Oil Press Q
 

My newly built 461 has a oilpressure issue.
Its a standard Mellingpump and it deliveres 20 Psi at idle(1000Rpm),but the thing is that at 3500 Rpm it delivers about 35 Psi.I know that 10 Psi per 1kRpm is considered "normal" ,but it feels to close for comfort.
The pump was delivered with a "High pressure" spring to be installed if i wanted,but my engine builder used the standard one.
When we dynoed the engine the pressure was steady and peaked around something like 60 Psi.I`m using 20/50 oil.
I use a Automerer Elec meter and the standard one,but theres a diff between the two of 10 Psi (Org meter 35Psi/Autometer 25Psi).
I would like atleast 35 Psi at idle and around 60 when i`m running in the upper Rpm band..
So,whats your idea on this issue? :smash: :cheers:

Edited,checked the Dynosheet,and it says 60 Psi.


[Modified by BB wowbagger, 10:29 PM 4/7/2004]

Re: Oil Press Q (BB wowbagger)
 

hate to say it but you might be looking at some bearing issues. I have a 383 that used to eat rod bearing but it changed its taste to mains on the last rebuild. The #4 spun and I have replaced it twice, oil pressure is good for a while then slowly goes down at idle to about 15 to 20 with a HV/HP pump. Pressure wavers a little under hard accelaration. Eng is coming out in the near future. :(

Re: Oil Press Q (BB wowbagger)
 

Might be. I can send you an Autometer Phantom mechanical oil pressure gauge. If you pick up shipping, that is.

Brett :thumbs:

Re: Oil Press Q (BB wowbagger)
 

Fighting same problem here. First engine had those symptoms and spun #1 rod brg. New rebuild with Melling H-vol shows only 15 at very hot idle but great pressure all other times but has knockingl sound on #1 now. :cuss
Got new everything but something still isnt right.

Going to build 383 with different block and tear old engine apart, mic everything and figure out whats causing. Will update later. Gut feeling is loose tolerances.

Re: Oil Press Q (Surfer69)
 

Funny (well more like :mad ) thing is I bought this short block with all new parts and it spun a rod bearing from the pan rail not being clearenced for the stroker crank. I did a couple half arz attempts at rebuilding with the same bearing go bad. This time I had the crank resized and finally had the rods resized too. Rods are fine and now the #4 main is bad. :mad Best i can figure is the bearing was not seated properly and was compressed against the crank or was restricting oil flow. Try draining you oil in to a fine mesh strainer and see if any bearing material is in it. Dropping the pan will def tell you if any bearings got chewed up.

Re: Oil Press Q (Fevre)
 

My "engine guy" has built alot of heavyduty raceengines and the oil press when it was on the Dyno was really nice and solid.He wouldnt release a engine if theres something he thought was "off"..
Maybe theres something with my gauges? :smash: :cheers: