Yamaha TRX850 Enthusiasts Forum

Im looking for the exhaust tract length from the valve seat face to the port and the port diameter please.

Can't help you I'm afraid but you've got me curious as to why you want to know

Ive just got hold of some 4 stroke pipe software and I want to test it out and see what it gives me compared to a known pipe.

Try this thread " TRX cylinder head crankcase 3D " or Dr Slumper's blog "thetrxproject.blogspot.com"

Tell us the outcome.

i got a spare head which is stripped, ive also got some soft silicone negatives of the head.

Gimmie a drawing of exactly what you want and ill do it for you.

All I need is a centerline length fron the center of the valve seat to the exhaust gasket seat and the diameter of the port at the exhaust gasket, oh sorry I need the exhaust gasket ID too please.

some say I have a demented head

i dont think its only some cobby.. its prolly most

Umm.. i left my verniers @ work so gimmie a few days to get some numbers sorry. Do you want the bent path ? or direct line "as the crow flys" ?
Red is a straight line, or blue is a path along the centre line and being curved. Purple is the valve and cam setup Hope it makes sense.
Which one do you want ?

I need the curved blue line on your drawing mate thanx for your help Quan-time

Any news mate please??