turbo 4.7 stroker junkyard build on the cheap

[shawnsack]

working on building a 4.7 stroker motor for my grand cherokee and i already know that if i just use a 4.2 crank and rods and 4.0 pistons i will have 9.5 to 1 compression and if i dish the pistons to 60cc and zero deck the block it will be 8.5 so i figure if i dont zero deck the block and dish the pistons less than 60cc and port and polish the heads i could achieve the same compression of 8.5 to 1 without having even more block work than the boring .60 that im already doing... now as far as turbo goes i dont want to build a racing engine just a good all around engine for the occasional towing and running down the highway and launch at the track for fun... but most of all i want a very user friendly setup as this is my second vehicle and my wife could end up driving it from time to time... i have 2 turbos laying around that i thought i could use. one of which is an hx35 from a cummins and the other is a smaller holeset turbo off of a 6cyl perkins engine in a tractor i believe the turbo is an h3... or if there are any other suggestions i would like to hear them... like i said i am trying to see how cheaply this can be done... i am good at fabricating so im not worried about building the header and the exhaust and intake tubing... i also to plan on running an intercooler larger injectors for the stroker kit and i hope they will accomodate enough fuel for the boost... also plan on using something to control timing and a waste gate to keep it at roughly 7-9psi... also can i use the stock cam and maybe some 1.7 or adjustable 1.6 rockers?

[gradon]

You definitely want the compression down in the 8's for forced induction, but I don't think you'll find a piston that can be dished to 60cc(even 30cc is pushing it, I believe the silvolites 2229s can be dished to high 20's--pm oleshot for his experience with dishing pistons). Were you meaning to say you would try to get the combustion chamber opened up to 60ccs? I think I read of someone that was using a hx35 in a jeep app. Do it.

[shawnsack]

i got those numbers from jeep4.0performance... and i read them wrong its only 30cc the pistons need dished and that will put me at 8.55 compression...
"4.6L Low-buck, low CR "rockcrawler"

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Silvolite UEM-2229 +0.030" bore pistons
Increase piston dish volume to 30cc
8.75:1 CR
CompCams 68-115-4 192/200 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Mill block deck 0.035"
Mopar/Victor 0.043" head gasket
0.058" quench height
Ford 24lb/hr injectors with stock 39psi FPR for '87-'95 engines, stock injectors with stock 49psi FPR for '96 and later engines
240hp @ 4700rpm, 315lbft @ 3000rpm

4.6L "poor man's" stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Sealed Power 677CP +0.020" bore pistons
9.25:1 CR
Stock 4.0 HO camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.088" quench height
Ford 24lb/hr injectors with stock 39psi FPR for '87-'95 engines, stock injectors with stock 49psi FPR for '96 and later engines
248hp @ 4900rpm, 303lbft @ 3500rpm"

the only difference between those 2 setups is im going .060" bore and i think my head is going to need to be milled for warping and i dont know how crazy i should go with the porting of the head

i believe that between the head and the pistons im sure i could get 30cc of extra space...
now a few questions
whats the difference between static and dynamic compression?
can i use the stock cam with some adjustable 1.6 or 1.7 roller rockers?
if i dont mill the block is .088 quench height a bad thing?

[johnhalabama]

Let me know how things turn out with the turbo.

I'm building a 4.7 for a 1936 Dodge running a 390 Holley carb instead of fuel injection. I'm getting a lot of crap from people about why I'm not putting a big block in it, or even a small block for that fact. I just want something different and I have became a big fan of the jeep stroker motors.

I've considerded ditching the carb and running a turbo with a mega-squirt fuel management system. I've got a little time before I get the engine done and I'm really interested in seeing how a turbo works out on a stroker.

Good luck with your build. I'll be keeping up with it.

John - Chesapeake, VA

[shawnsack]

well im not sure how quick this build is going to be especially since i plan on trying the head and piston work myself... which is mostly going to consist of just polishing and gasket matching the head and dishing out the pistons a little bit... if anyone has advise on doing those im all ears

[the_wrench116]

THIS LOOKS GREAT. on paper for timing and ignition duties msd makes a box that will work. i am aiming for 9:1 compresion for my setup and plan on using the factory manifold as a starting point as did turbo tom. good luck and keep us posted.

[shawnsack]

an msd setup might be the way too go i was looking at a mega squirt or aem comp but i would rather have something pigy back to the factory computer than a standalone so everything inside remains functional and user friendly for the wife to use if she ever needs to... im really hoping for a set it and forget it type setup although i know from experience thats hard to do with turbos cuz ur always looking to tweek something