alcoholbanshee

As said it is all trial and error............... What runs good on one engine will not run good on another. I know from my experience my stock stroke 69 bore Cheetah ran much better with big bore pipes. Now my 421 cub ran better with small bore pipes. The cub was ported by Trinity and the Cheetah was ported by Grand River. With all that said I know if Andy ported the cub it would have ran better with big bores........so in conclusion...Listen to your builder!!!!!!!!!

There are lots of guys around Michigan that use them.......They seem to hold up well!!!

I think custom domes are about the best option. But with that said the engine should be degreed to see if it is worth even spending time/ money on. It would be nice to know where the port timings are at, allthough most dont have the equipment to measure that....lol

Are you opening up the windows on the piston............I have seen a lot of times where people port match them and this happens. It weakens the piston greatly, not worth the smalll power gain IMO. Another cause would be the piston rocking in the bore because of the bore being too large. And last but not least, do you warm your engine up or just start it and give it hell? You should always warm the engine or it will cause this problem.

But if he is hitting the head with the piston with 1 base gasket....then 2 gaskets (assuming that they are indeed .012),the squish would still only be a maximum of .012. And we all know that is just a little bit tight....LOL!!! Not sure what the answer is here...............Now using the spacer plate with a stock base gasket you could not squish 2mm solder. 2mm = .078, so even if you took away the 1 base gasket you would still have greater than .066 squish. So in my opinion the base gasket is a dead end road. I guess my suggestion would be to get a measurement of the piston to deck at top dead center and pass that info on to a builder to have them cut a set of domes for his specific application. Another thing I would consider is degreeing this engine to see if it is worth wasting time on a set of cylinders that may or may not run like poo. There is obviously some issues with these cylinders.......LOL

If my memory serves me Durablue used to make them........hope that helps.......lol

Measure the stroke.........It will be either 54mm or 58mm depending on what crank you have. That is where you need to start. I am wondering if the builder set these cylinders up to run with no base gasket. What is the thickness of the base gasket you are using.

Could'nt you just remove the bottle to run in the other classes. Just cap the line off and run it. I dont know thats the way it has worked at all the tracks I have been to.

6mil cranks were fairly common several years ago. So it is very possible that is what he has. If you call crankworks or twister they will make you anything you can dream up. I have even heard of guys that get cranks built in half sizes to stay within class structures. EX. 10.5mil stroker.

How much fuel the engine is getting is what I mean. Was this on long pulls that the engine was detonating? Does the bike have a pingel valve? The engine has to be starving for fuel. The compression and timing are very conservative IMO. You may need big bowls on the carbs or delete one of the floats in each carb.

What are the dump tubes drilled to? The most common causes of detonation are fuel, compression, timing.

What was your timing at....what carbs/needles??????

The trails just north of Peacock are the Little O and Big O......They are some awesome trails!!!!!!!

I should have the snomo bike done soon enough to make some test passes on the ice....................just let me know when!!!!!!!!!!!! That reminds me.... I need to get out in the garage!!!!!!!!!!!!!!!!!!!!!

As said each piston should be matched to its own bore. It is very common to have one side be a few thou larger or smaller than the other. Any shop that bores without having the pistons to measure (before boring) is not worth going to. Assuming the one piston is only a few thousandths larger, I would run it. But you must be sure which piston goes in which bore. It will cause no ill effects whatsoever on your engine.

Check out this link.....................He builds some badass pipes and is a site sponser!!!!!! You will not be dissapointed. I have seen his 358 cub RZ at the drag strip and it is quite impressive!!! He has also built some RZ pipes for a few road racers. The site is http://www.twocycletech.com/ Make the phone call...you will love them!!!!!!!

Is your oven big enough to do say a 7' long rigid chassis?? Hook me up brother!!!

As said..........600.00 for cylinders and pistons is an awesome deal.....................................You have no idea what you are talking about dude, really!!!! It costs $1050 for cylinders and pistons new. So for 600, even if it needs plated ($250), the setup costs him $850,THAT IS A VERY GOOD DEAL!!!!!!!! Stop mucking up people threads!!! You have no idea what the stuff is or what it costs, so why are you here???? As stated, how would you feel if somebody did this to your thread??? I assure you that you will find out if you make it a pattern of messing with others for sale threads!!!!!

Off topic.....but that is the best signature ever John!!!!!!!!!!!!!!!!!

The few cubs I have put together, I always just put a dab of RTV on the threads and thread the plug in flush. Then let the RTV cure for a while and run it!!!!!!

http://www.bansheehq.com/forums/index.php?showtopic=99511 http://www.bansheehq.com/forums/index.php?showtopic=69622

And that tranny is in my 565cc engine now......with no failures. Although I do have a billet 2nd in there now!!!!!! As said cryo treating does work...and work well. I would think it is something anybody that is playing on asphault should look into.

I have ran many, many,many sets thru the years............they are a very nice pipe!!!!!!!!!!!!

Cant back out now................. We need a lady there to keep us in line.........LOL!!!!!!

Cool...will be good to meet some newbies!!! I got ya beat, I live 5 minutes from the track...................... You gonna run the bike???