John Trindle writes :
>
> Hi folks, my name is John Trindle, and I am new to the list. I am
> repairing a 69 Triumph Spitfire, and have a few questions.
Welcome !
>
> It consumes oil massively. Are there valve stem seals which can be
> replaced, or do the valve guides and valves have to be replaced?
>
> I have another engine from the same year. Should I swap cylinder heads
> and assemblies to see if the oil consumption changes? If I have the
> cylinder head off, should I just go ahead and replace the rings anyway?
>
> "Massively" means a quart every 150-200 miles. I am using Castrol
> 20W-50.
>
> Thanks!!
The test I have often used is -
Take a compresion reading for each cylinder. To do this remove the sparkplugs
from all the cylinders and also disconnect the 12v feed to the coil (this will
stop the car from trying to fire. In turn take a compression reading from
each cylinder. Relative readings are what matters most - if one or two
readings is much lower then that is where the problem is.
At this point to give an indication wether its the valves or the rings, put
about 15ml of oil into the cylinder with the low reading and repeat the
measurement for that cylinder :
If the reading is higher then the problem is probably the rings (the oil helps
seal the bore) if the reading stays roughly the same then the valves are
probably at fault.
The spitfire I used to have blew its rings on one cylinder - I tried the oil
test and decided it was the valves - fitted a spare head I had. The result
was that the car would hardly run at all and the compression reading was
still way down - It turned out the head had been skimmed and it was the rings
after all. The reason that the oil test had'nt shown this was that the
rings were REALLY gone. I ended up replacing the piston but luckily the bore
hadnt been damaged.
The car still ran fine when I sold it some 7000 miles later :-)
Best of luck.....
Cheers,
Ben.
--
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| Ben Hodson, | Email : hodsonb@prl.philips.co.uk |
| Philips Research Labs, | Tel : 0293 785544 ext 5750 |
| Crossoak Lane, |-------------------------------------------|
| Redhill, | I'd rather push a Triumph than drive |
| Surrey, RH1 5HA. | an MG, but best of all I'd vrooooommm |
| England. | in a seven. |
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