I've got a real head scratcher. '56 Desoto 330 hemi, new rebuild, 3rd time rear main seal(?) Leak on start up. I've done the install twice and another guy with 20 yrs building engines did 1. On tear down we can't see any probly with the seals or the rear main cap. Any suggestions/ideas are welcomed. HELP!
No the machine shop (no longer working on gas engines) polished the crank .003 under. Balanced but not align bored
How bad is the main seal leak? A few drips may seal as time p***es. A worn spot on the crank where the seal is suppose to seal? Excessive main bearing clearance? Defective seals? Just because they are new, doesn't mean they are good anymore. Crankshaft moving forwards and backwards? The oil leak is coming from higher on the motor and dripping off the main seal area? Too much crankcase pressure? You still have a way to vent off pressure, right? Misaligned crankshaft and transmission input shaft? Flywheel/torque converter out of balance?
I have a 330 desoto that is new but tight so far. I run a PCV valve in the valley cover plumbed to manifold vacuum. I know what you are going through though, I have a 455 Olds that I have replaced the rear main on a few times and have just decided to keep a piece of cardboard under it. Damn drippy Olds.
All God reply. Yes it has a pcv plumber from the valley cover to the vacuum port on the carb base plate. The drip is pretty bad, about a pint in 10-20 minutes running. I've used one FelPro seal, one Best gasket brand and one unknown. Only about .0015 end play on the crank. The crank was polished about .003 under. Thebtrans is an A518 with an adapter from Hemi Hot Heads. I haven't checked the run out on the torque converter/flex plate yet. I'll let you know how that comes out. Thanks for y'alls input
Are you using the Best rope seal or the rubber? Does the crank have serations or is it smooth where the seal runs?
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