceed Ben's/Paul's by a slightly greater amount.
To try to wrap up this point and move on, what I have done is to use original Volvo data (from memory, the R-sport Catalog was a leading source), and averaged it with what I've seen people come up with more recently in the field. In some cases, I've weighted the averages more heavily toward original Volvo design data.

*******

The method and tools that Ben and Paul use - a degree wheel and magnetic dial indicator- are very accurate at the higher lifts, but 'perfect' statistical accuracy can be difficult on the .010-0.015-0.020 measurements. I would say 2 degrees plus or minus, possibly 3 depending on how late at night it is... so say 4-5 degrees, total. At that point it can be useful to review, fudge, or "smooth" your data, based on how cams are ground. There's almost always a fixed mathematics used by any one manufacturer, and the cam is simply "grown" for greater duration applications. What this means is that the change from one lift to another, should take place in a very similar number of degrees in different duration lobes (statistically, the exception being the duration approaching max lift, though it's logical that this should be so). So, I can most assuredly point out a genuine error in the chart Paul posted: the Isky cams, #61 & 71 have an "anomoly" at .050"... they are 12 degrees different through out the range, except at .050, where they are reported to be only 4 degrees different.
Bearing in mind the size of the actual part, and that flat tappet cams are generally ground with a 3" radius wheel, it's barely possibly that this could be so, and if it were, one or the other would be an unhappy lobe design, due to the deviation from the basic parabolic shape. Far more likely, the information from Isky was misconstrued or mistyped.
Another example is that the K-cam was developed to help the K-Jetronic system give good throttle response off idle. I think it extremely unlikely that they radically extended the opening ramps. They may have slightly extended them for wear reduction or tappet noise reduction. In the given numbers I see an another *highly* unlikely anomoly with the low lift durations of the C& K vs the D. I suspect that either the C/K pair, or the D sample, was from a different lobe/manufacturer, and as such is not comparable in fine detail.

*****

I am not sure what you (Paul) are referring to when you state that the "enem 18" is "wrong"...without animous, possibly only that one of the several applying statistics are off by a couple numerals?
How have you determined this?
Bearing the above discussion about lobe families, how is it you have issues with the 18 but not the 16, 17 or 19?
Janne Careborn at Enem specifically states he used .020" as advertised, so the Adv. Dur. #'s (&lift, & lobe separation) are as given by his own paperwork and website...
By using the useful lift-at-TDC figures often supplied by Euro/Swedish vendors, you can "triangulate" and have a further data point. On the cams of that group, that was a great help in approximating the @.050".
On the other hand, it is faintly possible that Janne is doing something odd like taking the lash out, as the impression I got a few years ago was that Phil S's car doesn't really quite act like his K19 is as big as the stats show, so I am willing to listen.
Janne also changed manufacturing and/or design equipment since the original OHV range was offered, so again, it is faintly possible he is now making "artist's interpretations" of his own previous product, with slightly altered stats.

*****

When Paul originally posted the chart above, I copied it into a photo editor, contrasted it, sectioned it, and adjusted it. I'll add the result at the bottom. I am not even sure I regard this as a fully definitive set of stats, but more my revision of something I've seen posted.
I've also added along the bottom, mostly for my own use.
The A data is, I think, from Ben from Holland as well. It seems almost suspiciously short...
The Comp is CompCams of Memphis TN. The shown pair of lobes was "state of the art" in around spring 2003. I was seeking maximum lobe size while maintaining minimum duration.
The UDH is a prototype lobe that exists only in CAD/CAM type programming. It is the result of showing my criteria to an expereinced and well regarded designer for a competing cam company to Comp, and he deciding to "show off his design chops", and give me "more" of what I was seeking.
Interestingly, he stated he also designed for full original-equipment levels of durability.
Usually, when seeking short duration and max lift, you compromise durability, to a slight or great extent, depending on your cam designers ability and capability of translating that into an accurately made piece. There are known issues: the Volvo oiling system tending to not supply enough oil, and that the best wear reducing additives no longer being added to oils in representative quanities. Likewise, there are known solutions available tp the well informed b20 engine builder: oil additives, ceramic faced lifters, nitriding of the cams, machining for larger diameter lifters, and most easily, chosing the right valve spring. I regard the Isky-IPD double valves springs as gross excess. Depending on the machine shop cutting the seats, and tolerance stack up, you can see over 115 on the seat, and 210 over the nose. My personal car uses original Volvo lifters, a nitrided cam , and Crower-vended springs intended for air cooled VW applications. The installed pressures were about 90 and 150 over the nose, and a titanium retainer was used, as these spring pressures are close to minimum, and also because they looked cool and set up at a slightly better height than their steel equivalent. The spring retainer pkg does allow up to .620" lift, if that were ever required.
I will state that trading off durability for quick valve motions offers only subtle & theoretical gains, so I am not encouraging that for the vast majority of users.

