triumphs
[Top] [All Lists]

RE: Unleaded Head Update

To: jaltman@altlaw.com
Subject: RE: Unleaded Head Update
From: Bob Lang <LANG@ISIS.MIT.EDU>
Date: Tue, 27 Apr 1999 16:46:17 -0500 (EST)
Cc: triumphs@autox.team.net
On Tue, 27 Apr 1999 jaltman@altlaw.com wrote:

> My .02. Last December I suffered a catastrophic failure of an exhaust valve
> seat.  On pulling the head it was completely gone.  Sure it took 30 years of
> unleaded gas to achieve this result, but I guess my question is: If your
> head is off and you are spending hundreds or thousands to rebuild and
> restore, why not take care of the known problem area right and spend the
> bucks to be sure you don't have to deal with in the future?

Ah, but this _is_ my point. There's a lot of folks out there, right now 
from the UK especially who are facing the withdrawal of "four star" from 
thier pumps. What I've been trying to say for something like 2 years is 
that it really is not necessary _unless you have measurable valve seat 
recession_.

So, if you're driving a car that had been running on leaded fuel in the 
past - you do not, repeat _do not_ necessarily have to go out and 
remanufacture the cylinder head to keep driving the car. Keep an eye on 
it, and if you have a valve that has to have way more adjustment than the 
others, or you start to loose compression, then you have to act fast.

And presumably, there are folks out there right now contemplating this 
job and thinking that maybe they can't drive the ol' Triumph this year 
because of the phase-out of no-lead. I say horse-cookies. Drive it!!!

Further, a lot of us are real backyard mechanics, and wind up tearing the 
motors down for various reasons, in some cases because we screwed up - in 
others because stuff wore out. In other words, there _will be_ a point in 
time later where you'll probably have to do this job... but it does not 
have to be _right now_. And for those of doing or having done a frame-up 
- what's the chance that everything done to the car will be perfect??? 
I'll say in my case - very little. So I know I'm going to be tearing my 
motors down again in the future. This, in a strange way, is part of the 
appeal of these cars to me.

I guess I'm trying to allay (sp?) fears that the car is going to swallow 
a valve the first time you take it out for a spin without leaded fuel in 
there. It just ain't so.

And again, I'd like to put out the argument that spending an extra xxx 
dollars to make a head "ready for unleaded" is a waste of money if you 
don't need the work now.

So, it's your money, it's your car. Do whatever you like. Just be 
informed that this step (drilling the head and putting in hardened seats) 
is not absolutely required to keep your Triumph on the road. 

BTW, I'm not trying to flame or anything like that. I'm just trying to 
make sure that it is crystal clear that there is a valid choice _not_ to 
drill out your cyl. head and replace the seats. I think a lot of people 
on this list, while well intended are certainly misinformed on the 
necessity of this particular job.

> Jim Altman  jaltman@altlaw.com Illigitimi non Carborundum
> http://www.altlaw.com/metro/jaltman.html    69-TR6#CC28754L  W4UCK

regards,
rml
-------------------------------------------------------------------------------
Bob Lang                Room N42-140Q          | This space for rent.
Consultant              MIT Computer Services  |        
Voice: (617)253-7438    FAX: (617)258-9535     |
-------------------------------------------------------------------------------


<Prev in Thread] Current Thread [Next in Thread>