Oil pressure relief, oil cooler, and accusump interaction Options

[Seabird]

Good morning everyone. I am in the process of upgrading my oil system. This is on my dedicated track 914. The upgrades include remote oil cooler, accusump, and CB Maxi oil pump.

In my research for installing the accusump it seems like there are two places that are recommended, in the cooler return line with a check valve and direct to the block. I did not want to use the sandwich plate adapter so I opted for the block option. Simpler with less seals to fail.

As I looked into the workings of the type IV oil system I found a potential problem with both these locations; the oil relief valve on the front of the engine. VW used this valve to bypass the cooler when the oil is thick. But this also means the cooler is bypassed when the oil pressure is high. Does the use of an oil accumulator negate the oil cooler system by maintaining oil pressure?

While on the straights the pump could potentially make 50-60 psi of oil pressure. (the 30mm pump that was in the engine produces those pressures much of a 20 min session) At those oil pressures the cooler will be bypassed based on what I know of the relief valve (bypassing cooler at 60psi, partially open at 35 psi, and sealed at 12psi). The accusump will also build up to that pressure. When I go to brakes and the revs drop the accusump will start pushing back and keep the pressure up till the differential is corrected. If I am back on to the next straight in that time then the pump starts building the pressure again.

Options:

1. Am I making a mountain out of a mole hill? Leave it alone.

2. Plug that relief valve so it stays closed and let the oil cooler thermostat bypass the oil when its cold. This is a pre 76 case so there is the secondary relief valve by cylinder 1. Might be able just to invert the piston so the bypass grove is below the bypass passages.

3. There is also the high pressure pistons sold by pelican parts and others. Does this just shift the bypass window to a higher pressure range?

I would love to hear people's thoughts on this.

Miguel

[Seabird]

I just might.

Though this should get its own OT topic I'll give a short blurb here. We finished 6th at Daytona, two of our drivers had never been on the track before, and one of our drivers developed a fever while driving his stint. Had it not been for two silly penalties we would have been in the hunt for 1st place (15 min worth of penalties at sub 2:30 laps makes up the 6 lap differential at the end.) GRRRR.

Not bad for a team and car's first race! We are quite ecstatic to say the least!

Also I got to meet the George, the PaintedMan; which was cool.

OT race report over.

Mean while back on the 914 front I am excited for Chris's new solution to the oil cooler bypass issue! A week and a half away from getting to test it! Man its going to be hot at Sebring too!

Regards,

Miguel

[Jetsetsurfshop]

I just might.

Though this should get its own OT topic I'll give a short blurb here. We finished 6th at Daytona, two of our drivers had never been on the track before, and one of our drivers developed a fever while driving his stint. Had it not been for two silly penalties we would have been in the hunt for 1st place (15 min worth of penalties at sub 2:30 laps makes up the 6 lap differential at the end.) GRRRR.

Not bad for a team and car's first race! We are quite ecstatic to say the least!

Also I got to meet the George, the PaintedMan; which was cool.

OT race report over.

Mean while back on the 914 front I am excited for Chris's new solution to the oil cooler bypass issue! A week and a half away from getting to test it! Man its going to be hot at Sebring too!

Regards,

Miguel

Spoke with Chris today about this prototype for a bit. I'll block off some space next to my trailer for you. I'm track support for my dad on Sunday and will be able to help you out too. Looking forward to checking out the new components. Are you getting there Saturday night or Sunday morning?
Shane

[Seabird]

Spoke with Chris today about this prototype for a bit. I'll block off some space next to my trailer for you. I'm track support for my dad on Sunday and will be able to help you out too. Looking forward to checking out the new components. Are you getting there Saturday night or Sunday morning?
Shane

Should be there Saturday by 5 or so.

Just finished the accusump tonight. Finishing the cooler install is next.

So much to do so little time. (IMG:style_emoticons/default/biggrin.gif)

Miguel