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Do I need a crank scraper?

4K views 14 replies 5 participants last post by  Sephora325iX 
#1 · (Edited)
I'm working on a 1992 325i(E36) engine swap. The original motor blew a piston. So I found 1 from a 1991 E34 525i. Both are the M50 types. Besides the oil pans, the motors are identical. After going through my replacement engine, I have come into a slight stumbling block. The 525i block doesn't use a ***8220;crank scraper***8221; bolted to the block(it has it directly in the pan). My 325i block, has a scraper bolted to the block.

I can switch everything over(Pan, pick-up tube)-but not the crank scraper. This is because, on the replacement block there are NO mounts-casted on the inside of block.

Do I need to run a crank scraper? Has anyone ever ran into this before?
If I need to run 1, any body got any ideas on the mounting setup?

Thanks.
 
#2 ·
I'd never heard of a difference on the internals....I really don't know, sorry.

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#5 ·
Any way you could use the one out of the 525 pan to transfer over? It's got to be attached somehow. It's not cast as part of the pan, is it?

To tell the truth, you could probably run without it. A windage tray is only useful at high RPMs. Unless you're driving style involves a lot of high-revving, you can probably do just fine with no scraper/tray.
 
#6 · (Edited)
Thats a good idea. But the 525i pan, had the Windage tray riveted in , and in no way could fit in the 325i pan.
I don't plan on doing a lot of high Rpm work with this engine.

However, I have found a company that makes custom Crankscrapers. It's not a windage tray, but it would be better than nothing. I'm still on the fence either way about the stock windage tray.

From what I can tell, this problem is not too common with these motors. I was quite shocked when my replacement block had no mounts casted in it. It must have been from a very early 525i.
 
#7 ·
After some checking around, I believe I've found an answer. I talked to a guy (Machinst)who makes crank scrapers for many different engines. He has been dealing with these engines for a quite awhile. In his opinion, I should be okay without that Windage tray. Mainly Because, my pan has another built in tray towards the bottom.

Thanks for the help. Still if there is anyone, who has ever had this problem (no windage tray mounts) I would like to hear about it. It seems to be, that mine is the only documented case of missing the mounts.
 
#10 · (Edited)
A windage tray will not only keep your crankshaft from dipping into your oil at high rpm (causing parasitic drag and foaming your oil, which in some engines can cause cavitation and therfore oil starvation and eventually engine failure from it) it also keeps your oil from sloshing during hard acceleration and cornering, causing the same problems. A crank scraper removes excess oil from the crankshaft. If you look at a scraper, vs. A windage tray, they are completely different animals. Windage trays should be on all engines in some form. Crank scrapers belong on hardcore track cars. It costs a manufacturer millions to design and build an engine, especially one as durable and with as long a production run as the BMW inline 6. It wouldn't be there if it didn't need to be for one reason or another. Some of the external, emissions and drivability parts along with things designed with nvh in mind may be debatable, but am internal engine component is not. If I were spending my hard earned dollars to put an engine in my car, i would take my oil pan to my machinist, along with the oil pan off of the new motor, and tell him to make a secure attaching point on your stock pan at the same distance from the pan rail as it is on the pan off of the new motor. It should cost less than $100 and could save you premature engine failure. Worth it in my book.
 
#12 ·
What I was referring to was the fact that he was saying he had no provision on the new block to run is original windage tray, as the the replacement engine has its windage tray in the oil pan and he has to run his stock pan. The solution I was offering was to have his machine shop modify his stock pan to accept the windage tray from the pan that came with the replacement engine. I gave him a little more depth of the differences because he seemed to be confused on the difference, or the interchangeably of the two. From what he was saying, if he just ran his stock pan he would have no windage tray, just the baffles in his stock oil pan, which would not be enough, most likely.
 
#13 ·
Well you both raise a very good point, it's basically a gamble either way. :dunno:
If I had the extra funding and time, I would try to find a better solution for this problem. However the car is in pieces and all I want to do right now is put it back togehter. Maybe this time, I can have all the cylinders working:)
 
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