SBCGENII

We have had 3 cars lose oil pressure recently. 2 stock pumps and 1 Melling. I took the Melling apart yesterday for inspection and this is what I found. This is a Melling 295

I can move the piston Up and down in the bore and can see it rock while going over those ridges. Nice way to loose a motor when that valve gets stuck bypassing oil.

C5 Pete

Well, that's not good.

What was the issue with the other pumps? Same thing?

SBCGENII

I would say it was a similar problem. The symptom of this is sudden loss of some or all of your oil pressure. Cleaning up the machining in the bore and polishing of the edges of the piston should prevent this. I believe any trash in the system can cause similar problems since all of this is pre filter.

Fastbird

I think I had something similar happen with my car. Was giving it some full throttle pulls and coming back into my development it dropped pressure. I was notified by an audible chime and a check gauges light and by the time I looked down pressure was recovering. Hasn't done it since but I'm keeping a close eye on it until I can swing opening the motor up for other....upgrades.

SBCGENII

Picked up a L99 pump for my car today. I took some comparison shots of stock/m295 gears and the high volume ones in the L99 pump. Different number of teeth between the two. The high volume has one less tooth and the gears are .090 thicker. Also the area around the pickup resembles a ported stock pump.
Relief spring is also much longer in the DOD pump.

v8srfun

I am curious what oil weight do you use and do you put any additives in it.

SBCGENII

The Melling pump didn't come off my car so I don't know what weight oil. The guy did take really good care of his car though. I'm sure it was a 5 or 10-30 synthetic. No additives.

I wouldn't pull a car apart to check this unless you are having a problem or the Motor is apart. Some of these go 200k+ miles and are fine.

BLOWNBLUEZ06@RKT Performance

Good stuff mang!

Thanks for sharing! I hope all is well at your end of the world.



Bret

SBCGENII

I called Peterson last week to ask them about their 3 port external bypass. They said it wouldn't work for what I wanted but I order one from the local speed shop anyways. When I went down to pick it up one of the parts guys said he found some pictures of someone doing what I was wanting to do. The picture was of Hinsons C5 mile car.



Took the valve apart and was kind of suprised it wasn't going to flow much more than a DOD oil pan relief valve. Crazy difference in size not so much in flow.