Thread: Help me find my cam - 396, oval port heads, 10.1 compression

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Hello!

I've read through a few posts and see some good knowledge here. Thought I'd sign up to see what advice I can get.

I'm restoring my 1968 Camaro. It will be driven - not a trailer queen.

I'm not looking to build the fastest street car in America. I just want a stout motor that will "get the job done". I plan on running a 2000-2300 RPM stall in a Turbo 400. I want a motor that comes to life around 2K RPMs and goes up to 6K RPMs. I don't really want to push it much higher than 6K RPMs.

Lower end of motor is complete. 4 bolt main, forged rods and pistons. 10.1 compression. Very nice balance job.

Heads will be AFR Magnum heads. 265CC runners. Oval port.
265cc BBC Oval Port Cylinder Head - Air Flow Research

Intake will be one of the following (still figuring this one out).
Edelbrock RPM
Edelbrock RPM air gap
Weiand Stealth

Sorting out ignition. For now, let's just say HEI style with a super coil.

Carb: I have a Holley 750 that was modded years ago to allow all 4 barrels to open simultaneously. I had this carb on a pretty wild small block. It was a very touchy carb and I loved it. Debating if I need to go with a larger carb or jet this one way up for the big block.

Rear end: 12 bolt posi with either 3.55 or 3.73 gears. Also, still sorting this one out.

I've already read several posts in here about big blocks being nasty to cams and that a roller is recommended. I had already decided roller was what I wanted, info here has cemented that plan. I just don't know which cam to go with.

So... recommendations on a cam that's going to make for an engine with great low end and mid range oomph for a stoplight to stoplight killer?

And yes, I do plan on taking it down a 1/4 mile to see what ET I can get. Low 12s would blow me away!

Thanks,
Jason

Welcome Aboard Jason. And congrats on #1 son getting to college.
I'm not a chebby guy so I'll bow out with first hand info, but I'll ask if you've gone through any of the cam grinders websites?
Fill in some questions and it'll spit out some choices..

Since you've been reading other threads, have you read how much "we" despise the thumper line.? Most of us consider them a cam for a "poser"... I'm certain more than a few folks will be glad to offer you some help , I hope you enjoy your time here at CHR.

Welcome to CHR Jason:

First thought is that if you want to get into the 12 second range you may need a cam that come on in the 2500-3000 range and a 2800-3000 RPM stall converter.

I like this cam for your engine and heads - roller retrofit and about as aggressive you'd want on the street. With the 3:73 gears, those heads, a 750 and good headers, it should scare the snot out of most people at 3500 and you'll see God at about 5800 RPM.

I'd opt for the Weiand Stealth here. Others will certainly chime in.

Let us see some pictures and again, welcome to CHR.
Glenn

You'll like the air gap manifold at WOT, provided the engine is warmed up.

Part throttle, on the street, not so much.

Originally Posted by Jason_Lyman

It will be driven - not a trailer queen.

Great, then let's use some street driver parts, not race parts.

Originally Posted by Jason_Lyman

I'm not looking to build the fastest street car in America. I just want a stout motor that will "get the job done".

Great, I'll do my best to help you achieve your goal.

Originally Posted by Jason_Lyman

I plan on running a 2000-2300 RPM stall in a Turbo 400. I want a motor that comes to life around 2K RPMs and goes up to 6K RPMs. I don't really want to push it much higher than 6K RPMs.

You're going to need to begin stalling at 2800-3000 in order to use a cam that will make power up into the range. There is an effective range of about 3500 rpms or a little less for any cam that you bolt into the motor. For this application, I would use a cam that begins at about 2000 and noses over at about 5600, then use a 10" converter that comes on about 2800, giving you an 800 rpm lead on the motor, so that you're making hp when the whole mess hooks up. A 2800-3000 stall converter is a sweetheart on the street. Easy driver.

Originally Posted by Jason_Lyman

Lower end of motor is complete. 4 bolt main, forged rods and pistons. 10.1 compression. Very nice balance job.

A street motor at 10.0:1 with aluminum heads is just about as good as it gets, just make sure you use a composition head gasket so that the heads have a little wiggle room to prevent fretting. What did the squish/quench figure out to?

Originally Posted by Jason_Lyman

Heads will be AFR Magnum heads. 265CC runners. Oval port.
265cc BBC Oval Port Cylinder Head - Air Flow Research

Best BBC street heads on the planet.

Originally Posted by Jason_Lyman

Intake will be one of the following (still figuring this one out).
Edelbrock RPM
Edelbrock RPM air gap
Weiand Stealth

Stealth

Originally Posted by Jason_Lyman

Sorting out ignition. For now, let's just say HEI style with a super coil.

