BMW Motorcycle Pistons

[milnersXcoupe]

The BMW R series Motorcycles - flat Twin engines - from the 1970s
thru 200? came with cylinder Bore sizes virtually the same as your
Toyota / Lexus engines:


84+mm - /5 series 750cc

90 mm /6 series 900cc

91 mm over bore

94 mm /7 series 980cc



Mahle supplied Pistons - the later versions being 'slipper' style - .

Having had access to the BMW Roadrace Techs back then - their sourcing
for Pistons was VENOLIA - which BMW then used the design of for their production requirements from their supplier - they went 'slipper style' .

In the catalog back then:

Tool Steel wrist pins in various thickness for either NA or FI -

Teflon 'Buttons' to eliminate wrist pin lock failures -

Any type of chamber design -

Three piece oil rings -

'L' Dykes rings -

Ring selection of 'you name it' for the application -

Moly Coatings on skirts -

The 'Lightest' performance / racing Piston in the Industry.


Their 'Heritage' is Racings Premier Top Fuel / Funny Cars / Pro Stock / NASCAR / RoadRacing / MC Race Engines / MOAB race engines etc.




...... just thought you might be interested:argue: :sleeping: :28:

 

[striker]

Hey (old thread but anyway) whoops not so old I see!

funny that sometimes some people think exactly the same dispite being on the other side of the world hahaha!

I did a list with all major motorcycle manufacturers cylinder bores for the uz engine series.



bore 1uzfe = 87.5mm alternatives

ducati monster 800s 2003 88mm 8.25krpm
ducati S2r 2005 88mm 8.25krpm
Yamaha TDM 850 1991 89.5mm 7.5krpm
Kawasaki KLX 400 2004 90mm 8.5krpm
Kawasaki VN900 2007 88mm
KTM 400 1994 - 2005 89mm
Moto Guzi 1000s 1990 88mm 7.8krpm
Honda FT500 ascot 1982 89mm
Honda VT1100C Shadow 1985 87.5mm 6.5krpm
BMW R 850C 1997 87.5mm



bore 2uzfe = 94.0mm alternatives

ducati monster 1000s 2003 94mm 8krpm
ducati s4r 2003 96mm 8.75krpm
suzuki savage Ls650 1986 94mm
suzuki TL1000R 1998 98mm
Suzuki VL 1500LC Intruder 1999 96mm
yamaha BT100 buldog 1995 95mm
yamaha wr 450F 2004 95mm 9krpm
yamaha TT600 1991 95mm
Yamaha XT600 1984 95mm
kawasaki KLX 450 2007 96mm
KTM 525 2003 95mm
Honda VTR1000F 1997-2000 98mm
Cagiva T4 500E 1988 94mm 7.5krpm
BMW Krauser MKM 1000 1980 94mm 7.5krpm
BMW R 100 1980-1993 94mm 7.25krpm
Aprilia ETV 1000 Caponord 2001 97mm 8.25krpm
Aprilia RSV Mille R 1999-2007 97mm 9.25krpm (+tuono 1000r)



bore 3uzfe = 91mm alternatives

yamaha TDM 900 2002 92mm 7.5krpm
yamaha XT550 1982 92mm
Moto Guzzi 1100i 1996 92mm 7.8krpm
Cagiva Canyon 500 1999 92.8mm
Aprilia Atlantic 500 Sprint 2002 92mm 7krpm


does anybody have acces to a wristpin diamater list somwhere (JE or wiseco or something? I would like to cancel those that won't fit for sure.

grtz Thomas

 

[turboandrew]

And how many match the combustion chamber of the 1UZ? Or are you altering the surface of the pistons to match squish areas, valve reliefs, etc?

 

[nissan-lover]

And how many match the combustion chamber of the 1UZ? Or are you altering the surface of the pistons to match squish areas, valve reliefs, etc?

Bingo...

Mike

 

[Lextreme II]

As Andrew stated matching combustion chamber would be impossible. I spents many hours on this. Its a waste of time. The time u spent on searching would be alot cheaper to get a set from any custom piston shop.

There are many issues:
1. Combustion Chamber along with compression
2. Compression Height
3. SE thickness and diameter
4. Rod length

Basically, there is NO off the shelf pistons that are directly bolt on to the 1uzfe. If you find one, please let me know.

 

[milnersXcoupe]

Dave is 100% correct - unless it is a Flat Top piston - with the same pin height - pin bore etc. - or - you're using Custom Length rods and you find a 'match' to your Combo - fahgeddabout it.

The point I wanted to make is that there are Ring Paks that are available for
the 1 UZ and 2 UZ since a number of Motorcycle engines run this diameter -
stuff that survives 10,000 RPMs sustained - or - 'Blown' applications.

The Venolia L-Dykes work well with pressurized engines - takes a Custom Piston to use - three piece oil rings, nice but specify.

Any engine I build - once going thru the bother of opening it up - will have Custom Pistons - regardless - either that or just leave it buttoned up and replace it entirely when it / IF it grenades.

 

[striker]

Hey All,

I Absolutly agree with you on all the points,

the valve reliefe thing is more or less covered because all MC's above have 4 valves per cylinder offcourse cut out's must or can be altered but the deck is allready provided with adiditional strenght.

the thing is people tend to stick with make and manufacturer all the time, which I think is wrong because there are so many conrods and pisotn combo's made by varous manufacturers it should be near impossilbe that there are none that fit our application.

in the other thread (nissan lover's) I pointed out that the ford OHC 8v pinto people over here in holland use yahama XT pistons, offcourse the rod don't work but when the take 1mm off the big end journals of the crank and throw in a set of VW golf (believe rabbit in USA) 2.0 GTI 16v rods the combo is complete, hence that allows them to run 9500rpm on an engine without using one performance part, it's all stock manufacturers stuff so it's cheap. together with a nice cam and some head work they get 280nm of torque from an 2.0L 8 valve single cam ford sierra engine without the ting exploding in their faces,

so indeed a big search has to be done but I just wanted to point out that there are far more and better and cheaper ways to make something go really fast, than just calling wiseco or arias and pay up expecially in the NA department.
I've heard people using yamaha pistons in 4age aswell but helas never seen it.

grtz Thomas