The Stay At Home Dad 273 Build.

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Welcome,to the world of engine rebuilders.There is no"zero deck" piston.Not cost effective for parts manufacterers to make more than 1 or 2 part numbers.You could yank the heads,measure the deck heighth on all 8 bores,then order pistons.Then deck the block equally parallel,in reference to the crank center line .This will get you close,assuming all 8 rods are same size,end to end .
 
273 said:
In my Mopar Enigines book it state that 68-69 273 are 0.001" below deck if the deck height is 9.599" so basically zero decked, since there's a lot of misinformation out there who knows though.
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Egge's flat top 273 pistons have a compression height of 1.781" which I believe is pretty close to the factory flat top pistons. This puts the pistons .040" in the hole assuming everything else is stock. Another link I found puts the factory pistons at 1.768 compression height, which would be even further down.

You need compression height to be 1.822 to get zero deck with a standard 9.6 deck. I have yet to find any off the shelf 273 pistons with anything other than "stock" compression height.

P.S. Sorry to hijack your thread.
 
X2,makes cyl psi.Forty year old,blocks,rods,cranks do change.Make what you have work,this is a nice topend build.
 
Nicely done SeaBee. The car/engine are cool enough on their own, but the kiddo puts it over the top. "Is it fast?" "YEA!!" That's good stuff. Congrats on your build. That 273 sounds great.
 
Just looked it up in my book Mopar Engines 8th Edition 2 barrel flattops pistons
64-67 1.79" 68-69 1.82" but I've never measure myself,
 
273 said:
Just looked it up in my book Mopar Engines 8th Edition 2 barrel flattops pistons
64-67 1.79" 68-69 1.82" but I've never measure myself,
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Thanks for the info. Does that book give specs for Commando pistons?
 
273 said:
It says Commandos are also 1.79"
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Does it give the dome volume?

Abodybomber said:
No one has made that piston in 40 years,give it up.
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Egge does make a domed piston for the 273. They rate it for the same compression ratio as the factory domed pistons, 10.5:1. But, it has a lower compression height and they can't even tell me the dome volume of their own piston. Others on this site have built engines with the Egge pistons, only to discover that they didn't get the 10.5:1 they expected, more like mid 9's. I'd like to understand and know what I'm going to get before I spend the bucks.
 
65DartGTConv, Have you looked at www.Crower.com? . They're here in South SD and have a live chat feature on the site where someone from the shop will answer questions, those guys make high end custom parts for Mopar SB's and might no exactly where to get the pistons.

On a side note: I'm a novice at this, but wouldn't it be possible during tear down to measure the connecting rods and piston clearance, then order longer connecting rods and new rings for your old pistons or stockish new ones? Then adding a thin custom Comatic gasket with the proper bore size and shaving the deck to get the comp numbers?
 
One of the nicest 66's I've ever seen and the engine work looks top notch. I wish My 13 year old daughter knew as much about working on cars as your daughter.
 
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