L-79 cam

[Terry L.]

Hi does anyone know anything about this cam or know what cam works well in a 1966 L-79, thanks for your help. http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

[Duke W.]

Re: L-79 cam

I don't think that cam is built to the GM print. It has more than OE overlap, which will hurt performace, especially at the bottom end, and it's from Comp Cams, which is a red flag.

If you want a REAL L-79 cam, built to the GM print, just go to NAPA and order a Speed Pro/Sealed Power CS179R.

It's as good a cam today as it was 45 years ago.

Duke

[Michael F.]

Re: L-79 cam

I don't think that cam is built to the GM print. It has more than OE overlap, which will hurt performace, especially at the bottom end, and it's from Comp Cams, which is a red flag.

If you want a REAL L-79 cam, built to the GM print, just go to NAPA and order a Speed Pro/Sealed Power CS179R.

It's as good a cam today as it was 45 years ago.

Duke

Other than being an aftermarket company. Why is Comp Cams a "red flag"?

[Duke W.]

Re: L-79 cam

Comp Cams camshafts, particularly the XE series have a high failure rate. Check any automotive forum where guys typically install hot rod cams.

I don't think they Parkerize camshafts like GM did, and Federal Mogul/Dana Corp./Crane do now, which is a considerable aid to ensuring that the cam will break-in properly and not wipe a lobe early in life.

Comp Cams spends too much money on advertising and not enough building a quality product, which is why I wouldn't tough their stuff with a ten-foot pole, notwithstanding the fact that some the their products like the one mentioned by the OP imply that they are exact OE replacements, but they're not. That's false advertising!

Duke

[Jim S.]

Re: L-79 cam

[quote=Terry Lewis (51548);513805]Hi does anyone know anything about this cam or know what cam works well in a 1966 L-79, thanks for your help.

Terry ,

The GM part number for that cam is 3863151. GM Parts Direct sells , or did a while ago, a kit of the cam and lifters for $135 . Their part number for the kit is 12364050. Using either of these #s should help you search and see if they, or anyone else, still have them

I hope that helps,

Jim

[Joe C.]

Re: L-79 cam

Hi does anyone know anything about this cam or know what cam works well in a 1966 L-79, thanks for your help. http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

That cam has faster ramp rates than the original cam. The lobe centerline is narrower, at 112 degrees, rather than 114 as the stock cam.

.050" durations are longer than stock, but J604d (commonly referred to as "advertised duration") is significantly shorter than stock. The valve lift, at .468/.462 is marginally higher than stock (.447/.447), assuming a true 1.5:1 rocker arm ratio at full lift.

An easy to understand way to explain "relative ramp rate" is: the difference in degrees between J604d duration and .050" duration. Vintage camshafts are in the neighborhood of 60 degrees difference here, while "yours" is 47 on the inlet lobe and 47 on the exhaust. The smaller the difference between J604d and .050" durations, the faster the ramp rate.

A cam such as this will provide dramatically more torque bandwidth. The trade-off is that durability will suffer somewhat. If you plan to use your car as a daily driver, where you will conceivably accumulate over 80,000 miles in your lifetime, then I would not install this camshaft.

All of that being said, there is nothing wrong with Competition Cams. They have the largest cam library available, and are among the largest and most trusted camshaft manufacturers in the US.

Parkerizing is a phosphating process similar black phosphate. It is primarily used to provide CORROSION RESISTANCE with a small measure of surface hardness as an ancillary benefit. All of Comp Cams are "parkerized". However, if you want your camshaft treated specifically for hardness, then have Comp "gas nitride" it for you.

[Jack H.]

Re: L-79 cam

Terry ,

The GM part number for that cam is 3863151. GM Parts Direct sells , or did a while ago, a kit of the cam and lifters for $135 . Their part number for the kit is 12364050. Using either of these #s should help you search and see if they, or anyone else, still have them

I hope that helps,

Jim

12364050 is still a valid number on www.gmpartsdirect.com. The note says it is manufactured by Crane Cams and indeed looks to be the 3863151 with a set of lifters for $127.30 (as of today).

[Loren L.]

Re: L-79 cam

Apologize for not taking the time to read the preceding posts, but isn't there a DIFFERENCE between the 65-7(maybe 8?) and later 350HP cams?

[John H.]

Re: L-79 cam

Apologize for not taking the time to read the preceding posts, but isn't there a DIFFERENCE between the 65-7(maybe 8?) and later 350HP cams?

Loren -

Yes, there is. The "151" cam was used from '65-'68 in the L-79, and the 3896962 cam was used in the '69-'70 L-46 and in the '73-'80 L-82.

[Joe C.]

Re: L-79 cam

Apologize for not taking the time to read the preceding posts, but isn't there a DIFFERENCE between the 65-7(maybe 8?) and later 350HP cams?

Yes.
3863151 used for 1965-68 L79:
221/221..........447/.447........114

3896962 used for 1969 and later L46/L82:
222/222.......450/.460...........114

[W K.]

Re: L-79 cam

Just had my L79 motor rebuilt. Used the the SpeedPro cam, very happy. Sounds great, idles great. Almost like it was made for it. My motor is all original, carb, pistons etc.

[Terry L.]

Re: L-79 cam

Thanks everyone for the info, I ordered the cam from GM parts, $150 with lifters and freight