i started putting together my 383 stroker and my rods hit my cam.
i have forged pbr 5.7 inch i beams and a lt4 hotcam,the top of the rod bolts are hitting the cam. could i grind off enough for clearance?

 

Exactly how much interference is there? How much would you have to grind to clear?

 

maybe at most a quarter inch

 

Sounds like rather too much to get rid of by grinding the rod bolt. Look at the bolt, and imagine how much (little) would be left after you grind that much off of it.

Probably you should have used some other rods, perhaps some that were specifically designed to go into a long-stroke motor. In the meantime, you need a small base circle cam to have any hope of getting with you have to work. AFAIK GM doesn't produce that cam in a small base circle version so you'll have to get some other cam besides that one.

 

Grinding rods to clear a cam is a common way to build a 383. I had to grind some on my rods in my 383. It wasnt a whole bunch though, a 1/4 inch seems like alot. I actually only had 1 rod that was actually touching a cam lobe and it was only by a hair. I had to grind on 4 in total so they met the min cam to rod clearance, .050 is what you need as a min.

 

If you grind off too much, you'll pull the bolts through the top of the rods. Have you had this engine assy balanced? I'm running a 600 lift cam in my 383, 1.08 base circle cam. I had to cut them .050 to clear. Before I had the balance job done. You may be able to have your cam reground to a small base, and keep the same profile. I call comp or crane and talk to them about it.

 

try looking for a set of rods that use bolts instead of the bolt/nut arrangement, they offer a lot more clearance.

 

im short on funds. could i grind for clearance, ill be sure not to take off too much

 

When I built my 383 I used a Lingenfelter 74211 cam.
I tried using stock-type rods. The heads of the rod bolts didn't actually touch the cam but I couldn't get a feeler gauge in between.
You want .050" clearance minimum here.
I ground the bolt heads just enough to get my .050" and thought all was well.
When I torqued the rod bolts, one of the bolt heads became funnel shaped and started sinking into the rod. I never reached the proper torque; it actually started getting easier to turn.
Got another rod and the exact same thing happened.

Gave up and bought some Eagle H-beam rods. They clear the cam by a mile. You will however need floating wrist pin pistons to use the Eagle H-beams.

IMHO, grinding on rod bolts, especially on a stroker, is asking for trouble.

 

Well it just depends on the rod. You truely need to build the motor on a proven combo. Eagle sells 383 kits with thier I-Beam rods all day long. They come as complete kits assmbled by Eagle. They make you aware that proper clearancing and possible rod modification might be required. They run ARP Wavelock bolts though, not exactly stock. Anyway, I only had to perform minimal clearing to obtain .050 clearances all the way down the cam, a Comp XE cam with about .550 max lift, with the above mentioned parts. It was really no problem and the integrity of the ARP bolts was not deminished by the least.

You arent required to run H-Beam or expensive rods if you run a proven stock type rod that has worked in the past on numerous buildups and requires minimal mods.

 

I couldn't agree more. However finding a proven combo that's exactly what you want may be another matter.



This is true. They also sell H-beam kits that are guaranteed to clear cams with 3.80" throw cranks.



This is where I start getting uncomfortable.



I was using ARP wavelock bolts. They have one side machined flat where the clearance is needed. Still wasn't enough. There's not a lot of extra material in this area to be grinding away.
To make matters worse, it difficult to tell exactly where to grind since the interference is just abt impossible to see.


My LPE 74211 has a little more lift than that (w/1.6 rockers).
Besides, lift is not the only factor contributing to interferance.
LSA, cam degree offset and a few other factors come into play.



That's exactly what I was thinking, right up untill the torque wrench failed to click when torqueing my #1 rod bolt.



This is true. You're not "required" to do anything.
However, if you want to run a 3.75" stroker crank, in my block, with my cam, and my cam timing; the I beams won't work without grinding. The H-beams will, and the bottom end will be much stronger right where it needs to be.
Not only that, but installing the rod/piston/bearings, measuring the clearance, removing the rod/piston/bearings, grinding the rod/bolt, cleaning it all up, re-lubing the piston, reinstall it all, re-measure, remove, grind, etc ,etc, is a real PITA!!
Another thing to consider, if you bought a pre-balanced kit, then you're out another $175-$250 to get it all re-balanced once your done with the "mods". Plus your delayed another week or 2.

In all fairness, I could have run I-beams by picking a different cam, but I simply wasn't willing to do that. I had my heart (and wallet) already comitted to the LPE.