Tired of cracking cylinders!

[richiew]

i only have standard mahle/cima cylinders on mine and it sees 30+lbs all the time and have run 36lbs without them splitting,but also have split them at 24lbs when the tune was wrong,you need more fuel in there

cheers richie

[Chip Birks]

Thanks everybody for the great information.  This has really been very informative and has definitely provided us with many different options and directions to think about.  In all of the replies only one pump has been recommended, that was a holley blue, is this a sufficient pump?  What else is out there that will do me some good?  Again thanks for all of the responses!  This is great, thats why i love this forum!
Chip

[richiew]

I would put it on a return loop fuel system like you would with EFI and use a way to big pump then drop it down to what pressure you want,maybe even a good EFI pump,that way you always have the fuel supply there

cheers richie

[fiatdude]

It is always funny that things that work on V8's at 750 HP (Holley red pumps) won't / can't / don't work on VW's at 350 HP

There are numerous pumps recommended on various threads on this site do a search? I've got a Holley black on mine right now because a friend took it off his 1700 HP camaro when he was stepping up to 2000 HP -- but I'm worried it won't handle the volume of fuel needed when I add my 50HP N2O shot

[FITNESSFORYOUTOO]

Thanks everybody for the great information.  This has really been very informative and has definitely provided us with many different options and directions to think about.  In all of the replies only one pump has been recommended, that was a holley blue, is this a sufficient pump?  What else is out there that will do me some good?  Again thanks for all of the responses!  This is great, thats why i love this forum!
Chip

I ran the Holley black pumps with return regulators to keep them cool, one each for the carb and NOS.

[Nick Ortega]

How can you use a Blue Pump and regulator with a side draft? A blue regulator (PN 12-803) can only regulate the fuel from 4.5-9 psi. Wouldn't 4.5 psi already over come the needle and seat in the carb?

Maybe people are setting up there Red Pumps and regulators with the fuel pressure too high? As pressure goes up, volume goes down. Wouldn't you want the fuel pressure at boost to be JUST enough to overcome the needle and seat to keep the volume as high as possible while still overcoming the needle and seat?

Maybe it would be good to run 2 Red Pumps in parallel. This would bump up the flow while keeping the pressure reasonable. Can you run a Blue Pump with a Red Regulator (1-4psi)? This would give you more volume while keeping the pressure down.

Just some thoughts.

[RodNutt]

As pressure goes up, volume goes down.

That's the ideal gas law- as in gasses, not liquid.  That's talking about volume, not flow.

[Nick Ortega]

That's the ideal gas law- as in gasses, not liquid.  That's talking about volume, not flow.

I know what the Ideal Gas Law is- as in GASES, not liquids. I'm talking about volume as in volumetric flow rate as in volumetric flow rate ~ flow:

[Sam]

Man guys as much fuel as yall are running through those Turbo motors a water hose and a 2HP shallow well pump seem appropriate, maybe a 6" ball valve for a carburetor?

[2stroke]

Im with richie, cima/mahle cylinders good to 36psi if the car is tuned.

[2stroke]

Thanks everybody for the great information.  This has really been very informative and has definitely provided us with many different options and directions to think about.  In all of the replies only one pump has been recommended, that was a holley blue, is this a sufficient pump?  What else is out there that will do me some good?  Again thanks for all of the responses!  This is great, thats why i love this forum!
Chip

I ran the holley blue with a mallory bypass regulator with the boost reference port hooked up (with a check valve). This was feeding a dell 48 sidedraft. -8 feed -6 return

[turbo_bob]

Im with richie, cima/mahle cylinders good to 36psi if the car is tuned.

There is a point with the Cima/Mahle cylinders that Scott F got to, I think also around 36 PSI. His conclusion was the low RPM cylinder pressure that was the culprit of spliting the cylinders, no matter how good the tune was, and his engine was tuned.

EDIT: I stand corrected. Scott, I think my fountain of youth is slipping away 

I got part of it right, "low RPM cylinder pressure" "his engine was tuned."

[2stroke]

I ran 30psi and a 75 shot and the first thing that went was a hole in the head....so i dont think its the cylinders that are bad, its just tune, cylinder pressure etc.


..."some people can bend a crowbar in a sandbox"...

