On Thu, 13 Dec 2001, Matt M. wrote:
> Alright, I'm trying to figure out everything I need to
> buy to get ready to rebuild my TR6 engine. If I
> understand correctly, the TR6 has no cam bearings?
Correct. The cam rides directly on the block.
> Is
> it a worthwhile investment to install them?
This is a potential can of worms, but...
1. The job of align boring the block and installing the bearings can be
expensive. I've seen prices in my area from $150 to $350. I live near
Boston, MA, USA. Now it turns out that this is a case where you want the
job done right. So don't just go by the price. Why? If the job is done
wrong, you'll get axial play with the cam in the bores... one buddy had
about .005 of up and down movement in his - he broke a cam. Granted this
was a race car - but it represents the extreme. So, find a local shop that
knows what they are doing and then proceed.
2. If you have your block "checked" before you machine it, the machinist
can tell you whether the align boring operation is even necessary. Have
him check the bores and see if they are out of round. If so - then you
have to install cam bearings.
3. If you go to a radical cam with a lot of lift (over .400 at the valve),
then you should consider getting bearings. The more lift by the cam, the
more lateral forces are involved. The cam bearings will get things "right"
to start with. Also, if you intend to actively race or otherwise spend a
lot of time at high RPMs - then you should consider cam bearings.
4. If you didn't know, the cam bearings are the same as the Spitfire cam
bearings.
5. When you get the block back from the shop, make sure that the oiling
holes are all lined up okay. This is really critical, as the TR6 cam gets
precious little oil as is and if there's a problem with the oiling you
size the cam in the block or break it...
> Maybe I am
> just completely misunderstanding this, but thanks for
> all the help ahead of time.
You're welcome.
> Also, how many of you do
> not use the exhaust recycle valve on your TR6's? I am
> thinking of removing it, seems like it would make the
> engine breathe a little better. Thanks again...
Please don't forget that tampering with emmisions controls is regulated by
the federal government...
I had used the EGR valve in my car until very recently. The key here is
whether your state requires that the emmisions sytems remain intact as
delivered new... if your state does not require this, then removing the
EGR valve is fairly simple. I bought a bolt and lock nut at a local
hardware store (I think it's 3/4-18, fine thread in any case) for a couple
of bux$. When you do remove the EGR valve, don't forget to plug the
vacuum line at the carbies (it should be connected via a "T" to the rear
carb) - but the actual installtion obviously depends on the year of your
car (or motor, in some cases). You also have to plug your intake manifold,
this is a 1/2 NPT plug (same as the oil plug on your oil pan.) I bought
one of those at the hardware store too - or you can buy them from the "big
three". I ususlly keep 5 or 10 on hand for various projects.
> -Matt
Have fun.
rml
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