First, thanks to all who offered advice on the purchase of the TR-4A.
Couldn't write personally to each yet - too busy with the purchase (and
life) - but will. I like the car very much and bought it, but have not yet
taken delivery.
Regarding the low oil pressure (10psi at very hot idle), the consensus of
recommendations - with one or two sharply in contrast - was that it is
barely acceptable, but shouldn't necessarily bar the purchase. The most
interesting observation was that, as the car seems set up as a racer,
perhaps the previous owner put in high clearance bearings, as is often done
with cars that are raced. That is consistent with the engine behavior. I
just blip the throttle and it sings right up to 4500 RPM, while my TR-3 is
very sluggish in this regard.
So, the dealer's mechanic and I began to fiddle with the oil pressure
relief valve on a very hot day. Got the idle pressure up to about 15 and
at highway speed, 40 to 55 (it seemed to transition between these two
values several times a minute). Max was 60-80. Left the car overnight and
the next morning the dealer found an oil leak around the oil pump (I think)
and said he saw 100 PSI on the oil pressure gauge.
Three questions:
1. Do any of you think we caused serious damage with this experiment?
2. How do you correctly adjust the oil pressure relief valve?
3. What do you think of the theory about high clearance bearings, low oil
pressure and race cars?
Lastly, as I said earlier, compression is good and there are no other
symptoms indicating a rebuild is imminent. Motor runs and sounds fine,
there are no scary noises and it is strong and steady. Also, if I could
get a year or two out of the car, as is, I might not mind taking the engine
apart and either rebuilding it with the help of a mechanic friend or give
it to a shop to rebuild.
Thanks for the help.
John Cowan
|