The M20 pattern is a dual-scraper -- the added blade operates on the downstroke and shunts the oil to the side of the pan. M20 (L6): 2.0, 2.3, 2.5, 2.7 There are NUMEROUS variations that we have made over the years for stroked and stock engines. Please enquire.
Our M20 scrapers are very popular in NASA Spec E30 racing.
$109.95 [steel]; $239.95 [Teflon®]
Please note that stroker versions using greater than an 84mm crank are more expensive because the frames are more complicated to make. The IX pattern is listed separately below as well.
Some brief remarks about the M10, M20 and M30 engines with respect to oil control: These engines were designed with then contemporary elements, e.g. oil was allowed to drain onto the rotating assembly from the head. BMW US patent number 4,773,366 for a "Non-foaming crankcase configuration for piston internal-combustion engines" illustrates some of the engineering philosophy changes that went into the families of engines that replaced them. In 1994, SAE paper 940792 from FEV Motorentechnik, Aachen was presented that also goes over these design elements.
The crank scrapers we manufacture follow this design philosophy and extend it, particularly for vehicles that are used in extreme duty or competition (see "Kibort Effect"). We have had very favorable feedback over the years for these designs. It is worth noting that the designs have been updated in at least nine generations over ten years which is extremely rare among aftermarket manufacturers. The M30 design was one of our very first products and is part of our company logo.
Steel version above
Teflon® version pics immediately above and below
Here are a couple pictures of a Teflon 91mm stroker:
M20 IX pattern (all-wheel drive -- the drive shaft passes through the sump) is now a dual-scraper -- the added blade operates on the downstroke and shunts the oil to the side of the pan.
Stroker versions of the IX pattern over 84MM are $179.95 because of the added complexity. There are no Teflon versions of the IX pattern available.
Various M20 examples:
A picture of a special M20 2.0 version -- the cross supports allow the scraper to be used as a light duty girdle when studs and spacers are employed:
These pics of earlier patterns show the trap doors and how the pattern sits with respect to the pan.
Chuck Taylor, racer and owner of Factory 3 Performance writes:
This is what I know about crank scrapers:
Don't install an oil pressure gauge if you aren't planning to also install a crank scraper.
The factory oil pressure warning light is set to come on at around 7-8psi. Your warning light probably never illuminates while driving.
Once I installed an oil pressure gauge, I found that in the fast left hand corners (like T3 at Roebling) the car was dropping from 50PSI to around 16. Not good. Especially at 5000+ RPM. Even running a quart over full didn't help. Talk about too much information!
We installed one of the crank scrapers over the winter, and now the car holds full pressure everywhere on track.