Lastly in the photo, I've included stats for one of VPD-John Parkers cams. I believe this is the one referred to as the SP? Very nicely chosen lobes, it would appear. They should "crutch" the fact that there is little high lift exhaust port flow. Hopefully John doesn't mind my posting the measurements. I can't imagine that showing these would prevent anyone from buying his product, and I can imagine it may well encourage some sales. Hopefully these do not suffer from any delivery delays. The lobes used probably represent a well chosen point where quicker valve openings show diminishing returns vs wear failure possibilities.

It can also not be forgotten that the timing (lobe separation angle as well as overall timing)of the lobes to the crank position vary with different grinds. For example this is one reason the Isky grinds can act "larger" than the OE Volvo ones while appearing somewhat similar by charted measurement.

Best regards to George, Cameron, Paul, John & the rest,
IR

Just want to jump in and congratulate you on a very informative post - one of the best that I have seen on the brickboard. The importance is the degree of analysis, regardless of whether there are a few "facts" that could be in dispute or opinions that some might not agree with.

And no, I have no problem with your posting specs from our street performance cam,or other cams, since this is a perfect context in which basics of the designs can be understood. But I should add a couple of things of a practical nature.

Our SP, or street performance cam, is not our only cam, though its the most popular in terms of meeting the most common requirements. This year, after dyno testing over the winter, we added another version of this cam for our 2.3 and 2.5 liter engines, the 5th different cam design for those engines. We usually stock about 20 cams, but these are divided currently among 8 different cam grinds right, with one more under development. We stock more of the most popular ones and only one or two spares for the less popular race and rally cams. And our grinds are not always the same from year to year, as we improve the grinds based on experience/testing in different engines - applications. And I much prefer to sell them based on application, and as part of a particular package, rather than selling them based on specifications.

Delays in being able to supply cams have largely been do to a shortage of cores,
which, as mentioned, have only one source. On one occasion I had to buy cores from Europe, that were originally made in the US, just so that we could have a few more cams ground for customers.

There needs to be more of a discussion of the rest of the valve train, especially the rocker arms. In terms of practical application, it does not make a lot of sense to dwell on minute difference in cam design and then throw on rocker arms that can vary the actual valve lift, at .200 cam lift for example, by .025 or more. (Someone with a lot of time can go back and compute the affect of that difference in actual rocker ratio on the duration at the valve at various cam lifts. )

In the real world, very few people ( not companies ) can afford the time or money to experiment with cam design by having a series of different cams ground for a particular application ( especially a popular one like 40 year old Volvos ), but anyone can experiment using changes in valve lash settings and rocker ratios to simulate cam differences - add a little more intake, decrease the exhaust, for example. This is where having original equipment rockers with different ratios can be turned into an advantage.

Just some thoughts before I really have to go back to work.

John
V-performance.com

Why did you alter the data on the chart? I believe that the cams that Ben measured are the genuine article, but you've changed that for unknown reasons??

The method and tools that Ben and Paul use - a degree wheel and magnetic dial indicator- are very accurate at the higher lifts, but 'perfect' statistical accuracy can be difficult on the .010-0.015-0.020 measurements. I would say 2 degrees plus or minus, possibly 3 depending on how late at night it is... so say 4-5 degrees, total.

I get an accuracy of +/- 0.25 of a degree like Phil.

