Amc 258 engine restoration

Hey guys.

I am about to take my 258 out, tear it apart, and assemble it again. I will have it sandblasted, grounded and paintet. I will replace all gaskets.

Is there anything you would recommend replacing, when everything is torn apart anyway?

What should i look for when i get it torn apart, to see what is needed to replace?


Thanks!

 

By the way, when engine is cold, it have a hard time accepting accleration. (i have installed HEI)

 

Making it clean and nice won't affect the performance, just FYI.

What's the compression? Do you have a compression tester? http://www.harborfreight.com/compression-test-kit-66216.html

I would suggest that you diagnose your problem before you take the engine apart. You will learn more from testing a running engine than you will learn by looking at a disassembled engine.

 

and btw. it have 30000 miles on it, and it is from 1975!

 

im taking it apart, for a fun winther project with my ´friend who is a machine engineer. we will do some maintenance on it, to make it tip top. Im not taking it apart because of the problem when i accelerate.

Compression is uneven on the cylinders. have tested before:

1 - 9 Bar
2 - 8 Bar
3 - 9 Bar
4 - 9 Bar
5 - 8 Bar
6 - 8.5 Bar




By the way, the fuel line have a large notch in it, maybe that could be the reason? But again, it only occours when it is cols. When it is warm, in my opinion is is not good at accelerating, its slow.

 

Well, your compression is not terrible... in psi units: 130, 116, 130, 130, 116, 123.

The numbers indicate that you have some loss of compression, likely due to piston ring wear. But I would say those numbers are typical for an engine in good condition at, say, 150,000-250,000 km. I would expect a new engine to have 10-11 bar on all cylinders and less than +/- 5% difference between cylinders.

How much do you want to spend?

Typical service items would be a new timing set (chain and gears), plus the seals and gaskets. I would consider new rings and valve service (not sure what you call it in Denmark - in the USA we would call it grinding the valves). I would not touch the main, connecting rod or cam bearings unless the oil pressure were too low. I also would not replace the oil pump unless the engine has low oil pressure.

Now is the time if you want a hotter camshaft. If so, replace the camshaft and lifters.

 

If there is a hole in the fuel line, the engine could be starved for fuel - for the fuel pump, it would be like sucking on a straw with a hole in it.

 

well i have spend 85 us dollars so far on gaskets, a temperature sensor and a few other items. Painting will also cost about 150 dollars. But i have no upper limit, i just want it to be tip top!

grinding the valves... hmm... do you mean like this: http://www.youtube.com/watch?v=6-cJqjFwYa8 ??

i will consider the other things - and look at the prices. Should i look for scratches in the cylinders etc. ?