396 Build Up

[VintageMusclecar]

What car is this going in, what's the weight, trans/converter (/clutch), rear gearing, and is there any chassis work done?

450 honest flywheel HP will easily put a well-prepared 3500 lb car solidly into the 11's w/o breaking a sweat, and pushing 450 HP from a 396 is about as difficult as falling off a log. Unless you have your heart set on it, you don't need to bother with the added expense of a roller cam & lifters, a relatively mild flat tappet will easily do the job.

3/8" rods will be more than adequate with a good set of bolts and the obligatory prep work. The engine should be able to turn 6500+ until the cows come home.

Of the two intakes you mentioned, the C427X would be the better choice, and even that's going to be down on power over an OE 163 (or 198) intake. (read this thread for more info)

If the intake you decide to run has a center divider (assuming a dual plane intake of course), the 3310 will be the better choice. If your intake does not have a center divider, the 3418 will be the better choice, but it will need to be re-jetted. (read my dyno results from testing a 3910 against a 3418 on my own 496)

Please note that the 3910 was used in conjunction with the center divider intact, and the 3418 was used w/o the divider, as it was originally designed by Holley/GM to be used on the open plenum L88 intake.

Eric

[69 Post Sedan]

Eric, this build up is going in my 69 Chevelle. It's a M22 right now but I think I am changing to a M22W, Hays street/strip clutch, 3.73 gears and 27" tall tires.

The car weighs about 3700 with me in it.

My C427X intake is a dual plane with a cut divider.

Stock chassis other than boxed in upper and lower control arms and air bags in the springs.

Thanks for your information...it's greatly appreciated.

Kurt

[VintageMusclecar]

Kurt;

With your vehicle weight and limited gearing, you're going to want to concentrate on low-end and mid-range torque, not higher rpm HP. You're looking at a usable power range of ~3000-6000 rpm. Anything much over that is going to be wasted here.

In that regards, you might want to consider shelving the rectangle port heads and going to a set of open chamber oval ports, such as the 049's or 781's. (A set of 820's might work as well, but you'll have to watch the dome-chamber fit). You're also going to have to keep the cam timing fairly conservative as well to keep the power range down where it's going to do you the most good. Again, a flat tappet will suffice at this level. (FWIW, look at how quick guys are running with the factory L78/LS6 143 cams, and they're only .520" lift and 242° @ .050)

A wide ratio trans will be a benefit as well here due to the additional torque multiplication. You're going to have to concentrate hard on covering the first 60' and 330' as quickly as possible as that's where your e.t. is going to come from.

Again, the weight and limited gearing are going to make things a bit more difficult, but if you concentrate on keeping the power range down where you can use it and spend a little time to refine the combination, you'll get there. Keep one key factor in mind throughout this--the car itself has to work...there is a lot of e.t. to be found with the hood closed.

And you're welcome, I'm glad to help however/whenever I can.

Eric

[69 Post Sedan]

One of the reasons I want to run rectangular port heads is they really don't start working until the rpm's get up there. So, I won't be frying the balonies out of the hole...just hooking up. By the time I get the real HP going I'll be moving.

I know that there are guys out there running the 198 intakes to keep the power down out of the hole just for that reason.

That's how I ran my 427 Nova that I built and it worked wonderful, even with P215/70R14. I never got a chance to take it to the strip to see how quick it was...I sold it but here is video of my Nova from a while ago when it had a tired 69 396 325HP, M20 with 3.73 gears.

https://www.youtube.com/watch?v=B4hJS...feature=digest

BTW I ran a 13.93@100mph with the air cleaner off. Earlier I ran a 14.08 and a 14.06 with the air cleaner on. That was my first time ever at the track. And the brake lights were coming on every time I pushed in the clutch.

[VintageMusclecar]

Read this. This is what a well-thought-out relatively mild oval port 396/402 can do in a 3600 lb A body.

The 7.10 e.t roughly translates to 11.20's or thereabouts. Granted this is a dedicated bracket car, but that also goes to show how important the overall combination (i.e. "the <u>car</u>") is set up.

As far as trying to soften the hit off the line, that's only going to make your 11 second goal that much more difficult.

E.T. comes from covering the first 60' and 330' as quickly as possible, and what you give up in short times you can not make up down track (at a given HP level).

There's a thousand ways to skin a cat. Some are far more effective than others.

[Chevy454]

[ QUOTE ]
Originally posted by: 69 Post Sedan

One of the reasons I want to run rectangular port heads is they really don't start working until the rpm's get up there. So, I won't be frying the balonies out of the hole...just hooking up. By the time I get the real HP going I'll be moving.

[/ QUOTE ]
Wishful thinking, believe me...our class [and especially the FAST class above us] is the masters of killing bottom end power and moving elsewhere, and those huge ports still make enough grunt down to make things interesting to the 330' mark (and beyond, sometimes!)...

Listen to Eric, he's giving you great advice...with decent tires &amp; hook this should be a no brainer.

[markjohnson]

That's an interesting link that Eric posted and I'd love to see what the 454-468 version would be capable of! I know that it's the correct sum of parts that gets you down the Dragstrip faster than the next guy but if I had to pick one the "magic" part in that comination, it would have to be that Comp Cams XR274R Solid Roller. I've actually had my eye on that very camshaft for an upcoming project and it looks very promising. I've built and owned MANY Big Block Chevys and I've had 9.00 Comp. Pump Gas/Oval Port/Solid Roller motors that would just flat out embarass my 12.5 Comp. Race Gas/Rectangle Port/Solid Flat Tappet Motors. I had the good fortune to talk BBC's with John Lingenfelter quite a bit in the back in the Nineties and he's the reason I'm sold on Oval Ports for applications under 496 CID and .650 Lift camshafts. Your 396 CID would be very happy with a set set of oval port heads with the big 2.19/1.88 valves fitted to them with some nice bowl port work and a Performer RPM Intake Manifold. Don't worry about trying to kill of low-end power with those giant Rectangular ports on such a small CID engine. Make all the power you can.....and then worry about getting it to hook. That's the fun part!

[68427imp]

Don't mean to hijack this thread,but I have a '65 Impala SS with a 468 with 781 heads(no port work),2.19/1.88 valves,Comp Magnum 292 cam(.550 lift,244 duration@050),Edelbrock Performer RPM intake,9.5 to 1 forged pistons,out-of-the-box Holley vac.750,1.7 ratio roller rockers and 2" headers.Anybody know how much h.p. and torque this combo makes? Eric? Jim

[JLerum]

Bob West has the 9.98 wheel standing 71 chevelle. It's 505 cubes. oops!!!! I gave it away...!

Jim

[VintageMusclecar]

Jim;

Given the appropriate state of tune (and assuming all the machine work is spot-on and everything is fresh &amp; healthy), there's no reason that engine couldn't make 425+ HP on an honest dyno. The box-stock 750 VS and that cam are leaving some power on the table.

Eric