'74 351W Engine Blow By

bobcycleb wrote: What would you do different with the fuel line set up?

It MUST be steel with inverted flare fittings on the high pressure side from the pump to the carb. The alternate is a USCG approved hose assembly for that purpose.

You need to think marine where any fuel leak is trapped in the bilge unlike automotive and is a potential problem.

gun-driver wrote: Looks good but that fuel line setup looks a little scary

I sure agree. I missed seeing the potential bomb!! I feel Bob should be worrying about other problems other than blow by!!

Nice work, glad you got it ready for Summer.

Hi guys-- here are a few pictures--finally getting back to some good weather north of Denver!
Enjoy-- Bob!

Hi gang-- sorry it's been a while-- weather here in Northern Colorado has not been conducive lately.
Here's the scoop--when we rebuilt the engine last fall we ran out of time and went straight to outside storage--must have firmed up the front main gasket--was leaking a bit--replaced last week (was hardened) and no more oil from that area. Also replaced the thermo gasket (had a slight leak)--now we have no more water. Oil leakage had been reduced about half.--looked like it was just the excess pushing out between breather and valve cover (has consistently been an issue).
Installed a higher end oil/air separator (used older 351W valve cover with round hole (vs. original notched hole version for twist-ons) that was threaded and attached with locking collar between the baffle and valve cover itself.. Guess what--no more oil leaking from valve cover/breather area.
FINALLY-- no water and no oil leaks--truly ready for season!
Thanks for the ideas!

It is possible you broke it in too nice.   Once the cam is broken in as soon as the boat is up to temp I run it through approx. ten cycles of hard take-off to wide open throttle to hard deceleration back to idle. Let the gauges stabilize then repeat. If you have really put ten hours on without ever getting above 2500 rpm you were not doing the rings any favors.

Hi gang-- here we go-- rebuilt this engine twice in the last two years. Unfortunate rookie mistake is to run it without enough oil--fried some bearings and therefore the second rebuild.
Latest round all new rings, pistons, valve items/seals, gaskets, exhaust manifolds, risers.
We think the rings are sealing well--no oil leaks anywhere.
Getting blow by (oil in to tube between breather cap and flame arrestor). It then drips down the arrestor, down the back of the carb, on to the intake manifold, and eventually down the back of the block and on to the bilge area.
Broke it in nice-- about 10 hours at 2500 rpm max. Would get a couple of teaspoons of oil over a couple of hours.
Took it up to 3300 rpm and got noticably more oil right away--couple of teaspoons within 15 minutes.
I'm feeling like something is going on with the intake manifold itself (like rusting out--crossover is messed up maybe, etc.).
Ideas?? Things to check? (Vacuum off carb is at steady 16#--no matter the rpm's).