Well, after over a year of non-action (save for a LOT of reading and planning) since the “Tennessee trip”- off with her head! Was able to lift the head with int/exh manifolds as a unit and disassemble on the bench. Measured the cam lobes (Ser3 version 6 cyl head and matching EFI cams) and they came out (minus the average the “heel” measurement and .013 lash setting) to .375-ish lift. Which seems good.
But, I have 'little circles" on the followers. They aren’t very deep, I can’t really feel much with a fingernail- do I need to replace the “buckets” and/or cams? I suspect it was the soft metal chaff from the main and/or rod bearings shedding (is reason this is all coming apart, yet again but this time I am at home and can better take care of managing the machining, assembly and other sundries and not in a rush to get home to my life & wife).
Per Peter’s request, here are some representational pics of the “circles” top (2) intake the bottom (2) exhaust. I am glad he reminded me that the cams would need to be cleaned out, and I would do the cam feed lines, too, in the same fashion, when I think about it. I was pretty good about cleaning out the block & crank, last rebuild go-round, but will make sure that the assembly is done in a very clean environment, maybe cleaner that what I had, this time.
Huff, they show abnormal wear IMHO. Measure the guide to tappet clearance. Make sure it’s in spec as well as valve stem to guide clearance. As Crespin said, you had the equivalent of lapping compound through out your engine. Every component should be inspected & measured and cleaned. Pull tappets out and look for wear patterns on the tappet where it contacts the guide. A small half moon polished pattern is normal. A big polished area can indicate larger clearance and rocking. Vertical scratches on the tappet are bad too. Think of them as 12 little pistons. It has to be correct or Tap, tap, tap, when hot. If they measure up in spec, do what Norman said. Now’s the time to do it all right. Good luck. Dave
Thanks all, for the input. I am going to employ the little used portion of my feeler gauges, to check the clearance to the bore, inspect for wear marks and then make some decisions.
Ya can’t get a feeler gauge in there buddy, you need an inside & outside micrometer, and small hole gauge for the valve guide. Best to take it to a machinist you trust who uses those tools every day. One needs to have a “feel” for their use. Besides he’ll probably be the one replacing the guides (tappet & valve) for you if necessary. /Dave
