Keith Atlanta

What is a safe amount to overfill your engine oil? Its proven that the 496 HO, 454 Mag MPI, 502 Mag MPI and several others will run themselves dry (or close to it) with high volume aftermarket oil pumps. What is the safe overfill amount? I am running 1/2 to 1 quart overfull and thats great for 4500 to 5500 RPM runs but what about cruise, is enough oil supported to stay out of the windage tray?

Just curious...

Budman II

iTrader: (1)

Keith, I'm not going to claim to be an expert, but what I gather from reading about oil control issues is that overfilling the crankcase can be self defeating if you end up with windage issues and oil "roping" around the crank. When it gets whipped into foam by the crank those air bubbles get sucked right into your bearings. I had a thread on here a couple weeks ago that discussed oil drainback issues at length, because I ran screens in my lifter valley with a high volume pump and stock 8-quart pan (didn't know any better at the time). Also, my AFR heads have much smaller drainback holes than the stock ones. I was very concerned about oil starvation for a while. That being said, I dyno'ed the engine this week, and at one point we held it under load at higher RPM for several minutes, and there did not appear to be oil starvation issues that we could see. Oil pressure and temps held pretty steady. Now I don't know what might happen if I ran it at WOT for ten minutes, but I don't run that way anyway.

I'm not sure how you run your boat, but at cruise speed I would think you will be fine, and even the occasional WOT blast across the lake for a few minutes will probably be OK, unless you have a more serious issue.

What weight oil are you running in it?

MILD THUNDER

iTrader: (3)

I am unfamiliar with those issues on those engines. However, on my engines with Canton offshore pans, I run the oil level 1 qt low, to prevent any aeration or increased drag.

I recently was reading a build on another forum where a guy was building a blower engine very similar to mine. After all was said and tuned on the dyno, he removed 1 quart of oil from the crankcase. He picked up 27HP on the next pull.

mike tkach

iTrader: (3)

and that is why a dry sump oil sysrem is used in serioud racing,less oil for the rotating mass to hit =more crankshaft power.

Keith Atlanta

WTF cant win for losing. If there is too much you lose HP if there isnt enough you starve the main bearings...

Rookie

iTrader: (4)

I have been spinning my 454's with the stock 8 quart pans to 6500 for years. Filled to the full line on the dipsticks and to a quart low. I have larger coolers then my hp level and never had an issue. 5 mins at a time.

Budman II

iTrader: (1)

Rookie, are you running a high volume or standard oil pump? What weight oil?

Rookie

iTrader: (4)

M77hv and a 778c high volume

SB

iTrader: (1)

Pump your pan dry is bad.

Aerating your oil is bad. Crank windage not only causes hp loss, but heh, screw the hp loss, we should worry more about the air introduced.

So....why answer which is better ? Crazy to.

Here's the real answer:

If you run a HV oil pump you run a larger capacity system. 9-10+ quarts would be good.

If you want to keep a stock 6 quart or smaller pan, then keep the standard volume pump.

Those are the correct answers.

cheech

Interesting to hear from some of the builders out there, because I have always heard running em dry. Then I read this one time, straight from Melling, point number 2. http://www.mellingselectperformance....lume-pumps.pdf