Hello,

Maybe I am bringing old news, but I just found out there are real steel cams available for the B20, have a look here http://www.tgmotor.com
I informed about pricing but haven't gotten any answer yet.

Also multi layer steel headgaskets are available from Cometics.

B.R

Stefan

My thoughts on grinding large amounts of material from steel lobes is the workspeed and feed must be spot on with no rushing or burning will result. The arc of contact varies between base and flank. The urge to finish the job leads to damage that will lead to lobe breakdown and your back where you started. Regards Jack McIntyre.

Steel cam cores are for roller lifters, not something for a road car. Using a steel core for a flat tappet cam is a PITA. You have to grind it, send it off for nitriding & then do a final finish grind to get it up to the hardness of the CWC cast iron billets.

Exactly what I want them for.

John
v-performance.com

John, did you see my other message to you about 30 degree valve seats? Feel free to email me at B20Paul AT optusnet.com.au if you get the time.

Have not tried 30 deg seats.

John
V-performance.com

Nice! I've been looking at those SBC roller lifters that don't need the guides attached to the block (they just attach to each other in pairs) - but alas - no roller cams for B20's. I saw those steel cams on that site and they certainly looked like roller cam lobes to my eye.

I have my engine running (900 miles so far) with another new set of Isky SBC solid lifters and an Isky VV-81 - for some reason (recent experiences) I somehow half expect to see a flat lobe in another 5K miles. The 1.6:1 lifters, the stiff double springs, I think theres just significantly more stress there in my engine than stock, expecially when I sing it up to 7K. I'd be a definate customer for a roller cam if/when I redo the cam&lifters on my motor.
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I'm JohnMc, and I approved this message.

Hi,

The profiles on display on that site aren't roller profiles.
However I hope that John can get hold of some blanks that these guys use and can have a roller profile ground on them. I am experiencing the same fear as you, just installed my new KG6 cam yesterday and am fearing to see flat lobes in a few 1000 miles.
Maybe interesting to have a look, http://amazon.forum.bilia.se/phpbb2/viewforum.php?f=2&sid=287df3ec0d3f8323d110428f1c20192b
look in the 'B20 Motorporr' discussion, there you will find dyno results of a 2.5 B20 with the TG984 steel cam, nice numbers if you ask me !!! Very nice pictures there too, a must see for the B20 enthusiast !

B.R

Stefan

I have emailed them about the cams, but no response yet.
Hopefully their English is a lot better than my Swedish. It is Swedish, isn't it?

Impressive work on the head. There is something a little unusual about the dyno numbers though. Torque and HP peaks at almost equal rpms?? It would be interesting to know more about the engine - bore, stroke, CR, etc.
Can you translate any additional info on this that may be in the Amazon forum discussion?

John
V-performance.com

Hi Mister Mc,

Roller cams are the last thing you do to a B20. You need them when you want to get in to the 190BHP+ Zone. Roller cams need huge springs which then means that the Volvo valve collets are too weak & then you need to go to one-piece stainless valves & non-rotating collets. You would also need some 3/8" pushrods too, so the $$$$$$ keep adding up. All those things would probably cost a similiar amount of money to one of J.Parker's supercharger kit which would be much better bang for the buck.

Cam stress: The higher the RPM's, the less pressure there is on the lifter. Maximum load happens at cranking speeds. 1/2 the reason you break a cam in at 2000 to 2500rpm's is because it drastically lowers the pressure on the lifters/lobes, the other 1/2 is obviously the hope that there is extra oil being chucked around.

You don't think it creates more force overcoming the inertia of the lifter/pushrod/rocker/valve when you snap the valve open 10 times as fast at 7000 rpm as you do at idle at 700 rpm?

I am running an R-sport stage 3 head currently, with double valve springs that seem considerably stiffer than the stock springs. Why do you need incredibly strong springs on a roller cam - to overcome the added weight of the roller lifters? Do they reall weigh that much more? The SBC solid lifters I'm using aren't very light, but I guess the rollers would be somewhat heavier.

I've just had a string of wiped cam lobes that I'm getting tired of fixing. I have the thought in my head that roller lifters might solve that problem.
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I'm JohnMc, and I approved this message.

You don't think it creates more force overcoming the inertia of the lifter/pushrod/rocker/valve when you snap the valve open 10 times as fast at 7000 rpm as you do at idle at 700 rpm?

That force does increase, but the full open pressure reduces and this is the bigger factor of the two evils.

Why do you need incredibly strong springs on a roller cam - to overcome the added weight of the roller lifters?

That contibutes a little, cam makers have optional 'rev kits' which puts little springs on top of the roller lifter. Mostly you need bigger springs with rollers because roller profile open & close much faster and higher for more performance.

I've just had a string of wiped cam lobes

In the same block or are the cams from the same manufacturer? Some cam grinders don't know which way to taper the lobes so they just grind them all one way & hope for the best. Some blocks can have badly angled lifter bores.

I have recently heard of problems in chevy engines using the same SBC lifter.
Not sure what the cause is, or whether this will extend to problems using them in b20s. Up to this point have seen far fewer problems than with stock lifters.

One reason for a steel cam is that they are just stronger and the stock cam is a weak spot in racing with high spring loads. High spring loads necessary to control the valves with certain cam lobe profiles and running at 8,000 rpm or more.

Roller lifter cams can run more radical profiles that flat = more power over a broader rpm range as the valves can be open longer with less overlap. There is really no reason to use roller lifters unless you are going to take advantage of this.

They have been used in the UK for both historic racing and rallying with outstanding results. So outstanding that I have been told that they have been made illegal in historic rallying.

John
V-performance.com

That's good news, but only for all out race engines with high spring pressures.
Its the billets I'd like to get so the cam profile can be custom ground.
I've only got about 10 words of swedish, so I couldn't tell much from the website.

John
V-performance.com