Engine life ....

[brianthomas]

My buddy has a Pfaff 700 with over 200 trouble free hours. He originally figured he would have to rebuild the valve train and top end at this point, but after talking to Gordy he is good for at least another 200hrs, which of course bummed him out since he wanted to do the new whipple charger.
Would a really good synthetic oil prolong the valve train life? What exactly wears?

[BrendellaJet]

The answer is-it depends. Depends on part selection & power output as much as it does your driving style. If you have a stock merc motor I think the 400-450 hour marks are conservative and as long as you aren't a leadfoot they should run for atleast that long.
The higher output motors I would say will get a refreshin fewer hours, not because they cant handle it but because they get pushed harder because they can handle it, thus wearing them out faster.Its cheaper to freshen a high output motor than it is to do a complete rebuild.

[Boa1277]

The weak link of any BBC is the valve train. I imagine they want you to rebuild it sooner than later because when it goes it will take out a very expensive botom end. Billet cranks are not cheap. (not saying the Pfaff motor has a billet crank) either are really nice forged internals.

[Swoop]

thanks everyone, its amazing how much you can learn just from posting on this site