How to Measure Piston Deck Height?

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Nov 25, 2002 | 07:24 PM

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Thread Starter

Melting Slicks

Joined: Jun 2000

Posts: 3,215

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From: Tampa Florida

How to Measure Piston Deck Height?

Still trying to finalize my compression ratio on a late model LT4 OEM shortblock.

My final measurement is finding the piston deck height. I assume it is around .020 down in the hole, so to speak.

How can I measure this? Is this as easy as using a straight edge and feeler guage on clean piston and deck and top dead center?

I don't have many tools other than these...certainly no bridge and micrometer...:)

Thanks.

:)

Nov 25, 2002 | 07:59 PM

1MoorTym

Drifting

Joined: Aug 2000

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From: West Islip New York

Re: How to Measure Piston Deck Height? (No Go)

Quote:

How can I measure this? Is this as easy as using a straight edge and feeler guage on clean piston and deck and top dead center?

I think you've got it.

Nov 25, 2002 | 09:53 PM

SWCDuke

Race Director

Joined: May 2000

Posts: 12,712

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Re: How to Measure Piston Deck Height? (No Go)

A depth mike is nice, but a machinists bar and feeler gages are almost as good. You should rock the piston back and forth until you get the same measurement on both sides. Forged pistons at three to four thou can really make a difference - less with cast pistons at one thou, but rock them anyway until you're sure they're straight.

Duke

Nov 27, 2002 | 03:50 PM

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Thread Starter

Melting Slicks

Joined: Jun 2000

Posts: 3,215

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From: Tampa Florida

Re: How to Measure Piston Deck Height? (SWCDuke)

Thanks folks.

I will give it a shot.

:)

Nov 27, 2002 | 05:02 PM

belair55

Racer

Joined: Aug 2002

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From: Central IL

Re: How to Measure Piston Deck Height? (No Go)

A magnetic base dial indicater is the easiest and most accurate.

Dec 8, 2002 | 05:37 PM

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Thread Starter

Melting Slicks

Joined: Jun 2000

Posts: 3,215

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From: Tampa Florida

Re: How to Measure Piston Deck Height? (belair55)

Where would the best place to get a 'quality' tool?

Thanks again.

:)

Dec 8, 2002 | 06:41 PM

66427-450

Safety Car

Joined: Mar 2002

Posts: 3,780

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From: Southwest MI

Re: How to Measure Piston Deck Height? (belair55)

i agree with belair55, it also comes in handy to find TDC.

just borrow one from a local bud

Dec 9, 2002 | 10:06 PM

Jughead

Senior Member since 1492

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From: Just because I'm paranoid doesn't mean people aren't out to get me...

St. Jude Donor '09

Re: How to Measure Piston Deck Height? (No Go)

Quote:

Where would the best place to get a 'quality' tool?

Thanks again.

:)

I bought one from JC Whitney. I didn't want to spend a fortune for a tool I'd use only a handful of times. I think I paid $50 or so. So far I've used it to check crank shaft end play & rotor runout.