De-blowered 454 Mag
 

I looked at a 454 Mag power twin today that had (a) electric fuel pumps (b) high pressure fuel regulators (c) remote oil filter mounts (d) remote oil drain tubes (e) chrome x-overs (f) red valve covers and (g) four filled-in holes (where screws were removed) on the upper dash, either side of the compass. Boat is showing 130 +/- hrs. I am guessing the boat had blowers on it (and holes were for instrument pods with boost gauges), but broker doesn't know anything. Anyone dealt with a de-blowered 454 Magnum? Should I run in terror? Boat is otherwise in pretty good condition.

Do a comprehensive engine survey on it and if it comes through alright I wouldn't worry about it.

Compression & leakdown test, and run it hard with the valve cover breathers off and see how bad it blows by.

Mcollinstn,
If it does blow by, can we assume rings?
Russ

That should turn up on the engine survey, which will include (if you hire a good engine tech.) compression check, cylinder leakage test, oil pressure readings with a mechanical gauge, infrared oil and water temps, infrared exhaust assembly temps, and engine rpms at wide open throttle as indicated by a tachometer other than the ones at the helm, either handheld tach or one of the timing lights witha built-in tach. Some engine guys even pipe a barometer into a breather to measure crankcase pressure.

Blowby is cylinder seal. Sometimes it's just rings. Other times, it is an indication of "more" (as in a worn bore). If the bore is worn, it "may" have been aggravated by washing the oils off the cylinder walls. If so, oil may have been run in a contaiminated state, which can dilute the lubricating properties and smear the first or second layers off the crank and rod bearings.

It's all a vicious circle.