Super Jet ADA head keeps blowing o-rings

Waternut

Customizing addict
Location
Macon, GA
Trying to figure out if the head is warped or whether my fuel requirements need to be upped. I'm running around 200psi on my speedwerx big bore motor. The sleeves are level with the top of the cylinder and the old Speedwerx head that I had worked good but even straight avgas was pushing the limits of what that head was putting out. So I'm running the ADA head with 93 octane gas now and I blow an o-ring about every week or two. The domes were brand new when I got them but the shell was used. Any ideas what the problem could be?
 

waterfreak

I had a vision!
Site Supporter
Vendor Account
Location
s florida
it's most likely your head shell. I had the same problem and it turned out that the dome started spinning and machined itself a bit into the head dome thus creating enough clearance to blow the o-ring after every ride
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
I'd run a mix of avgas/92 on 200psi.
In fact, I have exactly 200psi on my big bore, and I run 3:2 100LL:92
That said, I doubt your o-rings would suffer because of it. I've broken plugs, but never o-rings.
 
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cookn

Kamikaze
Location
where you live
it's most likely your head shell. I had the same problem and it turned out that the dome started spinning and machined itself a bit into the head dome thus creating enough clearance to blow the o-ring after every ride

I also agree with this. The dome needs to have that interference fit to give you that crush to seal up the oring
 
Chucky @ XScream uses 1211 where the domes meet the head shell to slow down the wear caused by movement...he also torques the girdle studs to 38 ft/lbs....
 

Waternut

Customizing addict
Location
Macon, GA
Chucky @ XScream uses 1211 where the domes meet the head shell to slow down the wear caused by movement...he also torques the girdle studs to 38 ft/lbs....

I'll give the 1211 a go when I get my new o-rings. Holy crap on the girdle studs! I don't know if I'll go quite that far but maybe I'll try somewhere in the middle.
 
I have had the same problem, The Shell will squish over time and cause the o ring blowage... Before you spend loot on a new head, try putting thin shims in between the Dome and Shell. I have the smallest feeler gauge i could find cut up just to bring it out that little bit and have not blown a ring since.... knock on wood...
 

Waternut

Customizing addict
Location
Macon, GA
I was planning on doing the shim if I found some wear. I have some stainless steel tape. Whatever the issue, if I have to buy a new shell, it'll be the last time I touch ADA heads. I'd just buy new domes for my speedwerx head.
 

Waternut

Customizing addict
Location
Macon, GA
I added some 0.004" stainless shims today where the domes sit. We'll see in about a week if that made any difference at all. It worked for today but I didn't ride very long.
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
ada = crap good for 2 or 3 seasons then toss it. it will crack or ware out. shimming the dome COME ON!!

Humm....been using mine for 3 seasons now, about ~475 gallons of gas through it. No issues.
 

motoman96

Banned
Location
Lodi Cali
I've been running my ADA head for three seasons now and it was used when I got it. Originally it was on a 701 and now my bigbore stroker. I've never had an issue so far, I had that problem on an old westcoast head on a pos 550. Being an Ada dealer helps too.lol
 
Location
baldwin ny
Sorry if I haven't concluded to flushing my money down the toilet before giving it every possible fix....

pistons and a cylinder are much less money sorry i forgot that.
if you keep running a head that cant hold the dome in it :):):):)s the top of the cylinder up.
 
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