1956 camshaft

[Sheldon S.]

I have an early 56 with the 2 x 4 barely setup and I have read lots of old archives trying to figure out what replacement camshaft would be suitable. Is the 097 duntov cam a good replacement. If not any suggestions on what to use and where to get one. I realize I may have to do some machining on the rear journal for the oil supply issue.
Thanks
sheldon

[Joe L.]

Re: 1956 camshaft

I have an early 56 with the 2 x 4 barely setup and I have read lots of old archives trying to figure out what replacement camshaft would be suitable. Is the 097 duntov cam a good replacement. If not any suggestions on what to use and where to get one. I realize I may have to do some machining on the rear journal for the oil supply issue.
Thanks
sheldon

sheldon------


I think a reproduction of the original camshaft for 1956 is available from the early Chevrolet engine parts specialists, The original part number was GM #3734077.

[Duke W.]

Re: 1956 camshaft

Your engine would not have been factory equipped with a Duntov cam. If ordered when available later in the year I believe they were delivered in the trunk for dealer installation.

I believe the original cam was a mild hydraulic lifter type - similar to the '57 base cam, which evolved into what we usually call the 300 HP cam beginning in '67. Something like this will yield a smoother idle, more low end torque, and better fuel economy, so it might be a better choice depending on your objectives and driving style.

Duke

[Gary C.]

Re: 1956 camshaft

Duke,

All 1956's were mechanical lifters, no hydraulic cams in 1956. Hydraulic cams started in 1957.

Gary
....

[John H.]

Re: 1956 camshaft

Duke,

All 1956's were mechanical lifters, no hydraulic cams in 1956. Hydraulic cams started in 1957.

Gary
....

Yup. '56 standard 2x4 solid-lifter camshaft was P/N 3711354, casting #3711355.

[Duke W.]

Re: 1956 camshaft

Okay. I thought the first hydraulic lifter cam was '56. In any event, I expect the OE cam was fairly mild compared to the Duntov. Manifold vacuum at idle speed will tell the story if anyone has a '56 with the original cam.

Clem Z sent me a list of old camshaft specs years ago, but it's not in the file it's supposed to be in.

Duke

[Gary C.]

Re: 1956 camshaft

Duke, had this info in my file on the 56 solid lifter camshaft. Not sure of its accuracy. Several years ago knew someone who was looking for a '56 cam and couldn't find an exact reproduction. Gary....

Intake lift .404, Exhaust lift .413, Intake Duration 264, Exhaust Duration 266 w/ Rocker Ratio 1.50, Part #3711354 Casting # 3711355

[Joe L.]

Re: 1956 camshaft

Duke, had this info in my file on the 56 solid lifter camshaft. Not sure of its accuracy. Several years ago knew someone who was looking for a '56 cam and couldn't find an exact reproduction. Gary....

Intake lift .404, Exhaust lift .413, Intake Duration 264, Exhaust Duration 266 w/ Rocker Ratio 1.50, Part #3711354 Casting # 3711355

Gary------


It depends if it's a 225 HP or a 240 HP. I was assuming it was a 240 HP. However, now that I think about it, I'm not sure that any 240 hp were actually built. This engine used camshaft GM #3734077. If a 225 HP, then cam GM #3711354 was used.

[Duke W.]

Re: 1956 camshaft

Duke, had this info in my file on the 56 solid lifter camshaft. Not sure of its accuracy. Several years ago knew someone who was looking for a '56 cam and couldn't find an exact reproduction. Gary....

Intake lift .404, Exhaust lift .413, Intake Duration 264, Exhaust Duration 266 w/ Rocker Ratio 1.50, Part #3711354 Casting # 3711355

Those numbers sound familiar. GM never defined how they measured duration, but I think it's the lash point duration. In comparison, GM specified the Duntov duration as 287 degrees, so the base cam was considerably shorter. It's tough to duplicate the ...354 cam. I think there have been discussions over the years, but the OP will need to be more specific about what kind of engine characteristics he wants.

Joe - the 240 HP rating was with that first design Duntov cam that had the rear journal notch for lifter gallery oiling, but my understanding is that it was never installed at Flint. It was an RPO, but the cam arrived in the trunk for dealer installation.

Duke

[Joel M.]

Re: 1956 camshaft

I just spoke with John Neas who is on the road with the Copper SR1 headed to Amelia. He says that there were in the neighborhood of 110 240HP cars shipped from St Louis with the cam IN the engine.

[Sheldon S.]

Re: 1956 camshaft

Joe,
Do you have the names of a few of these places I could try? Not familar where to look.
Thanks
Sheldon

[Joe L.]

Re: 1956 camshaft

Those numbers sound familiar. GM never defined how they measured duration, but I think it's the lash point duration. In comparison, GM specified the Duntov duration as 287 degrees, so the base cam was considerably shorter. It's tough to duplicate the ...354 cam. I think there have been discussions over the years, but the OP will need to be more specific about what kind of engine characteristics he wants.

Joe - the 240 HP rating was with that first design Duntov cam that had the rear journal notch for lifter gallery oiling, but my understanding is that it was never installed at Flint. It was an RPO, but the cam arrived in the trunk for dealer installation.

Duke

Duke-----

The specs for the GM #3734077 camshaft were not the same as the 3736097.

[Joe L.]

Re: 1956 camshaft

Joe,
Do you have the names of a few of these places I could try? Not familar where to look.
Thanks
Sheldon

Sheldon------


Unfortunately, it's been so long I just don't remember the names of them. I recall there is one that specializes in early Chevrolet V-8 engine parts, although I don't know if they have this particular cam. There's always the custom route. Some of the major cam manufacturers will grind a cam to just about any specs you want.

[Duke W.]

Re: 1956 camshaft

Duke-----

The specs for the GM #3734077 camshaft were not the same as the 3736097.

I think any difference in specs is just a matter of how GM listed them. My understanding is that the ...097 cam lobes are the same as the ...077 lobes. The only difference is that the 097 does not have the notch in the rear journal for the early SB oiling system.

I have the engineering data for the ...097 lobes - lift in inches to five decimal places every cam degrees, so if you have specs for the ...077 we can compare.

Duke

[Steven B.]

Re: 1956 camshaft

Joe,
Do you have the names of a few of these places I could try? Not familar where to look.
Thanks
Sheldon

Sheldon, Egge Machine, www.egge.com, and Crane has done repro and custom grinds. Steve