Reproduction lobe thickness on 427 camshaft. Is this ok to use???

[Christopher A.]

NOTE: I do not have the gear set installed yet, so that might pull the camshaft forward a touch and align the lifters more evenly with the camshaft lobes. Obviously this appears to be much more off than a .05" thickness difference and i am wondering if the lobes were machined or cast in the incorrect place.

I bought this cam from Crane to replace the incorrect cam in my 66 427. I decided while the intake was off for gasket replacement to fix the choke and while i have the radiator and balancer off for replacement, i might as well put the factory spec camshaft in the engine. And yes, you can change the cam with the engine installed, but you must take the radiator support loose and shift it up and over so the cam can be pulled straight out.
Anyway, here are some pictures of the new cam installed. The lobes look way too narrow and i recently read in another thread, the one concerning the groove in the rear journal for the 66 blocks, that the cam lobe width on original cams is .0575, while some reproductions have a .52 lobe thickness. I still need to measure the ones on this cam.

Please look at these pictures and let me know what you think. Does anybody have a picture of an original cam with the lifters contacting the lobes. This cam lobes appear far too thin on this crane reproduction and therefore only half of the lifters are contacting the cam lobes. Before i go any further, i want to make sure that this will work and if not, find a correct replacement cam.

[Keith B.]

Re: Reproduction lobe thickness on 427 camshaft. Is this ok to use???

I have no answer for you but a question on what cam you bought from Crane. and I bought A Crane cam for my 66 396 Chevelle and had the grove cut and the machine shop told me that the rear journal was .900 narrow compared to a original GM cam.

[Clem Z.]

Re: Reproduction lobe thickness on 427 camshaft. Is this ok to use???

NOTE: I do not have the gear set installed yet, so that might pull the camshaft forward a touch and align the lifters more evenly with the camshaft lobes. Obviously this appears to be much more off than a .05" thickness difference and i am wondering if the lobes were machined or cast in the incorrect place.

I bought this cam from Crane to replace the incorrect cam in my 66 427. I decided while the intake was off for gasket replacement to fix the choke and while i have the radiator and balancer off for replacement, i might as well put the factory spec camshaft in the engine. And yes, you can change the cam with the engine installed, but you must take the radiator support loose and shift it up and over so the cam can be pulled straight out.
Anyway, here are some pictures of the new cam installed. The lobes look way too narrow and i recently read in another thread, the one concerning the groove in the rear journal for the 66 blocks, that the cam lobe width on original cams is .0575, while some reproductions have a .52 lobe thickness. I still need to measure the ones on this cam.

Please look at these pictures and let me know what you think. Does anybody have a picture of an original cam with the lifters contacting the lobes. This cam lobes appear far too thin on this crane reproduction and therefore only half of the lifters are contacting the cam lobes. Before i go any further, i want to make sure that this will work and if not, find a correct replacement cam.

the lobe has to be off center of the lifter center to cause the lifter to rotate. maybe this is why they are using narrower lobes to get better lifter rotation because if the lifter does not rotate it will wear the cam and or lifter. that is why i tell people when breaking in a cam make sure you can see the push rods rotating as this tell you that the lifter is rotating

[Christopher A.]

Re: Reproduction lobe thickness on 427 camshaft. Is this ok to use???

Thanks for the responses. I am not an engineer, so i never thought about the lobes needing to be off center. To me, it just seemed like the lifters were off the lobes by too much.
I just measured the lobes on the lunati cam that was installed and they measure .5 on the dot. I am going to measure the Crane cam shortly if i can get back out to the garage tonight.
The part number on this cam is 969391. It does not come with the groove cut in the rear journal, but crane will cut the groove in the cam for an additional 60.00, which i took them up on. Specs are 214/218 duration, .461/.480 lift on 115 lobe separation

[Glenn B.]

Re: Reproduction lobe thickness on 427 camshaft. Is this ok to use???

Chris,

Just for reference, I went and measured a new sealed power CS165R cam. This one just arrived from the Federal Mogul rep two months ago.

The heel of the lobes measures .570", the top of the toe measures .520", meaning the lobe width is tapered.

I also noticed a slight amount of core shift in the upper half versus lower half of the cam since it is a cast iron cam. I can post a pic if interested.

I would only observe the location of the lifter bore to cam lobe position when the cam is in the actual position you would find when the engine is running.

What I see in your pictures does not look concerning to me, especially if the cam moved forward a little (.020") with the timing gear installed.

Hope that helps.
Glenn

[Michael H.]

Re: Reproduction lobe thickness on 427 camshaft. Is this ok to use???

Christopher,

If you install the cam gear, that will pull the cam forward for better lifter alignment.

[Keith B.]

Re: Reproduction lobe thickness on 427 camshaft. Is this ok to use???

Christopher no cam manufacture sells one with a grove. I had a local machine shop cut one for me for $20.00. do you have L36?