Engine/Transmission (1998.5 - 2002) alright, I've searched... 12v engine into 24v truck?

[Forrest Nearing]

read about this on here before, but now can't find the post



I'm considering buying a 24v truck and converting it to 12v...



I have a 24v shortblock in the garage that I would build w/ good 12v pistons, aftermarket 12v cam, etc. this would give me the 24v block and crank which I believe would allow my factory gauge cluster to work as the crank sensor would still function.



now, would the 12v TPS plug straight to the factory 24v transmission harness?



no, I don't want a p-pumped 24v, and I'm not asking about just starting w/ a 12v truck... I've found a cheap high mile QC/SB 24v auto... I figure if I'm going to build a motor and transmission anyhow, why start w/ a low mile truck? plus the 24v truck will allow me to legally run without a cat and give me rear disks.



thanks in advance,



Forrest

 

[Cooker]

now, would the 12v TPS plug straight to the factory 24v transmission harness?

The 24v's use an APPS. It is a completely different sensor than the 12v TPS so as far as it plugging right in and working that's probably not going to happen.



I think there is quite a bit more electrical work than you are anticapting to get everything to function like OEM.



BTW - There is at least one truck out there that started life as a 24v that now has a 12v stuffed under the hood.

 

[KLockliear]

Call Lenny at Dynomite Diesel in Monroe, WA... he has an '02 with a 12v in it and everything works.



866-774-3966.

 

[SConklin]

There's about to be another.

 

[Fishin Guide]

Lenny's truck is kick butt!!



Dave

 

[rubberneck]

Just curious, why not a p-pumped 24 valve? Is there a performance advantage to sticking with the 12 valve? Or just want something different? thanks phil

 

[Forrest Nearing]

cheaper/easier... valvetrain is cheaper, no custom fuel lines, etc.

 

[SConklin]

When you price it out, it's neither cost effective, or of any performance benefit unless you plan on going past around 800hp. Beneath that, the general consensus is that the conversion is not streetable, or tunable, compared to even a regular 12v.

 

[bmoeller]

Beneath that, the general consensus is that the conversion is not streetable, or tunable, compared to even a regular 12v.

RonA has been having problems with getting his P-pumped 24v dialed in.

 

[Cummnzpowr]

me too

We are about to start a project as well... i found a 95' 12v motor with 120k on it going into the 98' because of a badly cracked "53" block. See luckily my truck has a Dana 80 disc rear, and NV5600 trans in it. . so no APPS b. s. to worry about there,i guess the main issue is connecting the harnesses and such.

 

[rubberneck]

When you price it out, it's neither cost effective, or of any performance benefit unless you plan on going past around 800hp. Beneath that, the general consensus is that the conversion is not streetable, or tunable, compared to even a regular 12v.

I dont understand this, I mean I'm not doubting anyone, but i have ridden in 3 p-pumped 24 valves and they seemed great. All of them were automatics, Two of them were some of the earlier ones done by Piers and 1 was a home conversion job. Granted i didn't drive them or tow anything, but they sure seemed like rockets on the street, and i would say not a whole lot more smoke than a vp 44 truck (unless you wanted it) I know different injectors made a big difference in the driveablility, but that would be the same 24v vs 12v. The 2 piers trucks had mitchell twins/cams and the home brew had stock cam/big bell turbo single (same one Joe D used I believe) I understand the cost of the valvetrain thing. I know the custom 24 valve valvetrain parts are spendy, I guess i just dont understand why the extra valves would hurt driveability. Any ideas on this?? Im asking, cause i have been considering doing this, but maybe i should rethink.....

 

[RonA]

The problem with mine was injector pop off pressure. It is fixed now and idles well. Knowing what I know now, the conversion would be a piece of cake. Probably aren't many people that could tell the difference between mine and a 12 valve just by driving it.



Ron

 

[Sea01Cummer]

Is it top secret or would you mind sharing the pop off pressures with us? I am compiling info on this just incase i decide to ditch the VP.



Thanks Steve

 

[RonA]

I just had them set the same as 12 valve injectors.

 

[Sea01Cummer]

Thank you!!!



Steve