Bearing in mind the size of the actual part, and that flat tappet cams are generally ground with a 3" radius wheel

The Repco cam grinder that is common here in Australia use a wheel that's about 18" in diameter.

So, I can most assuredly point out a genuine error in the chart Paul posted: the Isky cams, #61 & 71 have an "anomoly" at .050"... they are 12 degrees different through out the range, except at .050, where they are reported to be only 4 degrees different.

That's not an anomaly, the W-71 is 264@.020", 268@.017", it's no relation to the W-61, so why does it need to have the same ramps & flanks on it? The W-71 is a pretty close match to the VPD's SP exhaust lobe is you compare the two.

Usually, when seeking short duration and max lift, you compromise durability, to a slight or great extent

Short duration & max lift doesn't work well in a B20 except when your forced to keep twin SU's. I might consider using Comp Cams XS for the inlet, but I wouldn't risk using it for an exhaust, it's just too harsh.

There are known issues: the Volvo oiling system tending to not supply enough oil, and that the best wear reducing additives no longer being added to oils in representative quanities. Likewise, there are known solutions available tp the well informed b20 engine builder: oil additives, ceramic faced lifters, nitriding of the cams, machining for larger diameter lifters, and most easily, chosing the right valve spring.

The biggest factor I have noted is lobe width & lobe centre to lifter centre offset. I narrow my lobes to give the correct offset & lifter rotation if the block has a problem with the stock CWC billet.

Ian,

I'm the one that measured the Enem K18 and sent the info to Paul. I measured several lobes at .012", .020", .050", .100", .200", and .300" lifter rise and got consistent and repeatable duration numbers within 1/2 degree accuracy, so I'm pretty confident my numbers are right for the particular cam I checked, if not for all instances of the K18. Camlift was also consistent to .001". I've got that info stashed away somewhere -- it's likely Paul can retrieve it more easily than I can.

After way, way too long a period of being overbooked in the shop, I should have a break in another week or two and will measure the K19 in the MPPE. I've built a number of engines since using cams with less duration and lift which peaked at higher RPMs for both torque and HP (*not* higher numbers), so something may be off with mine, as you suggest. Or it may be an exhaust tuning problem, or both.

Paul is quite right that advertised duration doesn't always reflect .020" lash. I've been using custom cams from Schneider Racing the past few years, and they accurately make the advertised duration at whatever the recommended lash is for each cam, and that varies from .014" to .020".

I remember from an old Richard Gordon cam chart that the Volvo D was spec'd at .015".

I should have a break in another week or two and will measure the K19 in the MPPE.

I'm looking forward to that!

I've built a number of engines since using cams with less duration and lift which peaked at higher RPMs for both torque and HP (*not* higher numbers), so something may be off with mine, as you suggest. Or it may be an exhaust tuning problem, or both.

The torque curve of your MPPE reflects what mine does. No matter what you do, the head isn't big enough, so B20's thrive on an early opening intake which lifts the torque band through the usable rev range. If you take the cam that you have in MPPE & close the lobe centre up tighter, I'd expect to see torque climb higher between 3000 & 6000 due to the intake opening earlier & the intake reversion problem move to a lower point in the rev range due to the intake closing earlier.

It's worthwhile to measure the lobe around where it lifts off the seat, so that you can see how wide you can run the lash for testing purposes. ("Lash Loops")

"No matter what you do, the head isn't big enough".

Paul, that's not what my testing shows, at least with my heads and some I have tested done by others.
Whether I am flow testing or testing on the dyno I can usually show that it is
not the head that is the restriction, but rather its the intake manifold, the carbs, or the exhaust. Improving the head beyond a certain point does not help, but improving one of those other components does. Simple trial and error testing.

To elaborate -

If you flow test with carbs and intake on the head, you can often see that no matter what you do to improve the head beyond a certain point, you can't actually improve the flow without changing to better flowing intakes and carbs. I have a lot of heads out there that will outflow the components that are bolted on to them. In dyno testing this becomes very obvious with our larger displacement engines where the carbs, intake or exhaust becomes a restriction long before head flow does. In fact, we can use heads with exactly the same flow numbers in a 180 hp application and a 250 hp application.

