> Martin S writes (quotes?) - < snip >
> "The end-of-the-line 1493cc powerplant was essentially a stroked big-bearing
> 1296 unit. ... Hard driving will wear the crankshaft bearings. Unless you
> replace the shells every 30-40,000 miles, the crank will be lucky to last
> another 30,000.'
> ****************************************************************************
> ***************************
> Yes, I read that quote also, but I disagree. The rods and bearings are the
> same as those used in the TR6 and I don't see any major problems with bottom
> ends wearing out early on these engines. In fact if the same bore was used
> you would have over 1600 cc's. It is true that these engines don't like to
> rev as well, but that's owing to the longer stroke - as typical with all
> long stroke 'over square' engines, not the larger bearings. I don't see any
> problem with any engine getting larger bearings, - ( Just my opinion)!
> Check your oil pressure when hot, if it's within spec's then not to worry.
I believe that this quote was from John Kipping in Coventry and to be
honest I wouldn't dismiss anything he says out of hand. He's probably
rebuilt or otherwise dealt with more spitfire engines
than the rest of us put together. He's one of the biggest British
Small chassis Triumph dealers. If you have strings of customers
coming into your shop telling you that their Spit. 1500 engine has
thrown its big ends after only 70,000 miles, you begin to see patterns
which are not obvious when you know of relatively few other owners.
For example we all know of 1500 engines which are still fine after
120,000 miles , but that doesn't make it the norm. I've spoken to
John Kipping about this subject and his opinion is that you can pre-
empt crank wear by replacing the shells either at 35,000 mile
intervals or when you first notice that your oil pressure is getting
below spec. This can be done without removing the engine in a couple
of hours. This way the crank will almost last forever, or at least
until you need a rebore.
Just my view!
Jonathan
'77 spit 1500
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