Piston Stop problems

sy2207

sy2207

Donating Member
Well I threaded the piston stop in and turned the engine over with the starter. The engine seemed like it stopped once when it hit top dead center and now makes this banging sound every time I crank the starter? Its now not stopping at TDC. It sounds pretty loud. Did I break something or bend a rod??
























Yeah really funny huh?

Actually my problem is that the piston stop is threaded in only about a half an inch and seems to bottom out. Turning the engine over by HAND the piston is not touching? Is there some obstruction on the head this is stop is touching? The back side of the head? I am using this stop http://www.shopcranecams.com/cranecams/pisstoptopde.html I threaded the stop in by hand and I don't really want to force it. WTF?
 
jwaller

jwaller

Evil Genius/SyTy Guru
this is messed up. so you put the piston stop in. hit it while turning over the motor with your hand. then removed the piston stop and now you have a banging noise in the motor.? is that it?
 
sy2207

sy2207

Donating Member
No, the first part was a bad joke about turning the the engine over with the piston stop in by the starter :D I'm just a funny guy :roll:

I think that the problem is that the stop is the same diameter as the threads. Others I have seen are a little thinner in diameter http://store.summitracing.com/partdetail.asp?part=CCA-4795

I dont really know what it is hitting but like I said it only goes in about a half inch and then stops. Could this be the back side of the relief for the valve? I would love to have a borescope and look inside. Again, no I maybe a newbie to this board but not cars and trucks.
 
jwaller

jwaller

Evil Genius/SyTy Guru
could be that it's hitting the open valve or something. you are on the correct stroke?
 
sy2207

sy2207

Donating Member
I think I found the culpret: Trying the stop on an extra pair of heads it seems like the sparkplug isnt tapped all the way through. It goes in great for a half an inch and stops. I am going to Summit today to pick the two piece comp cams stop and see what happens.
 
Bill Z

Bill Z

Donating Member
Piston Stop problems

Wicked,

If you are on a budget, you can make a pretty good piston stop from an old spark plug (bust out all of the porcelain), a brass bolt and a couple of nuts. It is adjustable in length and cost les than the $12.00 plus tax that your's cost. If you need it to be vented, I suppose that there would be enough space between the inside of the spark plug case and the bolt to allow air to bleed by.

Just a thought.

Good luck on fixing your broken piston.
 
sy2207

sy2207

Donating Member
I DONT HAVE A BROKEN PISTON! ha! Man, you guys cant take a joke?? I found that the comp cams piston stop worked. The heads are not tapped completely through for the spark plug so the crane cams stop would not work. The Comp cams set up, worked but it was made out of steel instead of brass. I like the brass piece but I didn't want to tap the heads with them on. With Summit racing less than five miles away it didn't make sense to build my own piece, although I would probably be done sooner. Yeah after all this headache I found TDC was correct to the balancer. Again I don't have a ported piston! :)
 
You must log in or register to reply here.
Top