More head questions

Sternn · 02-10-2003, 01:45 PM

Got a call from my mechanic today. The head is FINALLY back from the machine shop (yaah!) but now there is a new issue. I was wonder if you guys have every had this problem and how much of an issue is it and how much should I expect to pay.

I was told while he was putting in the buckets (not sure what they are) there was some dragging on the bucket bores, so he had to take it to another shop to be knurled.

I have no idea what that means and what I should expect to pay for a good knurling. Any help here would be appreciated.

-S

profssr2017 · 02-10-2003, 01:59 PM

I would ask your mechanic to be more specific in his description. Knurling is used to raise the surface of the metal by rolling a grooved wheel on it. It's kind of like when a smooth steel rod is given a checkering, similar to what you would find on the stock of a rifle. By knurling, metal is forced by pressure out of the groove. For example, on my 1952 BMW R67/2 mo'cycle, during a rebuild, I needed a No. 2 oversized piston. But only No. 1 oversize was available. So I got a No. 1 oversize, and had it knurled to slightly increase its diameter.

In your case, if the bore was indeed knurled, it should have reduced the diameter, as material was expanded on the inside of the bore. This would make the "buckets" stick even more!!!

Perhaps he meant that he was getting the bore reamed to make it larger in diameter so the "buckets" would not stick.

By the way, knurling should not be expensive. It's a simple procedure for a machinest.

However, I still do not know what he is refering to as the "buckets", unless he is talking about the valve stems in the valve guides, or possibly the cam tappets - is this for an 8 or 16 valve head?

Sternn · 02-10-2003, 02:28 PM

I called him and he said its not going to cost anymore to have it done, it will just take an extra day or two. The buckets are the half quarter shaped pieces that sit on the valves and go on top of the cams. The knulring process he said is more like honging it and makes it a little smaller so they fit without dragging as much on the inside. Anyway, bottom line is no extra cost, so thats a relief, but it will take an extra day or so. Thanks for the info though.

-S

highboost951 · 02-10-2003, 04:14 PM

Sounds like he mixed up the order of cam followers with their respective places(where they were originally installed). Unless he installed new ones and is having problems, hmmm. Interesting, I've never had that problem but all engines have different historys and untold stories. Sounds like you'll be on the road soon, have fun driving it.