What pistons are these?
Chevy budget Olds powered
Joined: Jul 2011
Posts: 8,638
From: Elgin, Illinois
Deep low compression pistons from the looks of it. If you are trying to make ANY kind of power these wont work very well.
Edit: post was seen from my phone and it looked like it was posted in the sbo section. this might work in a bbo.
Edit: post was seen from my phone and it looked like it was posted in the sbo section. this might work in a bbo.
Last edited by coppercutlass; Oct 12, 2016 at 10:14 PM.
Registered User
Joined: Feb 2013
Posts: 15,394
From: Phoenix, AZ
The internet says those are Sealed Power replacement pistons for 68-70 455-4bbl engines. I couldn't locate info for the dish volume but all the 4bbl 455s of that era were high compression engines with at least 10.25:1 compression ratio.
Registered User
Joined: Jun 2009
Posts: 4,293
From: Palm Bay, FL
His piston would be the low compression version and has been replaced with a different part number from sealed power. You can look it up in their catalog online.
Registered User
Joined: Feb 2013
Posts: 15,394
From: Phoenix, AZ
I found a Hot Rod build article that shows an engine using those pistons coming in at 9.0:1 CR. Still can't find the dish volume spec.
http://www.hotrod.com/articles/ccrp-...-build-combos/
http://www.hotrod.com/articles/ccrp-...-build-combos/
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Registered User
Joined: Feb 2012
Posts: 5
Andrew the Sealed Power 2278P was superseded to the current piston numbering system in 4/99, the new number is L2323F, the 2278P number is for a standard bore application and fits a 455 Olds engine, the piston design is a dished top piston with -18.0cc dome volume and the compression height of 1.735", to figure out the compression ratio you will need to know the cc chamber size of your cylinder heads, the deck height of your block, if you are using stock crank & rods and the type of head gasket you are using.
On a stock deck height block with 72.0cc heads with stock crank & rods, with a stock Fel-Pro head gasket (8171PT-1), your compression should be 9.83:1.
On a stock deck height block with 72.0cc heads with stock crank & rods, with a stock Fel-Pro head gasket (8171PT-1), your compression should be 9.83:1.
I recently acquired a 455 olds motor and a TH400 for a 1965 Cutlass (which has a 330 in it). I am trying to build a good 455 street motor and build something a little better than stock. I have stock C heads that can be ported. I have these pistons. I also have 1.72 Rocker arms (These are just 455 parts that I had laying around).
So the follow up question is given that what I have (C heads, 1.72 rockers, the Above Pistons) does anyone have a recommendation on how to build the rest? What cam? Aftermarket Rods or use stock rods (I thought the rods were the week point of the engine and not the piston)? I know that someone recommended the oil restrictors for the engine for longevity.
Recommendations?
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delta881972
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Mar 4, 2010 05:14 AM
