Ways to cure 7M oiling issues

***bwest*** · December 19th, 2006, 03:53 PM

Greg (or anyone else that has done this) is there a reason you went with a braided line on the pump output vs having a hardline made up using a threaded pipe fitting? I have some concerns over the hardening of the rubber over time being submerged in oil (both in and out) and cracking, leaking, etc; leading to a loss of pressure and then the motor.

Thoughts? or do you not anticipate the motor lasting long enough for that to be a problem...

***3p141592654*** · December 20th, 2006, 11:21 AM

I would think a semi-rigid hardline with swagelok fittings would be better (but more expensive).

http://www.swagelok.com

**tig321** · December 20th, 2006, 01:08 PM

Originally Posted by 3p141592654

I would think a semi-rigid hardline with swagelok fittings would be better (but more expensive).

http://www.swagelok.com

That thought crossed my mind also. They are not cheap, but not really a huge price difference compared to AN fittings I geuss.
What do you mean by "semi" rigid?

http://www.swagelok.com/search/produ...art=SS-810-5-8
SS Swagelok Tube Fitting, 45° Male Elbow, 1/2 in. Tube OD x 1/2 in. Male NPT
Unit Price : 40.70
Availability : Call for Availability
http://www.swagelok.com/search/produ...part=M-810-2-8
Swagelok Tube Fitting, Male Elbow, 1/2 in. Tube OD x 1/2 in. Male NPT
Price: USD 34.50
Availability: Call for Availability

an fittings for $ comparison
http://store.summitracing.com/partde...5&autoview=sku
http://store.summitracing.com/partde...5&autoview=sku
Great writeup btw. Very good info in here. I'm glad to finally find pics of the group A ban baffling.

***bwest*** · December 20th, 2006, 01:19 PM

There is a swagelok distributer over in Sunnyvale that I'll try to check out next week. I'll see if they have something that makes 'sense' to use.

I'm going to look into having a hard line made up with a pipe fitting on the pump end and then change the output on the pump (similar to what Greg did). Personally, a hard line vs a hose makes me feel a bit more comfortable. If I was pulling the pan on a regular basis, that would be different, but since I'm not, I would rather not worry at all.

**supra87t/t4** · December 20th, 2006, 06:43 PM

Great thread!

Couple comments

" wether you are using the 5m or 7m pump, there is a clearance from the gears, to the lower case. there is a minimum and maximum tolerance. what you need to do is measure that, and then have the cover machined at the machine shop to put this as close to the minimum clearance as posible"

Machining the cover won't reduce the clearance as the cover is "flat". you would have to machine the pump body itself. Odds are you'd be better off replacing an out of spec pump than trying to "fix" it.

"the pressure releif spring wears as well...this is a linear spring, so it does open before max presure is realized...it starts being compressed the moment any pressure is applied and is fully open by the max oil pressure"

I don't agree that the springs (pump relief and squirters) are "wearing" they may relax some with age, but it's not hard to design a spring to perform the same over a long long time if done right. I doub't you'd see much difference between an new and used spring, if you do the designer should be fired. Also, the spring doesn't open immediately, the reson why is that it is preloaded. The same thing adding shims does. It increases the cracking pressure. The free length of the spring is longer than the length when it is installed so it has some static force on it keeping the ball forced closed. You have to have enough pressure to overcome that force before the valve will open at all. Good call on the squirter springs though, I've seen a few with metal shavings stuck in the springs (machinist must not have removed them before flushing the galley) at least inspect them carefully.

I'd be nervous about the stainless hose in the oilpan. You have to make sure that braided lines aren't touching anything or they will wear right into it. As for the swagelock stuff there's no reason to get that fancy, if you want hardlines just use an AN tube nut and flare the tubing. Hhmm, that would be a pretty nice product if you got a batch CNC bent and put all the fittings together as a kit.

Glen

***Mr.PFloyd*** · December 20th, 2006, 07:25 PM

why isn't this stickied yet?

***ViR2*** · January 1st, 2007, 06:20 AM

any one know where I could buy a copy of Group A magnesium oil pan?
I didn't want make a new topic so I've posted in this one

***QWIKSTRIKE*** · January 1st, 2007, 09:05 AM

Originally Posted by drjonez

arnout over in the netherlands makes a girdle and a windage tray IIRC....if a scraper isn't your thing.

IMNSHO the #1 fix is the stupid oil filter mount....next to a properly rebuilt engine, of course.

I concur with the good DR

***QWIKSTRIKE*** · January 1st, 2007, 09:11 AM

Originally Posted by supra87t/t4

Great thread!

Couple comments

" wether you are using the 5m or 7m pump, there is a clearance from the gears, to the lower case. there is a minimum and maximum tolerance. what you need to do is measure that, and then have the cover machined at the machine shop to put this as close to the minimum clearance as posible"

Machining the cover won't reduce the clearance as the cover is "flat". you would have to machine the pump body itself. Odds are you'd be better off replacing an out of spec pump than trying to "fix" it.

"the pressure releif spring wears as well...this is a linear spring, so it does open before max presure is realized...it starts being compressed the moment any pressure is applied and is fully open by the max oil pressure"

I don't agree that the springs (pump relief and squirters) are "wearing" they may relax some with age, but it's not hard to design a spring to perform the same over a long long time if done right. I doub't you'd see much difference between an new and used spring, if you do the designer should be fired. Also, the spring doesn't open immediately, the reson why is that it is preloaded. The same thing adding shims does. It increases the cracking pressure. The free length of the spring is longer than the length when it is installed so it has some static force on it keeping the ball forced closed. You have to have enough pressure to overcome that force before the valve will open at all. Good call on the squirter springs though, I've seen a few with metal shavings stuck in the springs (machinist must not have removed them before flushing the galley) at least inspect them carefully.

I'd be nervous about the stainless hose in the oilpan. You have to make sure that braided lines aren't touching anything or they will wear right into it. As for the swagelock stuff there's no reason to get that fancy, if you want hardlines just use an AN tube nut and flare the tubing. Hhmm, that would be a pretty nice product if you got a batch CNC bent and put all the fittings together as a kit.

Glen

I agree Glen...This IMHO is just an itch for issues that need not be addressed if a larger pipe can be made. Go to an aeroquip shop...they have made me hard pipes like this for my new turbo

***williamb82*** · January 16th, 2007, 09:22 AM

anyone found out the thread needed on the 7m block yet where the oil enters from the oil pump? i have a 7m block torn down now and dont want to take the whole thing tot he hydralic line shop to get the right fittings. lol. i figure someone may have found this out already. if not ill be sure to post it when i find out.