Penzoil 25/50 Racing Oil
 

I WAS CONSIDERING USING PENZOILS 25/50 RACING OIL.I HAVE USED THERE 20/50 STREET OIL IN THE PAST.I HAVE A BBC THAT IS APRROX. 400HP THAT I RUN QUITE HARD. 5400 RPM REDLINE AND LOTS OF 5000 RPM CONSTANT USAGE.I CHANGE OIL EVERY 25 HOURS.I BOAT IN WESTERN CANADA AND THE WATER TEMPS CAN BE QUITE COOL SO I DON'T WANT TO USE A STRAIGHT WEIGHT OIL.PENZOIL DOESN'T RECOMEND THIS OIL FOR STREET USE BUT I DON'T CONSIDER MARINE USE AS EASY AS STREET USE.THIS OIL SEEMS VERY THICK WHEN COLD (OLMOST LIKE ASSEMBLY LUBE)ANY COMMENTS APRECIATED.

Seems kind of heavy. What does your oil temp get up to? You don't want excessive oil pressure. I run Amsoil 10W40 in my 13:1 compression 496. At 6200 rpm and 230 degrees the oil pressure is 65 psi which is about perfect. Heavier oil is necessary on engines with open clearances that spend a majority of their time in race mode with very high oil temps. At WOT your engine will ideally have 55 psi. Anything more will just steal HP and wear your cam and distributor gear. I personally like to stay on the lighter side when it comes to oil viscosity. Free hp and I have never had a bearing failure or problem. Again, just my .02.

I used it for 5 years in a 454 motor and never had a problem with it. Our water doesn't usually get warmer then 70deg on it's best day no problems with foaming or condensation.

I think you would be better off with a lighter wt oil. Really depends on what oil temp is when cold starting vs running. As long as it is not too thick when cold I do not think it should be a problem as long as you get some heat in the motor / oil before running very hard.

Oh yea I like your idea or suggestion on a brace for pickup tube on oil pump. It is the little things that can make the differance on how reliable a motor can be. Besides cheap and easy to do! Most boat fixes are not.

Andy

MAybe if you had a faster boat, you wouldn't HAVE to run yours so hard:D

Is water temp rally the issue? I would be more concerned with oil temp. Get a thermostat and temp gauge.