John
V-performance.com

Are you talking about mid lift or high lift flow?

While you might find enough high lift flow, most cams don't have the valve open that high when the cylinder really needs it around 70 degrees ATDC.

In dyno testing this becomes very obvious with our larger displacement engines where the carbs, intake or exhaust becomes a restriction long before head flow does.

How big is the carbs & cam? Way back 20 years ago when we were playing with stroker motors, a 2.4 litre (3.625" x 90mm) would take a cam with 260 degrees at .050" and pull like a train at 1800rpms. This is the intake flow figures for the head that was on it:
Lift CFM@10"H2O
0.0875 30.5
0.1750 61.5
0.2625 82
0.3500 99.5
0.4375 113.5
0.5250 117

I think this is only enough gas flow for a 2.1 litre, what do you think?

Hi John .... Ok then ... what combination of carbs/injection, intake manifold combined with exhaust setup have you found to be optimum from a power producing standpoint ? Have you compared different pipe sizes and designs of headers i.e. Tri-Y vs 4 to 1 ?

Brett

--
Brett Sutherland & the 1.5 million mile 122 CANADIAN --- WINDSOR, Nova Scotia the birthplace of HOCKEY www.ecvintagevolvo.com

One answer is that no combination is ever optimum, because there will always be additional combinations that haven't been tried on a particular engine. There's only the best of the ones that have been tried, and sometimes there is really no difference between several different combinations, which is when I really worry that I have missed something. And sometimes I am certain that a particular setup would be better, but for some reason or another its not practical to actually use - such as a header or intake manifold with lengths that fit on the engine on the dyno, but will not fit on the engine in the car - so its a waste of time to test with that setup.

But back to the question. If you are keeping the engine ( the block and head ) essentially stock, and only trying to bolt on power, that's something I have had little interest in, because the route to real power is to make internal changes, the most important of which are porting the head and adding a cam that compliments what has been done to the head. After the head is ported for decent flow you can then increase displacement and do a bunch of fun things with the engine internals. What seems to work best is adding stroke, not bore size.

What intake and exhaust work best depends on engine specs and how it is going to be used. I've done a lot of testing where we have compared setups, and there is really a testing process that you have to go through in order to get the answers. On a new engine combination that I have not tested before it would not be unusual to do 30 - 50 dyno runs testing different carb setups, different exhausts, different ignition timing, different intake lengths, valve setttings, etc. How many different intakes or exhausts can you reasonably test on any one engine? How many different exhaust lengths do you test on each header? Assuming
a 4 - 2 -1 header and a 4 - 1 header, how many different tube lengths do you check on each?

For a recent example, on a 92 mm bore-stock stroke B20 with some port work and an IPD street performance cam, making approx. 165 HP with a set of 45 DCOE webers we found that it made almost exactly the same power with a pair of Mikuni HSR carbs on a stock SU intake manifold. Bump up the size of the engine to 92 x 92, and the mikunis performance fell off in comparison to the webers - due to the limitations of the stock intake - when power got into the 190 - 200 HP range.
Change the Mikuni intake manifold to one similar to the weber intake, and add two more Mikunis so you are comparing 4 throats to 4 throats on similar manifolds and the mikunis are now superior to the webers. Change the weber intake from the usual shorty manifold sold with most weber kits to a copy of the original R - sport Weber/Solex manifold, and suddenly you gain 12 HP and get much better throttle response without any other changes. Swap the rockers around to better match up the ratios and we are over 215 HP, using the same head and cam used to make 150 HP on a 2 liter motor, for a mildly tuned B20 street engine with great low end torque.

When it comes to exhaust headers you can't just say 4 - 1 vs 4-2-1 as there are an almost infinite number of combinations. Juggle the tube diameters and lengths and you can have either one beat the other. In general, its still a reasonably designed 4-2-1 being best for most uses, with a good 4-1 with equal length primaries of comparable tube size, doing better in the high rpm ranges that a race engine would hit. But there are now a lot of racecars using the
4 - 2- 1, but with lengths tuned more toward power in the high rpm range than low and middle ranges. So it depends on the specifics of the headers you are comparing and what you want the engine to do.

