Identifying Jahns pistons for 400 E-block
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Joined: Mar 2016
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Identifying Jahns pistons for 400 E-block
Hey guys. I'm new to the Olds scene, but I've been a longtime fan. I just rescued a '66 442, nearly the same as the one my grandpa used to street race in the 60's.
It came with all of the original parts and some Jahns pistons.
They appear to forged (no hatching underneath), They have "Jahns" and "941" embossed inside the skirts. I can't find any info online about this piston specifically. I was hoping someone here could help. Thanks in advance.
It came with all of the original parts and some Jahns pistons.
They appear to forged (no hatching underneath), They have "Jahns" and "941" embossed inside the skirts. I can't find any info online about this piston specifically. I was hoping someone here could help. Thanks in advance.
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Joined: Aug 2011
Posts: 32
From: MILWAUKEE WISCONSIN
Jahns pistons
I remember this old Nostalgia In my buddies dads garage. he started running old flat heads like Mondello then late 60's corvettes. Something about being bought out by Grant pistons & rings. Maybe they can help.
same but different
Joined: Jun 2007
Posts: 2,957
From: Central Missouri
According to a Google search, you might have better luck contacting Ross Racing pistons or JE pistons.
The same search indicates former relationships to both companies.
If you can accurately measure the piston pin, this might point you into what engine family they were made for. Those pistons should have more numbers on the underside besides 941.
This stuff is old. However nostalgic, they are cool pieces of racing history. They are heavy and have large ring packs, compared to modern.
The same search indicates former relationships to both companies.
If you can accurately measure the piston pin, this might point you into what engine family they were made for. Those pistons should have more numbers on the underside besides 941.
This stuff is old. However nostalgic, they are cool pieces of racing history. They are heavy and have large ring packs, compared to modern.
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Joined: Oct 2010
Posts: 1,213
From: Dover, Ohio
i believe the 941 may have something to do with the aluminum alloy? I have a set of Jahns 12.5:1 pistons on the shelf that i removed from an engine so that i could drive it with something lower than 110 octane gas!!
as they said above -- its the "compression height" ( pin to top distance) that tells whether its usable in an Olds motor -- (This height is different from chevy).
A good machine shop should be able to get you an accurate measurement. Barring that, you could always put one on a rod and drop it into a motor and see what the deck height measures? Lots of work!!
as they said above -- its the "compression height" ( pin to top distance) that tells whether its usable in an Olds motor -- (This height is different from chevy).
A good machine shop should be able to get you an accurate measurement. Barring that, you could always put one on a rod and drop it into a motor and see what the deck height measures? Lots of work!!
Thread Starter
Registered User
Joined: Mar 2016
Posts: 3
According to a Google search, you might have better luck contacting Ross Racing pistons or JE pistons.
The same search indicates former relationships to both companies.
If you can accurately measure the piston pin, this might point you into what engine family they were made for. Those pistons should have more numbers on the underside besides 941.
This stuff is old. However nostalgic, they are cool pieces of racing history. They are heavy and have large ring packs, compared to modern.
The same search indicates former relationships to both companies.
If you can accurately measure the piston pin, this might point you into what engine family they were made for. Those pistons should have more numbers on the underside besides 941.
This stuff is old. However nostalgic, they are cool pieces of racing history. They are heavy and have large ring packs, compared to modern.
Thanks. I have used search engines and came up with quite a lot about the company's history and many other pistons they produced. I have Googled the piston's specs and everything else I know about them, all different ways. What I really need is someone who knows about these specifically or has an old Jahns catalog.
Last edited by hoggster; Mar 16, 2016 at 04:05 PM.
Thread Starter
Registered User
Joined: Mar 2016
Posts: 3
i believe the 941 may have something to do with the aluminum alloy? I have a set of Jahns 12.5:1 pistons on the shelf that i removed from an engine so that i could drive it with something lower than 110 octane gas!!
as they said above -- its the "compression height" ( pin to top distance) that tells whether its usable in an Olds motor -- (This height is different from chevy).
A good machine shop should be able to get you an accurate measurement. Barring that, you could always put one on a rod and drop it into a motor and see what the deck height measures? Lots of work!!
as they said above -- its the "compression height" ( pin to top distance) that tells whether its usable in an Olds motor -- (This height is different from chevy).
A good machine shop should be able to get you an accurate measurement. Barring that, you could always put one on a rod and drop it into a motor and see what the deck height measures? Lots of work!!
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