L79 cam - again

**John H.** · April 4, 2005, 11:42 AM

Re: L79 cam - again

Jim -

Just my two cents, but I'd stick with the "929" base cam with your combination; low-end torque is your best friend with a 3.08 axle, and that's where the base cam shines. There must have been a reason why the L-79 was never available with an automatic transmission.

**Duke W.** · April 4, 2005, 12:30 PM

Re: L79 cam - again

I agree with John. Stick with the 929 cam. You can achieve a 5-10 percent increase in top end power and a strong pull with useable revs to 5500 if you pocket port, port match the heads and do a multiangle valve job.

I would also recommend raising the CR to the range of 9.5-10:1. Of course, you will have to use premium fuel. As originally configured with 8.5:1 CR your engine should run detonation free on regular unleaded. The increase in CR will improve torque/power across the rev range by about 5-7 percent. I don't recall you mentioning what CR the "flattop pistons" will yield. Does the machine shop know? Have they actually MEASURED the deck height and computed the CR using the measured deck height and planned gasket thickness for the computation? I have to wonder if these guys know what they're doing.

In any given configuration of short block and heads, the 929 cam will be stronger than the L-79 cam up to about 3500 RPM, and it will be MUCH STRONGER below 2500.

Think about the rev range where you spend most of your time. How often do you go above 3500?

IMO your machine shop is steering you in the wrong direction, but that's nothing new - happens all the time.

Duke

**Timothy B.** · April 4, 2005, 12:51 PM

Re: L79 cam - again

Jim,

Back in the late seventies I installed the 350 HP cam in my 72 vette with TH400/3.08 rear. It was the worst thing I could have done as the car would stall every time I put it in drive until completely warmed up and for my driving I think it ran better with the original cam. I agree with Duke and John, stay with the 929 cam. I have the 929 cam in my 67 and used it when I rebuilt my 63 and both cars run great.

**Jim Callan** · April 4, 2005, 01:02 PM

Re: L79 cam - again

Thanks to all,

I will use the base cam, but I don't really know the condition of my old cam so I will exchange this "151" clone cam for a cloned "929". Duke, I believe you stated the "929" specs at 194/202 at 108/116. What is the i/e lift ? Do you have a FM part number ?

Thanks

Jim

**Duke W.** · April 4, 2005, 01:59 PM

Re: L79 cam - again

Duration at .050" lifter rise and points of maximum lift are as you stated. Lobe lift is .2600"/.2733", but I don't have the F-M number. You should be able to get it by having a F-M dealer look it up. This cam was used in base Corvette engines from '67 to '80 and similar engines used in passenger cars and trucks, so it should be a common replacement item. GM must have installed something on the order of 10 million of these cams in OE engines.

Duke

**John H.** · April 4, 2005, 01:59 PM

Re: L79 cam - again

Jim -

The "929" cam is available from GM as a kit with lifters under P/N 12364051; lists around $150, or about $100 from Scoggin-Dickey or GMPartsDirect.com.

**Joe L.** · April 4, 2005, 04:54 PM

Re: L79 cam - again

Jim-----

I agree with all the other responders, too. For your application, and limiting the selection of the cams to either the '151' or the '929', the latter is the only way to go.

**Jim Callan** · April 5, 2005, 09:06 AM

Re: L79 cam - again

I'm working with the machine shop to exchange the L-79 cam (melling #22200) for a 300hp base cam. Problem is, he is not sure what the Melling # is and I can't seem to find a F-M # for him to xref with. I'm looking at 3 cams from Melling, which one do you think would be a 300hp cam or a suitable choice?

#22109 - 194/204 @.050, .398/.420 lift, 104/104 center

#22110 - 194/204 @.050, .398/.422 lift. 107/117 center

and this one looks possible

#22110 - 204/214 @.050, .420/.443 lift, 110/110 center

Thanks

Jim

**Duke W.** · April 5, 2005, 09:42 AM

Re: L79 cam - again

Forget Melling. Return the L-79 clone cam to Melling et the real deal from a real vendor. John gave a GMPP number for a cam and lifter kit. Are you saying your shop doesnt' know of an F-M dealer that he can order the cam from? Hard to believe. F-M is one of the biggest OE and aftermarket suppliers on the planet.

Duke

**Tim E.** · April 5, 2005, 01:01 PM

Re: L79 cam - again

Last fall, I went through the exact same process as you....my machine shop supplied the 350HP cam for a 300HP base motor 1966. Same story as you. After the same research you're going thru, I switched to the 300HP cam before I even fired up the engine the first time. My main reasons were...idle quality ("stock" for the 300HP and "good" for the 350HP) and the hope of a future PV.

I ordered Crane's blueprint 300HP cam from Summit Racing for $99.95 (p/n CRN-968711) and made the swap. I'm happy I did, the engine idles rock solid at 500RPM. Haven't driven it yet since I'm just now doing body & paint.

Summit's specs show: 195/202 and .390/.410.

L79 cam - again

L79 cam - again

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