Jerry Oliver wrote:
> I'm having problems putting my engine back together, apparently due to
> incompatible reproduction valve train parts. After blowing the head
> gasket on my 66 TR4A, and even though the engine only has a few hundred
> miles on it, I took the precaution of having the head redone. Since it
> was the original head to the car, rather than get an exchange head, I
> sent it to BPNW for rebuild. They welded a small corner that had been
> damaged by the previous rebuilder, resurfaced it, replaced the guides
> and ground the valves. I also bought their rocker arm kit, replacing
> rockers and adjuster. During reassembly the last few days I noticed that
> a couple of the push rods were less the perfect, so I ordered a new set
> from BPNW. While I waited for parts, I installed the head and all the
> various pieces back on the engine. Come to find out that the
> reproduction putrid cups are to small for the ball on the reproduction
> adjusters. Ok, I'll use my old adjusters. No, they're better, but not a
> good fit (ball does not go all the way into the cup). Ok, I'll just use
> my old push rods. Bolted the rocker arm set on, and began adjusting the
> valves. All adjusters screwed "in" as far as possible, and I got .010
> clearance with only a minuscule part of the threads of the adjuster
> screwed out. And on valve 6 & 7, although the adjuster is screwed all
> the way in, I can't get any clearance. Pulled the rockers, and compared
> them to the originals, and they appear very much alike. So, pulled the
> head (again) to check the valves. They appear to be setting just above
> the seat, though 6 & 7 are less so. I wonder if the combination of two
> surfacing and a rather deep cut in the valve grinds could cause this
> much problem? I have another engine, and tomorrow I will pull that head.
> Then bold it and the new rocker arms on to see if the problem persists.
> If it does, then I will change the rocker new arms for the old ones. But
> I'm afraid its in the head valve grind or worse that too much material
> has been removed during resurfacing. Has anyone ever had to grind the
> end of the valve stem for proper clearance? Bye the Bye, don't buy those
> push rods and rockers with adjusters until they solve this problem.
> Comments welcome. Jerry Oliver, Olympia, WA.
Jerry,
If you cannot get enough clearance with the ball of the adjuster raised to the
highest
point, your original pushrods are too long. You'll need to use the competition
type
tubular pushrods which are machined to length. The correct length depends on
how much
material was shaved from the head. Swab some machinist's layout fluid on the
tip of
the valves and rotate the engine, the tip of the rocker will 'wipe' across the
top of
the valve leaving a mark. The mark should apprear exactly in the center of the
valve. My guess from your description is that the mark will be slightly offset
to the
intake side of the head. If so, you'll need to shorten your pushrods until the
'wipe
test' shows that the mark is centered.
You can install a pushrod without capturing it under the adjuster then set the
adjuster to about halfway and compare it to your pushrod by holding them side by
side. From this, you should be able to get a good idea of how much material to
remove
from the tubular pushrods. The tubular pushrods are shortened using a parting
tool in
a lathe. If you don't have access to a lathe, you can carefully pull off the
ends and
grind the tubes to the correct length then press the ends back in, being very
careful
not to bend or nick the pushrod in the process.
Good luck!
Brian Schlorff '61 TR-4 '64 TR-4 '72 TR-6 '79 Spit
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