301 Turbo big end rod width

F

FormulaGuy

New member
Joined
Jun 16, 2020
Messages
7
Reaction score
0
Points
1
Location
Canton, OH
Does anyone know the big end rod width on the 301 turbo? I am researching my build and am considering going to a 6.000" Chevy rod, but would like to know if it's the same width as that would add to machining costs and thus not make the switch worthwhile. I'm sure the original rods use a narrow bearing due to the rolled fillets on the crankshaft, but I don't know that for sure and you know what they say when you assume things, so maybe someone knows the answer to that question as well?
 
Thanks for the response, I've already talked to Joe at TTA Performance, and he is super nice and knowledgeable, but I don't want to bug the guy. He's running a business and I'm sure he would rather spend his time with paying customers. I was just hoping someone on here might have done a build recently or happen to know the big rod end dimensions.
 
Sorry, I wrote too soon without thinking about your response. I am looking for the width of the rod, not the diameter of the big end bore. I need to know how thick is the rod. 1.000"? 1.050"? .940"? Something else? Thanks for the response though, it really is greatly appreciated.
 
Try Butler or Wallace Racing. The average guy isn't going to know especially since the 301 is so different from 326 to 455.
 
I've tried Butler, but they didn't know anything on the 301, or at least the guy that I talked to didn't know much about that engine. I've never heard of Wallace Racing, so I'll give them a try. Thanks for the leads!
______________________________
 
You sure you wouldn't be better off dropping in a different Pontiac engine or you just like the challenge?
 
I could use a different engine, and I have to admit I find the prospect exciting of trying to pull 400+ hp and 500+ lbs. ft. of torque from an engine that is widely regarded as poorly designed and made half that amount from the factory and where there is literally no performance aftermarket parts for it. You are left with ingenuity, research, and whatever talent a person has to complete the project. No, the primary reason I'm still using the turbo 301 is because I believe it will kill the value of the car if I replace it with any other engine.

It's a fun car to drive and I had already rebuilt the engine once and made several modifications over the years, but most recently I had installed a much larger camshaft, although still small by performance standards, and the car would really go with the new camshaft. The problem is that if the tune is not absolutely perfect, it's a short trip to a blown head gasket, shattered piston, or broken rod with each upgrade. I had stepped up the tune incrementally on the engine and got to the point where I was running 20 lbs of boost on the stock pistons, rods, and crankshaft with water injection. Unfortunately, even though I did not hear a single ping coming from the engine, it blew the composite head gasket out when I was out one day :( So, I have decided to pull the engine and rebuild the whole thing, only this time I would upgrade the internals, with the exception of the crankshaft, on this build. Since no one makes rods for this engine, the closest rod I could find was a Chevy rod and all of the dimensions are equal, except for the rod length, which is 6.000" vs. 6.050" for the Pontiac, but I don't know the rod width of the 301. I will measure it when I pull the engine and see if it matches the Scat rods I found for it, but if it doesn't, then that sends me back to the drawing board and sets me back on time as I don't care to pay for the machining costs to make the rods fit.
 
Sorry on my post, they used armasteel rods in your 301 and they were lightened to cut down on rotating mass, can't find the thickness anywhere. I know the crank was different than any other Pontiac engine also ( 2 counterbalance weights only) On my 151 Pontiac race engine, I had mine shotpeened and used ARP rod bolts and never broke a rod , but bent one when a wrist pin froze after the car was sitting for a while ....( Same pistons and rods as a 301)


Doug in P.R. 😎
 
I think that I will probably be right at the limits, or maybe even a little beyond the limits, of the connecting rods. Since it only costs a couple of bucks more to go to a 4340 forged rod, or perhaps even less if I go with I-beams, but still 4340 forged, over having the rods reconditioned, it seems like a no brainer going to the forged rod. I can pick up a set of I-beam 4340 Scat rods for a Chevy engine for $287. It would cost more than that to have the rods reconditioned and I am getting a good margin of safety with the forged rods. I want to make this a smart build in every way possible.
______________________________
 
You must log in or register to reply here.

Share this page

Back
Top