how much compression
Thread Starter
Drifting
Joined: May 2005
Posts: 1,258
Likes: 38
From: springtown Texas
how much compression
how much compression would this engine have. std bore 350. .039 thick head gasket. stock 89 corvette 113 aluminum heads, and this is a pic of the pistons. there cast GM pistons and its at tdc in the pic.
Drifting
Joined: Jul 2002
Posts: 1,697
Likes: 3
From: Woodinville WA
Try plugging your numbers into one of the compression calculators...here is one: http://www.csgnetwork.com/compcalc.html
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Need to know how far down the piston is in the hole, and the volume of the dish/valve reliefs. Typically on a flat-top piston the reliefs are about 2.5cc/set, or 5cc for the "either way" piston in the pic...but there appears to be a slight dish as well.
The 10088113 heads have a chamber volume of 58cc
For the piston deck height, you need a depth micrometer. To measure the volume, the quick and dirty way is to use modeling clay to build to an even top...and then pull off and drop the clay pieces in a cc-graduated container with a known volume of water.
Not sure if this makes sense
I can walk you through it if you're interested.
As a GUESS, pistons are typically about .020 down in the hole, and I could GUESS that the piston volume is around -10cc if you're just looking for a VERY ROUGH ESTIMATE.
The 10088113 heads have a chamber volume of 58cc
For the piston deck height, you need a depth micrometer. To measure the volume, the quick and dirty way is to use modeling clay to build to an even top...and then pull off and drop the clay pieces in a cc-graduated container with a known volume of water.
Not sure if this makes sense
I can walk you through it if you're interested.As a GUESS, pistons are typically about .020 down in the hole, and I could GUESS that the piston volume is around -10cc if you're just looking for a VERY ROUGH ESTIMATE.
Thread Starter
Drifting
Joined: May 2005
Posts: 1,258
Likes: 38
From: springtown Texas
thanks for the help guys, i found some pistons at summit that look identical and they say piston vol is 18cc so i used that in the comp calc website you listd and got 9.17 i mesured deck height and got .017
the machine shop is going to surface the heads so it may go up a little.
but i got a good enough idea of where i'm at.
thanks again!!!
the machine shop is going to surface the heads so it may go up a little.
but i got a good enough idea of where i'm at.
thanks again!!!
