Whenever you take your head in for machine work, take it for granted that
the cam towers will be removed. If you're unsure of the milling done on the
head then you can do the following. After the head is reassembled and bolted
to the block, you can test the camshaft to see if it is a good fit by doing
the following. Make note of the camshaft and valve orientation to the timing
chain. Remove the rocker arms (so the valves won't hit the pistons). Unbolt
the camshaft sprocket and mount it to the chain guide. Carefully use a
wrench on the camshaft (away from the polished surfaces) to rotate the
camshaft. It should spin without too much effort. If it doesn't spin, then
your towers may be out of alignment. At this point you could have a
machinist rebore the camshaft bearing centers.
Or, if you're daring you can take matters into your own hands. You can
loosen all 5 towers, readjust and tighten them down again. Check for the
interference spots on the bearings, and hone them yourself. They're
forgiving to a certain extent.
Fred - So.SF
----- Original Message -----
From: "Patrick P. Castronovo" <slick1@mohaveaz.com>
To: "Richard Rudden" <sequoia12@hotmail.com>;
<datsun-roadsters@autox.team.net>
Sent: Thursday, March 22, 2001 8:29 AM
Subject: Re: Needed: A Roadster friendly machine shop <long?>
> Be careful on Local! If these guys (oh yeah I can do this Job) have never
> had one of these heads in their shop, they are experimenting. I took my
U20
> head to a shop for a crack between 2+3 cylinder and they milled the head
to
> remove the crack.. by the time he was through the crack was gone and so
was
> most of the combustion chamber. I had to have Cam tower shims made
special
> to stretch the cam timing chain back to proper tension. I did'nt realize
> that when you loosen the cam towers you need to realign the cam towers. I
> did not break my cam ( I don't drive it anymore for now) and before I do i
> will get a new/used head and send/take my old head with the cam in place
to
> CDM and let them rework it to the right specifications. No guess work
> there.
> Pat
>
> -----Original Message-----
> From: Richard Rudden <sequoia12@hotmail.com>
> To: datsun-roadsters@autox.team.net <datsun-roadsters@autox.team.net>
> Date: Wednesday, March 21, 2001 11:09 PM
> Subject: Needed: A Roadster friendly machine shop <long?>
>
>
> >Well guess it's time to step out of the shadows... to lurk no more!
> >
> >My name is Richard Rudden I live in Santa Clara Ca. and I am the owner
> >(first,current and only) of a 1969 SRL311, #12388 to be exact. Started
life
> >as pewter grey, just like the one on the 68/69 brochure. After completing
> >(like they're ever complete) a restoration in 1987 it's now Nissan
Regatta
> >Red 013.
> >Anyway all was fun and right in RoadsterLand until #1 exhaust valve seat
> >decided to part company with the head, for this and other reasons she has
> >been a garage queen since 1994.
> >NOW it's time to start killing bugs and eating corners again! Shasta in
> July
> >is the goal!
> >Here's my dilemma (now he gets to the %$##$^% point)
> >I have a complete U20 I bought about a year ago, it's supposedly been
> >rebuilt. What I need is to find is a local, south of Oregon north of
> Fresno,
> >machine shop I can trust to thoroughly check out this head and block. If
> >need be I can take it to CDM or I understand Dean at Fairlady has a shop
he
> >recommends in L.A. If that's the best way to go that%27s what I'll do,
but
> >I'd rather find someone a bit more local.
> >
> >Thanks to all for listening, look forward to being a more active member!
> >
> >Richard
> >
> >P.S. Congratulations Annette on your new baby, the fun is totally worth
the
> >trouble!!
> >_________________________________________________________________
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