Ohio Pistons
Thread Starter
|
Postmaster
Joined: Aug 2001
Posts: 4,270
Likes: 5
From: Delaware
Ohio Pistons
Eric,
There seems to be some discrepancy between that data sheet and other information that I have. It gives the CH as 1.64, but the deck clearance of 0.028. That doesn't add up to a 10.297 block. The Compression ratios are also wrong for a 10.297 deck. The rod length is also wrong, it should be 6.58.
There seems to be some discrepancy between that data sheet and other information that I have. It gives the CH as 1.64, but the deck clearance of 0.028. That doesn't add up to a 10.297 block. The Compression ratios are also wrong for a 10.297 deck. The rod length is also wrong, it should be 6.58.
Posting Guru
Joined: Jun 2002
Posts: 1,099
Likes: 0
Ohio Pistons
I know Tom Monroe's book as a lot of little errors. The compression ratio given by Ford is a bit off.
10.297
-2.0
-6.58
-1.64
----------
=.077 deck clearance
78cc head
4cc valve reliefs
.040" x
4.10" gasket
4.030" piston
4.0" stroke
----------------
= 8.8:1 compression
10.297
-2.0
-6.58
-1.64
----------
=.077 deck clearance
78cc head
4cc valve reliefs
.040" x
4.10" gasket
4.030" piston
4.0" stroke
----------------
= 8.8:1 compression
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
Ohio Pistons
Some of these figures will not add up to a new engine deck hgt. It is usually assumed that the block and heads have been milled .010 during the rebuild process. The compression hgt on replacement pistons is generally but not always .010 less than the OEM unit except in standard size pistons. This practice can also vary between manufacturers.
The 1.64 is the max material limit I have listed in my files:
ERTEL PISTONS 800-428-4591 Order Desk 1-800-443-1905
1282P CAST.030 OVER
TOP LAND= 4.000x.300
COMP DIST (1.637) 1.635-1.640
VALVE RELIEFS .150 DP x2 AT 2cc EACH
PIN= .975 DIA .060 OFFSET
RING LAND= 3.600 DIA
RING WIDTHS= 2EA .0805 1EA .1885 (2x5/64+3/16)
LISTED AS- FORD 400 PERFORMANCE PISTON
FOR TRUCK LP GAS APPS FOR 9.0:1 COMPRESSION.
PLATEAU/GROOVE SKIRT FINISH TO PROVIDE INCREASED OIL RETENTION ON SKIRT
ENHANCING THE HYDRODYNAMIC WEDGE OIL FILM.
BROACHED SLOTS IN PIN BORE AND AN OIL HOLE IMPROVE WRIST PIN OILING.
BETTER THAN OEM CAST PISTONS INTENDED FOR 350-450HP ENGINES
TURNING UP TO 7,000 RPM.
PISTONS HAVE CHAMFERED SKIRTS, WITH REINFORCEMENT.
Newer pistons and non Ertel pistons maybe do not have the plateau/groove surface finish??? My Ertel pistons have the P/G surface finish but Ohio pistons I have seen do not have this extra manufacturing step.
Remember to subtract the milling volume from the head cc's, 4.00 dia by .0xx deep is a good approximation on an open chamber. Closed chambers are more difficult.
The 1.64 is the max material limit I have listed in my files:
ERTEL PISTONS 800-428-4591 Order Desk 1-800-443-1905
1282P CAST.030 OVER
TOP LAND= 4.000x.300
COMP DIST (1.637) 1.635-1.640
VALVE RELIEFS .150 DP x2 AT 2cc EACH
PIN= .975 DIA .060 OFFSET
RING LAND= 3.600 DIA
RING WIDTHS= 2EA .0805 1EA .1885 (2x5/64+3/16)
LISTED AS- FORD 400 PERFORMANCE PISTON
FOR TRUCK LP GAS APPS FOR 9.0:1 COMPRESSION.
PLATEAU/GROOVE SKIRT FINISH TO PROVIDE INCREASED OIL RETENTION ON SKIRT
ENHANCING THE HYDRODYNAMIC WEDGE OIL FILM.
BROACHED SLOTS IN PIN BORE AND AN OIL HOLE IMPROVE WRIST PIN OILING.
BETTER THAN OEM CAST PISTONS INTENDED FOR 350-450HP ENGINES
TURNING UP TO 7,000 RPM.
PISTONS HAVE CHAMFERED SKIRTS, WITH REINFORCEMENT.
Newer pistons and non Ertel pistons maybe do not have the plateau/groove surface finish??? My Ertel pistons have the P/G surface finish but Ohio pistons I have seen do not have this extra manufacturing step.
Remember to subtract the milling volume from the head cc's, 4.00 dia by .0xx deep is a good approximation on an open chamber. Closed chambers are more difficult.
Thread
Thread Starter
Forum
Replies
Last Post
Monster-4
EcoBoost (all engine sizes)
7
Jun 4, 2012 11:36 PM
