Excessive oil pressure?

[turbofabricator]

Well this is a first for me. I just got an on center Stage II with TA heads, Champion intake 274 cid up and running. It has a highly modified/detailed stock timing cover milled .125" to fit the on center block with a TA oil pump cover with -12AN feed, -10 AN outlet to filter and -10 AN from filer to block. It has. -6AN bypass line to the fuel pump block off plate. I am getting 125+ Psi on the gauge taken from the back of the block. The feed line attaches at the front side of the block. (Where the stock Turbo feed is on a 109 block, though on a StageII it is a 1/2" NPT) This pressure is at idle. Hot idle pressure is over 55psi. Bearing clearances are . 0022". The TA pump is a high volume version using stock style high volume gears. The end play on the pump gears is a trued .0005". With just approximately 1200 rpm on a drill motor it'll peg the oil pressure gauge. I talked with Nick to see if he has had an issue with the TA pump and he thinks it is because of the tight clearances in the pump and the efficiency of the TA pump cover. I would think that it should still bleed off what ever the pump can make. I have the shortest spring that is available in a pump kit and that did nothing. I installed a -8AN bypass hose temporarily into the valve cover and it filled the valve cover at idle. It also blew the o ring out of the oil filter causing Exxon Valdeze in the shop. (ever had oil dripping from your headlites? I must need to add blinker fluid now) I think that with the plugged oil holes in the timing cover and the blue printed oil pump clearances along with tight bearings and tight lifter bores the high volume pump is just too much? But GEEZE........125+psi at idle? No change with different springs? No change with an increase in bypass hose size? That TA pump is sure efficient albeit with out control of pressure. Any one have a suggestion? I am going to call TA and see what they say. I will either have to modify the pump to accept STD pump gears, buy a STD TA pump, or modify the bypass circuit to flow ALOT more oil.

 

[Mac in SD]

I've always had pretty high pressure in mine, like 70 psi cold at high idle, going over 100 at 2000 rpm. So I started using 0W40 synthetic oil, and it's much more "normal," especially cold. I'm running the Duttweiller pump housing with same size lines / fittings. Maybe it's not as tight or efficient as the T/A? Bearing clearances were a little bigger - in the .023 range IIRC.

But yours is unbelievable.

 

[turbofabricator]

I just tried few things. I completely removed the bypass spring and it made 20psi at idle. I then removed the shortest red spring and cut 1/4" off of it and it still pegged the gauge on start up. Removed the spring and cut an additional 1/4" off of it and now it makes 70psi at idle. ..............But........... it filled the passenger valve cover in about 20 seconds or so and dumped a good QT of oil on the floor. So, I'm going to up the bypass size to -8AN and see what happens. Long day..............I'm done.

 

[gnxtc2]

What is the motor going to be used for? Racing, street, strip??? Type of lifters?

Billy T.
gnxtc2@aol.com

 

[turbofabricator]

I finally solved the pressure issue. I talked with Mike at TA at penguin and we couldn't solve it over the phone. I ended up removing the TA pump cover and did alot of measuring and comparing to the stock pump cover. There just isn't a ay to bypass enough oil in the TA pump. I ended up adding a large radius deeper from the bypass port that the fitting screws into towards the bypass valve seat. I also added a relief around the valve just forward of the outlet port. I ended up using an orange spring that I had to cut off about 3/8". Theft adjuster is flush with the bottom of the bypass adjuster bolt. In other words I still have about 1/2" of adjustment if needed later. I also stepped up to a -8AN bypass hose into the fuel pump block off plate. I also added a .005" shim to the pump housing gasket stack up to reduce efficiency of the pump. Right now it makes about 55psi at idle and jumps to 90psi at rpm. Thanks Nick and Mike for trying to help solve it.
This is the first time in 22+ years in building Buicks that I have encountered oil pressure that high. That TA pump sure moves alot of oil.
This will be a street/strip car that will run no faster than 10.00. No roll cave and no desire to install one. He is more than happy running it at 10.01@134.9999999

 

[Ed Valvo]

Blinker fluid

 

[forcefed3.8's]

Bringing this back to the top. I am finally priming my engine with a Duttweiler oil pump (standard flat top one) with a high volume front cover (built in longer gears). I am using the yellow spring now (I took it out of a stock front cover, will have other springs in about 10 mins). I am seeing 90psi with a 1200 rpm drill. What should I be shooting for to tell if I am going to have a problem. Right now I am running a 6an bypass, but can go 8an pretty easily. I can make 15 to 20 psi moving the gears slowly with my finger tips.

 

[BlownV6]

1200 rpm drill would be turning at 2400 rpm engine speed. Pump is turning at 1/2 engine rpm right?? Mike

 

[forcefed3.8's]

I would think so being driven off the cam. I have black and orange springs to try. I have 10w40 oil in it now.

 

[forcefed3.8's]

60psi with the orange spring and the adjuster all the way out.

 

[Nick Micale]

I would think so being driven off the cam. I have black and orange springs to try. I have 10w40 oil in it now.

You may have to experiment with different springs until pressure is within a range you want.

On my recent build I had a case similar to Ken's situation, and used an orange spring that I shortened slightly.

I have always used a -8AN for the bypass line.

 

[forcefed3.8's]

I was figuring it would be trial and error. I was just making sure I would not have 125psi idle. I guess 60psi cold with a 1200rpm drill is a good place to start?? Atleast I know I can get it lower, so hopefully the -6an is enough. This is one of the things that has been in the back of my mind.