Thread: What Camshaft Do I Have?

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As a first timer on soon to be taking a stab at degreeing a cam, I'd like to test it out on a 355 hobby engine my Dad and I are working on the side, before I degree a race performance 383 when I get block back from machinest. Problem is we don't have the specs on the cam we are using and I feel I won't know if I'm degreeing a cam right without some specs to bump my readings/measurements up against. My Dad says it is a comp cam. The number stamped on the snout is "275 DEH." I googled that number and found some specs on Comp's website. Thing that puzzles me is it said the cam was for 396-454. This cam came out of a 327 running stock engine. Can someone shed some light on what specs I'd be looking at on this cam so I can compare against my degree wheel/dial indicator readings? Thanks

"275" is the Comp Cams Grind Number which can be applied to various blanks. If you go to Comp Cams website and search "SBC 275DEH" it comes up with a '58 to '98 small block with these specs - 12-209-2 - Dual Energy

Welcome to CHR!

In all likelihood you have a CS 275DEH-10. Here’s a link to complete specs:

12-209-2 - Dual Energy

I recommend against reuse - especially of a flat tappet cam with an aggressive profile.

Let us know a bit more about what you're building.

Best,
Glenn

Thank you DennyW, glennsexton, and rspears! The 12-209-2 seems to fit the profile. Glenn, to answer your question and give you a bit of history, might be long, here's what we're up to. A 1972 Chevelle was the first car I ever owned and it was purchased in 1994. I drove the car up until about 1998 and parked it. It had a 68' 327 stock motor that was rebuilt after we acquired the car. I only ran up about 10,000 miles on the motor. Fast forward to 2015. In this year I bought a 72' Camaro fully outfitted for drag racing only, with no motor. My dad and I pulled the 327 from the Chevelle and I sold the Chevelle this past December. The 327 block is to serve as the 383 race only stroker motor with all new parts, of which close to half I have. All the old parts that came of the block were placed on my shelf in the shop. Last week, we bought a 355 block that was honed with new cam bearings. As a side project while we wait on 327 block to come back from machinest, we're tinkering with the new 355 block and having fun just putting it together while we wait on 327 block. Its all sentimental as the first engine block I ever owned is going into the first drag car I've ever had and the parts that came off that block are going into this hobby 355 engine. That being said, this cam only has about 10,000 miles on it. My dad is an ex drag racer, hotrodder, engine builder, etc. and has taught me a great deal about chevy engines. He's probably forgotten more about engines than the average person knows about them, as the saying goes. I've also been fortunate to meet club members on this forum and other knowledgeable folks over the past year like Richard (aka Tech) and a California Racer, Chuck Norton. These two individuals have really taught and coached me a great deal on concepts that I'm new to like degreeing a cam, P to V clearance, etc. These were things I never really gave much thought on until I met them. That's a lot of words but that's a little about me and thank you for the specs! Now we've gotten some data to compare to

Thank for sharing your great story! You've got the makings of a real great project and there's a lot more than just the a cam being dialed in!

Keep us up to speed as the project develops. Sounds like your dad's a great guy and he sure has one fine son!

Glenn

Looks to me like you're pretty safe with the spec sheet posted, which Glenn also referenced. When you run the three numbers with Grind Number (Comp Cams term, not mine) 275 in that list above the first one (11-209-3) is an AMC 6 cylinder stick; the second one (12-209-2) is the SBC V8262-400 '58-'98; and the third (20-418-3) is a Chrysler V8 273-360 '64-'00.

Good luck on your practice run.

I'd like to practice and test for rocker geometry and pushrod length on this 355. Richard was nice enough to shoot me a You Tube link on these concepts and the video seems to be pretty straight forward. I don't have a cam card on the 275 DEH but 12-209-2 PDF is what I've been referencing for specs (such as when I degreed the cam a few weeks ago). The video speaks of needing to know my gross valve lift to make the proper calculations so I can make the proper amount of turns on the adjuster nut. Would anyone know the gross valve lift on this cam or would I need to call Comp? Thanks Bobby,

Originally Posted by glennsexton

I recommend against reuse - especially of a flat tappet cam with an aggressive profile.

I agree. Re-use a flat tappet cam only in the same motor it came out of with the tappets in all the same holes they came out of. Chances of finding two blocks with the same tappet bore angles are slim to none, even if you use new tappets on the old cam. Proceed at your own risk, but flat tappet cams just don't cost that much. Read here of all the ways you can frag a flat tappet cam......
http://www.crankshaftcoalition.com/w...ips_and_tricks

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I hear you Richard (and glennsexton) and if this was going in a vehicle I'd sure enough heed that helpful advice for sure. This motor is not going to see much run time at all, aside from so many minutes on our test stand (if that would be ok?), and then it will be pulled and stored away as the 383, once its built, will be placed there test/tune purposes. If way, way down the road I ever wanted to put 355 in a car, I'd upgrade to a new cam among a few other parts. I'm really just interested in tinkering with this motor for testing knowledge so I can gain more/new knowledge on things I've not done before.

Having something come apart is always a great way to stretch your personal knowledge. First statement is "Watch this!" followed by "Well I will never do that again!" Been there, done that. Good Luck.

Originally Posted by Scooting

Having something come apart is always a great way to stretch your personal knowledge. First statement is "Watch this!" followed by "Well I will never do that again!" Been there, done that. Good Luck.

Thought it was "Watch this!! Hold my beer!"

Well-actually---------A flat tappet cam that is properly broken in can be switched between engines and lifters as long as the lifters are also properly broken in and/or new quality units. The issue is initial and continuing lubrication . assuming that the lifters are free to spin in the tappet bores and oil to the top of engine hasn't been reduced and/or oil routing hasn't been compremised.
The act of reducing oil flow to the lifter galleys in engines like the sbc/bbc drasticly reduces flow to the top of the push rod which then runs down to lube top of lifter.
Another scene is that on lots of builds the know it alls(computer geeks) will install off shore rod/crank packages that have inadequate side clearance for oil flow thru the bearings and sling off to the lower cylinder walls and camshaft bottom. Thes new free shipping rods also no longer have the side squirter holes for spraying up into the lower block. And then also, everyone wants a oil pan that has windage trays, scoopers, etc---------many issues that kill off the oiling of the engines that has been around since they developed the spark plug.


Most dangerous words in aviation-------"Watch this"



Seems I've been hacked on my e mail address from someone in Vietnam---------don't open any e mail from me for a while til I get it cleared----Jerry

Originally Posted by jerry clayton

Well-actually---------A flat tappet cam that is properly broken in can be switched between engines and lifters as long as the lifters are also properly broken in and/or new quality units. The issue is initial and continuing lubrication . assuming that the lifters are free to spin in the tappet bores and oil to the top of engine hasn't been reduced and/or oil routing hasn't been compremised.

Good word, Jerry - I've reused a cam, lifters and push rods in the same engine and always made sure everything went back in it's original spot without issue. Never tried to put used cam in a different block, but your logic (as always) is sound and it makes sense if properly seasoned in another block.

A question - have you seen significant wear pattern(s) on the cam bearings that may impact placing a used cam in a different block with new bearings?

Love these kind of discussions thread and this ol' dog is always wanting to learn some new tricks!
Glenn

And I almost forgot - another dangerous phrase, "Here, lemme show you how it's done..."

egg cartons were made for lifters .......