John
V-performance.com

John,thanks for sharing your observations. You are right about few people having the time or budget to develop these old engines on their own.

Your comments about carbs and intakes has me wondering how the fuel injection manifold compares. With the available after market ECU's like Megasquirt it is quite cost effective and easy to tune. That is what I use on my SCCA FP car and I'm seeing pretty good HP out of a docile and very low budget motor. I have never tried sidedraft webers although they are allowed by the rules.

I still have some main bearing caps if you need them. I got side tracked fixing a rather large dent in my ITB car and forgot to get back to you about them.

Charlie

I have not personally done any comparisons of the FI vs. carbs on the same engine.
That was going to be done as part of two projects, both of which got put on hold for various reasons.
From all I hear the intake is good and can sustain at least as much power as sidedraft webers. The advantage goes to FI when you do a cam designed for it.

And yes, I still have blocks that lack main bearing caps.
I believe two blocks, maybe 3.

Regards,
John
Vintage Performance Developments

Based on my limited dyno testing I get the impression that the long runners of the FI manifold have a significant effect on tuning that differs from carbs. I'm on my fourth cam and think the engine wants more but duration but I'm currently a little short on time/money/enthusiasm for engine development in the production car. Having more fun with the ITB 142.

I have considered cutting open a fi intake and cleaning it up or "porting" it. Have you heard of anyone finding power doing this?

I have some cleaning up to do in my garage and storage shed this weekend so I'll dig out those main caps and email you directly about what I find.

I'm on my fourth cam and think the engine wants more but duration

How big are you up to?

I never got as much mid range torque out of the injection manifold as I did with 2x 48mm DHLA's, but I'm pretty sure the Dellortos were longer.

Have you tried using Helmoltz tuning theory on the throttle side of the manifold on either car?

I think the D-Jet manifold has a wide, shallow mid range hole in the power band. The mixture gets rich and torque drops. You don't see it much with a mild cam but it shows up when the intake valve closes late. It's not much of an issue on an engine that lives over 5000 rpm.

I was thinking of just a general clean up of the manifold.

The cam in the engine is too small. 254/254 deg @.050 108 lsa. My cam grinder never came through on the bigger cam I ordered. Need to find a new cam source.

FWIW, I recently built and tuned a street performance engine using the D-jet manifold and SDS injection, and the fuel needs were pretty much linear with RPMs. No midrange richness... but the cam was only 230/230 @ .050" w/ 108 LSA and I installed it 2 degrees advanced, so your intakes are indeed closing much later.

John Parker has experimented a lot with tuning the exhaust length on Weber-carbed race cars, and I've seen several dyno charts where he was able to eliminate a fat midrange completely that way. He uses premade sections of varying lengths that hook together with springs, so he can make changes quickly on the dyno. You might look into this.

I have a similar fat midrange problem on my street-driven 1800 with Webers and a biggish cam, and I can't vary the exhaust length and keep a reasonable muffler installed, so that's not an option for me. I am going to play with the cam timing.

(Paul, the engine's out now and I'll have the cam numbers for you in a day or two, at long last.)

Paul, the engine's out now and I'll have the cam numbers for you in a day or two, at long last.

Thanks Phil, the Enem profiles look ideal to me, they rocket up to .250" lobe lift, but don't need big lift to do it. They look better than anything you could get from Comp Cams or Crane.

shallow mid range hole in the power band. The mixture gets rich and torque drops.

I've had 2x DCOE motors do that. When I first switched from SU's to Webers, I went up to 260degrees@.050" but with 110 LCA, because I drove it to work every day. It would make a nsaty kind of sound before finally clearing it's throats & getting going. The cure was to tighten the LCA up to 102 degrees.

Do you have any flow figures for your head? Are you still using stock valves? I'd put in a tight LCA cam in first before doing anything to the intake manifold.

