Still wont work :( - The 1947 - Present Chevrolet & GMC Truck Message Board Network

78' Silverado · 07-05-2004, 04:46 PM

Well we ptu hte new cam in and its still hitting

So I thoguh our rods have to be to long. But I want to use 6 inch. Without goig to a smaller cam. Were using a 383 Scat Crank from summit, 6 inch rods, with a small base circle cam and it still hits! I don kno wat to do now guys. I a out of options. I looked at hte desp. online about our crank. Syas to use with 5.7 rods but we used 6. Would that make a difference in it hitting the cam and if so....is there a way to still sue 6" rods with that cam? I'm telling ya man, if the cam would work....we would have this baby done and installed in the truck. Thx for hte help guys!

Tom · 07-05-2004, 05:03 PM

My 5.7" rods hit a standerd cam with that crank. What they means is that crank needs at least 5.7" rods to not have the rods hit the counterweights, using 6" is fine. What you need to do is either get clearenced rod bolts or else start grinding those down to clear then have the assembly re-balanced.

GMC1tondually4dr · 07-05-2004, 06:12 PM

You can grind the rods where they hit on just on only the rods that hit, you don't need to grind all the rods. You need about .060 clearance between the cam lobe and rod bolt head. Grind the long way on the rod and try to polish out most of the grinding scratches. Proper engine assembly sometimes is a long drawn out process, assemble and check, fit, clearance, etc, etc.

but in the long run it is worth the effort.

CCDually

78' Silverado · 07-06-2004, 04:13 PM

Thx Guys!!!!

07-05-2004, 04:46 PM	#1
78' Silverado \/ My Loves \/ Join Date: Mar 2003 Location: Midland,Texas Posts: 462	Still wont work :( Well we ptu hte new cam in and its still hitting So I thoguh our rods have to be to long. But I want to use 6 inch. Without goig to a smaller cam. Were using a 383 Scat Crank from summit, 6 inch rods, with a small base circle cam and it still hits! I don kno wat to do now guys. I a out of options. I looked at hte desp. online about our crank. Syas to use with 5.7 rods but we used 6. Would that make a difference in it hitting the cam and if so....is there a way to still sue 6" rods with that cam? I'm telling ya man, if the cam would work....we would have this baby done and installed in the truck. Thx for hte help guys! __________________ 78' Silverado - Blue - (In a Coma) 04' Silverado -Red- 383 Stroker in progress for the 78'!!!

07-05-2004, 05:03 PM	#2
Tom driving is in my blood Join Date: Dec 1999 Location: Mesa AZ Posts: 5,720	My 5.7" rods hit a standerd cam with that crank. What they means is that crank needs at least 5.7" rods to not have the rods hit the counterweights, using 6" is fine. What you need to do is either get clearenced rod bolts or else start grinding those down to clear then have the assembly re-balanced. __________________ -78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me.

07-06-2004, 04:13 PM	#4
78' Silverado \/ My Loves \/ Join Date: Mar 2003 Location: Midland,Texas Posts: 462	Thx Guys!!!! __________________ 78' Silverado - Blue - (In a Coma) 04' Silverado -Red- 383 Stroker in progress for the 78'!!!

07-05-2004, 06:12 PM	#3
GMC1tondually4dr Registered User Join Date: Jun 2004 Location: Rosemount, MN Posts: 341	You can grind the rods where they hit on just on only the rods that hit, you don't need to grind all the rods. You need about .060 clearance between the cam lobe and rod bolt head. Grind the long way on the rod and try to polish out most of the grinding scratches. Proper engine assembly sometimes is a long drawn out process, assemble and check, fit, clearance, etc, etc. but in the long run it is worth the effort. CCDually



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