I plan on replacing my cam and am wondering if this is a good match with the following components installed when I rebuilt the engine a few years ago.

Engine: 350 +.060
Piston head type/material: Flat with slot, forged (TRW#L2417F L-82 piston)
Deck: stock height
Compression ratio: (10.0:1+)
Edelbrock 2101 intake idle-5500rpm (also have Stealth Manifold: idle-6800rpm)
Edelbrock RPM heads (64cc)
Edelbrock 600cfm carb (thinking of ditching for my new in box Mighty Demon 750)
Do not recall cam specs of current cam, it was a Lunati cam.
Stock convertor.

After all of that: Here are the specs of the two cams im looking at:
RPM range: 1,800-5200rpm
Adv Dur: 274/274, Dur @.050: 218/218
Valve Lift: 450/450
LSA: 106
Description: Largest cam for stock convertor 9:1 and higher cr, lopey idle, excellent midrange power.

Cam#2
RPM Range: 1,500-5,000rpm
Adv Dur: 272/272, Dur@.050 lift: 216/216
Valve Lift: 454/454
LSA: 110
Description: Lopey-Rough idle, excellent midrange power 9:1 and higher cr, stock convertor.
Phew, comments please.

 

Those are both very mild cams for a 10:1 engine, the durations are both under 220 degrees @.050" which will make for a mild idle and possibly detonation, it depends on the valve timing. The GM 151 cam for example is 222 degrees and works nice at 10:1-11:1 with an automatic trans and has a noticeable idle. It has a slower ramp rate and will create a lower dynamic compression for you. I think you may have problems with those two cams listed with your SCR of 10:1. The "151" makes some great torque too. It just depends on what your goals are.

Another good cam you might want to look at is the Engle 21043-H with 222 degrees on a 110 LSA.

 

My goal is to have a cam that will not be a dog with a stock convertor with good midrange power and won't effect power brakes/headlamps. I cannot afford a higher stall speed convertor. I would like to get a higher lift/ longer duration,( .500+ lift and maybe 230+ duration but probably no more) cam. I also notice that larger cams move the power band further up and most will not make power until until you reach the desired rpm range of the particular cam without having a high stall speed convertor. BTW is the 151 cam the cam used in the 327 engine?

 

Well you certainly do not want a 230 degree cam then, I wouldn't use anything more than the '151' or L82 cam otherwise you WILL need a 2,500 stall converter with a 230 cam. They both idle at 850-900 and work well with a stock converter. I'm running the '151' in my sons '76 with a 10.3:1 350 and it works very nice. You can buy a Sealed Power '151' at Northern Auto for about $70.

Yes, the '151' was used in the L79 327/350 HP cars.

 

If your CR is exactly 10 to 1 you need an intake valve closing point of 57 degrees ABDC with aluminum heads to run pump fuel safely. The intake valve closing point ABDC is calculated in the following manner. Divide the advertised intake duration by 2, add that to the lobe separation and subtract out any ground-in advance. Lastly, subtract 180 degrees.
LSA, Duration @ .050, Lift and ground in advance and advancing or retarding cam from straight up will affect the mannerisms of the cam but to get the right DCR this is the closing point you need and the way to find that closing point.

 

Or just look at the cam card.

 

Seems as if you cannot get anything larger than the L79 and L46/82 (old technology) w/o a 2500+stall convertor.

 

Well the '151' might be old but it works very well and you don't have to worry about lobe wear when you use the stock springs. If you want a little more aggressive sounding cam try the Comp 270, it works nice at 10:1 as well.

 

A lot of the cam ads like the Summit 274 cam posted do not include the cam card in the advertising. To figure out if it will work with pump fual in your engine you need to know the actual intake closing point and the DCR that point will generate with a given compression. I took your compresion ratio and figured what intake closing point would be the smallest to safely run pump fuel figuring 8.4 to 1 DCR. Just trying to help.

