Hitchcocks Forum

good evening folks.i have just acquired a new composite head gasket for a g.t. 250.from our hosts.is it best practice to use any jointing compound with these or not? head is weeping from normal place around push rod tunnel.thanks for reading

I used Blue Hylomar on my composite gasket when I rebuilt my engine. 1000 miles later, everything is still hunky dory.

Hi. When I used the composite gasket on my 500 I didn't use any sealant and it's been fine. Just remember to torque the head down again after a few miles.

Hi there, (somebody pleasant)--????? I have 2 Classic 500 Bullets, both of which have our hosts American made composite gaskets fitted. With respect to BARRY Q, the instructions tell you quite clearly to fit them ----dry & NO JOINTING COMPOUND. It's not required. If you are re-using a copper one then yes, that does need a non-setting compound such as WELLSEAL..... Is this head-weeping BEFORE or AFTER fitting the composite gasket ?? As a precaution just measure the gap left when the head is placed onto the barrel. Compare that with the thickness of the head gasket---the gap MUST be smaller than the gasket else it wont have any clamping effect. The DIFFERENCE between the two will be that clamping effect. It's not a touch of that old porosity is it ??

thank you for taking the time to share your ideas.to elaborate a little further the oil seepage is from around the pushrod tunnel while the engine is running.i recall many years ago that on the crusaders this was a common occurance.as the engine has been completely re-built i would hope the fitting of the composite gasket would cure this,otherwise why change it?the gasket that is.also has anyone modified the two allen headed bolts that are very well hidden in the pushrod tunnel,seems a bit of an afterthought.thanks again.

I fitted mine dry (350 classic) and on advice someone who knows, didn't bother with retorquing. Seems they don't need that either. Anyway, no problems 2000 miles later. It is important to get the top of the barrel really clean and I rubbed the head flat and clean on an emery board.

Hi EP, the 2 screws are an afterthought, they went from none to one to two over the years and still didn't really fix it! Your options are: spot face the holes and fit non countersunk screws, or cut the countersink off old screws and use as a washer with non countersunk screws. The tightening procedure that works on my GT is to do the screws first then the nuts. probably wrong but achieves maximum tension! By the way, there is a Yahoo News Group (Google it,) especially for 250s called Crusader Technical Group, come and join in!
REgards, Mark