Don Terrill’s Speed-Talk

Has anyone had a camshaft to con rod issue on any of these builds ? I just put a 4.25 stroker crank into a 428 FE block. I did not check the cam to rod clearance and now I have one rod just touching the camshaft ever so slightly. I can feel it, but it does turn right past the touch spot-- ANUONE ?




JOE SHERMAN RACING

bigjoe1 wrote:Has anyone had a camshaft to con rod issue on any of these builds ? I just put a 4.25 stroker crank into a 428 FE block. I did not check the cam to rod clearance and now I have one rod just touching the camshaft ever so slightly. I can feel it, but it does turn right past the touch spot-- ANUONE ?




JOE SHERMAN RACING

I've built two 390' FE block/engines with a Scat 4.25" crank and Scat 6.700" H-beam rods. No clearance issues at all. What crank and rods are you using?

The problem maybe the cam/ cam timing. Where is the contact?

I did use I beam rods, not H beam, and the cam is a solid roller with 630 lift. I just never thought this could be a problem




JOE SHERMAN RACING

bigjoe1 wrote:I did use I beam rods, not H beam, and the cam is a solid roller with 630 lift. I just never thought this could be a problem




JOE SHERMAN RACING

At this point, not much choice than to pull the oil pan, rotate the engine a few turns and see where the contact is.

bigjoe1 wrote:Has anyone had a camshaft to con rod issue on any of these builds ? I just put a 4.25 stroker crank into a 428 FE block. I did not check the cam to rod clearance and now I have one rod just touching the camshaft ever so slightly. I can feel it, but it does turn right past the touch spot-- ANYONE ?

JOE SHERMAN RACING

I used an "I" beam rod with through bolts once and the bolt heads interfered with some cam lobes; the "I" beam rods with cap-screw type bolts having square surfaces at the bolt thread end will probably hit also. The "STROKER" type rods I have used, both "I" beam and "H" beam, cleared fine.

What is odd, ONLY ONE touches




JOE SHERMAN RACING

bigjoe1 wrote:What is odd, ONLY ONE touches




JOE SHERMAN RACING

Is it definitely touching the cam,? Or something else. If only one is 'just' touching the cam the others are probably 'very very' close !!

Ive built 4 in the past year One 427 and 3---390. all stroked. I have a 455 on stand now with I beam. I will look in the morning what it looks like but I do know it turns with no hits any place. All the others had H-beam.
reed

I built a 447 out of a 390 block a few years ago. Can't remember much about it and it just got a relatively tame hyd. flat tappet cam. No issues.
Brian

Sounds like oil pump or pump tube. Built a 445 a couple years ago, had to make room there.

It can get close with capscrew rods and a big cam.

Bigjoe doesn't use girly cams...lol. I'm sure it is close.

cgarb wrote:Bigjoe doesn't use girly cams...lol. I'm sure it is close.

I don't think that the "size" of the cam has a whole lot to do with the "size" of the lobe.. But what is interesting about that is how sometimes a change can cause it to hit when before it did not.

A couple of months ago I was rebuilding a 383 Chevy for a customer. This engine had been running for years with an old set of Carillo rods and a flat tappet cam. I changed it over to a hydraulic roller using a cam that was ground to full size and I had to do a little grinding on the rods. The flat tappet was also full size with a lobe height that was nearly identical so it had to be just barely clearing.

What's the min you can get away with ?

digger wrote:What's the min you can get away with ?

I usually shoot for about .050