Brian:
Thanks for the advice it states everything that I've been dreading. I
must admit that mine doesn't sound quite as severe as 72. Could you
enlighten me on the difference between a dry and wet compression test ? I'm
in uncharted waters here.
Tim Hutchisen
CC57787 1971
"Shine she may, but run she must"
Brian Kemp wrote:
> Tim,
>
> >Date: Wed, 06 May 1998 15:07:24 -0500
> >From: karen hakala & tim hutchisen <hakhutch@megalink.net>
>
> Below is my experience. I've had the car for 18 months and learned
> quite a bit in that time.
>
> Just finished a rebuild on my 72 TR6. Before I got 150-200 miles per
> quart of oil. Lifting the accelerator pedal on the freeway at 70+ mph
> produced a very noticeable cloud of smoke (engine braking - oil sucked
> down the valve guides). My compression numbers were about 130 dry, 160
> wet. The engine had 126,000 miles on the believed original piston
> rings. The previous owner claimed a valve job 15,000 miles ago. I was
> also a victim of low oil pressure, but the car performed very well, able
> to accelerate from 80 mph in O/D in a noticeable manner.
>
> I removed/dissembled the engine and painted the engine compartment. I
> took the head to a local auto machine shop to get a seat replaced and be
> checked out. The valve guides and one valve were worn and needed to be
> replaced. I had new bronze guides put in.
>
> The pistons seemed glazed. I honed and measured them and was suprised
> that they were still well within tolerances. I replaced the piston
> rings, all bearings, and seals and put the now clean and freshly painted
> engine back in the car.
>
> I have 450 miles on the engine and have only used 1/3 a quart of oil.
> That included about 20 minutes of track time at Buttonwillow raceway
> during the VARA/Moss event last weekend (used a full quart on the track
> last year). There is no hint of smoke during engine braking and my hand
> in front of the exhaust no longer gets covered with black spots. I can
> even tell my oil pressure gauge is working with the engine at warm idle.
>
> My engine ran very rich when I got the car (10-12 mpg). I think I saw
> somewhere that this can glaze the cylinders and allow gas to dilute the
> oil, allowing it to burn off faster. Try a wet compression test and see
> if the numbers go up much. If so, suspect rings.
>
> To test the valves, try some heavy engine braking. If you get smoke
> your valve guides may not have been replaced or you valves may be worn.
> There are others tests for the valves/guides, but this is an easy one.
>
> Hopefully this will give you more information to improve your car. I
> know many people that would be happy to get 500+ miles per quart of oil
> in their Triumphs. You may just decide a quart of oil every so often is
> worth living with.
>
> Brian Kemp
> 72 TR6
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