Boxerworks.com

I spent the day working on the 1973 R75/5 and I have some questions:

Is the deeper sump worth it (it increases oil capacity by 1 Quart but it's $219,00!).

Is the Thermometer/dipstick useful or is it just "bling"?

Vince

Some like the deeper sump because it increases the crankcase volume, making the breather valve work a lot less hard. To do this you still run the stock oil volume.

Temp stick = bling. If I lived in Death Valley, I might consider a bar mounted temp gauge valuable, but I wouldn't have it down by my foot.

Unclviny wrote:I spent the day working on the 1973 R75/5 and I have some questions:

Is the deeper sump worth it (it increases oil capacity by 1 Quart but it's $219,00!).

Is the Thermometer/dipstick useful or is it just "bling"?

Vince

If you do decide to get a deeper sump, don't neglect to get the oil pickup extension as well. Like the Major says, the benefit is increased crankcase volume, not more oil. That's why BMW put them on the later bikes. I'm not sure if the /5 center stand will clear some of the aftermarket sumps. Also, forget new, check with the used parts guys and keep an eye on ebay. They do turn up from time to time.

The $219.00 includes the pick-up spacer. I did not even consider the centerstand-interference, that is a deal-killer for me as I am a centerstand kinda-guy.

Vince

Unclviny wrote:The $219.00 includes the pick-up spacer. I did not even consider the centerstand-interference, that is a deal-killer for me as I am a centerstand kinda-guy.

Vince

Mac still makes a brand new one with the pump spacer that will clear your stand for under $100.00.
http://www.macperformance.com/store/cat ... tLevel=top
This kind of sump comes up on eBay relatively often. They sell used for around $50.00.
I've got one on my 1975 R90/6. To go to a later pan you just need to cut out the center brace on your center stand. The later bikes came with out that brace.

I don't get how you guys can say that it doesn't increase the oil capacity... it says on the Mac site that it requires 2 extra quarts. I always thought that by having more oil, your engine didn't run as hot because there was more oil volume to circulate throughout the engine - thus not get as hot, as fast.

I went through this with my /5 and my R100S. (One has a deep oil pan other doesn't). if you get a later center stand (perhaps from a /7), it is the same mounting procedure and dimensions as a /5 stand but the center cross bar (that would interfere with some deep oil pans) is in a lower position and can clear the oil pan.

jjwithers wrote:I don't get how you guys can say that it doesn't increase the oil capacity... it says on the Mac site that it requires 2 extra quarts. I always thought that by having more oil, your engine didn't run as hot because there was more oil volume to circulate throughout the engine - thus not get as hot, as fast.

I went through this with my /5 and my R100S. (One has a deep oil pan other doesn't). if you get a later center stand (perhaps from a /7), it is the same mounting procedure and dimensions as a /5 stand but the center cross bar (that would interfere with some deep oil pans) is in a lower position and can clear the oil pan.

The oil capacity BMW specifies for all airheads through 1980 (without oil coolers) remains the same, deep or shallow stock oil pans. The Mac and others may have higher capacity for the reasons you state. I personally don't see any reason why running more oil in the deeper stock pan would hurt, other than the crankcase breathing issue. How thick is the pickup spacer, maybe 3/4"?

jjwithers wrote:I don't get how you guys can say that it doesn't increase the oil capacity... it says on the Mac site that it requires 2 extra quarts. I always thought that by having more oil, your engine didn't run as hot because there was more oil volume to circulate throughout the engine - thus not get as hot, as fast.

I went through this with my /5 and my R100S. (One has a deep oil pan other doesn't). if you get a later center stand (perhaps from a /7), it is the same mounting procedure and dimensions as a /5 stand but the center cross bar (that would interfere with some deep oil pans) is in a lower position and can clear the oil pan.

I run with the extra oil. I don't have blow by issues, so I go with the extra capacity. Plus...I like my original dip stick.

Thanks for the link! I would not have checked with Mac for a sump.
Those pans look good, add more oil than and are 1/2 the price of the other one.

I'll probably order one tomorrow.

Vince

Anton has a pretty good page on oil pans and dipsticks:

http://www.largiader.com/tech/oilpan/

Kurt in S.A.