Cam for 55 56?

**Mark P.** · September 24, 2008, 10:26 AM

Re: Cam for 55 56?

Ed - try calling Bill at Performance Chevy in Phoenix Arizona.
(602) 254-9586.

I got a cam from him for my 1960 after calling around a lot (i.e. Summmit, Crane, etc) and not getting too warm of a feeling the others could get me the right cam.

Mark

**Duke W.** · September 24, 2008, 12:19 PM

Re: Cam for 55 56?

The issue with the '55 and '56 camshafts is that they need a "notch" in the rear journal. I think John Hinckley posted a photo of this feature in the last few months. Also, I believe all '55 SB cams were mechanical lifter.

From '57 to '87 all SB cams are basically interchangeable. It's just a matter of finding the correct lobe design and phasing.

The base cam used from '57 to '66 is not longer available as an off the shelf item, but I don't recommend it because it has too harsh dynamics. The '67-up base cam is the way to go for '57-'66 engines that used the base engine cam. It will yield the same idle quality and performance characterisitics. All other OE cams of this era are available as off the shelf catalog items from several vendors like Federal Mogul and Crane.

Ed - if you get no other leads, call Jerry Clay at Crane,(386) 252-1151 ext. 1-4208 He may have to talk to one of the old hands to understand the notch, but I suspect they can grind any of the OE cams you want and add the notch.

I also have a cam that may be of use to you. A friend who vintage races a '56 Corvette had what he thought was a '56 Duntov cam. He got it from a buddy who bought out a dealer's parts inventory about 20 years ago. It's in a tube labeled 3734077, which is the part number for the '56 Duntov cam, and it has the notch in the rear journal. The ID on the cam is 078, which is "correct", but it's hand stamped.

We had the cam checked on a Cam Doctor and the lobe data says '67-up base engine cam - 3896929.

The whole thing is very mysterious.

Bob sort of "gave" me the cam, but I have no use for it. If your interested let me know. I'll check with Bob and if he has no problem with me passing it on, I'll give it to you .

In the meantime if anyone can shed any light on this cam...

The front face has a blotch of green and blue paint. The rear face has a blotch of green and yellow paint and there is also green paint between the last and second to the last lobes.

Duke

**Edward M.** · September 24, 2008, 12:24 PM

Re: Cam for 55 56?

Thanks for the info Duke. I am not sure if I need a cam yet. I have to get the engine out and see what I have. I hurt my back and can't work on it right now.

I am not getting oil to the top of the engine. I suspect that the cam (and / or rear cam bearing) may be wrong.

I do have a question. If you run a 265 engine for about 2 hours total without getting oil to the top of the engine, what would your recommend replacing. Cam? Lifters? Rockers? Etc?

**Duke W.** · September 24, 2008, 12:44 PM

Re: Cam for 55 56?

If you run a '57-up cam without the notch in a '55-'56 block, there will be little oil to the valve train, but I think the cam bearings themselves are adequately oiled.

As far as whatever damage might be done, it will really require inspection of all the parts. Maybe some older hand like Clem Zahrobsky can offer better advice based on experience.

Duke

**Michael L.** · September 24, 2008, 02:03 PM

Re: Cam for 55 56?

Ed, I just went through this with my 265. The builder notched the cam, but the notch was too narrow to allow oil to both the bearing holes ( rear bearing) also, he "forgot" to put in the front journal plugs which really limited oiling... I ran mine for 20 minutes before quitting with no oil to the top. I did not have cam or other damage that I can tell. I just have over 200 miles on the motor.

The Tri 5 Chevy site has a lot of good info and pictures on 265 V8 cam and oiling.

Mike

**William C.** · September 24, 2008, 03:32 PM

Re: Cam for 55 56?

the '55 195 hp cam and the 56-225 hp cams are MECHANICAL lifter cams. Any good mechanical judge doing a PV on a 55-56 without the "sounds" of a mechanical lifter cam should fail it immediately for incorrect camshaft. The chevy part number for the cam was 3711354, and the casting number on the can was 355. It had the flat, but so dod other cams used in the passenger cars with hydraulic lifters, but as best I can tell, the Corvette solid lifter cam was the only one to use the 3711355 Casting number. I cannot state for certan what the part number was used on the '56 210hp engine.

**Duke W.** · September 24, 2008, 06:49 PM

Re: Cam for 55 56?

I have a photocopied published source (don't know what) list of old cams that Clem sent me. Here's what it says.

Part number...........Year.....Horsepower.............. ..............Lifter type

3704212................55........162.............. ..........................hyd
...........................56-62...170, 180
3711354................55-56...195, 210, 225..........................mech
3733431................57-62...283/220, 230, 245, 250, 275.......hyd
...........................62-66...327/250, 300
3334077 (Duntov)...55-56...240........................................me ch

The ...431 was replaced by the 3896929 in 1967, and the ...077 Duntov is the early version with the rear journal notch for 265 blocks.

