1966 L36 Camshaft

[Michael J.]

I am looking for the best OE replacement camshaft for my engine. I want it to be as close to original factory spec as possible. Any ideas on a source and what part number the original was? Thanks.

[Duke W.]

Re: 1966 L36 Camshaft

Sealed Power (Federal Mogul) CS1093M. Manufactured to the GM print for the OE L-36/68 camshaft. It should have rear journal groove for the pre-'67 oiling system design. Be absolutely certain to use the proper "three-hole" rear cam bearing in pre-'67 blocks. It's also okay for '67-up blocks along with the proper single hole bearing for the later oil system design.

[Joe R.]

Re: 1966 L36 Camshaft

Duke,

Think I have one 3904359 camshaft in stock. Is this the one to replace all hydraulic camshafts from 67-72? We have discussed this before but it's been a while and my memory, well it doesn't work as well as long ago!

JR

[Duke W.]

Re: 1966 L36 Camshaft

Yes, that's the '67 to '72 OE L-36/68/LS5 camshaft. The only difference between it and the '66 version is that it lacks the rear journal groove, which wasn't required with the '67-up oiling system. If used in a '66 a rear journal groove must be machined.

[Michael J.]

Re: 1966 L36 Camshaft

Thanks Duke, do you know if Comp Cams makes an OE equivalent?

[Michael J.]

Re: 1966 L36 Camshaft

It would also help if I knew the part number for the original '66 L36 camshaft, for the grind info.

[Joe L.]

Re: 1966 L36 Camshaft

It would also help if I knew the part number for the original '66 L36 camshaft, for the grind info.

Michael------



GM #3883986.

[Michael J.]

Re: 1966 L36 Camshaft

Thanks Joe! That's a great help so I can get it right.

[Duke W.]

Re: 1966 L36 Camshaft

Thanks Duke, do you know if Comp Cams makes an OE equivalent?

...don't know, but I would not buy anything from Comp Cams unless they were the only source... quality is poor and there is a lot of anecdotal evidence of lobe failures. I'm also skeptical that some cams they say are OE replacement are actually ground to the GM drawing lobe specs. In the past they did not Parkerize their cams, though I've heard that it is now "optional at extra cost". Federal Mogul manufacturers OE replacement came for nearly all applications to the GM drawings, which includes Parkerizing that aids break-in. Bottom line: for any OE replacement cam I recommend Federal Mogul or Dana Corp. (Clevite brand) manufactured products, period!

[Joe L.]

Re: 1966 L36 Camshaft

Thanks Joe! That's a great help so I can get it right.

Michael------


By the way, as far as flat tappet cams go, the GM #3883986 (and 3904359) is probably the best street cam ever devised for a big block.

[Duke W.]

Re: 1966 L36 Camshaft

I concur. On Memorial Day I evaluated a '69 427/390, TH400, 3.08 axle Coupe. During a test drive after checking out the tune and advancing the retarded initial timing I asked the owner if he had ever punched the throttle from a dead stop. He said no, so I said give it a try. (We were on some wide open, low traffic roads behind LAX - my "test course"). It lit up the 275/60R15 tires like a top fuel dragster from the sixties - massive low end torque! Come my turn I just eased into the throttle to avoid wheelspin, and it pulled strong and linearly to the 5500 redline and wanted to keep pulling beyond. The cam is very close to the L-79 cam - 214/218/115 vs. 222/222/114 - that makes for a very flat torque curve on this long stroke engine with reasonably tame idle behavior - 14" @ 600 in Drive. The primary problem turned out to be that the TH400 would not downshift to second gear at WOT above about 35-40 MPH, which is the subject of a nearby thread. That drivetrain combination makes for a sweet ride, but it uses a lot of fuel.

[Michael J.]

Re: 1966 L36 Camshaft

Thanks for the input guys. I have never had an L36 before this one, but I have to say I really do enjoy driving it now, and want to rebuild it the correct way with the best original style parts I can get.