Jeep Strokers

cherokee wrote:The Mopar Jeep Engines (3rd ed.) book that covers the 4.0 mentions notching the cylinder bore for rod clearance when using a 4.2 crank (pg 135). However I can't recall seeing pictures or reading that anyone had to do so.

I believe I asked about the main girdle on the yahoo strokers group and was told that spacing it could interfere with the oil pan. That was a number of months ago and it's possible I've remembered wrong.

I put a 258 crank in my 4.0 block with a set of 258 rods and 4.0 rods(Just doing some comparing). You don't need to notch the cylinder walls. There is plenty of clearance.

gonridnu wrote:This vehicle does not have any trans cables other than the shifter cable...it does however have cruise control with a fairly elaborate cable and bracket system...does that change as well....it's starting to sound like keeping the Renix head would be a whole bunch less trouble and possibly not a lot less horsepower...If need be I can do some port work to make up the difference and probably have less time in it than messing around with brackets.cables and manifolds...not to mention keeping my Borla header

The RENIX head sucks pretty bad compared to the 7120, even with a bunch of port and polish hours, its worth it to go with the 7120 casting. There really isnt that much involved with moving over to that head... The hardest part in your case would be finding a cruise control system from that same year range.

Mgardiner1 wrote:You are right, the Renix head would be much easier to preserve everything in its stock form, especially the cruise control. IIRC the Renix throttle is facing the rear of the engine, and the HO is on the front side.

That being said, i think with the exception of the TPS, the rest of the sensors shouldn't be a problem. I think you just wouldn't use the coolant temp sensor in the thermostat housing, as the Renix should have one in the side of the block for that.

You would use the RENIX thermo housing, so that boss for the sensor wouldnt even be there

I would go with a HO head, this will let you use the 99+ intake, from some of the threads i have read here, it really makes a huge difference. I would also try and find a late model core, some of them have cylinder walls thick enough to bore to 4", this would put you into custom pistons, but i think it would be worth it.

Allright so it's been like a year since I started this thread. Since then we sold our house and moved closer to town and I finished and installed the 540" B-1 in the Dodge. It made 711HP and 666 torque @ 6000 rpm on pump gas with a flat tappet cam. Anyway I went down to the machine shop today and stripped my wife's engine.

It is already .040" over.....is .060" overbore a problem on the earlier blocks?

I've decided to just do some port work on the Renix head and see what kind of flow numbers we can get on it. We have a superflow bench and a lot of experience so we'll just try that. Like I said this is my wife's driver so a few H.P. here and there is not a big deal to me and it will be way easier for me to make everything work ie. cruise control.

My old shop, the one I do my work at, is right next door to Silvolite/KB plant in Carson City so I'm gonna use their pistons on a 4.0 rod and I think I already mentioned I have a 12cw crank.

I need to know on the block asap 'cause she'll want her car back and if I gotta go get one I need to do it quick

If anyone can help it would be appreciated. I have block casting number 8933002665 and it is already .040" (although a very nice .040") I have spent a couple hours reading threads but cannot find a definitive answer as to wether this block can go .060" or not.

Can someone help a brother out

Only way to really find out is to grab a sonic checker and start taking measurements.

If you are going to a "forged piston" setup... you can spend just a little more to get any size piston that you desire.

AFAIK all 4.0 blocks can handle a .060" overbore. It's been mentioned that some of the renix blocks can handle .090"+, with a sonic check strongly recommended. Jsawdust has a +.080" custom piston setup in a 93 block.

Thanks for the response guys....

Just in case I ran up to a bone yard and found a complete NVH engine core #53020569 for $200 . I haven't bought it yet and was gonna check the thread before I did....I like the idea and it gives me the newer manifold and head to see what I can make work with the renix set up.

Thanks again...

That casting number is shown to be 96-98 block and it shouldn't have the newer intake manifold.

Picked up the NVH motor today and stripped and jet washed all the parts. It is standard and in really good shape. It has a raised port head and associated intake and exhaust. Sorry for the misdirection I meant newer than renix head and manifold. I will line hone it and rough bore it tomorrow then deck it after a trail assembly. Looks like I have to drill and tap one hole on the drivers side of the block for a sending unit but there is a boss there so it shouldn't be an issue. It also has a boss on the raised port head for a renix temp sender that is not drilled and tapped. I'm gonna get it short blocked and worry about which head to use later. I'd like to use the newer head and manifold and will see what I can do about making my linkage work from the renix stuff. The manifold is obviously aluminum so it is very easily welded and machined to achive that.