Cam recomendations

[Johnnyz453]

Building my 350 and its time to order a cam. Going with a comp cams hydraulic flat tappet but dont know what specs to go with. Its a chevy 350 out of my 83 k10 bored .030 over, flat top pistons(4 reliefs), 64cc aluminum heads 185cc intake runner 62cc exhaust runner, 2.020 and 1.600 valves, should be around 9.5:1 when done. Want a great sounding cam but for it to still be streetable and have bottom end torque. The heads im getting have a max lift of .575. Has a 2800 torque converter and a turbo 350 trans. With 373 gears on 35's

 

[Georgeb]

Start here:
http://www.gmsquarebody.com/forum/showthread.php?t=17375

 

[rich weyand]

With that set-up, I would look at the 12-239-3. Probably 407-ish hp and 436 lbft. It's amazing what more compression and bigger valves can do for you at the top.

You don't want to go much higher in torque than that, or you'll dynamite that TH350. Biggest stock engine with a TH350 was 410 lbft.

Probably nudge the stock torque converter with that cam, maybe an 1800 rpm stall. The torque curve comes on real fast, with 350 lbft at 1800 and 400 lbft at 2200.

BTW, the 12-239-3 is the next "bigger" cam in the same series as the 12-235-2. With the higher compression ratio you are looking at compared to stock heads, you can go to a longer duration without killing the dynamic compression ratio down low.

 

[Rusty Nail]

Bah.

I'd run the L-48 or L-82 camshaft in a heartbeat before I considered anything else.

 

[rich weyand]

Bah.

I'd run the L-48 or L-82 camshaft in a heartbeat before I considered anything else.

You should mark sarcasm so someone doesn't take you seriously.

That is, I assume that was sarcasm....

 

[Rusty Nail]

I know!
Who wants a 350hp - 350 c.i. engine built with Chevrolet parts?!

Blasphemy!

 

[74 Shortbed]

I know!
Who wants a 350hp - 350 c.i. engine built with Chevrolet parts?!

Blasphemy!

Lmao..

 

[Johnnyz453]

With that set-up, I would look at the 12-239-3. Probably 407-ish hp and 436 lbft. It's amazing what more compression and bigger valves can do for you at the top.

You don't want to go much higher in torque than that, or you'll dynamite that TH350. Biggest stock engine with a TH350 was 410 lbft.

Probably nudge the stock torque converter with that cam, maybe an 1800 rpm stall. The torque curve comes on real fast, with 350 lbft at 1800 and 400 lbft at 2200.

BTW, the 12-239-3 is the next "bigger" cam in the same series as the 12-235-2. With the higher compression ratio you are looking at compared to stock heads, you can go to a longer duration without killing the dynamic compression ratio down low.

So would my torque converter still work ok with this cam? And around what compression ratio would this be good at because it might end up a bit lower than 9.5:1

 

[rich weyand]

I know!
Who wants a 350hp - 350 c.i. engine built with Chevrolet parts?!

Blasphemy!

The production L-48 in the 1980 Corvette was 190 hp, while the L-82 was 230.

What am I missing?

 

[rich weyand]

So would my torque converter still work ok with this cam? And around what compression ratio would this be good at because it might end up a bit lower than 9.5:1

What is so sacrosanct about that torque converter??? I don't get it.

 

[Rusty Nail]

*l46.

 

[rich weyand]

*l46.

That's what I figured you meant. The L-46 and L-82 ran the same cam, but the L-46 was pre-emissions and the L-82 was the smogger engine.

Which would be great if the OP wanted to run 11:1 compression and burn $5/gallon avgas illegally on the street to get 350 hp and 380 ftlb with a 50-year-old, slow-ramp cam design.

Or he could run the 12-239-3 fast-ramp modern cam at 9.5:1 on pump gas and get over 50 more hp and 50 more ftlb than the L-46.

 

[Rusty Nail]

Uh huh.

I don't think that is as cool so I recommend a cooler camshaft.

Some jazz about compression ratio? Given 4VR flat tops, smaller chamber heads, more modern induction, I don't think the difference would be as great as you make it out to be. Plus, I've got Corvette cool factor. I mean, if that comp cams was so terrific, why didn't the General ever put one in a 350hp/350ci 1969 Corvette? Everybody knows that dog was a pile of ****...Maybe it just needed a "fast ramp modern cam". I'm not convinced that is the best choice for a 30 year old truck with a 30 year old motor in it. My recommendation is to run a 50 year old Corvette cam, because that's cooler.
I'm not the guy on record saying the General got it wrong, Rich...
Don't mistake my teasing for care. Idgaf what dude does to his truck .
I guess I'm trolling...
Ported vs. manifold vacuum..
Camshaft "recommendations"...? LoL
Is this the internet still? I'm not the kind to query advice from strangers, especially not about my truck!
Seriously though, I fail to figure how using "modern" cam technologies in a platform that remained unchanged for 60+ years could be of benefit. The principal purpose has not changed. The valvetrain components have not changed. Numbers don't change. It's the same science that is was in 1969, am I to believe that man's "understanding" of valvetrain science has evolved? Because I don't. It's a seriously simple principal?

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I re-read the original post. Dude WANTS a comp cam...Whatever.