Weld Cracked Dome?

[SkiDaddy]

I have a second hand Wamilton's Big Bore w/custom machined domes in a Greater head, one of which has developed a crack.:banghead: Can this be welded if it's gonna take a couple of weeks to get a new one?:sneaky:

FWIW, the crack is about an inch long, tangent to the bore, and at it's closest point is a few millimeters from the inside edge of the squish band. I rode almost a tank of gas with it (thought it was a bad o-ring) & the engine still ran OK. Compession was down 20 PSI in that cylinder.

Cylinder is at 86.0mm. Domes are stamped 36cc but read 170 PSI on the heavily ported cylinder.

 

[WaHoo_1]

I have a second hand Wamilton's Big Bore w/custom machined domes in a Greater head, one of which has developed a crack.:banghead: Can this be welded if it's gonna take a couple of weeks to get a new one?:sneaky:

FWIW, the crack is about an inch long, tangent to the bore, and at it's closest point is a few millimeters from the inside edge of the squish band. I rode almost a tank of gas with it (thought it was a bad o-ring) & the engine still ran OK. Compession was down 20 PSI in that cylinder.

Cylinder is at 86.0mm. Domes are stamped 36cc but read 170 PSI on the heavily ported cylinder.

is it really worth the risk? I'm not quite sure what the downside destruction would be if something went wrong as a result of the weld not holding..

 

[yamaslut]

why did it crack???
I would want to know that first

 

[Robert]

I had one crack from water ingestion. It cracked the dome and the head shell. Basically popped the dome when the piston tried to compress water. I would weld it if you can't get a new one by the weekend. Weld, grind and polish it and I bet you can't see a difference between that one and a new one after the first ride. Triple check you head shell for cracks.

 

[kid4now]

Those domes greater, protec, riva have a tendency to get hair line cracks in them. I have had a couple fail like that.

 

[SkiDaddy]

Who does welding of these here in Florida?

 

[RideItLikeYouStoleIt]

Doesnt sound like a great idea to me.

 

[SkiDaddy]

Short term only, while waiting for another to be custom machined.

 

[yamaslut]

Short term only, while waiting for another to be custom machined.

Daytona has about 750,000,000 welding shops

 

[GDFL]

Daytona has about 750,000,000 welding shops

Just tell them it's for a custom chopper of some sort and they'll be all over it.

 

[RoyalFlush@PCB]

Just tell them it's for a custom chopper of some sort and they'll be all over it.

:haha:

 

[Big Kahuna]

RIVA's crack also.

 

[kid4now]

Well I have protec which is the same as the greater domes and had them fail. Sometimes its real hard to see its such a small hair line crack. I still like my head though I just keep spare domes on hand just in case. RIVA is here say from me I have been told it happens to them also.

 

[SkiDaddy]

Well Greater has discontinued their domes, anybody have a 36cc of whatever bore size dome they wanna sell so I can have it machined to match my discontinued Wamiltons dome?:banghead::banghead::banghead:

 

[xjetrider]

What type of pistons are you running? Flat-top or domed? I have 36cc domes for a 81mm bore with stock domed pistons in stock. They are $49.00 each. Let me know if you need one.


John

 

[Robert]

I have greater yamaha 35 cc domes. Call me if they will work for you. They are for 701cc. Advanced Machining is right around the corner from me.

 

[Robert]

I still say weld it.

 

[SkiDaddy]

Well Pro-Tec has interchangeable domes in stock, & can sell me a pair (one as a backup) machined to match the 86mm bore for $120. I may go that route pending talking to Paul.

Het Robert, does anyone at Advanced Machining do aluminum welding? I've ~some~ work related business with them...:sneaky:

 

[BombThreat]

I think Paul has about a 2 week turn around right now. It took even longer to get my domes cut from him but that was mostly b/c of unexpected issues.

 

[SkiDaddy]

Parts from the west coast may not be much faster....