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Has anyone tried using a single sidedraft DCOE Weber.
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How did it perform? How was the mileage. Was it reliable?
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To answer those questions for a dual DCOE setup.
Yes, no, yes.
Although I understand you *can* tune for both decent MPG and great gobs of power, mine seem happiest running fairly piggy rich all through the range. Great fun to step on the gas pedal though, the SU's never responded instantaneously like they do, and they never got the motor to try as hard either.
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'63 PV544 rat rod, '93 Classic #1141 245 +t
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What jets are you changing to lean it out?
I find that 1 or 2 farts/km give the best MPG. Nil with the proper Volvo soft mounts.
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I was dinking around with the float bowl levels to lean them out slightly, a MM ot two there seemed to have an effect on the mixture, but perhaps that was why it got snorty?
I have the soft mounts, good for taming engine vibrations (the new engine is pretty smooth at revs, it got a nice balanced bottom end in the rebuild, the previous more shade-tree bottom end was a little rougher). but they can't do anything about bumps in the road or corners.
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'63 PV544 rat rod, '93 Classic #1141 245 +t
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Volvo softmounts or aftermarket?
Set the float level properly & forget it.
Main Jets & air correctors: use the sizes that give the best full throttle power.
Idle jets: use the ones that give 1.5 turns out for idle.
Idle air correctors: this is the one you adjust your part throttle mixture with.
Pump bleed: make sure you have a 50 or at least a hole in it, just make sure it's not a blank.
Pump rod: 10mm, spring: I can't remember, Pump jet: small as possible.
Emulsion tubes: F16 or F9 for the raciest engines, F11 or F15 for mediocre sized cams, F2 can be made to work, F7 & F8 are special purpose or V8's.
What are all the jets, etc., you have now?
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I'd have to check, it's been years since i looked at them.
That's one good thing about the DCOE's vs. the SU's, the SU's needed seasonal (at least) tweaking, to maintain a decent tune. The DCOE's needed to be set up once, then they've worked the same ever since then.
I guess it helps that they have very few 'adjustments' on them, instead relying on replacing parts. Makes tuning them more expensive, though.
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'63 PV544 rat rod, '93 Classic #1141 245 +t
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That's one good thing about the DCOE's vs. the SU's, the SU's needed seasonal (at least) tweaking, to maintain a decent tune.
My first Volvo, a '68 142 with an overdrive badge, but no overdrive to go with it, had dogs for SU's. I fitted new throttle shafts, made lock nuts for the jets & got some lock nuts for the idle & choke speed screws & never looked back. Just add ATF to the dashpots & pull the chokes down fully & put on some moly grease during each oil change. I guess in an American winter you would need to richen them a couple of flats, but I think that got solved with the newer HIF6 carbs, although nearly every B20B I have ever seen has the cheaper Strombergs on them.
Also, your DCOE's aren't tuned 100% either by the way you describe them. They can run as well as your injection, BUT, given that you are so comfortable with injection, I would say to you fit MegaSquirt & forget learning the ancient art of carburettor tuning. Take the aux & main chokes out of the DCOE's & replace them with a length of aluminised exhaust pipe or a full length home made ram tubes & enjoy the sound of Webers combined with the joy of injection. Then you can go straight to experimenting with the intake length.
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I was thinking about that once. Stuck a D-jet mani on the motor while the carbs were off once and found that it didn't fit into the tapered front end of the PV engine bay. Then there's my R-sport head, which doesn't have injector ports drilled. Then I looked at DCOE style throttle bodies, and decided that for the price the DCOE's really do work quite well enough.
I have seen injector pad drills that you can use to drill into a carb body and make an injector mount, if you are somewhat crafty you can even mostly hide the end result inside the fuel bowl. I've seen SU's converted like this in the past that had the injectors hiding in the now empty dome.
As for the current state of tune on the DCOE's - it's a case of the good being the enemy of the better. It's good enough now that I'm not wanting to start messing around with expensive sets of jets in sets of 4 to make it better. Starts in cool weather, gets lousy MPG, goes like stink, and maintains a nice 13:1 ish mixture most of the time (when not going over bumps or around corners).
