Thread: how do you make piston stop??

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trying to find true tdc on stock 350(pretty much). i read you can use old sparkplug and 3/8 bolt threaded through it. how long should the bolt be to get true tdc(to stop piston on tdc). no one has one in town, except friend @ machine shop and he said didnt know if it would work because he uses it for dome pistons(homemade). it didnt work, bolt not long enough. what to do, what to do .!.!

it would have to be long enough to stop the piston to check this run to piston up till comp by using your thumb to plug the spark hole and here it pass now put a screw driver in the hole mark how much needs to go in to hit the piston now that is how long your stop needs to be make you stop screw in the hole take all plugs out hand crank by hand till it stops mark the damper turn the other way make a mark now the center of the two marks will be TDC
you may want to mark the timing tab or may have to make a pointer that will hit your first mark may not line up no were by your old timing tab

How do you make a piston stop? (ok ok I dont get em tossed in the air like this very often, so I gotta hit it out of the park.)** TURN OFF THE KEY!!! Sorry, couldn't resist.

Originally Posted by jimmyjeep

How do you make a piston stop? (ok ok I dont get em tossed in the air like this very often, so I gotta hit it out of the park.)** TURN OFF THE KEY!!! Sorry, couldn't resist.

If you didn't do it I was about to

must be a mich thing you guys are smart

Originally Posted by jimmyjeep

How do you make a piston stop? (ok ok I dont get em tossed in the air like this very often, so I gotta hit it out of the park.)** TURN OFF THE KEY!!! Sorry, couldn't resist.

just drop a valve that will stop many things

No need to get real fancy. I use a welding rod with the flux buffed off, and have rounded the tip over so it won't scratch anything. Get the piston close to the top, set the wire in through the plug hole. Slowly turn the engine over by hand with a Johnson bar, just watch the wire, it will show you when your at TDC. Of course, this isn't nearly as sexy as a threaded piston stop, but it doesn't cost like one either!

You can buy a piston stop for $10.00 or less, and you'll have a tool that will last a lifetimg.

Originally Posted by jimmyjeep

TURN OFF THE KEY!!! Sorry, couldn't resist.

I wear my nose a little bit crooked because I used to make wise comments like that.

Jim

I've made 'em in the past with an old spark plug, knocked out all the porcelain and threaded for 3/8 NC. Use a 4-5" piece of 3/8" allthread, available at any hardware store or NAPA.

In reality, I have to agree with Jack. Buy one from Summit and have it shipped to you. Here's a budget unit for $6.95
http://store.summitracing.com/partde...5&autoview=sku
Or you can get a really nice one with a hole drilled in it to let the air out as the piston comes to the top like this for $11.50
http://store.summitracing.com/partde...5&autoview=sku

Just a cautionwith the threaded ones, try not to hit the piston against it very hard as you can raise a burr on the piston which can cause a preignition. Just bump it, mark the damper and reverse it around and bump it again. Mark it. Split the distance in half and you have top dead center

Originally Posted by pat mccarthy

just drop a valve that will stop many things

Be careful Pat, last time I was a smart a$$ a few of them tried to attack me.

[quote=erik erikson]Be careful Pat, last time I was a smart a$$ a few of them tried to attack me.[/quo THEY WILL ASK ME TO LEAVE??? IF THEY CAN NOT TAKE THE ANSWER