Jeep Strokers

I’ve been kicking around the idea for building a stroker engine for almost half a decade, but my current 4.0 has finally reached a point where it's days are numbered. The stroker will be replacing a well used 240k mile 4.0 in my 92 YJ on 35’s. The Jeep is mainly used as a summer toy and off roader. I’m not so much looking to squeeze as much power as I can out of this build. I’d prefer an engine with more power than stock, with decent reliability and good low end torque.

Here is what I have so far:
•’92 4.0 block (most likely will be bored .030’ depending on cylinder wall condition.
•12 wt crankshaft from an ’80 258 engine
•Jeep 4.0 connecting rods
•99+ or stock ‘92 style intake manifolds available for use
•I have a the existing ’92 7120 head or a ’96 0630 head available for use.
•I also have a cylinder head I purchased from a forum member years back, but after reading his build thread (camshaft issues) I’m now hesitant to use it for my project.
-See viewtopic.php?f=8&t=2405&start=45andhtt ... f=8&t=3912
-’98 0630 head
-Has GM 3911068 springs, spring seats were cut for proper valve spring height.
-Mopar P5249877 Intake valves and Mopar P5249876 Exhaust valves
•Preference is to use replacement stock style rocker arms for reliability.

I’m torn what to do with the cylinder head and camshaft choice as well as what pistons to use.
So any advice or information regarding the cylinder head, valve train, cam selection and piston choice would be appreciated!

I carry a full custom piston line with multiple dish volumes.

I’d also be happy to forward you information on my cylinder head and intake manifold porting services along with stroker kit related parts Including camshaft recommendations

Feel free to drop me a call or email

Thanks,
Russ Pottenger
Bishop-Buehl Racing Engines
531 N. Lyall Avenue
West Covina, California 91790
Work (626) 967-1000
Cell (626) 673-2203
Email: [email protected]

My stroker is .030 overbore, offset ground .020, block shaved to give a .000 deck height, I would get the largest dish CC piston you can to keep the compressions down, I would run the 5.7 hemi valves in the 7120 head and get the associated valve work done instead of the small block chevy valves I am running. 2000 intake, 6 into 2 into 1 exhaust manifold, which would give you about 250 hp. Oversize throttle body and mustang injectors. It runs great power wise, but it is a little lean. Good luck. Tim

astjp2 wrote: ↑July 23rd, 2019, 8:52 pm My stroker is .030 overbore, offset ground .020, block shaved to give a .000 deck height, I would get the largest dish CC piston you can to keep the compressions down, I would run the 5.7 hemi valves in the 7120 head and get the associated valve work done instead of the small block chevy valves I am running. 2000 intake, 6 into 2 into 1 exhaust manifold, which would give you about 250 hp. Oversize throttle body and mustang injectors. It runs great power wise, but it is a little lean. Good luck. Tim

I would tweak your advice just a bit.

I wouldn’t recommend getting the “Largest Dish CC Piston”
You want to get the “proper dish volume” for the octane fuel you’re planning on running in your engine.

Running too low of a static compression ratio is just unnecessarily giving up potential power.
I see some of these recipes with a static compression ratio of 8.8:1 on a normally aspirated engine.

A properly designed piston with a reverse mirror dish with a proper quench, You’ll be able to safely put some compression in the engine

Well we only have 85 octane for our regular and I have a 22cc dish and wish I had 26cc or more to get my compressions down to normal levels. I had 204 psi for the low cylinder 212 for the hi and I was getting some ping because it is either lean or advanced too much in my YJ. A wide Lobe separation angle will up your dynamic compression ration by quite a bit. I like a 114 lsa for EFI engines. Tim

Why gas stations bother to supply 85 octane cat piss is beyond me. I suppose the only reason is because it's cheap, and there's still a handful of surviving sub-9 compression low performance iron headed motors that'll run on it.

Regarding the fuel, I'd prefer an engine that runs well and makes decent power on regular gas, worst case mid grade. I still like to drive the Jeep as much as I can in the summer and premium is a bit pricey for that.

He he, if you think premium gas in the US is expensive, try living in Europe where the price of premium is $5-7 per gallon and the government takes roughly 70% of that in taxes!

Cheromaniac wrote: ↑August 1st, 2019, 9:47 am He he, if you think premium gas in the US is expensive, try living in Europe where the price of premium is $5-7 per gallon and the government takes roughly 70% of that in taxes!

Oh I'm well aware, I travel to Europe and Canada quite often for work. Our fuel is cheap by those standards for sure.