Budget build advice

[Unclewolverine]

Starting to plan the rebuild of my old motor. Since I depend on my xj for my livelihood I want to build it for longevity and reliability. But it has to be on as much of a budget as possible. The motor was running when pulled but had no oil pressure and a lot of metal in the oil. Pretty sure I tossed the cam bearings when I blew the headgasket and watered down the oil. Going to send the head to the machinist and tell them to make it new. The crank may need turned, but interestingly it still had no blowby, so fingers crossed maybe I won't have to bore it and I can re-ring the pistons. Either way the block is going to the machinist to be tested and checked out. Probably need a new cam, lifters, rings, and full bearing set at the least. Ive heard that a timing chain with an advance can boost low end torque which might be nice between mail boxes, but would it hurt fuel economy? I would like a set of aluminum roller rockers but not sure if I can justify the expense since stock ones seem to work just fine. Any other ideas? (Not stroking it unless you are paying!)

 

[75SV1]

I don't see a year for your XJ. I'd probably upgrade the cam. Possibly the timing chain to a dual row roller. Maybe a High Volume oil pump. I'd put in a 99+ 'horse shoe' manifold, a 60mm Throttle Body. You might need new springs with an Upgraded cam. I think I went (or have for a stroker) a 268 Comp Cam. I'd probably check Russ Pottenger at Bishop Buel racing for prices. Replace the harmonic balancer, too. No need to get fancy on the water pump or harmonic balancer.

 

[RCP Phx]

You can buy a timing set with degree options in the lower gear. I have a set of Harland-Sharp rockers (500 miles on them but warranteed for life) if your interested.

 

[Unclewolverine]

Its a 95, I would do a hotter cam if it was the same price without having to add many other parts or re do the ecu. Definitely going with high volume oil pump, probably going to get the horse shoe manifold but need to check to see if it will work with rhd brackets, maybe a cheap header too, manifold was cracked and re welded last time I had it off. RCP, going to pm you on those.

 

[75SV1]

I remember $150 for the cam from Russ. I ordered the nitride one though for $300. I do not remember if that was with or without lifters.

 

[CJR]

Two suggestions on your budget rebuild:

1. It's most important that you replace ALL the connecting rod bolts. These bolts are "reversed-cycled" therefore subject to fatigue life. Use new ARP connecting rod bolts to prevent putting a piston through the head.
2. Re-ringing used cast pistons can be "iffy" during ring break-in. The aluminium, between the ring grooves, can break (due to fatigue) and you'll hear a clicking noise. Power will be down since the rings can't side-seal against the broken aluminium pieces and compression gases will blow-by the rings and pressurize your crankcase and valve cover.

Best regards,

CJR

 

[Unclewolverine]

Cjr- is that a jeep specific piston problem? I only ask because I've re-ringed many a Ford and chevy motor and have never encountered a situation like that. It really sounds like the ring landings were damaged by someone knocking the pistons out of the bores without cutting down the ring ridge. I have a ring ridge removal tool.

 

[CJR]

No, it is not a Jeep specific problem. There are cast pistons and there are cast pistons. Aluminium cast pistons have low fatigue lives. I've lost count of how many cracked/broken cast aluminium pistons I've pulled from engines over the years. As a result of my $$$$$$ experience, I only use forged pistons in my rebuilds.

Best regards,

CJR