I rebuilt my 1970 GTO RamAir 3 engine using Melling M54f. After 500miles i heard noise coming from the engine while driving 75miles. We pulled the engine out and found out after taking it apart that the oil pump check valve is out. I don't know why this thing happened??? Should i change the pump. Which oil pump should i buy???
Well, I guess we know what the "f" means. Agree with bigD
. I checked the Mellings website and the M54f
description says, " Standard volume and pressure, Ram Air engine, 30% more pressure than M-54D-S." Whaaaaat? Now Butler lists the pump as "Melling Pontiac RA/SD High Vol. 80 psi Oil Pump-w/o Pick-up MEL-M-54F."
If it is the 80PSI pump, personally, too much pressure unless you have a lot of bearing clearance and plan on racing the engine and spinning high RPM's.
I found this description on another site as well as Butler for the Mellings 10540
pump for the Pontiac, "High pressure performance upgrade for the M-54D-S. The housing is CNC machined and phosphate coated. Includes 3/4” diameter oil pickup screen." The description says it is a standard volume/high pressure
pump, BUT, at the top of the page showing this pump at Butler, the header says, "Melling Performance Pontiac High Vol./ 60 psi
Oil Pump-with Pick-up MEL-10540. A little bit confusing to say the least.
You don't really need more pressure than the 60 PSI for a stock engine, but more volume and the 3/4" pickup is
I went with this Butler pump that bigD
pointed out. Yep, more money, but at what cost is another engine?? It is 60PSI, flows more volume, and I cannot recall if it uses the 3/4" pickup/screen (although the descriptions does not state this, but Butler builds their Pro pump off the M54DS which they state has the 3/4" pickup). Oiling is essential on a Pontiac and can be the weak spot, so why chance it? https://butlerperformance.com/i-2445...tegory:1234738
And if you did not get a hardened oil pump shaft to replace the stock one, get one.
I saw that the Mellings M54f had a 12 month warranty, so you might be able to get your money back.