willysjeepseller
I think I finally found out what is wrong with my engine. I think it was rebuilt with uneven length valves. Since the AMC has no adjustment=problem. I am tearing it apart tomorrow to verify and take the heads into a shop for a fix.
I also want to replace the cam as the shop that did the poor work put in a cam I didn't want. They put in a crower baja beast, 1800-4000ish rpm. I am looking for torque at idle. Anyway the engine has only about 5k on the rebuild. What do I need to change as far as additional components? The distributor is a msd billet that was installed at the time of rebuild. Should I replace the gear and other items? I read a lot of threads and I am scared of making things worse.
Thanks
jeepsr4ever
At 5K just check everything out. If you dont already install a double roller T chain set. Such low mileage nothing SHOULD be damaged but check for bearing damage.(cam and crank)
ironman_gq
look at engle cams. I have a cam from them in my 304 and it makes a ton of torque down low till about 4500rpm
willysjeepseller
Guess what. Rust pitting in two rear cyl. Looks like no bore and hone on the rebuild. Looks like just a quick glaze break and ridge ream. Come to think of it those cyl were the ones with low compression, the reason for the first rebuild. The rebuild that cost me a couple grand. Crud. Square on here i am 5 years later. Bad rebuild.
tufcj
Measure the bore before you confirm it wasn't bored. I got a 390 that was supposedly fresh bored .040". It still had a deep scratch in one of the cylinders that probably wouldn't have cleaned up at .060. The block had some other issues, so I sold the bare block to a guy that was willing to sleeve it. I used the internals in another block. Remember a .030" overbore only takes .015" off the cylinder wall.
As far as the heads, the valve stems being uneven really isn't a problem as long as they aren't noisy. The plungers in the lifters allow a lot of room for error. As long as there's enough room for the plunger to compress to pump oil to the rocker, you're OK.
Now if the valve seats or valves were re-ground too deeply, that's another issue. That can cause poor flow, overheating of the valve edge if there's not enough margin, and not enough spring tension on the closed valve.
Too bad you didn't discover it sooner, you may have had some recourse with the shop. I guess at this point, another rebuild is in your future.
With that few miles, maybe just a bore, new pistons and bearings, and the new cam you want.
I like the Edelbrock performer cam. It does well for low end torque in my 360. It's a good off road cam for 360 or 304, probably not enough for a 401.
Bob
tufcj
