KuHL 951

I was tearing down a spare N/A motor that came with the 83 and ran into a weird problem. There are 4 bent valves from what I assume was timing belt failure. The lifters and head work look like new but one of the lifter bores is tight no matter which lifter I swap. Nothing is visibly scored, ridged, or deformed. What is the best procedure to clean this bore for proper clearance? Would a brake cylinder hone be too aggressive?

Thanks,
Steve

shophobbit

I'd have a machine shop do this. They can put a polish on the surface that you probably can't match at home. I'd also check around the upper lip of the bore for deformation. I have found this before when someone was not careful with the valve job. sometime the removal tool can damage and roll over the lip creating interference. In those cases you may be able to knock down the deformity with a rotary tool or die grinder if you're careful.

Good luck

KuHL 951

Thanks for the response. I was hoping to avoid the machine shop and I agree about trying to get that mirror polish with tools I have. It must be a deformation between the bottom and lower1/4" of the bore. That one lifter will start to bind at that point, can be pushed in by hand with minimum pressure, it will lift with the cam but won't drop back down like the other ones. If I was to try remove a minor bad spot is there a tool, polish, or procedure I could try at home. I have a die grinder, drill press etc. Do you think that using valve lapping compound spun on a spare lifter might work? Sorry to sound so cheap but this is just an "auto-training" motor on a stand I'm using to teach my son some basics about the 83 he'll be driving. I think dad could use some lessons too!

Thanks,
Steve

SoCal Driver

Get a can of bluing. Apply to the lifter bore then push a lifter in and out of it several times. Any tight spot will rub off the bluing. I would use a dremel with a cloth wheel and fine polishing compound to knock the binding part down if it's in the bore. If it's just a bent over lip (this is what I have seen most of the time) then one of the small diameter stones will do the job.

KuHL 951

SoCal thanks for the bluing tip. I'll give it a try for sure.

Peckster

This is probably related to the bent valves and imo polishing won't help. I wouldn't avoid the machine shop, they have the guages and tools to tell you exactly what the problem is and then fix it.

Not worth screwing around with your head if you make it worse. I had an S with worn lifter bores that I had to replace.

Anyhow, how much can they charge?