Improved Cam Shafts

[Roger W.]

Power & Performance News Magazine, Fall Edition, has an article about the new Nostalgia Plus Series of classic cams from Comp. The 3 Chevy cams that are reviewed are the 300 Horse 327, 350 Horse 327 and the 30-30 solid lifter cam. The new cams have the exhaust sound of the originals and the performance, with a few improvements. The 30-30 cam has more torque and more vacuum than the original.

The article can be read at www.PPNdigital.com . There is also an article comparing the performance of the 350 horse 327 and the 350 Horse 350.

[Duke W.]

Re: Improved Cam Shafts

I don't have time this morning to go through that entire web site looking for the specific article you talked about. Perhaps you could provide a specific link to it.

Based on discussions with users I don't consider the Comp Cams Nostalgia Plus series to be an improvement over the OE designs. They are definitely not the same and appear to have more aggressive dynamics, which requires stiffer valve springs that can reduce valve train durability/reliability.

The OE camshafts are very good and bulletproof in terms of valve train reliability, especially the later designs from the C2-3 era.

About ten years ago I designed two replacement camshafts for base engines. The second design that I named "McCagh Special" was the best of the two. This design REQUIRES massaged heads and uses OE lobes and valve springs, but the timing, particularly the inlet side is more like a modern Corvette engine. The exhaust timing is different because of the difference in E/I flow ratio of massaged vintage heads versus modern LS heads. The attached article gives all the design details, analysis and dyno test results.

For 327 and larger OE mechanical lifter engines I recommend the LT-1 camshaft and L-46 camshaft, advanced four degrees from as-manufactured for L-79s, and massaging the heads will provide noticeably improved top end performance and 500-1000 more useable revs. These cams are manufactured to OE spec by Federal Mogul, and that's the manufacturer I recommend.

For OE mechanical lifter 283s the Duntov cam is still pretty good, but I recommend it be ground with POMLs of 110 deg. ATC on the inlet side, and 118 deg. BBC on the exhaust side. This increases the LSA to 114 deg. and yields timing essentially the same as the L-79 cam or L-46 cam, advanced four degrees, albeit with less lift. Crane has Duntov lobe masters and can grind a "modified Duntov" to the above POMLs that I recommend.

Duke

[Joe C.]

Re: Improved Cam Shafts

Power & Performance News Magazine, Fall Edition, has an article about the new Nostalgia Plus Series of classic cams from Comp. The 3 Chevy cams that are reviewed are the 300 Horse 327, 350 Horse 327 and the 30-30 solid lifter cam. The new cams have the exhaust sound of the originals and the performance, with a few improvements. The 30-30 cam has more torque and more vacuum than the original.

The article can be read at www.PPNdigital.com . There is also an article comparing the performance of the 350 horse 327 and the 350 Horse 350.

These cams are not new. They've been around for awhile. I had the N+ 30-30S in my 327 some years ago. It has faster ramps than the original 30-30, sounds the same and develops NOTICEABLY more torque across the entire rev range. The downside is that you need stiffer valve springs with it. This means that there is more sliding friction and faster wear. I had to adjust my lifters more frequently when this was installed.

Bottom line: I would never install a flat tappet cam that required stiffer valve springs. I currently have a very BIG solid roller in this same engine (.610 valve lift) and I've not yet had to adjust the lifters after 4 years.

PS: Besides having faster ramps, the solid lifter Nostalgia Plus cams from Comp have smaller clearance ramps, and so specify less valve lash. This is a GOOD thing as far as PERFORMANCE is concerned.....but not so durability. Because of this, the NP cams' lifters are quieter than those of stock cams; this is easily detected by anyone who doesn't have a tin ear.

[Gene M.]

Re: Improved Cam Shafts

Power & Performance News Magazine, Fall Edition, has an article about the new Nostalgia Plus Series of classic cams from Comp. The 3 Chevy cams that are reviewed are the 300 Horse 327, 350 Horse 327 and the 30-30 solid lifter cam. The new cams have the exhaust sound of the originals and the performance, with a few improvements. The 30-30 cam has more torque and more vacuum than the original.

The article can be read at www.PPNdigital.com . There is also an article comparing the performance of the 350 horse 327 and the 350 Horse 350.

Roger,
I do not see an article on camshafts you refer to on web sit stated. There are plenty of Crane Cam advertisements. But as Joe stated these profiles are not new. I have seen them referred to in distance past.

[Roger W.]

Re: Improved Cam Shafts

http://issuu.com/xcelerationmedia/docs/ppn2016-3_issuu/109?e=3821562/38124058

Gene and Duke. This link should get you to the Cam Shaft article.


Roger

[Roger W.]

Re: Improved Cam Shafts

Joe,
I guess these cams are not such a great improvement over the OEM's.

Roger

[Dan P.]

Re: Improved Cam Shafts

Duke do recommend advancing the 098 cam 4 degress. I am not planning om have it reground.

[Duke W.]

Re: Improved Cam Shafts

If you choose to use an OE equivalent Duntov cam (I recommend Federal Mogul CS-113R) install it with the 25 dollar OE replacement, non adjustable truck roller chain, which will place the inlet POML at 108.5 deg. ATDC.

The only OE cam I recommend advancing is the L-46 when installed in a 283 or 327. Advancing four degrees brings the inlet POML back to 110 - same as the L-79 cam. As ground the L-46 cam inlet POML is 114 deg. ATDC, which is okay for longer stroke engines, but not a short stroke 283 or 327.

Duke

[Duke W.]

Re: Improved Cam Shafts

Joe,
I guess these cams are not such a great improvement over the OEM's.

Roger

It's really tough to beat the best vintage OE cams for broad torque bandwidth and bulletproof durability with OE valve springs. I was able to improve the 300 HP cam as long as the heads are properly massaged. I tried improving the SHP cams, but the only way I could get broader torque bandwidth was to reduce overlap... so much that idle behavior would smooth out to the point of being easily distinguishable from OE, which violated a basic ground rule of the exercise that was to maintain OE idle behavior.

The one exception was the Duntov cam. Reindexing the lobes causes a bit smoother idle - more like a L-79 cam than the Duntov, but setting the idle speed down about 650-700 will roughen it up enough to sound like a Duntov at about 800.

Duke

[Dan P.]

Re: Improved Cam Shafts

I am using a 327 crankshaft with 305 pistons so advancing the cam would help ??

[Duke W.]

Re: Improved Cam Shafts

Nope. In fact with a longer stroke you could consider retarding the cam, but an even better choice would be to install a LT-1 cam.

What heads/valve sizes/induction system will be installed?

Also, don't even THINK about using OE 283 rods. Buy a set of Eagle SIR5700 rods - about 250 bucks.

Duke

[Gene M.]

Re: Improved Cam Shafts

http://issuu.com/xcelerationmedia/do...21562/38124058

Gene and Duke. This link should get you to the Cam Shaft article.


Roger

Roger,
This site you posted is so small I can't read it. If I attempt to blow it up it is all a blur. It is some kind of pdf that is not easy to see. There appear to be some kind of graph of the L79 and their cam. Sorry can't help.