[gangforward]

I had rimco power sleeve my cima's and I ran them up to 36 lbs.  Never cracked one.  I ran a holley fro Jon Karcey.

[RodNutt]

I know what the Ideal Gas Law is- as in GASES, not liquids. I'm talking about volume as in volumetric flow rate as in volumetric flow rate ~ flow:

That's fine, but you're not going to cure a lean problem by turning down the fuel pressure.

[turbobug56]

There is a point with the Cima/Mahle cylinders that Scott F got to, I think also around 36 PSI. His conclusion was the low RPM cylinder pressure that was the culprit of spliting the cylinders, no matter how good the tune was, and his engine was tuned.

Nope Bob...   I never cracked a cima cylinder in the old 2276.  30psi boost and 50 shot NOS.  This was with a very small cam and turbo resulting in lost of low end torque and major cylinder pressure.  The failure point was the case.  I pulled the upper outer #1 headstud on a mag and a bugpack AL case.  We had cimas in the Baron part of the first year.  Cracked cimas is a tune issue unless you are making over 500hp. 

We have never ran a power sleeve either. 

[turbotype1]

It is always funny that things that work on V8's at 750 HP (Holley red pumps) won't / can't / don't work on VW's at 350 HP

That's pure fantasy 750 hp with a red pump? Come on

I've got a Holley black on mine right now because a friend took it off his 1700 HP camaro when he was stepping up to 2000 HP

1700hp with a holley black??

 Now that one is seriously funny 

Pete

[RodNutt]

Bob Glidden ran 8's with a single holley blue.

[fiatdude]

That's pure fantasy 750 hp with a red pump? Come on


1700hp with a holley black??

 Now that one is seriously funny 

Pete

What can I say -- I've done 200 mph in the quarter -- have you ?

and my wheel stand is bigger than yours -- Take that

[turbotype1]

Bob Glidden ran 8's with a single holley blue.

Really ? I would like to hear more about this..

What can I say -- I've done 200 mph in the quarter -- have you ?

And what kind of fuel pump were you using a Holley red? or was it blue? or maybe the killer black. So you've been 200 in the quarter, So what does that have to do with a holley red pump?

[ForcedInduction]

You rarely hurt things being rich for the short runs we do in drag racing. You can almost count on hurting things when your lean. Richie is right you need more fuel.
I use a high quality pump (magnafuel prostar 300 with a magnafuel reg.) -8 line and at boost 24 lbs. I run 16lbs of fuel with a side sraft, big needle and seat never a problem.
                                                                                                                                                                                                                         Tim

[Jeremy_Owen]

You rarely hurt things being rich for the short runs we do in drag racing. You can almost count on hurting things when your lean. Richie is right you need more fuel.
I use a high quality pump (magnafuel prostar 300 with a magnafuel reg.) -8 line and at boost 24 lbs. I run 16lbs of fuel with a side sraft, big needle and seat never a problem.
                                                                                                                                                                                                                         Tim

Tim how on earth do you run 14psi through a side draft? What type of side draft is this? When I hit 14 with my dellorto things went to hell. And over 9 it is unhappy, and it seems to like 7 when I'm hitting full power. Of course if you are using all the fuel you are putting in it doesn't matter what the psi is.  Where are you measuring pressure and how is your fuel system plumed?

As for thos that think a holley red can't make big power you are wrong. It just can't do it on a side draft turbo VW. You must consider all things in a fuel system. The biggest restriction in a side draft turbo set up is the single needle valve in the carb inlet. This presents a problem for a red pump because the only way to get fuel into the side draft faster is to up the inlet pressure. As you up the inlet pressure the red pump can't provide the necessary volume at the required pressure. I will make a nice detailed write up on fuel pumps and pressure in the next day or so. But for now I will leave you with this. Through experimentation I have found that .166 gallons of fuel per hour are required to make 1 horse power on a turbo side draft vw. I would round this up to .17 for simplicity. To make 400 horse power you need 66.4 gallons per hour. A holley red pump is rated to flow 67 gph at 5 psi (on a very good day with a charging system). A modified dellorto side draft will flow ~68 gph at 5psi at the needle depeding on a few variables. So the red pump and the side draft reach an equilibrium at about this point. So a holley red is good for just over 400 hp on a turbo vw with a side draft dellorto. How bout that. Now the monkey wrench here is the regulator. A standard holley "red" regulator uses a restriction to control pressure, so the pressure on the inlet side of the regulator (what the pump feels) is higher than the outlet side when flow is low into the carb. The problem this can create is that you may drain the bowl before the pump can relive the pressure on the inlet side of the regulator through the restrictor in the regulator and catch up with flow. This is why we usually run a one way check valve on the regulator to keep it from seeing vacuum. Since when it sees vacuum it increases pressure on the pump side of the regulator even more (more restriction) and has lower pressure at the carb so the increase in flow would be even slower. Now this isn't usually a problem as the regulator can react fast enough and the pump can increase flow quickly, but with age in the pump (and voltage drop in the  battery) and the regulator (diaphram gets hard) it may not be as fast as we would need. The way to avoid this is to use a return style regulator. But this isn't the only advantage of the return style... More to come

