Engine/Transmission (1998.5 - 2002) Why not 12v LP on 24? (with DD cam)

[WadePatton]

Why not put the mechanical pump from a 12v on the 24v when you install an aftermarket camshaft with the pump-driving lobe?



I spoke with JD about it and he thinks that the pulsations from the LP would be too much for the VP44.



Has it been tried? Could the pulsations be minimized someway?



Has this been discussed before? (I'm tired of searching. )

 

[SEmerson]

I have disussed the same thing but got no good info. The pulsing could be reduced with a large seperator after the pump. And also use of large rubber fuel lines.

 

[KLockliear]

It works, but it's not cheap. The 12v lift pump alone is like $225.

 

[WadePatton]

If you're putting in a cam anyway--that's cheap enough--especially when you only have to buy one per 100-200k.



$225 doesn't come close to the cost of an electric LP, uprated fittings and lines, and pusher pumps.



So Keith, what other nasty details are there?

 

[G21]

Wade,



I lost 5 of those crappy stock lift pumps in a two year period. Sure, we were pushing them alittle, but they are still junk.



If someone can think up an idea, Lawrence at DD has either already tried it, or has/is thinking about it. . He has been there, done that. I have 8500 miles on my mechanical 12V pump mounted in my 2001. 5. Aside from the pump, there are a few other things that must be attended to... but those are DD's secrets.



Not many guys are running 32 psi at idle, 54 psi at WOT.

Glancing at the fuel pressure guage makes me feel really good, after losing so many electric pumps.



Still 465hp+ daily driver and LOTS of fuel!



Good luck,



Mark

 

[A Johnson]

Cummins sells an industrial 12 valve electronic 6bt with a VP-30 on it. Looks similar to the VP-44 but uses a diaphram lift pump like the first generation engines. Horespower on the one I looked at was 152 so it was considerably less than the vp-44 will produce. My thoughts are that I doubt the pulsations from the lift pump will hurt the vp-44, even using a piston type lift pump. If a diaphram type pump will supply enough volume I would go that way.



A Johnson

 

[WadePatton]

AJ, that's the beauty of the diaphram pump, they're more durable and provide MORE pressure with RPM not less.



HOLY CRAP, 54psi! surely that has to be pressure regulated to prevent blowing the input pump of the VP.



Secrets?! Seems like a market would exist. Well maybe not a big market, very few of us are going to change camshafts. I will, but it won't be anytime real soon.

 

[SEmerson]

What is the price of aftermarket cams now?