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rod to cam clearance on 400sbc

2K views 8 replies 5 participants last post by  406chevelle 
#1 · (Edited)
Looking for more guidance on my 400 build.

I am attempting to check the rod to cam clearance, but I can not see or maneuver the feeler gage where it needs to be very well, is this just how it is or Im I missing something and being dumb about it.

What are the experiances that all of you have had with rod to cam clearancing????

400sbc
400 crank
scat 350 rods
comp cam XE274H

Thanks,

406chevelle
 
#2 ·
Can you post a picture Or explain a little clearer what you are asking?:confused:

Troy
 
#3 ·
pics

Hey troy,

Thank you for your interest,
These are not the best pictures, kinda difficult to even take a picture of where I need to check the clearance.

Sorry I do not explain very well, I need to check to make sure I have the proper clearance between the cam lobes and the big end of the piston rods.
 
#4 ·
Your pictures didn't post.

The cam lobes will not be anywhere close to the big end (crankshaft) of the connecting rods. And there sure isn't any way to adjust that.

I presume this is what you are asking.:confused:

Troy

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#6 ·
What the man is trying to do is make sure the cam lobes don't hit the upper outer edge of the rod bolt head. This sometimes happens on a long rod (5.7) 406. TAKE a common large paper clip and straighten it out, then turn the motor over till you get the rod closest to the cam then try to get the paper clip wire between the bolt head and the lobe. MOST of the time there is no problem but some do hit!! I usually grind the top of the rod bolt and rod at about a 60 degree angle. Grind away about .060, then remove any burrs and it doesn't seem to hurt the rod or the bolt. I have never had a failure from this clearance procedure.
 
#7 ·
Sorry about that troy, attaching the pics did not work, so I put them in my gallery but they do not tell a very good story.

I have checked the rod to block clearance and some are very close but OK.

My problem is that the piston side of the big end of the rods where the threads are (pic of rod) comes very close to the cam lobes, I can reach into motor and feel it but I can't see how close or get a feeler gage in there to check the clearance.

I was told that some times you must grind a little off the rod to get a .050 clearance so the rod does not hit the cam lobe, maybe I have been miss informed, but some of them sure feel real close.

The rotating Assembly turns without hitting, i just want to make sure it doesn't hit while turning 4000 rpm.

406chevelle
 
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