I want to restore my 1957 283 2X4 to its original glory. During the last engine overhaul 20 years ago, the camshaft, lifters and rockers were changed to a hydralic system for ease of maintenance. I would like to put the original hi-lift cam, solid lifters and adjustable rockers back in. Where is the best place to obtain these individual components?
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Re: C1 Engine Parts
Mike-----
First of all, I don't know why the engine would have had the rocker arms changed when the conversion to a hydraulic camshaft was done---the rockers for hydraulic lifters and mechanical lifters would have been the same at that time. As long as what you have are stamped steel, unguided rocker arms, then you have what you need. Unguided, stamped steel rocker arms are no longer available from GM so, if you need them, you'll have to go aftermarket. The absolute best, in this regard, are the Crane Nitro Carb rockers. These are quite expensive for a stamped steel rocker, but they're the best. Their configuration is very similar to the ones originally used on your car.
For a camshaft, you'll need to get a reproduction of the GM #3736097. This cam was discontinued by GM quite a few years ago. I believe that Federal Mogul manufactures a camshaft that is the same or close to the original specs. The part number may be CS-113R. The lifters used with this cam would be Federal-Mogul AT-992.In Appreciation of John Hinckley -
Re: C1 Engine Parts
Joe, thanks for the quick response. I am going to do some research tomorrow on the rockers that are in the car and hopefully get a picture posted. If you don't mind giving some addition help, I would appreciate it.
As for the camshaft, Corvette Central has a 'Duntov hi-lift cam' listed along with the solid lifters. What do you think? What about the pushrods? I am guessing they will work.Comment
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Re: C1 Engine Parts
Push rods should be the same. Ask Central who manufactures their cam.Comment
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Wayne, what kind of response am I looking for from CC? Is there one that is better or worse than the other?Comment
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Re: C1 Engine Parts
Mike - why not just get the parts Joe mentions from your local jobber? They will always be cheaper than going through specialty corvette suppliers....CraigComment
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Re: C1 Engine Parts
Joe,
I looked at the rockers and 14 out of 16 are the same (rocker on left in picture) and some have orange engine paint on them. They also have a small triangle synbol stamped on them. The last exhaust rocker on each side is different (rocker on right in picture). The two that are different definitly are a lot thicker metal. Are both of these stamped steel unguided rockers? What does 'unguided' mean? I do have a better close-up picture of the rockers if your interested. The push rods have a number 48015 on them. Thanks again for the help!
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Re: C1 Engine Parts
Hi,The 48015 is a the part number for a TRW SB Chev. push rod.(Thompson-Ramos-Woolridge) If my spelling is correct. DaleComment
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Re: C1 Engine Parts *NM*
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Re: C1 Engine Parts
Used these when I was young and crazy
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Re: C1 Engine Parts
Mike-----
The rockers with the "triangle" ID mark are likely the original rockers. GM rocker arms used for 1955-62 small block applications were of GM #3746241 and carried this ID mark.
The rocker arms used on small blocks from 1963 until very late 1969 were of GM #3843359. These rockers were somewhat similar to the earlier and carried an "O" ID mark. They also replaced the 3746241 for SERVICE of all 55-62 applications when that part was discontinued in May, 1964.
The rocker arms used for very late 1969 through the 1986 model year were GM #3974290. These rocker arms are also somewhat similar to the previous and carried a "V" ID mark. They replaced the 3843359 for SERVICE of all 55-69 applications when the 3843359 was discontinued in March, 1970.
The rocker arms used for the 1987+ small block applications were GM #10089648. These are the "guided" rocker arms. They have "ridges" on either side of the tip to align the rocker with the valve stem. The use of these rockers eliminates most of the need for guide plates (on those 70+ small blocks that originally had them or others which had them added at some point). The guided rockers do not work well with mechanical lifter engines due to the difficulty that they create for valve adjustments. However, with a very narrow feeler gauge, they can be used. The GM #10089648 rockers replaced the 3974290 when those were discontinued in August, 1989.
Both of the rocker styles represented among the complement currently present on your engine are the unguided, stamped steel variety. As I mentioned, the ones with the "triangle" ID mark are likely original (or, original GM replacements purchased before May, 1964). I don't know what the other 2 are. They may be the later GM replacements if they have one of the ID marks I mentioned (I can't see that from the photo) or they may be aftermarket replacements. If all of the rocker arms are serviceable (i.e. rocker balls, ball socket, and tips not galled, grooved, or worn), then you can use them for your conversion to original-style mechanical lifters. Otherwise, you'll need to replace some or all as I've previously described. You can no longer obtain unguided rockers from GM, so you'll have to go aftermarket.
Your pushrods are replacements. These are the "welded-ball" style pushrods and they were not originally used on your engine. I don't know what the number means, but I'm sure that it's the manufacturer's ID number. It's not a GM part number or ID number that I know of for push rods. However, the current GM replacement pushrods for your application are of the "welded-ball" type. These are GM #14095256. They will have a configuration just like the ones you have.
The original pushrods used on your engine did not use the "welded-ball" ends and were of GM #3837152 (yes folks, that IS the original part number for the pushrod originally used for all 1956-61 small blocks). Instead, they used rounded, pressed-in tips. You can obtain pushrods of this configuration in the aftermarket or you can use the GM SERVICE-only pushrod of GM #14044874 (a set of 16 of these is available under GM #12495491).
Keep in mind, though, that although they were not originally used on your engine, the "welded-ball" pushrods you have are 100% functional for your application. Although they are sometimes "maligned" by the misinformed, the "welded ball" end is a great design. "Welded-ball" end pushrods are what's called a "210 degree" design. They provide 210 degrees of rotation surface which can be a particular benefit in high lift cam designs. Also, the welded ball provides and absolutely round and hard surface.
The original design pushrods used for your application with the rounded ends are what's called a "180 degree" design pushrod. They have only 180 degrees of rotational surface. For most applications, this works just fine, though. The pressed-in ends for most fo these pushrods are not necessarily PERFECTLY round, though, and they may not be as hard as the "welded-ball" design.
The ONLY potential downside to the "welded ball" style pushrod is the possibility of the ball-to-tube weld breaking and the ball becoming detached. I've never seen this happen, though.In Appreciation of John HinckleyComment
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Re: C1 Engine Parts
Dale-----
It's Thompson, Ramo, and Wooldridge.In Appreciation of John HinckleyComment
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Re: C1 Engine Parts
Roy-----
GM never used this style of rocker arm alignment; it must have been aftermarket only.
GM's first answer to rocker arm alignment for engines with ball socket rocker arms was the use of guideplates, first used for 1965 Mark IV engines. For small blocks, the guideplates were first used for 1970 LT-1 applications.
In 1987 they abandoned the guide plates (although similar looking assembly-only guide plates were used for aluminum head applications) and went to a guided rocker arm. This design achieves virtually exactly what the kits you have posted did, but in a cheaper, lighter design. It took GM until 1987 to come up with this, though. It looks like the kits which you pictured, and which I was not previously aware of, had the same, basic idea figured out about 30 years earlier.In Appreciation of John HinckleyComment
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Re: C1 Engine Parts
Joe, you're information was awesome! Thanks for all the help. All my questions have been answered. I will use the rockers and pushrods that I have. I am going to price out the cam and lifters from a few different places. I plan on printing and saving the info for future reference. Thanks again!!Comment
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Dale, thanks for the help with the push rod number.Comment
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