Mystery Pistons help ID

[dwire67]

here is what I know
4.040 bore
.984 wrist pin
1/16 1/16 3/16 rings
compression height around 1.50

I thought these where for stock stroke 360 3.58
but with that size C/H they seem they are for 4.00 stroke?

have no idea who made them only markings are F/T with a lighting bolt cast in underside
They sure have one big dome?
Any idea's?

Unless they are not Mopar , what else would have .984 pin size?

 

[cletus]

http://victorylibrary.com/mopar/deck-height.htm
^^^
I can't speak to the accuracy of this, but maybe it helps.
Wild *** guess - did they come from a stroker kit for a 340?
I have Speed Pro pistons with lightning bolts on them, maybe that helps narrow it down?

 

[dwire67]

I picked them up some where and was told they where 360 .030 over and they are really .040 over ...Speed pro ? could be

 

[dwire67]

Anybody else ??

 

[cosgig]

Isn't 4.04" a standard bore 340??

 

[JBurch]

Could be old NASCAR slugs.

 

[dwire67]

I thought they might be 340 pistons, but the C/H is wrong -340's 3.31 stroke and would have 1.80 or higher C/H

 

[70aarcuda]

1.50 from the Center of the pin to the flat part of the piston?

 

[dwire67]

1.50 from the Center of the pin to the flat part of the piston?

yes as best as can measure with the calipers I have

 

[Marcohotrod]

a standard bore 340 or a +.040" 360, with a 4" crank. nascar did not use a 4" crank. looks old school, could be ForgedTrue

 

[70aarcuda]

measure from top of pin hole to flat part of piston and add 1/2 the wrist pin diameter

 

[dwire67]

a standard bore 340 or a +.040" 360, with a 4" crank. nascar did not use a 4" crank. looks old school, could be ForgedTrue

I checked out some pictures of Forged true pistons and you hit it right on, from what I can tell they are Forged True , now I just have to get the right C/H

 

[dwire67]

measure from top of pin hole to flat part of piston and add 1/2 the wrist pin diameter

:cheers:

That worked!! 1.667
So it for 360 .040 over with stock stroke 3.58 and 6.123 rod