Jeep Strokers

Hello everyone,

I have been a long time board stalker, but finally joined up to get as much assistance as possible with my future build. Long-Short version, I have a 98 ZJ with the tired 4.0 in it (Runs fine, just gutless) and I have been contemplating doing a stroker build for it for a while. Jeep is regularly used for trails and wheeling with hopes to hit the Rubicon at some point in my life, as well as regularly driven as a grocery getter.

Currently, I have a spare 4.0 that I bought for $100 from a running 98 XJ. Guy pulled it for another engine he built and didn't need it. Has approx 300k on it, already tore it down, and it is in really good condition considering the miles. Plan is to do a 4.6/4.7 with it, and being it's a spare engine, time isn't an issue. Ultimate goal is well-built reliability with some more power. Don't want to go crazy with it, keep it reasonable, but plan on replacing most everything while it's apart.

My history with rebuilding engines is fairly decent...I have done several L4's, everything from nissans, mazdas, ford, etc. Built a few V8s in my time, typical 350s and a few LS builds, as well as rebuilt a few transmissions (to include the 42RE in the jeep) and several transfer cases. Basically, I have been working on various car and truck projects for the last 20+ years. This is my first stroker build, and I like to research to death on everything because I don't want to do stuff twice.

Parts I have so far:
98 4.0L Core and head
New Melling Standard Volume oil pump and pickup
New Cleveite Cam Bearings
New Gates water pump
Fel-pro gasket set (Will do a separate MLS head gasket once I figure out the thickness I need)
New Brass Expansion Plugs
New Head Bolt kit
Working on port matching intake manifold (Spare one)
Various other small parts

I've read many times on here to get ahold of Russ to get internals, so that will be an option being I have not ordered anything reguarding that yet (i.e., crank, rods, pistons, cam, etc.). Been looking at Cleggs stuff, but want to make sure everything works well together and can drive around on at least midgrade 89 or less fuel. Additionally, I have a machine shop lined up, but not done anything yet as far a machine work, waiting on what parts are needed first.

Any help on where to go next is much appreciated!

What's your budget and how much HP/TQ are you hoping to get out of your stroker?

Budget is sort of up in the air as I'm piecing it together as I go and have time, but not trying to spend thousands of dollars either, it's a 98 jeep, so trying to stay realistic. I'd say $2000-$3000-ish, but not set in stone. As for power, whatever I can reliably make on pump gas, I figure 270 range is plenty...If i can get more, then that's fine, not building a race car. Most off roading I do is rock crawling, so I tend to be easy on the skinny peddle, tryin not to break things.

Biggest issue I have now is the poor thing is anemic at best...thought that by gearing it I could help it out, but not really. I have to punch it to the floor to go up the slightest hill doing 55...Off road it's great in low gear for the most part, but she struggles on regular drives, and I don't think I have ever been able to get over 65mph downhill with the wind to my back.

Something like this would suit you fine:

4.6L low-buck stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Custom forged +0.030" bore pistons, compression height 1.380", dish volume 18cc
9.6:1 CR
CompCams 68-231-4 206/214 degree camshaft
Russ Pottenger ported HO 2.00"/1.55" 62cc cylinder head
Mopar/Victor 0.043" head gasket
0.043" quench height
Ford 24lb/hr injectors for '96-'04 engines
268hp @ 4900rpm, 326lbft @ 3500rpm

That is basically what I was going for, I assume Russ can hook me up with the pistons?

Also, I looked into that cam, and for whatever reason, it states not for EFI use, is there a reason for this?

Hi KC,

You’re welcome to shoot a call or email out to me and if you give me a few days I’d be happy to put together some information and pricing and get it out to ya.

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]

Russ Pottenger wrote: ↑June 29th, 2023, 9:14 am Hi KC,

You’re welcome to shoot a call or email out to me and if you give me a few days I’d be happy to put together some information and pricing and get it out to ya.

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]

Sent you a PM good sir, I think it went through.

If you have an already Please reach out to me at [email protected]

Thanks,
Russ

Russ Pottenger wrote: ↑June 29th, 2023, 9:39 am If you have an already Please reach out to me at [email protected]

Thanks,
Russ

Sir,

I did send you an email a while back, around June 2nd. Can reply back to that one, should be from my [email protected] account...If you didn't get it, I can resend.

Hi Justin,

My apologies. Looks like your email slipped through the cracks.
Thanks for the information in your email. Give me a day and I’ll get some information out to you.

Thanks,
Russ

KCKrogoth wrote: ↑June 29th, 2023, 9:12 amAlso, I looked into that cam, and for whatever reason, it states not for EFI use, is there a reason for this?

I never understood that given that the 68-231-4 cam has been used successfully in many EFI applications. I guess it might be because it's one of CompCams oldest grinds and has been used in carburetted 4.2L engines.

Cheromaniac wrote: ↑June 30th, 2023, 9:29 pm

KCKrogoth wrote: ↑June 29th, 2023, 9:12 amAlso, I looked into that cam, and for whatever reason, it states not for EFI use, is there a reason for this?

I never understood that given that the 68-231-4 cam has been used successfully in many EFI applications. I guess it might be because it's one of CompCams oldest grinds and has been used in carburetted 4.2L engines.

I believe It’s mainly due to the 111° lobe separation angle.

Most of the camshafts that Comp lists in their catalog I have them change the LSA from their 111° to 113° or 114° in order to help improve manifold vacuum.

For comparison, I'd originally built my stroker with the Crane 753905 cam (112* LSA) back in 2004 and it had 17 in H2O vacuum at idle. With the stock cam (also 112* LSA but shorter duration) it was 21 and it also delivered better gas mileage.

Thank you for the email Russ, all looks pretty good to me, only real I have question is are the pistons zero deck or do I need to get the block cut? Or should I have the Machine shop run the cutter over the top and surface it then see how much he takes off before ordering the pistons?