Most of my tinkering these days is done on the 245. Which is megasquirted, running on E85, 16V turbo.
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'63 PV544 rat rod, '93 Classic #1141 245 +t
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My twin 45DCOEs seem to run piggishly rich as well, and I manage a whopping 16MPG. It could be because it is so fun to hear them howl when you step on the gas! I'm glad I knew their foraging habits before I decided to buy them. I'd like to try the Mikuni conversion from VPD someday, but I hear that they are not necessarily a bolt in cure either.
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The problem with VPD twin Mikunis is that it uses the terrible twin SU manifold. You need 4x Mikunis to match 2x DCOE's, unless you are running a weenie cam.
When I ran 2x 45mm DCOE's on a 2130cc engine with a big cam I could get 27 imp MPG at 100km/h, what cam head & exhaust are you running?
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Paul;
In answer to your question above this post and my response below this post:
B20F bored .030" over Fuel injection head
balanced rods and pistons
flywheel lightened 5 lbs.
IPD cam 2A7001 +2A7002
Intake timing Exhaust timing
Open 30* before TDC Open 67* before BDC
Close 58* after BDC Close 21* after TDC
Cam lift .294" Cam lift .294"
Valve lift .441" Valve lift .441"
Hope this helps.
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What exhaust?
What are all the jets, etc., you have now?
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I'm currentley running an equal length 4 into 1 header with one inch pipe down to a 3" collector. The pipes are about 28" long, if I recall. As far as what jets are in the carbs, I truly don't have an idea. I didn't set this vehicle up. All the work was performed by a shop in Sydney, BC.(British and European Motors) where the previous owner and I went to look at the car together. Is there a way to find out the jet sizes on these carbs without a ton of sacry dismantling? I've never had the courage to get into carbs in general, and these Webers in particular, although I do have a book for them. Right now, it is in truth a long way down on my to do list, as the engine was running "okay" when I took it out of the donor car. I've got a ton of work to do before I can even fire this thing up and start messing with it. I'll be glad to at least listen to what you've got to say about improving things, though.
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I'd get rid of the 4-1 headers. The stock exhaust manifold works as good as anything with a small cam, get a decent 2.25" or 2.5" exhaust & use 24" long engine pipes.
4-1 headers need a big cam to work well over a wide range + the stock exhaust sounds great with a good muffler.
Come back for DCOE tuning when you get it registered & you have the money for a fist full of jets or a friend with jets.
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Thanks, Paul. I'll be interested to see what that learning curve is all about.I presume you are talking about a late style stock manifold. I'll have to check my inventory.
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This is from Volvo's 1979 R-Sport catalog. They recommend their small bore 4-2-1 headers for small to mediocre sized cams (215° to 240° degrees at .050") used in their GT, Stage I & Stage II kits. For their stronger Stage III & IV engines with very large cams (250°@.050" and larger), they recommend simply using a fuel injection exhaust manifold (or saw odd car dual downpipe) + a stock engine pipe with 4" added to the secondaries. There really is very little difference between the 4-2-1 manifold & stock exhaust manifold for all uses except: full tubular 4-2-1 headers are lighter, but the stock manifold is a little more quite & it sounds better (& they are free). I've used both & there is no real difference in power.
For a large cam with tight lobe centres, I recommend decent 4-1 headers, but they have to be decently designed like BHP's, Stahl's or TG Motor's, not junk like IPD's. The exhaust for 4-1 has to be 2.5" or 3" with very good straight through mufflers, but your engine has to be very strong.
For a smallish cam like you have, I would recommend similar to the 2.25" Rally Sports system shown. I'd add 6" or more inches to the engine pipe simply by stepping it up one size, then transitioning in to 2.25" at least to the muffler. If your head is fairly stock, then a genuine B20E/F exhaust system is just fine.(2.125") The original Volvo mufflers are high quality straight through type & the bends used in them are mandrel type.
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Three 164's, Two 144's, One 142 & a partridge in a pear tree.