Edit: The comp 270H has an intake closing point of 61. It will work but you can go a little lower on the intake closing point to bump DCR and lower your operating range. I would look at a split duration cam especially if you don't have 2 1/2" free flowing exhaust. The RPM heads are a little weak on the exhaust side.

 

The springs on my heads can handle lift to .575. Is that more or less stronger than stock springs?

 

I'm learning

 

You really need to know the seat pressure or part number of the springs you have or they may not be compatible with your new cam.

 

OK. Will call edel tomorrow.

 

Your first choice has an intake opening of 59 degrees
Cam # 2 has an intake opening of 62.
The "151 cam has Advertised duration of 290/290, Duration @ .050 is 222/222, LSA is 114. Intake closing point is 79. These were used in an iron head 327 and like lots of RPM. The wider LSA opens up the operating RPM range as you will see when you start comparing cams. It will reduce peak power slightly at high RPM but it will pull better at the bottom and midrange where you use it most. This is why the factory used 114 LSA on most of the old school grinds.
Going a little bigger than 57 is not all bad. That is an absolute minimum I would go. A later intake closing is safer from detonation. A little more lift and duration @ 50 will help with cylinder filling, (valve is open longer and for more time) somewhat compensate for lower dcr it also increases power. You are making use of the capacity of your heads. This also increases your ramp rate. Nothing is free.
I like this cam for your build. Intake closes @ 61 ABDC This is a very commonly used cam for your build level.
http://www.compcams.com/Company/CC/c...x?csid=86&sb=2


This one gives you more lift and duration @ .050. Gets you closer to your 230 dur .500 lift while still having a 270 advertised duration with an intake closing point of 63 ABDC. Look at the operating range. A vette has a better torque convertor stock than your other chevy's, I believe 1800-2000 RPM.
http://www.compcams.com/Company/CC/c...x?csid=97&sb=2


PS: I always recommend a roller cam but it sounds like it is not in the budget. Use proper break in procedures, Moly break in lube, ZDDP additive during break in, good geometry and High ZDDP oil. Be careful.

 

I would check the seat pressure, open pressure and rate of your springs and compare them to the recommended springs for the cam you select. They need to be almost an exact match.

 

IMO for any mild build automatic sub 360 ci build anything below 112 LSA just destroys MPG and drivability. My original 355 had this crane cam with 1.6 roller tips.

http://www.cranecams.com/product/car...detail&p=23979

up around 20 mpg with a 3.55 rear end. compression did get me with flat tops and iron 64 cc heads and I went to its bigger brother the Crane 278.

I would run the 600 carb and the stealth manifold. I used a EDL 750 VS carb for more than 10 years on my 355 ci mouse motors with single planes and a 1/2 inch wood thermal spacer. The stealth is a better choice and a 1/2 inch thermal spacer

 

As for your PS, I wish I can get a roller cam. One day. A lot of people lean away from comp. I think that is due to a combination of things: must jump through hoops if you wipe a cam, improperly following break in procedures, and not using an oil w/ high zddp content. Yes having a roller cam spares you of the break in procedure. Thanks, I'm learning quite a bit.

 

I left out that I have crane 1.6 roller tip rockers on ny valve train. Plan on going back to 1.5 stock rockers. I used a ci caculator and came out w/360ci (hope I plugged in the correct info)

 

.060 over bore and 3.480 sroke is @ 358 ci

when you are talking about lobes with sub .500 lift with 1.5 rockers They need any help that they can get with 1.6. lift gives more flow without the adverse side effects of additional duration. That is why I went to high .600 to over .700 lift exhausts

When a motor makes more TQ you don't have to go to increased stall T converers. A 358 with 10 ish compression makes way more power than the original L-82 sold in the late 70's vettes.

Your aluminum heads will help on the pre-ignition, but modern cams and your better heads fill the cylinders better which leads to the need for more duration to keep dynamic pressure lower. If your pistons are flat tops with like -8 cc for valve reliefs I would lean more toward the crane power max 278

 

a link to the Crane 278 112 LSA

http://www.cranecams.com/product/car...detail&p=23975