The flow numbers I have were at 25 inches depression and top out around 162 cfm intake and 120cfm ex depending on the cylinder. Stock was around 148/90 cfm.
flow picked up at all lifts on this head. This is with stock valves back cut and swirl polished.

Right now the engine is the best part of the car. Ive been putting more time into handling. And it needs a close ratio gearbox.

I plan to try bigger cam on tighter lobe centers when I can get one. I ordered one in April but I'm still waiting on it. I pretty much gave up on that cam grinder. Maybe Elgin will follow through better than my previous cam guy.

Your 260 deg cam on 110 LCA would have had quit the late intake closing. No wonder it didn't like low rpm.

A friend of mine just put in a ISKY VV-111 which is upper 260's on 108 LCA and it's pretty soft coming off corners. I think he went too far with that cam.

Your 260 deg cam on 110 LCA would have had quit the late intake closing. No wonder it didn't like low rpm.

It was OK at low RPM, but would dip later then come good again like the dip you are having only I had no problem with jetting, the engine it's self was never 100% right every where in the rev range.

Hi John ... thanks for the info .... What I was thinking of was, of course, some sort of idea what would make a good street setup that any of us could bolt together and be able to feel the performance improvement..... or perhaps see the improvement in mileage in today's climate. Most of us don't have access to shops with your capabilities or experience .... and have heard all sorts of comments that "it doesn't help to port the B20 head". I suppose that there may be a shop or two in the Metro Halifax area the do porting and polishing but I can almost guarantee that their experience is with either Chevy Small Blocks or Rice Rockets with a number of V DUBS thrown in for good measure.... and from what I have heard, it ain't cheap... My buddy Rick, who owns an engine rebuild facility, sent his B20 head out to be ported and built his engine with the downdraft Webber and the IPD Street Performance cam, the dual downpipe cast manifold and the larger diameter exhaust system. Ole Reliable is running the IPD Street Torque Cam, twin SUs dual downpipe and full 2" exhaust through a 14" MagnaFlow and 10" bubble type Glass Pak to quiet it down so it didn't deafen me on the highway. Performance wise, the two cars are almost equal. What intake manifolds aside from various variations of stock or the Webber manifolds are available? One comment I heard from a guy running twin Webber side drafts on a B20 was that it would pass everything but a gas station and anyone who is going to put some serious miles on one of these cars really doesn't need to deal with that ... unless the price of gas drops radically. The reason I stayed with the dual downpipe manifold was because a number of years ago ... like 1972, I bought a new Cortina GT with the 2 liter OHC engine and fitted it with HOOKER 4 into 1 headers.... performance was noticeably improved ... but the problem I had was that a harmonic kept destroying the welds both at the block and at the collector .. I would like to know how many times I had them re welded only to suffer the same problem again and again .... eventually I reinstalled the stock manifold that I fortunately had not thrown out... and I just didn't want to go through that hassle again.

Anyway, this is getting long enough. Any further comments would be greatly appreciated ..

regards

Brett
--
Brett Sutherland & the 1.5 million mile 122 CANADIAN --- WINDSOR, Nova Scotia the birthplace of HOCKEY www.ecvintagevolvo.com

Some of these questions do not have definite answers.
But here are some comments.

What is needed is more testing. Chassis dyno testing is now comparatively inexpensive and readily available. http://www.smokemup.com/utils/dynosearch.php

So your friend had his head ported - so what was the improvement in flow
before porting vs. after porting? If we don't know what the improvements were why is it even worth discussing?

What is the dyno comparison of the two setups you described?

I have never seen anything that indicates to me that there is any reason to use the "IPD street torque cam" and have seen a number of dyno results that show that its a pretty bad idea.

There are a lot of details in how each engine is built that make a lot of difference but cannot be seen from the outside.

Why are either of you running setups that were available 35 years ago rather than something newer? There has been quite a bit of progress made in those years applicable to old Volvos.

The stock dual pipe exhaust manfold, such as on the FI cars, is not bad for most street performance applications when coupled to a decent exhaust system.
With headers its the design and quality of the particular header that counts.
All headers are no more alike than all people.

