Cylinder Head Installation - Torque Angle

[stneckel]

Recently saw some leaking coolant after changing out the cylinder head gasket on my D900 (had to replace the lower cam chain guide). Not a lot of coolant, but enought for me to want to change out the gasket again.

I've done this work before and never had a leak, and I'm wondering if maybe I didn't quite get the final torque sequence right. I'm especially concerned with the final 90° torque angle on the head bolts, since there is really not enough space under the frame to get a torque angle gauge on every one of the bolts.

Anyone have any advice about getting that torque angle correct, or any opinions about how critical it might be?

Thanks,
Sean

[t552]

Triumph did have a bad batch of gaskets recently, so i hear.

[KitNYC]

I never used a torque angle gauge on mine; 90º is a quarter turn and I can do that pretty precisely without one. I just started with the ratchet parallel to the front of the case and ended with it perpendicular, IIRC.

Cheers,
-Kit

[stneckel]

T552 - do you remember where you heard that from? I'd like to do a little searching on that one, if for no other reason than to make me feel a little better. Like I said, I've taken cylinder heads off before and never had one leak. I'd like a confidence boost!

The gasket I got did seem pretty cheaply made, compared to the one that came off the bike. Mostly fiber, with just some inset copper rings at the cylinders. The previous one was a laminate of some sort.

Thanks, Kit. I pretty much did the same thing, so I guess I couldn't have been too far off. I'm going to get a new gasket, pull the head and be extra careful about putting it back on.

Thanks to both of you!

[KitNYC]

Good luck, let us know how it goes. Gaskets ought to be made of some sort of titanium/gold alloy for what Triumph wants for them. I am not looking forward to the months of ramen noodles I'll be eating when I do this to my T625; I'll be screaming bloody murder for sure if I get a bad gasket!

Cheers,
-Kit

[t552]

I think it came from David Clarke, author of the recent t3 book.
He refreshed a speed 3 motor and had a problem with a leak. It came from Peacocks in the UK

[Triplets]

The first gasket I did my head with looked like it was made from recycled cardboard. It failed.

The one I have now looks more substantial and has a bead of factory applied sealant around its perimeter.

To control the 90 degree turn: clean the bolt ends and use tippex to mark the bolt head then just turn that bolt 90 from a point on the head you visually align the tippex mark with - a degree or two either way shouldn't matter.