Tell Me if I'm Crazy?

Can I run a Renix head on an HO block?

My new toy is a 96 2-door XJ, 2wd, 4.0 with the AX-15. It has at least a blown head gasket according to the dealership that took it in as trade. The long term goal is to build a stroker and convert her to 4wd with the parts I already have, but for now, I just want the XJ to be road worthy again. It does run but very rough right now.

Anyway, I have a Renix head that has been completely reworked that I never used due to an engine swap in my 89. I'm thinking about pulling the head on the 96 and dropping in the Renix head. Other than the manifold issues, which I think I can work around, is there any reason this won't work?

it will work, it will be less than ideal.
Part of the HO head design was for higher performance, but it also changed the head to cope with the deletion of the EGR valve.
as far as bolting up, yes, it will, performance wise, who knows.

You will also need the renix manafolds because the ports are different. Plus an adaptor for the HO throttle body

You CAN bolt up the HO manifolds to the Renix head though the runners won't line up 100% perfectly with the head ports. It'll function well enough though.

Dr. Dyno said:

You CAN bolt up the HO manifolds to the Renix head though the runners won't line up 100% perfectly with the head ports. It'll function well enough though.

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I thought that renix to HO would work but not HO to renix.

Pretty much any AMC I6 head can be bolted to any AMC I6 block (199/232/242/258,) the bolt patterns are the same.

You'll usually just run into manifold issues, and some performance issues due to revision of the heads over the years.

5-90

Sell the Renix head and use that money to rebuild the Ho head. That way all the manifolds will fit and the motor will stay all HO.

Midnight Krawler said:

Sell the Renix head and use that money to rebuild the Ho head. That way all the manifolds will fit and the motor will stay all HO.

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The final engine will be all HO. Just want to get this 96 back on the road while I finsh my 89. If the 96 head is good, I will save it for the rebuild. The engine got pretty hot from what I was told. The head may be cracked. I just hope the damage is limited to the head or I'll be pulling the whole engine. This engine has 169,000 on the clock, so I'm not looking for a long term fix here.

Thanks Dr. Dyno! I thought it would work and it will allow me to get this thing running again in one weekend. I only paid $600 for the XJ. The body and interior are in beautiful condition. Plus it has a working a/c!

I'll let you know how it runs after the swap.

Pulled the 96 head today. It was cracked in two places. Had a crack between the valves in #1 and crack between #3 & #4. Had evidence of water in those 3 cylinders. Found that the radiator was where the original leak was, good thing I have a spare one. Also found that the temperature sensor lead was broken. So, I guessing the poor guy didn't even know he was burning up his XJ.

The block looks good, so I cleaned it up and bolted on the Renix head. Got the head completely back together and the valve cover back on today. Have to wait until next weekend to wrap it up. The exhaust manifold will bolt up fine, but the intake will need to be lowered a little. I will adjust the pin holes and use a Renix manifold gasket.

I'll let you know if she runs next week.

She runs again! The Renix head works great. The 96 manifolds bolted right up with no adjustment needed. It runs very good too.

The only modification I had to make was to the manifold gasket. Neither the 89 nor the 96 gasket covered enough of the intake mating surface due to the slight misalignment. So I actually cut the gasket between the intake and exhaust ports and lowered the intake gasket sections just a little to give it just a little more overlap. It might have worked without this, but the 96 gasket rides pretty high on the intake ports and there wasn't enough overlap there for my comfort. Don't even consider a Renix gasket, the intake openings are larger and it won't mate well.

Best of all, since I had the rebuilt Renix head and the radiator already in collection of jeep stuff, my total investment was only about $50.