Joined
·
1,203 Posts
I know this a common practice, but I'm seeing a problem and I wanting to get some oppinions. The stock 460 rods are 1.000" wide and my journal is 2.017" wide. This would theoretically make a side clearance of .017". The big block chevy rods I'm seeing are .990" width which would theroretically make for a side clearance of .037", more than double that of stock rods. Is this standard when converting to these rods. The machine shops I've talked to and most publications I read say .037" rod side clearance is an awful lot, but I can't see another way around it if I use a big block chevy rod. Any oppinions?
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
Author Reply
George Huff
(no login)
152.163.204.68 Side clearance
No score for this post February 2 2001, 7:38 PM
Good point! I also am building this combo, and my crank is offset ground to 4.125 stroke and has a width 2.020. I'll keep my rod bearing clearance tight to try to help this, only because it at STD. Chevy size and bearings are available to do it.
I have also been told, that when you take it to 4.150 it puts the oil holes too close to the edge of the bearing. I will be using a dual-entry "CJ" pump and CJ Pan. Watch out, all so called "CJ" pumps are not dual
entry! I also plan on a oil cooler for added capacity.
The other problem with increase of side clearance is at low r.p.m. oil pressure suffers. If you stay about 1000 or more it seems to be fine. I hope to here from others on this. Publications don't seem to mention it.
Thanks, George
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
Glen
(no login)
207.227.203.101 stroker cranks and bbc rods
No score for this post February 3 2001, 4:50 PM
I have run this combo for some time and have had no problems whatsoever. my stroke is 4.500 inches with a .990 width bbc 6.700" aftermarket rod. oil pressure is good with a dry sump but do not know about using a CJ pump. The clearance is .039 side clearance
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
Mike R.
(no login)
32.97.239.28 BBC rods
No score for this post February 6 2001, 11:50 AM
Thanks Glen, that's the type of experience I was looking for. Sounds like it works for you. If you're using a true BBC rod then I guess there's no way around having that extra side clearance. I have an article on a 500 Cadilac that has .050" rod side clearance, so I was thinking that it must be possible. I'm mostly concerned about it wearing the bearings out if the rods are able to move from side to side that much, but people have been building these setups for alot of years so it must work out okay.
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
Author Reply
George Huff
(no login)
152.163.204.68 Side clearance
No score for this post February 2 2001, 7:38 PM
Good point! I also am building this combo, and my crank is offset ground to 4.125 stroke and has a width 2.020. I'll keep my rod bearing clearance tight to try to help this, only because it at STD. Chevy size and bearings are available to do it.
I have also been told, that when you take it to 4.150 it puts the oil holes too close to the edge of the bearing. I will be using a dual-entry "CJ" pump and CJ Pan. Watch out, all so called "CJ" pumps are not dual
entry! I also plan on a oil cooler for added capacity.
The other problem with increase of side clearance is at low r.p.m. oil pressure suffers. If you stay about 1000 or more it seems to be fine. I hope to here from others on this. Publications don't seem to mention it.
Thanks, George
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
Glen
(no login)
207.227.203.101 stroker cranks and bbc rods
No score for this post February 3 2001, 4:50 PM
I have run this combo for some time and have had no problems whatsoever. my stroke is 4.500 inches with a .990 width bbc 6.700" aftermarket rod. oil pressure is good with a dry sump but do not know about using a CJ pump. The clearance is .039 side clearance
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
Mike R.
(no login)
32.97.239.28 BBC rods
No score for this post February 6 2001, 11:50 AM
Thanks Glen, that's the type of experience I was looking for. Sounds like it works for you. If you're using a true BBC rod then I guess there's no way around having that extra side clearance. I have an article on a 500 Cadilac that has .050" rod side clearance, so I was thinking that it must be possible. I'm mostly concerned about it wearing the bearings out if the rods are able to move from side to side that much, but people have been building these setups for alot of years so it must work out okay.
