2000 4.0L head on 87 Renix engine

If you were keeping the renix, I've got a 67mm (2-5/8") throttle body and Mopar performance control box.

Thanks to Ron I now have a bored out Renix throttle body! Much easier to bolt that on than to modify an HO TB and make an adapter. He also offered me a used Jeep performance computer that has a bit better fuel map and timing curve. It was an offer I couldn't refuse! Not sure when I'll try that, have the head work to do.

I have the head cleaned now, ordered a head gasket set and will pick that up tomorrow. Has anyone put a 91+ HO head on a Renix block? I know the ports are higher on the HO head, but are the push rods the same length, or will I need HO push rods? I haven't taken the engine apart yet, and want to make sure I have everything on hand so the head swap goes quick.

I discovered the problem with using a Renix intake, and a solution. Someone told me they had done this, and added some material (by welding) to the top of the port area on the Renix intake so it would seal. Well, that works, but creates a port misalignment. So what I'm going to do is fill in the alignment dowel holes on the intake with epoxy then drill new alignment holes roughly 1/8" lower (I'll measure closely!). That will bring the intake back into proper alignment. I might have to make some steel plates to clamp the intake on that way though.

I cleaned my spare intake. It came from an engine that obviously was burning oil -- there was a lot of gunk built up inside the intake. I used oven cleaner to get most off, and foamed the inside of the intake really good with the stuff. I let it sit for about 15 minutes and most came right off. A bit of scraping the tough spots and another coat should finish it up, especially since it went in an oven this time!

No, not in the kitchen! The old range in our house went (I'm living in and remodeling my grandmother's old house). It was just the oven thermostat, but that's a $200 part on a self-cleaning oven!! $250 to repair, so we bought a new one.  The old one is in my shop now. It gets up to temp just fine, but once the thermostat turns the oven off, it won't turn it back on to maintain temp. If you bump the temp up a little it will come back on until the new temp is reached. I figured I'd set it at 500 with the oven cleaner coated intake inside. It should hold temp a while, and slowly cool down. Then I'll take it out and hose it off. Should work well, waiting for it to cool down now. If it does, I'm going to see if the whole head will go in at an angle. Might put the oven on "clean" (about 750 degrees) with the iron head, didn't want to try that with the aluminum intake. It won't melt I know, but afraid it might warp. I know the iron head won't, machine shops "cook" off grease and such now. I don't know if they put aluminum intakes in their ovens though -- probably so. They likely put aluminum blocks and heads in, but they are a bit sturdier than a long I-6 intake.

I have had a 4.0 intake powder coated that had oil deposits like you describe. They put it in there oven to burn it off (the oven that flows out the powder) and I had no problems with leaks when it was installed so I don't think it will warp. They also said that the had to cook it a few times to get all of the deposits out of the intake.

Edited by 71gremmy - Aug/14/2007 at 11:45pm

I warped a bellhousing at ~500 degrees in my machininst's oven. It distorted it enough that it would line up on the block anymore. IIRC he bakes aluminum at around 400 degrees, but doesn't like to doing it because of the risk involved.

  Is the Mopar Performance Computer for the Renix system still available? What is the part number? I just added a 88 Cherokee to the back lot. Got a great deal on it! Runs great but no title salvage-impound so parts only......