4.1 pistons for 4" bore??

I may have a solution to using a long rod after all. Two possibilities. A 300 buick v8 has the same rod bearing diameter and is longer, or a friend of mine that is into chevys is bringing over some bbc rods that may be able to be used. The diameter of the rod bearing is about the same. The diff is the legnth and they're avalable up to 6.5" so feasibly a pin height of 1.2" which will increase dwell time for the piston and increase durability.
 
Ateurv8, Just a reminder to please post the pics of the rods and if you can measure the thickness diffs if there are any. Thanks.
 
I don't know but this one is about rod legnth. And I now have a set of 6.5" carrillos on the way. Looks like I'm going to be buying custom pistons after all. Unless someone else comes up with another part # or idea.
 
Sorry to anyone who has been waiting for me to put some info on here about the 3.0 rods. I have worked late all week and I couldn't find my cord for my camera!
However, all excuses aside, I will try to put something on here tonight or tomorrow.
Jeff:biggrin:
 
Sorry for taking so long to post this!!!!!!:redface:

I measured a two dot N/A 3.8 rod and a 3.0 rod and took some photos. I can't seem to find any three dot turbo rods so maybe this is not such a useful comparo against the 3.8 rod.
Anyway this is what I have. The measurements are not exact, but fairly close considering casting flash and whatnot.

Rod 3.8 3.0


Length 6.0 5.18


side of beam .660 .494

Face of beam 1.04 .935

If anyone wants the photos of these I can send them to you because I guess they are all too big to put on here.:mad:

Jeff
 
Here are the photos of the two rods together and alone
 

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From what I can see one side is narrower but the other is quite a bit thicker. I think the width diff would be a plus for strength. Ateur, I think you might have gotten some of your measurments backwards though. The 3.0 should be the longer and it looks like it's wider, or maybe I need new glasses?
 
Nope, I was suprised too. I always thought the 3.0 rod would be longer as well. If you look real close you will see that the long rod is a two dot rod out of carbed 3.8:confused:
 
I MAY be mistaken, but I believe there were two versions of the 3.0. The later one was a short deck deal with the short rods. The taller deck, same as a fwd 3.8, had the 6.3x" rods and flat top pistons. Maybe...from my dealership days in the late '80's. GB
 
AH!!!!
That would make sense! these 3.0 rods are out of an 87 somerset T. Does anyone know what a 3.3 has? I have one of those too! But it is still in a running car so it might be harder to see them!:D
 
The 3.0 was made with 6.33 rods to comensate for the different stroke. The 3.3 uses a different rod all together.
 
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