cylinder head temperature- R80/R100 twins

**bryan** · #1 25 Jul 2003

what is the "normal" working temperature for the cylinder head on the old airhead twins ?
i appreciate this will vary with the ambient temperature of the surrounding air,
any ideas ?
thanks

**dc lindberg** · #2 25 Sep 2008

A very good question!
And not even one reply since 2003 ?!

Has anyone used IR-heatgun(?) and measured the heads temp ?
The original question has no answer since BMW have not published any data on head temps.

References to VW heads ?

What optional coolings of the heads have you tested ?
CC-Racing or was it Luftmeister made valve-covers with o-ring sealing instead of the gasket => enhancing cooling of the heads they claimed (no temp data was published - was it only a sales gimmick?...). There is an R90W in EU - neat build! Still - what head temps could be considered normal ?

**dc lindberg** · #3 29 Mar 2009

R90W:
http://blitztest.tripod.com/ChiHeads/Photos_R90W.html

Chiang Jiang:
- the only WaterCooled 2-cylinder boxer in production:
http://www.chang-jiang.com/bmw/m1cool.html

**Global Rider** · #4 11 Apr 2009

Quote:

Originally Posted by bryan

what is the "normal" working temperature for the cylinder head on the old airhead twins?

What do you mean by "normal working"? Run two up loaded with gear and it'll be higher.

In general, I would guess somewhere around 350°F to 375°F with a maximum at 425°F. These numbers based on aircooled aircraft engines.

**tatters** · #5 9 May 2009

Took theses today after a hours ride, 1992 R100GSPD stock setup with plugged air injection system.

Cylinder head temp is around 300 degrees

**Global Rider** · #6 9 May 2009

Quote:

Originally Posted by tatters

Took theses today after a hours ride, 1992 R100GSPD stock setup with plugged air injection system.

Cylinder head temp is around 300 degrees.

So that was taken when you were parked and not under load at 60 MPH.

**tatters** · #7 9 May 2009

Theres not going to be much temp diffrence from riding under load around london to stopping straight way and taking a couple of shots from a hand held imager.

**Global Rider** · #8 9 May 2009

Quote:

Originally Posted by tatters

Theres not going to be much temp diffrence from riding under load around london to stopping straight way and taking a couple of shots from a hand held imager.

Well temperatures drop off quickly at first...sort of like a discharging capacitor.

It would be interesting to see what the cylinder head temperatures would be at a steady cruise of 60 MPH or higher.

I remember the cylinder head temperatures in an air cooled aircraft engine.

**dc lindberg** · #9 10 May 2009

Tatters,
Your pics were most interesting.

They have settled one issue - an indication on how hot the cylinders and heads may be at stop-lights and in city-jam.

Alex's point on how hot the heads may be at normal cruising speed is also interesting - far more tricky to get photos of though -

Could this be a gadget that may be a useful aid to get pics in speed?
Panavise Test