496 BBC ADVICE?

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longrodsbc

496 BBC ADVICE?

Post by longrodsbc »

Im currently building a 496 BBC spec as follows

4.310" bore
Probe SRS mid dome pistons 6.385" rod
Scat H-beam 4340 6.385" rods
Scat 4340 4.250" crank

I need some advice and/or suggestions on the head selection. Im really either going with Canfield 310cc heads or the 355cc heads.

Im leaning towards the 355 cc heads because after looking at the flow numbers these heads have outstanding low-mid lift flow, much better than the 310cc heads.
I E
.100 82 74
.200 176 123
.300 250 175
.400 313 213
.500 350 256
.600 367 284
.700 376 309
.800 380 320

so im thinking of using the 355cc heads with 113cnc chambers and a smaller cam. the cam I have in mind is a comp solid roller, 288/296 254/262 .714/.714 108*

the CR with the 113 CNC chambers will be 10.5:1

The car is a full weight 72 chevelle (approx. 3600lbs)
4.10 rear gear
28" tall tires
th 350 with a ATI 3600-3800 stall
the intake, I was thinking of using a Victor Jr with a 1050 dommy.
the headers I have are 2" longtubes, 3" dr gas x-pipe, spin trap mufflers and 3" exhaust.

MSD Dizzy and 6al ignition.

Street/strip application, will not be driven daily.

any suggestions or advice is appritiated.


longrodsbc
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Post by DOTracer »

Between the two choices you listed, go with the 310cc. Forget the flow numbers and size the head runner for your cubic inch, rpm range, compression, cam timing, vehicle weight, intended usage, etc. From what you listed, that engine would be lazy and not perform to it's best with such a large head as the 355cc.
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Post by MileHighMan »

I absolutely Agree. Good Luck. Dan.
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Post by needforspeed66gt »

I think the Dart Pro 1 is a better head, regardless; the 310cc head is the right choice.
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longrodsbc

Post by longrodsbc »

Thanks for the replies, So go with the 310cc heads and what cam? Im wanting around 1.36hp per cube, and yes I knew the 355cc heads were BIG for a 496, but looking at the mid to low flow numbers had me a lil fuzzy headed.

I like the canfields because of the price and quality, Im thinking something around 320cc would be perfect but who makes this runner size around the same price as Canfield? or will the 310cc heads be sufficiant?


thanks, longrodsbc
longrodsbc

Post by longrodsbc »

needforspeed66gt wrote:I think the Dart Pro 1 is a better head, regardless; the 310cc head is the right choice.

I like the Pro 1's as well, but my budget will only allow something around the price range of the Canfields, ( even then I have to buy them bare)

longrodsbc
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BB Chevy heads

Post by bigjoe1 »

I see that the advice you are receiving here leans toward a smaller head, I just remembered I have the AFR 325 fully CNC ported heads from my Engine Master contest motor that I would like to sell. If this might interest you, call my shop and we can discuss it.
JOE SHERMAN RACING
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Post by Ed-vancedEngines »

My suggestion is for you to contact Mr. Joe. Besides the fact his heads will be probably right for you and maybe even a right price, Mr. Joe was in on a lot of the things to make your monster run and run better. He can also give you suggestions about a BB in a Chevelle. He had the first 9 Second Chevelle in History.

Ed
longrodsbc

Re: BB Chevy heads

Post by longrodsbc »

bigjoe1 wrote:I see that the advice you are receiving here leans toward a smaller head, I just remembered I have the AFR 325 fully CNC ported heads from my Engine Master contest motor that I would like to sell. If this might interest you, call my shop and we can discuss it.
JOE SHERMAN RACING


Joe, Thats awsome! one problem, I cant find the number to your shop, can someone please give me a number to contact Mr Sherman?

thanks!

longrodsbc
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BB Chevy advice

Post by bigjoe1 »

Ed has the nicest things to say about me, I am almost embarrassed. OH well, I do have a web site with lots of info, but I will still give you my shop phone number . It is 714 542 0515. Try to call in the morning, between ( 9am and 12 noon, west coast time. I would be glad to help in any way I can.
JOE SHERMAN RACING
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Post by machine shop tom »

I recently finished a good friend's 496 build very similar to yours. He used an Eagle kit with the same rod and piston specs. The car is an early 80's Olds 88 (I'll correct this tomorrow), with the same gearing and tires, with a TH400.

He is using an older Lunati hydraulic roller with Jeg's (Canfield) 310cc heads with 10.5:1 compression.

The engine is very responsive with an 850 Holley DP carb and pulls that big car like nobody's business. He hopes to get some time slips when he's not busy getting his friend's BBC '37 Chevy truck into the 8.80s.


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longrodsbc

Post by longrodsbc »

Id like to thank Joe for taking the time to talk to my dad, thanks Joe!




Machine shop Tom,
Id also be interested in the times with the 496 with the 310cc canfields as well, any idea on the cam specs? intake and carb on that combo?


thanks, longrodsbc
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Post by machine shop tom »

longrodsbc wrote:Id like to thank Joe for taking the time to talk to my dad, thanks Joe!




Machine shop Tom,
Id also be interested in the times with the 496 with the 310cc canfields as well, any idea on the cam specs? intake and carb on that combo?


thanks, longrodsbc
I'll get back to you tonight with the specs.

tom
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Post by machine shop tom »

The Lunati cam specs are:

Lift: .595" intake, .612" exhaust.
Dur. @ .050": 242 intake, 252 exhaust.
110 Lobe separation,
108 intake centerline.

Intake is the Edelbrock RPM airgap, carb is 850 DP

The car scales a 3959 lbs empty, He guesses your car at 400 lbs less.

His only complaint is the hydraulic roller cam is very noisy. I was wondering if he could run solid rollers on it with .004"-.006" lash.

BTW, his friends 37 is a coupe, not a truck.

tom
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longrodsbc

Post by longrodsbc »

machine shop tom wrote:The Lunati cam specs are:

Lift: .595" intake, .612" exhaust.
Dur. @ .050": 242 intake, 252 exhaust.
110 Lobe separation,
108 intake centerline.

Intake is the Edelbrock RPM airgap, carb is 850 DP

The car scales a 3959 lbs empty, He guesses your car at 400 lbs less.

His only complaint is the hydraulic roller cam is very noisy. I was wondering if he could run solid rollers on it with .004"-.006" lash.

BTW, his friends 37 is a coupe, not a truck.

tom

Thanks Tom, Sounds like a potent combo, I think we will use the Canfield 310cc heads as well.

Im thinking so ok they dont flow as much as the AFR 325's, Flow isnt everything, and I know the Canfield's or even Brodix RR heads will make serious power. We are on a tight budget and the Canfields are Cost effective, and later on I could always Port the heads if need be.

Thanks everyone for your input, the Canfield 310cc heads will be on the way!


longrodsbc
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