The Ford Barn

stegomo · 11-06-2016, 11:17 PM

I know the piston pin is offset but there is no mark on the pistons to indicate which way to install. there is an oiling slot on the skirt, does it go up (intake side ) or down (exhaust side )?

Brian · 11-07-2016, 12:24 AM

Is there not a notch in one edge of each piston crown? That faces front

Mac VP · 11-07-2016, 06:23 AM

Not all piston mfrs make the flathead pistons with an offset on the wrist pin. If there is no marking, this generally means it can be installed either way. If it has the mark on the top of the piston, you place the marked side to the front. As always, check with your supplier for verification.

Kurt in NJ · 11-07-2016, 07:16 AM

From the blueprints I have seen the cylinders have the offset---something like 0.187, that piston markings have more to do with thrust--non thrust sides

chap52 · 11-07-2016, 07:23 AM

Like MAc said (post #3) some piston have a little dot dimple on top. This goes towards front of engine.

stegomo · 11-07-2016, 09:01 AM

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there is no mark on the piston tops,There is a vertical slot cut in one side of the skirt between the two oil rings should it go up or down?

Ol' Ron · 11-07-2016, 10:23 AM

Put the piston on a pencil , If it stays level it doesn't have an offset.

Karl Wolf · 11-07-2016, 11:28 AM

Quote:

Originally Posted by Ol' Ron

Put the piston on a pencil , If it stays level it doesn't have an offset.

Another method is to use two wrist pins to connect three pistons. Use a flat surface, pistons on their side, and roll the pistons separetely to look for an offset.

Karl

51 MERC-CT · 11-07-2016, 11:38 AM

As Ol'Ron says and it's simple.

rotorwrench · 11-07-2016, 02:01 PM

Here is a link about expansion slots. http://www.fordbarn.com/forum/showthread.php?t=106721

Ol' Ron · 11-07-2016, 06:32 PM

When it came to off set pistons, back in the 60 we would revers the offset in the Chrysler hemis, Olds and Pontiac engines. Probably the SBS too, but we usually used aftermarket hi conp pistons in them. (Cheaper) the Hemis liked the switch and put out more revs and torque. Stock engines use the offset to quite the engine. Reversing it adds torque.

11-06-2016, 11:17 PM	#1
stegomo Junior Member Join Date: Sep 2015 Location: Victoria BC Canada Posts: 24	8BA piston install I know the piston pin is offset but there is no mark on the pistons to indicate which way to install. there is an oiling slot on the skirt, does it go up (intake side ) or down (exhaust side )?

11-07-2016, 12:24 AM	#2
Brian Senior Member Join Date: May 2010 Location: Masterton, New Zealand Posts: 3,834	Re: 8BA piston install Is there not a notch in one edge of each piston crown? That faces front __________________ Unfortunately, two half wits don't make a whole wit!

11-07-2016, 07:16 AM	#4
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,159	Re: 8BA piston install From the blueprints I have seen the cylinders have the offset---something like 0.187, that piston markings have more to do with thrust--non thrust sides

11-07-2016, 07:23 AM	#5
chap52 Senior Member Join Date: Jun 2013 Location: Marana Arizona Posts: 1,776	Re: 8BA piston install Like MAc said (post #3) some piston have a little dot dimple on top. This goes towards front of engine.

11-07-2016, 09:01 AM	#6
stegomo Junior Member Join Date: Sep 2015 Location: Victoria BC Canada Posts: 24	Re: 8BA piston install Sponsored Links (Register now to hide all advertisements) there is no mark on the piston tops,There is a vertical slot cut in one side of the skirt between the two oil rings should it go up or down?

11-07-2016, 06:23 AM	#3
Mac VP Senior Member Join Date: May 2010 Location: Cincinnati, OH Posts: 1,361	Re: 8BA piston install Not all piston mfrs make the flathead pistons with an offset on the wrist pin. If there is no marking, this generally means it can be installed either way. If it has the mark on the top of the piston, you place the marked side to the front. As always, check with your supplier for verification. __________________ VANPELT SALES LLC Cincinnati, Ohio Office: 513-724-9486 www.vanpeltsales.com www.classictransmission.com

11-07-2016, 10:23 AM	#7
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8BA piston install Put the piston on a pencil , If it stays level it doesn't have an offset.

11-07-2016, 02:01 PM	#10
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,431	Re: 8BA piston install Here is a link about expansion slots. http://www.fordbarn.com/forum/showthread.php?t=106721

11-07-2016, 06:32 PM	#11
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8BA piston install When it came to off set pistons, back in the 60 we would revers the offset in the Chrysler hemis, Olds and Pontiac engines. Probably the SBS too, but we usually used aftermarket hi conp pistons in them. (Cheaper) the Hemis liked the switch and put out more revs and torque. Stock engines use the offset to quite the engine. Reversing it adds torque.