Rod Clearance Issue
#1
Rod Clearance Issue
I have a problem. My 383 was being put together today and the builder ran into an issue with the rods hitting my camshaft. Rods are Eagle (part number SIR6000BBLW) and the camshaft is a Lingenfelter 211/219 (part number 74211). I thought the rods were clearanced from Eagle so that I would not have to run a small base circle camshaft.
Would it be best to take it to the machine shop and have them remove the rotating assembly to grind the rods and rebalance it? Or, should I just purchase a small base circle camshaft? I bought the camshaft from Lingenfelter about 4 months ago so I really don't think they would allow me to return it. What would be the safest way?
Would it be best to take it to the machine shop and have them remove the rotating assembly to grind the rods and rebalance it? Or, should I just purchase a small base circle camshaft? I bought the camshaft from Lingenfelter about 4 months ago so I really don't think they would allow me to return it. What would be the safest way?
#2
I would not have used those rods to begin with, I don't like eagle products and a Scat Pro-I beam would have been a better choice with no clearance issues.
At this point you can either clearance the rods and rebalance, or buy the Scat's and re-balance...or IMO you should buy a bigger cam on a small base circle - that cam is itty-bitty for a 383
At this point you can either clearance the rods and rebalance, or buy the Scat's and re-balance...or IMO you should buy a bigger cam on a small base circle - that cam is itty-bitty for a 383
#5
The SIR I-beams are not the strongest rods around, so even though the 211/219 is tiny for a 383 I would stay on the smaller range for the cams anyway. Too much power for the parts used will lead to an early rebuild...
It seems that the cheapest way to get it up and running would be to take the hit and sell off the LPE cam, and have a slightly more agressive small base circle cam ground for you.
Good luck.
It seems that the cheapest way to get it up and running would be to take the hit and sell off the LPE cam, and have a slightly more agressive small base circle cam ground for you.
Good luck.
#7
I would not have used those rods to begin with, I don't like eagle products and a Scat Pro-I beam would have been a better choice with no clearance issues.
At this point you can either clearance the rods and rebalance, or buy the Scat's and re-balance...or IMO you should buy a bigger cam on a small base circle - that cam is itty-bitty for a 383
At this point you can either clearance the rods and rebalance, or buy the Scat's and re-balance...or IMO you should buy a bigger cam on a small base circle - that cam is itty-bitty for a 383
Since you need a larger cam anyway, if you are confident in your rotating assembly then give Ron and Phil at Advanced Induction a call and get a custom grind billet small base circle cam for $400. www.advancedinduction.com. refered by Cook Peformance. It would be your best bet if you want to go the cheapest route. I have never had a problem using Eagle products.
Jake www.cpengines.com
Jake www.cpengines.com
So, the most economical way to handle this is to purchase another camshaft?
How expensive would it be to have the rods ground down and the assembly rebalanced?
Thanks for the responses gentlemen.
#10
I'm wondering if: even with a small base-circle camshaft that the rods might still hit the cam. It's possible don't you think?
The shape of those rods have so much big-end shoulder sticking up.
If it were my motor I'd just have the spot on the rod machined down and not do a rebalance.
Karl Ellwein
The shape of those rods have so much big-end shoulder sticking up.
If it were my motor I'd just have the spot on the rod machined down and not do a rebalance.
Karl Ellwein
#11
I'm wondering if: even with a small base-circle camshaft that the rods might still hit the cam. It's possible don't you think?
The shape of those rods have so much big-end shoulder sticking up.
If it were my motor I'd just have the spot on the rod machined down and not do a rebalance.
Karl Ellwein
The shape of those rods have so much big-end shoulder sticking up.
If it were my motor I'd just have the spot on the rod machined down and not do a rebalance.
Karl Ellwein
I know the camshaft is not desired by most but I was trying to copy ABA383's build. I figured it would make a excellent street car while maintaining great drivability.
#12
I'm wondering if: even with a small base-circle camshaft that the rods might still hit the cam. It's possible don't you think?
The shape of those rods have so much big-end shoulder sticking up.
If it were my motor I'd just have the spot on the rod machined down and not do a rebalance.
Karl Ellwein
The shape of those rods have so much big-end shoulder sticking up.
If it were my motor I'd just have the spot on the rod machined down and not do a rebalance.
Karl Ellwein
He should be able to get you exactly what you need without a problem.
Depending on who is assembling your shortblock, machining the rods may or may not be a cheaper route.
FWIW, I'm running 6" Eagle forged rods and a custom cam from Bret Bauer and did not have any issues.
I think the rods you are using have a little more material though, it will likely require a little more planning.
Last edited by user 647483; 10-22-2008 at 01:12 PM.
#14
#15
My Eagle Sir rods hit the cam the same as yours. My builder just ground them just enough for the cam to clear. No re-balance, no issues.
Run the cam you want. Only you know whats best for you.
Run the cam you want. Only you know whats best for you.