There are several very different manifolds for the downdraft weber, as well as different downdraft weber carbs, and they give different results. Its not a carb and manifold setup I would recommend for performance. It needs a lot of work to make it anywhere near right. This comment is based on a good deal of testing that was done in part for me, but that I did not personally do, when we were evaluating what carbs to use on some of our performance engines. A very good professional race engineer who happens to use a 122 as his daily driver, spent most of one winter working on the downdraft weber setup before he got it right. By the time it was "right", the amount of work required to do the necessary modifications made it impractical. At the same time I was testing other carbs including single barrel sidedraft webers that would bolt on a stock
SU intake manifold.

Sidedraft webers usually are hard to tune to get both good performance and good fuel economy. Its a design that has not been changed since the 50s.
Try a modern carb design like the Mikuni HSR. That's what we settled on after testing most of the carb combinations that were/are available.

"it doesn't help to port the B20 head".
Is this a joke?! Does anyone actually believe that?
For anyone who might, two examples.
1) In the 90s when I was doing some engine and porting development I documented the progress of one b20f race head that was used and tested on the same 2 liter B20 race engine, same cam, same exhaust header, same intake manifold and carbs,
from 1992 thru 2004. The engine started out with another head at approx. 200 hp, dropped down to only 150 with the new head, and then went back up to 200 HP as that head went through a series of modifications. So over a 50 HP range the only change was to the head ( and carb jetting to accommodate the changes ) , and a number of different port configurations were experimented with.
2) A customer with a couple of 1800s had a head ported out on the west coast. He was going to use it with our supercharger system. At that time we were using the stock C cam with the supercharger, so that's the cam he had in the engine. There were delays on the supercharger installation, so he ran the car without it. To his surprise the car was faster than his other 1800 which had a stock head with IPD street performance cam, header, etc.

When its comparatively easy, and not very expensive in terms of time and cost to improve the exhaust flow in an F head by 45%, how could anyone argue that it does not help to port the head. ( check the previous thread on a head for sale where the porting done was in the $300 range ).

You can't take a 35 year old Volvo head to a head porter whose experience is with Chevy or Ford heads, and expect to get good results unless you and he are willing to work on numerous heads until he figures out what works and what does not.

4 things need to be emphasized:
1) improvements in head flow are the key to improved performance
2) the rest of the setup needs to match what has been done to the head -
3) to take advantage of the head improvements its the match of the whole system that is important, you cannot just change one component and expect satisfactory results
4) there are a lot of things being done out there, that people have been doing for the last 40 years on these engines that just plain do not work, but because there is no systematic documentation of results of changes everyone is working on anecdotal information. "I rebuilt my engine and put on a downdraft weber and the engine felt much stronger than it did before the rebuild and weber installation." So does that tell us anything other than how little it takes to sell a lot of carbs?

John
V-performance.com

Thanks again John ... gives me all kinds of food for thought. I am in the middle of Ole Reliable's rejuvenation and eventually will be seriously thinking about what I want to do with the engine .... The Street Torque Cam was a Xmas present ... so you don't look a gift horse in the mouth .... My engine is a B20E that has been bored .030" but other than that is pretty well stock ... I did richen up the carbs with larger needles and jets that made quite a bit of difference especially on the top end ... with the old needles and jets the engine just would not wind much past 4000 rpm now she winds past 6000 rpm with no complaints. I had Tom Bryant in Maine rebuild the carbs and after we sorted out the jetting have been very satisfied with them.

Other than the compression ratio, what other differences are there between the "E" and "F" heads? If I remember correctly the CR of the "E" head is at 9.5:1.

I guess we all know that the old equation SPEED & POWER = $$$ .... and I guess it will all come down to how much SPEED & POWER we can afford to make.... as well as the final driveability factor will come into play. Driving a hairy chested balls to the wall performance engine in rush hour traffic is not my idea of FUN ....

Brett

--
Brett Sutherland & the 1.5 million mile 122 CANADIAN --- WINDSOR, Nova Scotia the birthplace of HOCKEY www.ecvintagevolvo.com

Have to limit the answer time here.

There are false economies. Installing a cam because it is cheap or free can be one of them. Save a couple of hundred $ and then spend a lot more than that trying to make the engine give you the performance you want.

