258 Questions

[T-$$]

got an 84 CJ-7 w/ a 258 and am re-doing the entire. took the tub off and am going through that and soon will come to the engine. it alway ran and ran fairly well. but it always leaked a lot of oil with the pcv valve in place and with it out you could see a lot of gases coming out of the valve cover grommit. I also had other problems with a bit of "milk on my dipstick" (as talked about in a previous thread)

before i crippled the rig in my garage, i did a compression test on all the cylinders and got about 120 psi (+ or - 5) on all cylinders.

couldnt find a spec in my book. anyone know what they should be? or have ideas on what may be the problem.

and what do you think of the replacement engines in quadratec?

[dreymeek]

Your rings are shot. 120 psi is low, and the blowby and water in the oil screams rebuild time. The AMC block has some hard iron in it, so you may get by with just rings and bearings unless it got really overheated and that's causing the blowby and water in the oil. It's a simple engine to work on so if it were me, I'd tear it down and see how bad off it is.

[T-$$]

I have looked a bit at replacement engines and bout $1500 seems to be the norm. I guess I could do it myself, but i'd rather make sure its done right and all areas are looked at.

I can get a wagoneer (witha a 360) with low miles for bout $250. so i think i'm gonna do that.

[dreymeek]

The 360 will bolt up to your 258 bellhousing, but I don't know if flywheels will swap. The Wagoneer frame mounts bolt in so you could utilize them in the conversion. You'll need a radiator for the V8 and if you don't have power steering, the Wagoneer has all you need to do that. Good score on the donor car!

[Mr. Plinkit]

The milk in the oil is water, usually a head gasket and the gassing is blow-by. You can find the exact location of the blow-by by doing a leak-down test instead of a compression test. Rebuild is a good suggestion or upgrade to a small block V8. The chevy small block is as cheap to build, offers a lot more but you need the adapters. Fuel injected is more costly and time consuming but gives you few if any altitude drivability problems.

Originally Posted by T-$$

got an 84 CJ-7 w/ a 258 and am re-doing the entire. took the tub off and am going through that and soon will come to the engine. it alway ran and ran fairly well. but it always leaked a lot of oil with the pcv valve in place and with it out you could see a lot of gases coming out of the valve cover grommit. I also had other problems with a bit of "milk on my dipstick" (as talked about in a previous thread)

before i crippled the rig in my garage, i did a compression test on all the cylinders and got about 120 psi (+ or - 5) on all cylinders.

couldnt find a spec in my book. anyone know what they should be? or have ideas on what may be the problem.

and what do you think of the replacement engines in quadratec?