Cam ground for 383???
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From: Fort Bragg, NC
Cam ground for 383???
Hey guys my brother is going to be building a 383 stroker. I was told today by a guy I know that knows a TON about motors (kind of an old-school guy as far as engines goes) that when u build a 383 stroker that bc of the longer stroke the camshaft needs to be ground down so that the rod doesnt slap it as it comes down. Being that he is kind of old style tech I didnt know if this was true or not on the LT1, also I have never read anything about it so I was sceptical. Anyone have any input?? Thanks alot, Dustin.
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Re: Cam ground for 383???
I have a '96 WS6 with a 383. Altough I had the engine pro built I don't remember ever hearing about or them talking about such a thing. I find this very hard to believe. If the cam was ground down what kind of lift would you have. The lift is directly related to the centerline of the cam itself and the bearings. Also the when does the cam ever come anywere near the crank and the rods.
Wait. I just realized what i said. The lift is not relative to the center of the cam but only to the change in the lobe from highest to lowest. I still find this hard to believe.
Steve
Wait. I just realized what i said. The lift is not relative to the center of the cam but only to the change in the lobe from highest to lowest. I still find this hard to believe.
Steve
Last edited by redbird1; Feb 26, 2005 at 12:24 PM.
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From: smog zone adjacent to a great lake
Re: Cam ground for 383???
It depends on the type of rod used. 'H' beams with studs usually clear. Conventional rod with nut/bolt usually more of an issue. Needs checking, regardless of rod used. It is certainly NOT automatic, that it will interfere, or that is will not interfere.
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Re: Cam ground for 383???
Originally Posted by arnie
It depends on the type of rod used. 'H' beams with studs usually clear. Conventional rod with nut/bolt usually more of an issue. Needs checking, regardless of rod used. It is certainly NOT automatic, that it will interfere, or that is will not interfere.
Now I'm really confused, you sound like your talking about removing metal near the bottom of the cylinder wall's for clearence, In that case yes.
But, Chevy Tuff, forgive me if I'm being ignorent, but how would grinding the cam down have any thing to do with the length of connecting rods
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Re: Cam ground for 383???
Originally Posted by Eff
Now I'm really confused, you sound like your talking about removing metal near the bottom of the cylinder wall's for clearance, In that case yes.
The original theme was in regards to cam/rod clearance, or more precisely, a lack of it, between the rod (in the area of bolt head) and in actually, [a couple] of cam lobes. If you are familiar with the construction and pysical operation of the engine, you will understand how the cam can interfere with the rod, and where.
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Re: Cam ground for 383???
Originally Posted by arnie
It depends on the type of rod used. 'H' beams with studs usually clear. Conventional rod with nut/bolt usually more of an issue. Needs checking, regardless of rod used. It is certainly NOT automatic, that it will interfere, or that is will not interfere.
Yeah I've seen Eagle H beams and Scat I's clear without problem while some bigger I beams or stock style rods have a problem with clearance.
A smaller base circle is only needed on cams with a small lift at the lobe, the lobe lift will not change if you go to a small base circle.
Bret
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From: Fort Bragg, NC
Re: Cam ground for 383???
The cam in question here is an lt4 hotcam. Yes i know this cam is small for a 383 but we just want to put a smaller cam in first bc its easier to tune and we can make sure the engine is running the way it should be before we start putting big cams in it.
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From: LA (lower Alabama)
Re: Cam ground for 383???
Especially check #2-6-7 cyl and you want at least .050 between the cam and rod. I generally run a small base circle cam on ANY 383 regardless of the rod,just to keep from having to buy another cam if it hits or out of spect for the clearance.
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From: scottsdale, az
Re: Cam ground for 383???
if im interpreting this right and by rod you mean connectiong rod, then what he said doesnt make any sense. how could the rod come anywhere near the camshaft. the cam is between the banks, right in the middle of the block. 
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Re: Cam ground for 383???
Originally Posted by scott's94z
if im interpreting this right and by rod you mean connectiong rod, then what he said doesnt make any sense. how could the rod come anywhere near the camshaft. the cam is between the banks, right in the middle of the block.
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Re: Cam ground for 383???
Originally Posted by scott's94z
if im interpreting this right and by rod you mean connectiong rod, then what he said doesnt make any sense. how could the rod come anywhere near the camshaft. the cam is between the banks, right in the middle of the block.
Some engine assembly guidelines from World Products:
Other Clearances To Check:
1. Once the crankshaft has been fitted to the block, assemble one piston and rod with rod bearing and connect it to the crank (just snug the rod bolts and no rings are required at this time), rotate the assembly and check for interference with the block. If there is interference with the block or the rod is very close to the block, mark the area that needs to be clearanced, remove the assembly and grind the block. Clean the block and reinstall the assembly again to check. Continue this procedure until a minimum of .050 clearance is obtained. Once the clearancing of this cylinder is done, move on to the other cylinders and repeat the procedure.
2. Now that the block has been checked and relieved for proper clearance of the rotating assembly, install the camshaft and degree it in. Check for
connecting rod to camshaft interference. If clearance is needed, acquire a small base circle camshaft or grind the connecting rods to achieve a
minimum clearance of .050.
1. Once the crankshaft has been fitted to the block, assemble one piston and rod with rod bearing and connect it to the crank (just snug the rod bolts and no rings are required at this time), rotate the assembly and check for interference with the block. If there is interference with the block or the rod is very close to the block, mark the area that needs to be clearanced, remove the assembly and grind the block. Clean the block and reinstall the assembly again to check. Continue this procedure until a minimum of .050 clearance is obtained. Once the clearancing of this cylinder is done, move on to the other cylinders and repeat the procedure.
2. Now that the block has been checked and relieved for proper clearance of the rotating assembly, install the camshaft and degree it in. Check for
connecting rod to camshaft interference. If clearance is needed, acquire a small base circle camshaft or grind the connecting rods to achieve a
minimum clearance of .050.
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From: LA (lower Alabama)
Re: Cam ground for 383???
Originally Posted by Injuneer
You need to find one of those old clear plastic models of a Chevy SBC (I believe they were called the "Visible V8") to understand how the relationship of the connecting rod to the camshaft changes as the bottom end of the rod follows the crank throw, rotating on a 3.75" circle, while the upper end is limited to sliding with the piston in the bore.
Some engine assembly guidelines from World Products:
Some engine assembly guidelines from World Products:
He seems to not understand the relationship of the cam and crank when rotating in the block.
Some research is called for on his part,ie. the center line of the two bore and the available space vs the used space and why they make raised cam blocks.
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From: Fort Bragg, NC
Re: Cam ground for 383???
We've looked at the Eagle H beam rods and i think thats what we are going to go with. It says in the advertisment that they will clear cams up to 3.8 stroke and I beleive the 383 is 3.75 if I am correct? AS far as degreeing the cam in, i didnt think degreeing a cam in an lt1 was all that effective??