[ForcedInduction]

     Jeremy, I run a Magnafuel Prostar 300 pump rated @ 950 h.p. . my reg, Magnafuel also  is actually a unit made to run two carbs ( 4outlets ) I only use one outlet with a dash 6 to the carb. I had to reduce the pump pressure to 18 psi. My initial pressure is 1.5 psi. after the reg.- no boost. When the engine reaches max boost 24psi. the reg is set at 16psi. I was told by the guy that built my carb this is too much but after seeing what I was doing he changed his mind. The Carb is only a 40mm with 36 chokes. The engine is a 1915. I ran this combo several years and will again. I run a check valve as you also. Interesting side note I am helping a buddy do the Pikes peak Hill Climb. He has a 2165 with a 45mm Weber blue pump 2 regs. One to bring the pump pressure to about 17- 18lbs. the other down to 1.5 lbs. at idle - it is referanced. We took out the check valve because the engine would load up (go rich) when he let off the throttle in the corners, making it hard to leave the corners efficiently. We run about 16 psi fuel pressure at 20lbs of boost. Grant it the engine runs out of fuel when he drives off boost when he is driving slow, we have a fix for this. My reg. is a none return style reg. I run -8 from the pump (the pump returns internally @ 18 psi) When I bench test the system I set my compressor at 25 psi. - blow into the boost reference line. With the pump running and the  carb top off and in a bucket the psi. gauge mounted on the reg, reads 16psi. on boost and 1.5 psi. no boost. Grant it I crunched no #s but it works and no engine failure. I realize this seems crazy - it works well! Now I have a friend with a 2332 we set it up the same he uses a aeromotive pump and reg with a 48mm dellorto side draft. I have not given up but we are having a hell of a time making it run as well as mine. His car weighs the same as mine his best pass is around 11.05 mine 10.64. All I can say is there is more than one way to skin a cat. I will share all I have learned but I feel more comfortable with a weber, and I am still learning about the dellorto. I wiil tell you this the Magnafuel equipment is far superior to the holly, as I see how smooth according to the gauge that the Magnafuel stuff is compared to the holly - the holly is a erratic and the magnafuel equipment is more dynamic. One thing is for sure we all have opinions!
                                                                                                                                                Best of luck Tim Haugen

[Jeremy_Owen]

Tim I stilll don't understand how you are using all that fuel. I agree the magnafeul stuff is very nice and you should have no problem making all the power you want with it. I don't have any experience with the weber side drafts at this level but I just can't imagine that much pressure at thw needle. On a dellorto that would be well over 100 gallons per hour going into the carb.  I guess the weber can handle that kind of pressure and still shut down the needle enough to control flow.

[turbotype1]

As for thos that think a holley red can't make big power you are wrong.

I'm sure you could make power with that pump IF it would actually flow the numbers that were advertized. The problem I have seen on numerous customers cars was that these series of pumps ( red-blue and black) would not CONSISTANTLY flow the advertized volumes.

If it works for you...good luck to you. But for me, I'm not gonna cheese out on mine or any of my customers fuel systems.

Fuel delivery systems should never be just marginal.

My .02....Pete

[Jeremy_Owen]

I guess I should also add I think holley is crap. But I do run a black pump, it was free and flows enough for me. But I have a tricky return set up to control the flow.

