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Engine Specific Info and Questions => IDI Engine => Topic started by: colhel59 on April 04, 2010, 08:28:06 am

Title: swapping to a 12mm head
Post by: colhel59 on April 04, 2010, 08:28:06 am
i have a VE/1261100L954 pump off of a cummins engine was wondering if it was possible to swap the 12mm head on too my azz pump unsure if the number on this pump thank in advance
Title: Re: swapping to a 12mm head
Post by: Rabbit on Roids on April 04, 2010, 08:49:00 am
looks like its a 6 cyl cummins pump? you need 4 cyl parts for 4 cyl engines.
Title: Re: swapping to a 12mm head
Post by: colhel59 on April 04, 2010, 09:02:12 am
definetly a 4 cyl pump i typed the number in wrong VE4/1261100L954 sorry about that and another questoin would i swap the cam plate too its a di engine its coming from.
Title: Re: swapping to a 12mm head
Post by: Rabbit on Roids on April 04, 2010, 09:48:23 am
you need the pump head, springs, cam plate and maybe some other things.

why would you want a 12mm head? your gonna have an effective redline of like 4 grand now. dave cross was making almost 200 horsepower with a stock 9mm head. i would try and make power with a smaller head, and make up for it. so i could still have lots of rpms to play with. thats just my thoughts tho.
Title: Re: swapping to a 12mm head
Post by: darrenjlobb on April 04, 2010, 02:48:02 pm
How on  earth do you manage to make 200hp on a 9mm head?.....what else do you do to these things?
Title: Re: swapping to a 12mm head
Post by: truckinwagen on April 04, 2010, 02:54:10 pm
I have a 12mm pump in my car, and have no issues with spinning high RPM's.

on a four cylinder you can spin a 12mm VE pump in excess of 6000 RPM before there are issues(thats plenty fast) its the 6-cylinder VE pumps that can only spin 4000RPM

I have a complete 4BTA pump in mine, and the only modification is the governor spring, which allows me to go to 4500RPM, but the pump is capable of much more. runs like a dream, and fuels much better than a turned up 9mm pump(was a real beast until the supercharger blew up)

I say go for it, you wont be sorry.
(I dont have much info about the pump head swap though, sorry, as I swapped the whole pump)

-Owen
Title: Re: swapping to a 12mm head
Post by: 53 willys on April 04, 2010, 03:37:41 pm
I think 12mm is way to big...least for my car it would be...I'm gonna take my 11mm head off and put my 9mm back on.
my .02 8)
Title: Re: swapping to a 12mm head
Post by: truckinwagen on April 04, 2010, 03:52:14 pm
it depends what you want from your car.

I was building an all out grunt machine, so the 12mm pump did really well for me, for a family hauler I would stick with a 9 though.
Title: Re: swapping to a 12mm head
Post by: colhel59 on April 04, 2010, 05:25:18 pm
I was going for the freebi factor, since i got the pump for free thought maybe i could use this pump to mod mine it was just a thought tho. I still have to swap the azz into my 92 gti, going to keep it stock till shes in there.
Title: Re: swapping to a 12mm head
Post by: fatmobile on April 04, 2010, 07:50:50 pm
The 12mm pump injects the same amount of fuel in a shorter stroke.
 Sooo when you are at higher RPMs the proper amount of fuel is injected quicker,..
the plunger doesn't have to travel as far before the breaking pressure is reached.
Title: Re: swapping to a 12mm head
Post by: truckinwagen on April 04, 2010, 08:14:00 pm
yep, the same amount of fuel in a shorter injection event.

makes it rattle louder, but it keeps the injection(all of it) in the proper timing under heavy throttle.

again, I would not do a bigger pump head in a family cruiser, but makes a bunch of power.

-Owen
Title: Re: swapping to a 12mm head
Post by: 53 willys on April 04, 2010, 09:58:45 pm
I cant imagine a 12mm be "good" for anything but a track beast...my 11mm injects more fuel then my turbo can clear at 25psi it's stupid smokey...my 11mm does not run well turned down either..it's all or nothing.
I think my stock 8mm head was better fully maxed out then this 11mm.

mind you this is at 4,500ft above sea level..

pm me if you want a low mile 11mm pump head and springs :P

and my car is no famliy wagon...it's waaay to smokey for that...it's barely daily driver style at this point...
some one should buy my car from me so I can buy a A3 diesel...lol
Title: Re: swapping to a 12mm head
Post by: truckinwagen on April 04, 2010, 10:24:01 pm
I will admit that there is much less pedal definition between a little and alot of fuel, but I plan on changing the distance from the pivot that the throttle cable attaches to the pump arm, so it takes more pedal travel to move the throttle. that should make it easier to drive down low.

honestly most of my drivability issues come from bad motor mounts, not the pump though...
Title: Re: swapping to a 12mm head
Post by: darrenjlobb on April 05, 2010, 10:38:01 am
"rabbit on roids"

So are you running the 12mm camplate as well as head etc?