My question is, what does the street torque cam do for you in terms of actual performance that the C cam does not? Where are the torque peaks and power peaks. Of course we would have to dyno the two in the same engine to really know the differences.

E vs. F head. The castings are different both on the inside and outside.
The F head is thicker, giving a larger combustion chamber and lower compression ratio 8.7 v 10.5 , but some of the difference between the stock CR's were differences in the thickness of the gaskets used. And those gaskets are not currently available in their original thicknesses. the intake ports are the same,
the exhaust ports are different. The E ext flows better stock. The F ext flows worse stock, but can be modified to flow better than and E can be modified to.
So we use F head castings for our performance heads.

As to expense. The head work I recently did on the head that was for sale in a thread here, was the least expensive route to a significant performance improvement as it addressed a specific restriction that was limiting increases in performance in that engine. All the bolt-on, and bolt-in ( cams ) performance parts could not address those specific issues other than in "bandaid" fashion.

"the final driveability factor will come into play. Driving a hairy chested balls to the wall performance engine in rush hour traffic is not my idea of FUN "

I'm not sure about this comment. Do you want more power or not?
I'm guessing that you still have the old idea of what a performance engine has to be like, or what you have to give up in driveability to get more power.
The answer is that you only give up driveability when you take what I refer to as the "bandaid" approach, where you try to bolt on improvements rather than address fundamental issues like head flow. Put in a long duration cam with a good deal of overlap, in order to flow more air to the engine without addressing head flow issues, and you get an engine that moves the power up the rpm scale, and often leaves you with an engine that is hard to drive at low speeds since it has less low end torque than stock at low rpms. Too me its simply the difference between doing something the right was and doing it the wrong way. One gets good results, the other does not. All of the engines that we build have more torque at low rpm than stock, and often have power bands where peak power is at the same or a lower rpm than the stock motor.
And being able to blast past traffic with a simple press of your right foot is a lot of fun, especially when its an old Volvo blowing past that BMW.

John
V-performance.com

Hi Brett,

I took a slightly different approach to the header issue after having some pretty bad experiences with poorly made headers in the past. I ported and polished the stock dual down (from the FI engine) and had it ceramic coated inside and out. This then flows into 1.75" stainless X 2 then into 2.25 stainless pipe after that with a couple of Magnaflows to keep it "quiet".

I'm very happy with this setup and the fact that I shouldn't ever have to do it again.

Mmmmm PURDY !!! BTW A week from Monday I am headed back to Wabasca, Ab for the next school year where I am working as the Shop Teacher. Too bad Calgary is so far away ... bad enough Edmonton is 3 1/2 hours away ... worst of all the closest Tim Hortons is in Slave Lake .. 125 km away ... guess that is why I get Northern Allowance ;-) .... sat next to a fellow Nova Scotian on the flight home for the summer ... he had just returned from a stint in Afghanistan and was working in High Prairie, Ab .... he was astounded to find that they were even farther from a Timmies than I was when they had had a Tims in Kandahar ... Dang .. I'm going to have to apply for HARDSHIP ALLOWANCE ..... ;-)

Brett {_}D

--
Brett Sutherland & the 1.5 million mile 122 CANADIAN --- WINDSOR, Nova Scotia the birthplace of HOCKEY www.ecvintagevolvo.com

*nod*

My suggested revision to the chart includes a .015 row. I believe this to be correct for the Volvo published data for the lettered cams, both originally fitted and R-Sport.


It seems to me that is would be most hard to measure .010 or .015 duration with stock cams which have extended ramps. I'm impressed you were able to get that accurate even with the performance cams and their more distinct actions...

Paul's got my email addy on file somewhere... ;)

Paul,

I must admit, all this cam info looks like a foreign language to me. Is there a good resource you know of on the web that can give me more information about how to understand the specs and an idea of what it all means when tuning a red block?


this link has the basics, but any more information would be great.

http://www.auto-ware.com/combust_bytes/camspecs.html

Tyler

http://www.elgincams.com/campaper.html

Is a good read.