[ForcedInduction]

   Jeremy, the prostar fuel pump is adjustable at the pump and has an internal bypass, it is factory set at 26-28 psi too much for the reg. to bring down to 1-1/5 psi. that the Weber needs so not be overwhelming the needle and seat flooding the engine. Magnafuels factory was here in Colorado Springs I went there told the guy's my delima and they gave me a lighter spring (the pump is  adjustable too) I then could bring down the pump pressure to 18 psi. which then allowed the reg. to bring the pressure down to 1-1.5 psi. at idle. When the engine boosts the fuel pressure rises at a 1/1 rate untill 16 psi. with the boost pressure ultimatley reaching 24 psi.
        What I have experianced with the holly regs. is that they "creep" i.e. they actually increase pressure when static (pump running engine not) this overwhelms the needle and seat flooding the engine at idle. We tried to fix this running 2 holly regs. on the hill climb car it helped but did not completely fix the problem. The Magnafuel is rock steady no creep! The reason that I increased the pressure to 16 psi. was due to the fact that I was going lean even with 220 mains - after the increase all was well.
     I bet that part of your problem stems from the holly regs., like turbotype 1 one said don't skimp on you fuel system you may regret it!

                                                                                                                                      Tim Haugen

[Jeremy_Owen]

Tim are you blow through or draw through? I am am all to familiar with pressure creep on cheap holley regs. I don't use holley regs so that isn't a problem. I also know how the magnafuel stuff works and I can tell you the bast thing to prevent pressure creep is the return at the pump. I have seen magnafuel and aeromotive regs that claim to stop pressure creep have pressure creep when the engine isn't running.But I just can't see the carb being able to handle that much pressure with out turning the jets into injectors. I am also seriously confused by your 220 mains? I am not disagreeing with you in any way I am just trying to understand how your set up, is set up. I hope I can learn somethings other than the hard way

[ForcedInduction]

     1'st apologies if if Chip feels we hijacked his post, it is relative. Assuming everything else is right i.e. timing, compression etc. The currant set up that I am running is at what I believe the end of the world I've tried even more boost but it really does not make any more horse power. I only have a t3-t4 hybrid turbo - no intercooler I believe I have moved into what they call super heating the charge. That being said This probably would not work on the street. Stop and go driving would not be real nice remember this is a dragcar only.
Your thought on spraying fuel out of the jets my be true I have never had the motor on a dyno  watched down the carb and probably could'nt see that anyway. My realativty to what I judge my horse power is comparing my time slips.I really don't care what it does at full boost as long as I can get up to the line do a burnout (which I really don,t do) stage, run and not hurt the engine. I have draw thru setup. I have heard several comments it can't work it does. and there is not much to say when you see the car run. As far as 220 mains their big but some guys claim they remove the main jets. The biggest problem making the weber run that much fuel is controling the idle pressure.

[2stroke]

i started with a 320 main jet on my drawthrough.

[Jeremy_Owen]

Tim 220 mains are tiny to most. Even for an NA engine I have run bigger.

[S/P4884]

 If my memory is right, which isn't often these days, didn't Dave Kawell run a side draft carb on the squareback. He ran a 9.08 at 154 MPH in 1988. There must be some tricks to running a sidedraft!!

[Nick Ortega]

Tim 220 mains are tiny to most. Even for an NA engine I have run bigger.

I run a 220 main on my 2017 with 45 DCOE and 32 vents. AFR ratio comes down to high 10s on boost, so I think its just right.

[Ohio Tom (DdK)]

You guys know how to make something simple really complicated.....

My sidedraft 40 dell has 2.50mm needle/seat in it.
I run a Carter pump (similar to Holley red) that puts out 14-15psi static.
I runa modifed Holley 1-4psi regulator. I modifed it for boost ref with a checkvalve to the intake manifold.
The fuel pressure "off boost" is steady 2psi at all times.
As soon as she goes positive boost, the fuel pressure matches boost all the way to 15psi.
I have a fuel pressure gage in the car (NOT oil filled). I can watch the pressure while I drive.
The response is instantanious and rock solid. No slow response or fluxuations.

Nothing fancy or expensive and it works fine as proved by the fuel pressure gage IN the car.

The pressure gage is the key to knowing for sure weather or not what you have is up to the task....

[Nick Ortega]

nm