If this data is correct it leads to a conclusion that all 55-56 Corvette engines used the same ...354 mechanical lifter camshaft.

For 1956 the advertised 265 Corvette engine CR increased to 9.25 from 8.00:1, which is probably the reason the 195 HP engine rating was increased to 210.

Duke

**Bernard M.** · September 24, 2008, 09:30 PM

Re: Cam for 55 56?

I had Clay Smith (claysmithcams.com) grind a solid lifter camshaft for my 265. He notched it as required and everything oils as it should. I had him use a pattern he suggested that closely matched the original camshaft design.
Bernie Myers

**Stuart F.** · September 25, 2008, 04:51 AM

Re: Cam for 55 56?

Duke;

Two comments on the data Clem sent to you:

1) I know from memory that the early 55 Chevy passenger car V8's had solid lifters. I recall this as my brother took delivery of a 162 hp 210 Del Ray coupe in July 1955 that was one of the first with hydraulic lifters and I was terribly disappointed. I had just got my license and couldn't wait to start driving his new V8 Chevy. Within a week I had installed dual exhaust so everyone would think he had a power pak, Ha!

2) There was a different cam in the 56 power pak engine. Again from memory, I put one of them in a 55 V8 which had the 162 hp engine along with a 4-barrel carb from the 56 engine and dual exhaust. It was a Bel Air w/ powerglide. The car improved in the 1/4 mile by about a half second and 3 mph. I have no p/no or specs on it, but it was understood at the time to be a "higher Lift" cam (50's speak; high lift vs. full race) than the 55.

Now either my memory has gone south when I moved to Florida or the data is perhaps incomplete.

Stu Fox

**Clem Z.** · September 25, 2008, 07:27 AM

Re: Cam for 55 56?

Originally posted by Stuart Fox (28060)

Duke;

Two comments on the data Clem sent to you:

1) I know from memory that the early 55 Chevy passenger car V8's had solid lifters. I recall this as my brother took delivery of a 162 hp 210 Del Ray coupe in July 1955 that was one of the first with hydraulic lifters and I was terribly disappointed. I had just got my license and couldn't wait to start driving his new V8 Chevy. Within a week I had installed dual exhaust so everyone would think he had a power pak, Ha!

2) There was a different cam in the 56 power pak engine. Again from memory, I put one of them in a 55 V8 which had the 162 hp engine along with a 4-barrel carb from the 56 engine and dual exhaust. It was a Bel Air w/ powerglide. The car improved in the 1/4 mile by about a half second and 3 mph. I have no p/no or specs on it, but it was understood at the time to be a "higher Lift" cam (50's speak; high lift vs. full race) than the 55.

Now either my memory has gone south when I moved to Florida or the data is perhaps incomplete.

Stu Fox

yes the very early ones were solid lifters engine as i had a new 55 power pac but they changed to hyd during the model run. i think this was done to limit the RPMs the engine would turn so guys like me would not be blowing up so many.

i did put a 195 HP (corvette) cam in mine and later added the 2 X 4 carb setup

**Duke W.** · September 25, 2008, 10:58 AM

Re: Cam for 55 56?

At one time it was my understanding that all '55 small blocks had mechanical lifters.

Okay, so now I understand from what Clem said that a hydraulic lifter cam replaced the mechanical lifter cam on the entry level passenger engine as a running change.

So is the '56 "Power Pack" cam a hydraulic lifter type and not on the above list?

Clem - do you recall the publication this list cam from. You sent me a photocopy several years ago, which I keep in my "cam file"?

Can someone list all the '55 and '56 passenger car engine configurations - HP and major differences like cam, CR, and carburetor type?

Duke

**Steven B.** · September 25, 2008, 11:51 AM

Re: Cam for 55 56?

I have friends who have used EGGE for pistons, etc. and I believe cams. EGGE has prints back to the early 1900's and cut parts to original specs.

**Clem Z.** · September 25, 2008, 12:45 PM

Re: Cam for 55 56?

Originally posted by Duke Williams (22045)

At one time it was my understanding that all '55 small blocks had mechanical lifters.

Okay, so now I understand from what Clem said that a hydraulic lifter cam replaced the mechanical lifter cam on the entry level passenger engine as a running change.

So is the '56 "Power Pack" cam a hydraulic lifter type and not on the above list?

Clem - do you recall the publication this list cam from. You sent me a photocopy several years ago, which I keep in my "cam file"?

Can someone list all the '55 and '56 passenger car engine configurations - HP and major differences like cam, CR, and carburetor type?

Duke

AMA specs supplied to drag racing assoc. goto http://nhra.com/tech_specs/engine/bl...ts/CHEV-56.rtf for specs,http://nhra.com/tech_specs/engine/bl...ts/CHEV-55.rtf