Lifter scoring in head - what to do?
 

This is the '99 head I'm working on for the new build.

IS there anything I can do about the lifter grooves - polish them? will it work long term? Is it anything to worry about? Last thing I want is a stuck open valve because the lifter got stuck... Pics from android - not the best, but hopefully you can see the rings in the aluminum head. There is about 5 that catch the "fingernail" test. Mind you, this will have new supertech springs and valves and under crazy boost ( If it's not f'ed.


https://www.miataturbo.net/attachmen...1&d=1322013871
https://www.miataturbo.net/attachmen...1&d=1322013871
https://www.miataturbo.net/attachmen...1&d=1322014314

Ouch. I'd find another head for my build if those are as bad as they look.

Y u no VVT?

Me was broke - 99 head cheap, now C why.

Didn't go VVt b/c was skeared of finding a way to control it then - maybe not so much now.

Finding this after paying for shave and P&P on head sucks balls - never will use that machine shop again, especially after finding alum shavings in the stem seals - they didn't even remove them when doing the work - nor tell me about this :facepalm:

This is Grreeaaaattt...

I'd think in the big question here is whether any of the grooves are standing proud such that they protrude inwards into the bore.

If they are merely recesses, then I can't see them doing much harm. If they are protruding, perhaps you can just shave them down a bit with a knife and run a brake cylinder hone through it lightly?

None of them seems to protrude into the bore, just grooves into the wall.

Another thing I noticed during dis-assembly, was the well-worn steel washers/spacers/perchs that the springs sit on to prevent grooving into the head - one was half worn, and they put it back in, dumb asses.

John Day Custom Engines has stacks of good 99 heads at the shop, that might be your best bet.

In for information.

How much clearance between the lifter and the bore itself? Is it within spec?

I can't see that causing any issue. I mean the lifter isn't going to wobble due to those small grooves, it will slide right past them. I am curious as to how they came about to begin with.

Yeah me too... I haven't mic'd them, but I'd bet they're in spec, just the presence of the"rings" has me concerned. I'll probably try polishing them. The lifters themselves look great.

I'd be careful trying to polish them. If you use a small drill hone you don't want to enlarge the entire bore.

I've used a handful of engine builders over the years and none of them want to use any parts that show wear like that. Their point is being that why use something like that when you can spend a couple hundred bucks and get one that's "right". Let's say that those grooves don't protrude inward- then what are they going to do to the oiling of the lifter in the bore? Do you want to try it out and see or do you want to just find another head and not...?

Cam journals look like they're worn also from the pics. If that's the case it's probably a thrust bearing head.

^ yes, from experience, the lifter itself does not wear, the bore wears.

If the bore is badly worn, perhaps the lifter could rock when the cam moves over it. This is the only explanation I can think of, that could possibly cause this kind of mark in the bore. This is why I asked you what the clearance was.

If the clearance between bore and lifter is ok, then I would use the head, without buffing out the mark. I can't see that the mark itself, could cause any problems.

I think m2cupcar has the right idea- looks like a thrust bearing head.

with above info, i think it is too risky to not get a new head. i would take the head back to the builder and demand they reperform the work on the new head. those marks were obviously there before the work was performed. was this southern cylinder head?

Yep - and i doubt they'd do anything since I've had it for so long. I shoulda pulled it all apart soon after I got it back. You guys are right - better safe than sorry and cut my losses now before risking a valve to piston contact or alum shavings floating around should 'something' happen remotely related to the scoring. Maybe this is my opportunity for a VVT head with the controller...