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Discussion Starter #1
I am in the market for a Dial Indicator to use for determining TDC and deck heights & maybe other things I can't think of right now. Easy for a DIY'r to use, can some one make a recommendation on brand or source that will fit the bill.
They seem to be 25 bucks and up and measure from 0-.25" and 0-1.0"
 

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I bought a cheap power fist model but it compares very well to a more expensive unit my brother bought many years ago..If you are going to be measuring camshaft lift buy one that measures up to an inch.I also tried the snake like holding fixture and had to return it since it wouldn't hold its shape enough to take repeatable measurements....One other thing to be aware of if you are using a dial indicator to find TDC and mark the crank balancer is that the crankshaft still rotates several degrees with the piston at TDC..This will give you an inaccurate measurement at the crankshaft damper..The best way is to use a piston stop.
 

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Last year I dropped my expensive dial indicator I had for probably 15 years :rolleyes: . Went to Harbor Freight and bought a $15 cheapy. Took it to work to check the calibration with a surface plate and gauge blocks. It was just as accurate as the $180 Brown & Sharpe I use at work.
 

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Get one with a magnetic base, and foot long slider with 3 axis movement joint.


Carefull when checking TDC. +/- 10 degrees of crank rotation while trying to find TDC will show very small amounts of movement at the piston. If the gauge is not on a solid moount, it will really mess you up.
 

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I agree with frdnut

Buy one, buy a good solid base, and use the heck out of it

But dont use it for TDC, Just use a piston stop. Only real way to measure TDC with a dial indicator is to use it like intake centerline method of degreeing a cam

Find the piston .500 down, then go the other way .500 down (or any numbered pair) and split the difference in degrees travelled.

It can be done, but a good solid piston stop is much more precise and faster
 

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Discussion Starter #6
Thanks for all the advice.
I will use a piston stop for tdc as suggested. Now what about measuring how deep the slug is in the hole? Do I need a bridge to get that done accurately?
 

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If you use it for tdc make sure you are pushing the piston up on both measurements. If you push the piston up for one and pull it down on the other, bearing clearance can mess with the results.
 

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Thanks for all the advice.
I will use a piston stop for tdc as suggested. Now what about measuring how deep the slug is in the hole? Do I need a bridge to get that done accurately?
If you are only building one motor, it is hard to justify too many tools. You can get close with a straight edge and feeler gauge. Just make sure you measure on the sides of the bore and not top and bottom. Piston rock will make those number wrong.
 

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Thanks for all the advice.
I will use a piston stop for tdc as suggested. Now what about measuring how deep the slug is in the hole? Do I need a bridge to get that done accurately?
I had trouble trying to do this with a dial indicator because you have to move it to get a reading on the deck surface and then on the piston top.Any time you move the base I wouldn't trust the readings..I used a straight edge and feeler gauges as well because I didn't have a bridge.
 

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Discussion Starter #10
Thankyou all so much for the help and advice.
I 'm in the start up phase of upgrading a 357 short block into a long block w/afr 205's.
Wanna order a custom cam and be able to provide accurate info.
And then install it correctly
 

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Discussion Starter #12
When setting up a dial indicator, should I push the plunger in a little, set it aginst the item being measured for travel then Zero out the dial, then measure movement / lift?
if so how far in the indicators travel should I push it in. My indicator has 1" of travel.
I don't have anything to measure the indicators accuracy, but know if I let it "free wheel" back to Zero it does not end back up on zero.
Does this sound right?
 

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ya, you sould get it set solid so its depressed at least a little, and set to 0, then take your measurement. Just make sure you still have enough travel when you push it in, and i think your fine.
 
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