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Wow! I'm exhausted! Thanks for the input. My cylinder head has been gasket matched and smoothed out some, but I don't belive it has been cc'd. The engine does pull pretty strong from about 3500 up to 6500, but isn't particularly stout below that rpm. As I say, I've got a BUNCH of work to go before I'm even at the point of recording any performance times here, but I'll look forward to seeing if I can squeeze some more out of this thing without turning it in to a one-dimensional screamer. The car is a hobby car that I will use for the occasional Volvo club get together and pleasure driving. The rest of the fleet works pretty well for the daily drivers. Thanks again for all of the advice and input!
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My cylinder head has been gasket matched and smoothed out some
Gasket matching the combustion chamber is good, especially around the inlet valve.
Don't gasket match the exhaust ports, leave them as stock size at the face, but do take the headers or exhaust manifold out to gasket size to help prevent exhaust reversion.
The engine does pull pretty strong from about 3500 up to 6500, but isn't particularly stout below that rpm.
Most likely the 4-1 is killing the motor below 3500rpm. The stock manifold is a lot better than 4-1 with the cam you have. When set up properly, the DCOE's & the cam you have should pull very strongly from 2000rpm & be lots of fun to drive.
Is the cam degreed in like the data you have given? Because that's perfect. Because you have a symmetrical, single pattern cam, it is dead easy to check your cam timing just looking at the valves. With the lash set the same on both inlet & exhaust (is it .020"?) at TDC, the inlet valve will be open slightly further than the exhaust on the cylinder that is on overlap. If you set the crank to 4° BTDC, they should be at the same height.
Next job is to look at the distributor curve.
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Three 164's, Two 144's, One 142 & a partridge in a pear tree.
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You can just unscrew the little lid on top of the float bowl, the round lid secured with a wing nut. Leave the rest of the float bowl lid attached. This exposes the 4 jets, 2 for each throat. These can be removed with a screwdriver. They consist of several parts that fit together, the small bottom tip being the fuel jet, the long tube in the middle being the 'emulsion' tube, and the small fitting on the top being the air corrector jet. IIRC you can read the number off each part without taking them apart.
Then just replace, gently tighten down, and replace the cap. Should only take 5 minutes or so.
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'63 PV544 rat rod, '93 Classic #1141 245 +t
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That gets you some of them. The smaller two assemblies are the idle jet. Unfortunately the idle jet & it's air corrector are one piece & it's the idle air corrector that needs the most adjustment. The similar Dellorto DHLA has these two things as separate pieces which makes life a lot easier.
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Paul;
I'll have to take a look at the paperwork on the engine and see if I can determine what all has been done to it. I didn't order it up, but it does seem to run pretty darn good. I'm going to put it in a lightened (?!) 130 project that I have in mind. A light 130, now there is an oxymoron.
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I seem to average in the upper teens. Pretty much the same reason, it's so fun to romp on the pedal. Below 3000 rpm there's more noise coming out from the carbs than there is from the tailpipe. Then the exhaust takes over.
I used to have a wideband O2 sensor and gauge on the car when I first installed them, to help with the jetting. Any time you tried to lean it out some, they'd get all snorty, lots of little wheezy backfires. Running nice and rich (12:1 or so) they are as happy as can be.
BTW, the O2 gauge showed them to be pretty erratic in terms of fuel delivery. Lots of things could upset them. Going around corners, for example, lean one way, rich the other. Go over some bumpy pavement and they spike rich.
Great for just occasional 'spirited' driving, I think if I was daily-driving the PV I'd stick some SU's back on it.
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'63 PV544 rat rod, '93 Classic #1141 245 +t
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At present I'm running a 38 DGAS and was wondering if a single 45 DCOE would be more fun.
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A single DCOE would be a waste of time. Either go to twin sidedrafts and get the fuel mileage they are capable of (terrible)and power (amazing) or stick to SU's, which are the best compromise between the two.
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I advise you to trust Rhys on this one..go for the gusto or find a pair of SU's in good shape. (He can help you with ones in good shape!)
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Thanks to all. This helps me in my decision. Thanks again.
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