I suppose this is a dumb question, but that never stopped me before - are
you sure you are getting oil to the lifters? (It would seem to me that if
you are able to adjust for the proper gap, the problem is not in the size of
the lifters or the shimming of the rocker arms, but then I am much shorter
than you in these waters)
Bob
> I need some serious gearhead help for this one...
>
> After 10 years of restoration work, I finally managed to drive my TR4A
> to the end of the block and back yesterday. No hood, interior, tranny
> tunnel, guages, etc., etc., but it still made it. This is also the
> first time the rebuilt engine has been run.
>
> One of the first things I noticed (after I got the exhaust to work) was
> the incredibly noisy tapping from the valve train. First step was to
> check rocker clearances; all are at 0.010" cold. Now is where it gets
> tricky...
>
> The head is shaved 0.080". I'm also using a shim steel head gasket from
> Ken Gillanders at BFE, as well as a performance cam from him (don't
> remember the specs off the top of my head). I'm also using his heavy
> duty competition valve springs, along with the lightened aluminum (?)
> retainers. Also using his chrome-moly pushrods. I thought that I had a
> standard pushrod length, so my first guess what that I had to turn them
> down a bit to make up for the head shaving. However, when I measured
> one, I found that I actually have 257mm pushrods (roughly 10.125") and I
> believe the standard pushrods are 260mm (roughly 10.25"). I don't
> remember ordering shortened pushrods, but that was a long time ago and
> my record keeping isn't what it should be. This may actually be too
> short based on what I took off the head, but I would welcome comments.
>
> I'm using the standard shaft, with the standard rocker arms. I didn't
> rebuild it (yet). I pushed a few of the rocker arms up and down the
> shaft to check for wear, and I can see some discoloration on the shaft,
> but it is not enough to catch my fingernail on. I'm thinking that this
> should be servicable for now, and shouldn't be causing that much noise.
>
> Next I checked the valve at half-open according to the competition prep
> manual. The manual says that "the axis of the valve stem and the rocker
> arm should be at 90 degrees to each other, and the rocker arm tip should
> be centered on the stem" or something like that. Problem is, this is
> just about impossible to eyeball, but it looks right.
>
> So, where is all that noise coming from? I think I've ruled out a worn
> rocker shaft, and I also think I've ruled out bad rocker geometry (I've
> been wrong many times before, though!). Are those heavy-duty valve
> springs along with the high-lift cam making everything noisy? Are the
> pushrods too short? Is there a better way to check the geometry?
> Should I shim the pedestals? Will it just go away over time as the
> engine breaks in?
>
> Sorry for the rambling, but this one has me stumped. All responses
> welcome.
>
> Thanks,
>
> Dave Rupert
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