justman234
New member
Hey guys, I'm wondering if the forged pistons from classic inlines will fit the Australian motors, I'm wanting a set for my 221(xw motor)
forged pistons from classic inlines, Aussie block?
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justman234
New member
The ones for the 200 are the ones I need?
Yes. The factory dish for the 200 varied from 5.5 to 12 cc's, and anything from any good American supplier will be any thing from a pure "0 cc" flat top to a 12 cc dish. Any kind of cc in that range will work fine. The forged pistons have been around from other supliers, like TRW for example, for years, and are able to be dished by machining if your compression ratio becomes too high.
More variance can occur through the different head chamber cc's, head gasket types vary from 22 thou to 62 thou, with 45 thou common, and any small Ford six can cope with a 90 thou head skim, which can remove up to 16 cc or more from a stock 60 or 52 cc nominal chamber size.
In Australia in extreme long distance sedan racing conditions, we've tended to use High Silicon content cast ally pistons from Duralite, then Repco, and then Mahale via Aussie company ACL. If the piston has drilled oil holes rather than cut slots, they can handle well over 240 hp and rev past 7500 rpm in 3.3 liter six with a 3.25" stroke, like all the old triple carbed XU1 GTR Holden Torana's. Those were 215 to 235 hp sedan racing engines with 100% factory components expect for carburation alterantions. People use forged pistons because they have failed to study how good a cast alloy piston can be if its clearanced right.
TRW made regular 200 and 250 pistons in two cc sizes, but take up for forged six cylinder pistons has always been low, so if a supplier offers them, take the option. The stock 255 V8 and 2.3/2.5 and 200/250 US made replacements sometimes don't survive hard use, and there is a wrist pin offset change between inline 4 and I6 and V8 pistons, with the 2.3/2.5 four cylinder piston at 90 thou verses a stock I6's 60 thou offset. I' don't have any evidence to say that a cast alloy US 200/250 piston is any different to an Australian 200/250 or3.9/ 4.0 OHC one, but in turbo installations, CP forged pistons have become the preferred option. Our Aussie engines with x-flow heads have smaller combustion chambers of a nominal 53 cc or near to it, and after 1976, the cross flow pistons needed 15.5 and 22.9 and then 27.9 cc dished to drop the compression enough for regular gas. So Aussie stuff doesn't always suit US stuff
Support people who make good gear, and if you need a forged piston, and Classic In-lines supply it, get it through them.
More variance can occur through the different head chamber cc's, head gasket types vary from 22 thou to 62 thou, with 45 thou common, and any small Ford six can cope with a 90 thou head skim, which can remove up to 16 cc or more from a stock 60 or 52 cc nominal chamber size.
In Australia in extreme long distance sedan racing conditions, we've tended to use High Silicon content cast ally pistons from Duralite, then Repco, and then Mahale via Aussie company ACL. If the piston has drilled oil holes rather than cut slots, they can handle well over 240 hp and rev past 7500 rpm in 3.3 liter six with a 3.25" stroke, like all the old triple carbed XU1 GTR Holden Torana's. Those were 215 to 235 hp sedan racing engines with 100% factory components expect for carburation alterantions. People use forged pistons because they have failed to study how good a cast alloy piston can be if its clearanced right.
TRW made regular 200 and 250 pistons in two cc sizes, but take up for forged six cylinder pistons has always been low, so if a supplier offers them, take the option. The stock 255 V8 and 2.3/2.5 and 200/250 US made replacements sometimes don't survive hard use, and there is a wrist pin offset change between inline 4 and I6 and V8 pistons, with the 2.3/2.5 four cylinder piston at 90 thou verses a stock I6's 60 thou offset. I' don't have any evidence to say that a cast alloy US 200/250 piston is any different to an Australian 200/250 or3.9/ 4.0 OHC one, but in turbo installations, CP forged pistons have become the preferred option. Our Aussie engines with x-flow heads have smaller combustion chambers of a nominal 53 cc or near to it, and after 1976, the cross flow pistons needed 15.5 and 22.9 and then 27.9 cc dished to drop the compression enough for regular gas. So Aussie stuff doesn't always suit US stuff
Support people who make good gear, and if you need a forged piston, and Classic In-lines supply it, get it through them.
justman234
New member
Great post!
Cheers mate
Cheers mate
