new engine build question . low oil pressure at idle !!

[turbo john FL]

hello guys ,
i just had a complete engine built from a local machine shop that had great rep. just did my initial start up and have driven just around neighborhood . after car reaches about 160 - 170 degress i am seeing alomst no oil pressure at idle . i have a mechanical auto meter gauge for reference .this was major build new pistons , new stroker crank , new rods, rjc girdle, new roller cam , td roller rockers ,
currently the oil in car is conventional oil 10-40 with a little break in additive this is oil from initial start up . also have hi volume oil pump installed with higher pressure spring installed . now once car rpm.s increase oil pressure goes up to over 60 pounds . the basi oil press upon start is only around 10 pounds then falls off to pretty much zero

any insight on what to do or look at etc will be appreciated
this has me really concerned after all this money invested thanks in advance everyone JOHN

 

[87_we4]

My freshly built motor hold 20psi of oil pressure when hot. Oil pressure should go up by 10psi per 1000rpm

 

[HelloBozos]

Is there a oil cooler on this build? Who did it? Who build it an Assembled it? My fresh CFSM build runs right around 40 psi with 20-50 valvoline. You should contact the builder ASAP.

 

[turbo john FL]

motor was built by a local machine shop who does lots of race engines locally here north of tampa , i contacted him last week he says to run a few miles dump oil and run valvoline 20/50 race oil and add a quart of lucas oil additive and that should help im concerned guys after all this money

 

[williamsGN]

Mine did the same after 10 minutes of break in.. I pulled the filter, cut it apart to look for metal, nothing there.. new filter, topped off oil, 20/50 and reprimed with drill and had pressure. All I could figure is it lost prime somehow. Otherwise I would look at the oil pump gears/spring for proper assembly. Wouldn't touch the gas unless you have pressure and shut it down quickly if it starts to fall.

 

[turbo nasty]

Also verify oil flow up to both heads

 

[turbo nasty]

Oil pump clearance?

 

[Chris Hogeland]

More than likely he set the rod and main clearance to loose. He Probley set it up like A small block Chevy. I can set you up A front cover that will help get the psi up if you want.

 

[turbo john FL]

chris how does the front cover help with oil pressure ?? should i pull the oil pump and check clearences ?

 

[williamsGN]

ask your builder for the clearances he used and post them up.

http://turbobuick.com/forums/thread...-for-street-strip-engine.388253/#post-3131219

 

[GNTIM]

somethings really wrong here. Unless there is something wrong with the oil pump or front cover, it needs to come apart. That low of pressure will kill it quick.

 

[Chris Hogeland]

chris how does the front cover help with oil pressure ?? should i pull the oil pump and check clearences ?

Oil pump clearances does Make A difference. I do some machining on my front covers that helps. Iv done A few for guys with to much clearance and it has worked pretty good.

 

[Chris Hogeland]

somethings really wrong here. Unless there is something wrong with the oil pump or front cover, it needs to come apart. That low of pressure will kill it quick.

He said that its just at idle it has low psi. When he gives it gas the psi comes up. Most of the time that's caused from to much clearance.

 

[turbo john FL]

yes once i give it some rpms the pressure comes right up but its cold here in florida todat and to see it fall off on pressure warm now in summer it will die for sure im going to call machine shop in am and see if he can tell me what clearences he used . i know i told him it could not be run lose like a small block and he said he had built some gn motors before grrrrr this sucks !!!

 

[Chris Hogeland]

yes once i give it some rpms the pressure comes right up but its cold here in florida todat and to see it fall off on pressure warm now in summer it will die for sure im going to call machine shop in am and see if he can tell me what clearences he used . i know i told him it could not be run lose like a small block and he said he had built some gn motors before grrrrr this sucks !!!

The best thing would be to Check it all again. I have had to redo a lot engines that have been done by guys that said they have built GN motors . Good luck hope he works with you.

 

[earlbrown]

Do you have a GM timing cover or a chinese aftermarket cover? Also try and find out if whoever assembled the oil system "opened the HV box and installed the parts" or if they measured and clearanced all the parts. From what you've typed I'm going to guess the first.

What oil filter are you running? If you've got a short factory replacement Fram on there, that might be your entire problem. (other than having a HV pump)

Any idea if the engine was primed with a hand drill before it was fired off for the first time? -That one is a VERY important question. If the engine was busted off with a locked up pump, that won't be good.

 

[ek02]

I have a 3.8 as a spare engine, and it has .003 on the mains. It idles at 20 PSI with a high volume pump and 10-40 oil, 70 PSI @ 5000. My guess is too much clearance in the pump. If the mains are too loose you can always put .001 oversize bearings in it. If your machinist swears the mains are .002 or less, then I would get a front cover from Chris Hogeland. Most front cover oil pump housings are not square to the pump gears. Most are .001-.002 or more off. If that is corrected and the gear to cover clearance tightened up, the idle pressure will come up. Another possibility might be that one of the front oil gallery plugs has come loose or there is something wrong with the cam bearings, but I would pull the front cover and go from there. You might as well pull the pan too while the cover is off and put a new gasket on it instead of trying to piece it together. Look up and make sure all the cam bearings are where they should be when you pull the pan.

 

[earlbrown]

Are you seeing .001~002 on GM covers or china covers? I've never seen anywhere near that much out of square.

 

[Paul Lohr]

I think it is important to carefully manage the situation with the machine shop / engine builder. If you break their confidence, their attitude will likely become poor and they may not provide satisfactory service. It seems like you are being reasonable with them. I have made the mistake myself.

I would be asking for a copy of the build measurements. This should have the clearance for every area they saw as important. Areas they did not see as important won't be detailed.

Even if the mains and rods are a little loose on vertical clearance, assuming all else is well, you should have 10 psi at idle. Maybe a bad assumption at this point. My 142K mile Buick V6 holds 10 psi at idle with an OEM pump.

It does no good to worry. It will work out.

Paul Lohr

 

[ek02]

Are you seeing .001~002 on GM covers or china covers? I've never seen anywhere near that much out of square.

I just took a brand new GM cover out of the box and checked it and it is .001 out. I just set up a used GM pump that was perfect. I have an aftermarket cover that checks perfect. The GM cover I am currently running is out .0015, but still has 24 PSI at hot idle.