Was it from a DI engine ? Or IDI?

How does it run....

And how much boost was running to make 200hp from a 9mm head, was that on pure derv? no propane etc?
Title: Re: swapping to a 12mm head
Post by: Rabbit on Roids on April 05, 2010, 11:44:34 am
"rabbit on roids"

So are you running the 12mm camplate as well as head etc?

Was it from a DI engine ? Or IDI?

How does it run....

And how much boost was running to make 200hp from a 9mm head, was that on pure derv? no propane etc?

me, im running a bone stock turbo pump, only has gov mod and LDA messed with. it still has a 9mm head in it. i never built 193 horse with a 9mm, dave cross did. he owns passenger performance. hes kinda a big deal. builds really cool stuff too. i dont know how he did it, but he did on nothing more than diesel and compressed air.

i have nothing more than a stock 9mm head in my pump as of right now. i may play around with a different head in the future, but for now, 9mm is way plenty.

if i were to swap in a larger head, i would use the cam plate, springs, shim, head, everything to make it work right. the pump, springs, shim, and cam plate are all matched specific to the pump head from what ive gathered.
Title: Re: swapping to a 12mm head
Post by: truckinwagen on April 05, 2010, 12:02:10 pm
while dave did make 200 HP on a 9mm pump, I think(from what he posted) he did that to see how much power could be made with a stock bottom end and injection system.

it does not mean that modding the injection system will not help make more power.

I am running the whole cummins pump(which is a DI motor) and it runs great, it does not have the throttle response of a cadillac, but nothing else about my car is like a cadillac anyway.
Title: Re: swapping to a 12mm head
Post by: Rabbit on Roids on April 05, 2010, 12:05:13 pm
i think if you wanted to owen, you could mod a VW style governor to work with your pump and make it a little more like how normal automotive pumps are. instead of having the big rig feel, unless of course you like that feel.
Title: Re: swapping to a 12mm head
Post by: truckinwagen on April 05, 2010, 12:22:31 pm
I dont mind the big rig feel, but I already tried to stick a VW governor spring assembly in it, and it interferes with some of the pump top and LDA stuff, I would have to get a VW LDA pump top to make that work...
Title: Re: swapping to a 12mm head
Post by: Rabbit on Roids on April 05, 2010, 12:34:06 pm
whats keeping you from doing it? lack of funds? or lack of interest to do so?
Title: Re: swapping to a 12mm head
Post by: truckinwagen on April 05, 2010, 12:37:27 pm
no TD pumps kicking around, and why spend top dollar(what everyone wants for an old leaky TD pump) just to use the top?

the throttle is not bad, just different, so I spend my money elsewhere.
Title: Re: swapping to a 12mm head
Post by: Rabbit on Roids on April 05, 2010, 12:42:31 pm
thats pretty much what i figured. its stupid how everyone thinks that a turbo ip is worth its weight in gold.
Title: Re: swapping to a 12mm head
Post by: truckinwagen on April 05, 2010, 02:59:09 pm
yeah, im not sure why people insist that old unknown condition pumps are worth more than a core charge.

I don't have plans to swap the pump top and throttle assembly, but I do plan on swapping in the VW advance and cold start assembly to make the timing curve match better

but other than that, I am happy with the performance of the pump, even with the DI camplate.

Title: Re: swapping to a 12mm head
Post by: colhel59 on April 05, 2010, 04:46:40 pm
well thanks for your guys input i think im just going to stickto the stock pump with a gov mod and boost pin and crank her up abit and see how every thing goes any more a guy could do to get the most out if it?
Title: Re: swapping to a 12mm head
Post by: 79rabbit4dr on April 06, 2010, 11:32:27 am
well thanks for your guys input i think im just going to stickto the stock pump with a gov mod and boost pin and crank her up abit and see how every thing goes any more a guy could do to get the most out if it?


as lame as this answer is, FAQ --> http://www.vwdiesel.net/forum/index.php?topic=16687.0 (http://www.vwdiesel.net/forum/index.php?topic=16687.0)

I refer back to it ALL the time.