blackedout96 Posted July 4, 2009 Report Share Posted July 4, 2009 (edited) Just bought this motor from a member on here and having BIG trouble.... First, the guy I bought it from was running 28mm gas carbs and CPI in-frames. The only changes I have made to the set-up are 34mm PJ alkys and Shearer in-frames. Here's the motor... 4mill standard rod Stock Cylinder Dune Port +5 timing 1dir reeds Boss Billet Intake Chariot Head Custom Cut 22cc Gas domes I had a terrible time getting this motor running in the first place due to a bad stator. Once I replaced the stator it fired right up but did sounded really weak when revved. Took it for a quick test ride and had virtually no power band. I figured it was just old plugs..... On Thursday I took it to the dunes for its first real test. With new plugs I fired it up and again it sounded weak and still no power. I started out toward the hills giving it just enough throttle to see if there was any power, there wasn't. I turned around to head for the truck and then coolant started blowing out of the overflow, giant white clouds from the exhaust, tranny fluid leaking from clutch cover and left side plug backed completely out. I got back to the truck and did the obvious thing, pulled off the cool head to check the orings. the inner rings that go on the bottom of the domes were completely shredded. I replaced the orings, got it fired back up and it did the same damn thing. Just pulled the head back off today and the orings are shredded again. I was told by Jeff at Fast that I should have no trouble at all running alky on the gas domes, so I know that can't be the problem. I do have some alky domes that I'm putting in now anyway, I have em so why not. What could I have done in the set-up that could cause this to keep happening? Please let me know what you all think.... Edited July 4, 2009 by blackedout96 Quote Link to comment Share on other sites More sharing options...
wesw Posted July 4, 2009 Report Share Posted July 4, 2009 sounds like air leak lean to tight of squish have to get down to the basics Quote Link to comment Share on other sites More sharing options...
FireHead Posted July 4, 2009 Report Share Posted July 4, 2009 If the o-ring are shredding on the domes, the cylinders may not be sitting on the same level with respect to each other. If there is variance there, then you will have a myriad of issues........ Quote Link to comment Share on other sites More sharing options...
blackedout96 Posted July 4, 2009 Author Report Share Posted July 4, 2009 If the o-ring are shredding on the domes, the cylinders may not be sitting on the same level with respect to each other. If there is variance there, then you will have a myriad of issues........ So your thinking a bad base gasket, warped head, uneven torque or something like that? Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 5, 2009 Report Share Posted July 5, 2009 22 cc domes shouldn't be too small, that's for sure. Need to check for an air leak and squish for starters. Quote Link to comment Share on other sites More sharing options...
Darthwall Posted July 5, 2009 Report Share Posted July 5, 2009 I had a simular problem like this in the past the cylinders had been decked down and one sat lower than the other they had just been machined and didnt think anything about the height being different well sortly after firing it up it sprayed coolant all over poped the head off and the dome rings where burnt to shit. I would measure the cylinders and see if they are the same could be warped? I dont know but that is my expieriance with the prob Quote Link to comment Share on other sites More sharing options...
FireHead Posted July 5, 2009 Report Share Posted July 5, 2009 So your thinking a bad base gasket, warped head, uneven torque or something like that? Yeah, or you could even have mismatched cylinders or a warped top case half. :geek: Quote Link to comment Share on other sites More sharing options...
PassionRE Posted July 8, 2009 Report Share Posted July 8, 2009 If your head is machined properly and domes are seating properly, you either have a compression ratio/octane discrepency,squish velocity design issue, squish offset design issue more than likely. If your engine is has an air leak problem, more than likely you are goiing to see seizure, detonation problems. Does the engine seem to be overheating besides the blown orings....Jim Quote Link to comment Share on other sites More sharing options...
blackedout96 Posted July 9, 2009 Author Report Share Posted July 9, 2009 If your head is machined properly and domes are seating properly, you either have a compression ratio/octane discrepency,squish velocity design issue, squish offset design issue more than likely. If your engine is has an air leak problem, more than likely you are goiing to see seizure, detonation problems. Does the engine seem to be overheating besides the blown orings....Jim Yes, I can hear the coolant boiling. One other thing that I thought was crazy... I have a BOSS billet one piece intake and the thing was ice cold. Motor was smokin hot and the intake was abnormally cold, like it had been in the fridge for hours....Is that from the alky? I don't think so but everyone keeps telling me that. Last thing, I just swapped out the gas domes for the alky's I bought and the squish is @ .037, is that safe or do I need to throw in a thicker base gasket, if so what thickness I have a .020 in there now. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 9, 2009 Report Share Posted July 9, 2009 Yes. Aluminum intakes will almost frost up from methanol. They will certainly get condensation on them. 100% normal. Throw a .011 or .012 base gasket under there. I like mid to high 40s for a stock cylinder. Quote Link to comment Share on other sites More sharing options...
Keyser Soze Posted July 9, 2009 Report Share Posted July 9, 2009 Ditch the cool head. Pick up a stock head for 15 bucks. Quote Link to comment Share on other sites More sharing options...
blackedout96 Posted July 9, 2009 Author Report Share Posted July 9, 2009 Is there anything electrical that could cause any of this? Quote Link to comment Share on other sites More sharing options...
PassionRE Posted July 9, 2009 Report Share Posted July 9, 2009 Yes, I can hear the coolant boiling. One other thing that I thought was crazy... I have a BOSS billet one piece intake and the thing was ice cold. Motor was smokin hot and the intake was abnormally cold, like it had been in the fridge for hours....Is that from the alky? I don't think so but everyone keeps telling me that. Last thing, I just swapped out the gas domes for the alky's I bought and the squish is @ .037, is that safe or do I need to throw in a thicker base gasket, if so what thickness I have a .020 in there now. Are you sure your not lean? Raising the cylinder will drop blowdown pressures and reduce effective displacement, on some porting styles this might not be detrimental to performance. Engines with targeted time/area and matching blowdown pressures for a specific rpm will lose performance and acceleration if the t/a bd pressures were correct for the expansion chamber and compression ratio to begin with. This is caused by the transfer efficiency range being moved to a point higher in the rpm range your expansion chamber/CR is not set for. Tune the engine so rich on methanol it wont even come on the pipe and then back up till it just cleans up and pulls cklean hard rpm. Most methanol engines actually run harder and faster running the AFR richer than the dyno says it needs.....Jim Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted July 10, 2009 Report Share Posted July 10, 2009 Ditch the cool head. Pick up a stock head for 15 bucks. Yea that will work sweet with a 4 mill. Quote Link to comment Share on other sites More sharing options...
FireHead Posted July 10, 2009 Report Share Posted July 10, 2009 Yea that will work sweet with a 4 mill. That's funny right there.... :yelrotflmao: Quote Link to comment Share on other sites More sharing options...
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