yakmastermax

Gah could use some help, really too many options.

Building a 383 stroker using a Vortrc 880 casting roller block. Hoping to use my 1991 L98 or 1985 L98 oil pan. Got an MSD 8366 Small cap distributor coming.

Street and time attack car. What oil pump to get? There are so many?

M155HV
M55
M55HV
M99HVS

icsamerica

Stock M55 if you're running stock clearances. Just take the bottom plate off and smooth the casting as it enters and makes the turn up to the pump gears. You need the HV pump if you run more bearing clearance, that's common on race motors that are set up loose or get hot and stay hot for long periods of time. The high pressure pump just robs HP and heats up the oil a bit

I just got a M55 Melling from amazon for 39$ and took it apart and I was impressed with the quality and smoothness of the pieces.

WVZR-1

1991 and 1985 are very different oil pans - both cant fit your build!

yakmastermax

Good catch, I will be using the 1991 pan as it is a one piece rear main pan and the block is a one piece rear main block.

icsamerica

Just to put a finer point on it you could do some things to keep the oil where is needs to be and go thus obviating the need for HV / HP pump. One big oil pressure looser is the dstributor boss. Some machine an oring into the dist housing so it's seals at the top of the oil galley. You dont want to double Oring the dist becasue you neeed some oil to flow down to the cam / dist gear interface. If your block is modern and the dist is modern they might be tight enough as is. Something to consider and check though. Same deal for each lifter and lifter bore. The next oil trick is to focus on your drain back. There are lots of YT videos about valley extension tubes, and gettng the oil to flow back in the valley and take the most direct route back to the sump.

My track engine is on its 3rd refresh and the rod bearings seem to be taking a beating so one thing I'm trying this time is to run the mains at the tight side of spec in a effort to get more oil pressure at the rod journals.

jmgtp

I just put in a Melling SharkTooth pump. It is standard pressure and 10% volume. Lots of debate on on the extra volume, and while I’m not in the camp of “it needs”, I don’t think it does, my motivator was the thicker casting that the SharkTooth pump offers. The standard Melling pumps have thinned down necks and are not recommended if you run solid motor mounts as they can break. I believe Moroso also offers a thick casting in lieu of the cheaper thinned down design. SharkTooth has some other claimed advantages in reduced friction and oil pulses.

yakmastermax

Found a little information out, the "55" series from Melling have 5/8" oil pick up tubes while the "155" series are later (I think 1996 and onwards so non LS Vortec motors?) And have larger diameter 3/4" pick up tubes.

jmgtp

Yes if you do go with an M series you want the M155 with 3/4 pickup.

tpi 421 vette

I agree, that the pump I always use