DUI

Originally Posted by Jason_Lyman

Carb: I have a Holley 750 that was modded years ago to allow all 4 barrels to open simultaneously. I had this carb on a pretty wild small block. It was a very touchy carb and I loved it. Debating if I need to go with a larger carb or jet this one way up for the big block.

I would adapt an 800 CFM Quadrajet to the Stealth.

Originally Posted by Jason_Lyman

Rear end: 12 bolt posi with either 3.55 or 3.73 gears. Also, still sorting this one out.

You have enough cubic inches to pull, I might use the 3.55's with the 2800-3000 converter.

Originally Posted by Jason_Lyman

I've already read several posts in here about big blocks being nasty to cams and that a roller is recommended. I had already decided roller was what I wanted, info here has cemented that plan. I just don't know which cam to go with.
So... recommendations on a cam that's going to make for an engine with great low end and mid range oomph for a stoplight to stoplight killer?

I like Howards. They're reasonably priced, have a good reputation and have been grinding cams since Noah was a teenager.

Part number CL123315-08 cam and roller lifters. This cam was chosen for performance, not for intake manifold vacuum. Vacuum brakes could be problematic. A change to all-around non-vacuum disc brakes would be the best fix. This cam has a lobe separation angle of 108 degrees for max power. If you need to adjust to less power with more intake manifold vacuum, have this cam ground by Howards with a 112 degree lobe separation angle.
2000-5600 rpm operating range
Advertised duration 280/280
0.050" duration 227/227
Valve lift 0.555" / 0.555" with stock ratio rockers
Intake centerline 104 degrees
Exhaust centerline 112 degrees
Lobe separation angle 108 degrees
Hydraulic Intensity 53
Mild, rough idle, Hot street, must have good exhaust system. Use an X or H pipe immediately after the collectors.
Howards calls for a 2500+ torque converter (meaning 2800-3000)
Cam requires minimum 9.5:1 static compression ratio

Originally Posted by Jason_Lyman

And yes, I do plan on taking it down a 1/4 mile to see what ET I can get. Low 12s would blow me away!
Thanks,
Jason

Hmmm - great minds think alike here Tech!

Ditto on the Quadrajet as those monster secondaries open up it will be a thing of absolute beauty!

Thanks for the great info. I will certainly look into the above.

I ran a Stealth on a small block years ago. Loved it. May go with it here on my 396.

I also ran a 3500 RPM stall as well (with a Victor Jr). That thing was nuts (but I loved it though)! Not looking to go up to a 3000 with this build, looks like 2500 will be my best bet.

Power disc brakes will be in use. No vacuum.

Pics... Let me figure out how to get a pic to show up in the gallery!

Thanks,
Jason

Converter technology has come light years of what it was just even ten years ago. You can get a converter that'll flash 5K and be tight enough to drive every single day with minimal slippage. You NEED a converter higher than your sissy ass 2500. Remember, there were factory high stalls that stalled higher than that, so you are still in STOCK territory.

Dude in post #5 knows what he's talkin about. The only point I would make different would be that IF you are on a budget, a roller might be out of your range. They just slap eat a LOT of money out of a project. Plenty of great modern flat tappet grinds out there and with the correct lifters, some can rival the power of a roller. Just be careful with your selection.

I know I will get flack for this.......but I kinda like Comp's Thumpr cam series. They are ground to sound WAY nastier than the engine actually is. Narrow LSA, a WIDE duration split, and late intake IVC. All that adds up to a nasty idle. It's nothing new, either. Crower did it fifty years ago with its Hydraulic Hauler series. Those cams worked great......and so do the Thumper series, IF you build the engine accordingly just like any other cam.

Good luck!

Originally Posted by Jason_Lyman

....Power disc brakes will be in use. No vacuum.

Pics... Let me figure out how to get a pic to show up in the gallery!

Welcome, Jason! First, how are you going to have power disc brakes without hooking to vacuum? HydraBoost?

Second, you'll be much happier posting pictures in your thread as attachments vs using the gallery. The gallery is like a big box that you throw things into, with no way to organize anything, just a jumble. Take a look at this - http://www.clubhotrod.com/shop-talk/...es-thread.html

Originally Posted by rspears

Welcome, Jason! First, how are you going to have power disc brakes without hooking to vacuum? HydraBoost?

I'm bettin' that what he meant was manual disc brakes, jockeying the master cylinder bore and pedal leverage.

.