I have a 351 Cleveland. It has 4V heads, that have been modified for
adjustable rockers. I'm running a Comp Cams solid roller cam. 623 lift
244 @.050 duration. I'm using Crower 1.73 roller rockers. I'm using Ferrara valves 2.200 intake 1.710 exhaust. I have about 120 miles on the engine. I noticed the car idled roughly when cold. The next day I went to adjust the valves, and found 2 broken guide plates. I'm using Comp Cams guide plates. Other than this the engine runs really strong. Everyone I talk to is saying, the guideplates need to be relieved, by grinding away some of the material. Is this true? A friend of mine gave me a Manley push rod length checker, for a big block Chevy. Is the rocker arm ratio close to the Clevelands (1.73). Any advise would be much appreciated.
Breaking Guide Plates
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bill jones
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-Had that guideplate problem on SBC's off and on years ago, and I found that the corners of the slots has sharp edges led to the outer edges of the guideplate breaking off.
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-And the guideplates are hard and full of a lot of carbon so the only way I found they can be repaired for a quicky emergency fix is by torch brazing, meaning I've tried to weld them with with a tig a and various rods and I even tried using a mig welder.
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-We used to hand prep (sand) the corners and smooth the edges where the guideplates get rubbed on by the pushrods---and a lot of SBC's we've had to lengthen the slot when we run higher ratio rockers because the pushrods would be bottoming out in the slot.
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-As far as I know the Ford rocker vs the BBC rockers are not the same in the distances from the trunnion out to either end.
-I bought a pair of Crower stainless BBC and a pair of SBF Cleveland rockers to use for a Studebaker project where I was changing from stock shaft mounts to the higher ratio and there was very obvious differences.
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-And the guideplates are hard and full of a lot of carbon so the only way I found they can be repaired for a quicky emergency fix is by torch brazing, meaning I've tried to weld them with with a tig a and various rods and I even tried using a mig welder.
--------------------------------------------------
-We used to hand prep (sand) the corners and smooth the edges where the guideplates get rubbed on by the pushrods---and a lot of SBC's we've had to lengthen the slot when we run higher ratio rockers because the pushrods would be bottoming out in the slot.
-------------------------------------
-As far as I know the Ford rocker vs the BBC rockers are not the same in the distances from the trunnion out to either end.
-I bought a pair of Crower stainless BBC and a pair of SBF Cleveland rockers to use for a Studebaker project where I was changing from stock shaft mounts to the higher ratio and there was very obvious differences.
Bill has made some very good suggestions. If you are breaking the outside ears on the plates.....I just wanted to remind you not to forget the simpler things such as piston to valve clearance, retainer to guide/seal clearance, coil bind problems and pushrod to cylinder head clearance (a real factor with larger diameter puchrods)
Also the pushrod checker probably wouldn't be accurate on the "C". Although the trunion to roller tip is advertised as the same, the stud to stem angle is different. There are differences between BBC and the SBF "C", enough to cause problems? Probably not, but still isn't right.
Also the pushrod checker probably wouldn't be accurate on the "C". Although the trunion to roller tip is advertised as the same, the stud to stem angle is different. There are differences between BBC and the SBF "C", enough to cause problems? Probably not, but still isn't right.
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