If I replace the cylinder head on my XJ do I need to replace the rings? I've got a 2000 Jeep Cherokee XJ, engine rebuilt in 2009 (cylinder head replaced with an 0630 during the rebuild), daily driver, ordinary street use, no abuse. If I don't replace the rings will the difference in wear cause oil to get sucked past the rings, or cause other stresses in the engine? Don't know if an adapter was used when the head was replaced.

 

No, you don't need to do the rings. Why do you need a new head after only two years?

 

Good question. I don't need one. I am considering upgrading. Dunno if that makes sense, but thought of either going with an Alabama cylinder head (has coil pack mounts) late 0331 (2002 or after - once they fixed the cracking), or 7120 (due to better flow).

 

Seems to me i'd be more worried about the BLOWN motor. Before if decided to upgrade the head.

 

Not sure what you mean about a blown motor...?

 

If it aint broke, don't fix it.

 

Back in uh, July I guess of 2009, when I was about to buy it, the seller wanted to first fix two noisy rockers. Fixing these revealed a cracked head - no surprise right? So the head was gonna be replaced before I could buy it.

I'd always heard it's best to have the same amount of wear on head and block, so paid a small portion of the rebuild cost to have it done at the same time.

Anyway, I was wondering if there was much of a risk in replacing the head without also replacing the rings. I am hearing its best to leave it alone...

 

dont waste money on a new head, save your money and to everything at once. Oversize the cylinders, port and polish the intake, new cam and lifters. Roller rockers, headers. If you want more power, do it right or else you won't feel the difference.

 

I heard one shop tell me they put a new top end on a motor under warranty, and not long after the bottom end went out. They claimed the new top end caused it.

Personal Experience - I put new heads on a Chevy 454 big block motor and did nothing to the lower end. Ran it till I sold it and the guy who bought it ran it until he sold it with no problem.


Having said that ... I think if I had to put a new head on my jeep, considering how much already needed to be dismantled I'd probably go all the way and do the whole motor.


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Good feedback. Seems replacing just the cylinder head could be a problem. On one hand I could wait and redo the whole thing, going full blown stroker when it needs a re-do. On the other, replacing the cylinder head alone might work.

Wonder how much more to replace rings if the head is already off, to put a fresh head on...? The rest, except the push rods, was done last go round at a good shop.

I don't know if an adapter was ever put on to account for the difference in the 0630 and 0331 heads. If not, would that mess something up?

 

if the motor was rebuilt in 2009 you will be fine the new head old motor applies more to high mileage motors than has most likely been put on yours in two years

 

That is awesome information, and glad to know. Especially if the rings, pistons, cylinders have had a chance to seat and develop a unique fit, I'd rather not mess with them if I don't have to.