Oil System Mods For Big Block Refresher Course Please

Wonderful Bill!

Any good soul could do something like these for a LA small block !? Or the main mods can be used ?!


BR//

anyone save the oiling diagram when the new world block was coming out? or link?

Bill,

I sent you the oiling mods that I have for a small block as well. Could you post those up to? I tried to make them a smaller file, but can't seem to get them small enough to post.

Brian

I acctually didn't resize the first ones you sent so they were easier to read. I
m not home now but I can post them later tonight when I get there.

If you still have them in the original size send me those and I'll see what I can do with those.

Yeah I've been thinking about lowering the pressure some...definitely don't need 90psi.
The clearances are same old....002-.003

This thread and the bigblockdart thread have some good information. Thanks.

....The old rule of thumb is 10 psi. for every 1000 rpm. Now a days it is more like .8 or even .7 for every 1000 rpm. The key is volume, keeping the volume up and the pressure down is the key.

Anything over 70 plus psi can cost you 10hp to 15hp easily.

We make 1120hp and spin the engine to 8800rpm+.....the engine never sees over 70 psi. and no, it's not a dry sump.

20-30 psi, hot oil, at a low idle (800 rpm) is not a problem, IMO. But it should come up quickly at rpm (maybe 40-50 at 1500, and 60-70 going down the track. Cold oil is another story altogether with oil pressure. But think rpm and pressure.

Why does this stuff sound mighty familiar......

subscribing !

440Jim, I have never seen such effort put into a Melling pump or a stock oil pump cover

I took the easy route and bought an aftermarket block, Milodon pump, Ted Billet pump cover, and dual swinging pickup

That was part of my test. That pump was a standard volume pump and I ran it and a off the shelf high volume pump on my race car for comparison. I used the same relief spring, and the pressure going down the track was the same. I was happy with the standard volume pump, but I didn't see any significant track ET improvement.

My street 440 sees higher oil temperatures and lower idle rpm, so I run a high volume in that. With the HV, hot oil and 900 rpm it gets 25 psi. The main bearings are wide groove full and I think that bleeds some pressure too. Driving down the road at 3000 rpm, it is 65 psi, hot.

My thoughts are...
There is only a few horsepower difference between having an oil pump with 60psi versus one with say.. 70 or 80psi. Not enough for me to take chances on overheating bearings, journals or rocker gear. Oil pressure doesn't rise at the same rate as rpm. It lags just a tad behind at first because it has to be forced through the oil passages, while the pistons,crank,valvetrain are already spinning fast. If you have close bearing clearances it can be argued either way... for or against it... But not enough oil can lead to overheated oil and burn engine parts.
I like to run bearings a little loose(.002-.003) so I want my pressure to be 65-75 psi at idle hot and.. because I don't run over 7000rpm.
Aftermarket blocks with revised oil passages don't apply IMO. This is for stock blocks and oil pumps because not everyone needs a WORLD block or Indy or Ray Barton oil pump.
I've been building engines this way for ever and ever and never lost a bearing. ..until recently. But that was because of a mistake I made in bearing choices .

25psi@900rpm.. you scare me

How about 10 psi at idle with oil hot and thats idling at 1100 to 1200 but i have 75 goin down the track.And i do pushrod oil with a mega block and dual line milodon system.

My philosophy is pretty much this. ALL the oil has to pass through the pump and the filter...what is the point of a HV pump and a 1/2" pick up if the internals of the pump inlet and discharge are barely 3/8". it's like icreasing your motor displacement without porting your heads?

The tricks Jim outlines are essentially those I've been doing for years on stock volume BB pumps and the one I built for the Moparts engine masters 470 motor so many years back now. With a race motor the pump demand requirement should be proportioanl to the RPM increase, pumping 25% more volume at idle and mid range speeds always seemed to me to be a relic of the past where we ran 40 and 50 weight oils and we made up for higher than normal pump demands by increasing the internal volume. As I have found and I think Jims back to back testing bear out) a ported SYSTEM from the pickup through the pump itself is typically way more than adequate and I would argue heats up the oil a lot less than pumping more volume through the same small "stock" pump inlet and outlet orifices. Does it save any power? maybe not enough to measure but it puts that much less stress on the timing chain and cam and in-turn the crank so it's more EFFICIENT if nothing else and as an engineer HP is about efficiency.

I used to do all the drilling of the mains but please remember again this is how we used to do it before the super surfactant lower viscosity oils we havwe today.......back 40 yrs ago oil passages were made larger than required partly because engineers correctly factored in oil "coagulation" (like plaque build up in the atreries) over time with the older pariffin based stocks of years past. Now ironically engines suffer oil related failures from orifices designed smaller than prectical because engineers didn't factor for sub-grade "jiffy-lube" oil changes having the opposite effect.

FWIW

I the big block diagram it says not to drill the #1 main passage. Why not ??

Guys...Great thread!! I will move this to the archive...This will be good to have for future reference!

Thankyou,it is much appreciated