[dually502]

Well combo is as follows.
496 BBC
11.1:1 Compression
ProComp 320cc castings (manley valve train)
Solid Flat tappet cam
(SPecs below)
ADV Dur: 287/295 Duration: 252/260
Valve Lift w/1.8 RR: .653/.678 Cam lift: .363/.377 Lash .022
Lobe center: 108 Intake Centerline: 104
TDC Overlap:40 Intake open/close: 22/50 Exhaust Open/Close:18/62

1 Head ported with 2.25/1.88 valves and flow tested on 4.400 Bore.

Its just the bowl reworked.
Intake runners are still restricted at Intake surface to bowl. I need to set it up to an Intake and port match it. Then i can finish opening up the runner and Hopefully get more flow out of them. The exhaust walls looks like it might be too thin to get anymore out of it. I am still comfortable with them but anymore would make me nervous.

.100"-79/69
.200"-174/139
.300"-246/185
.400"-299/210
.500"-333/243
.600"-358/261
.650"-364/269 (As requested per cam lift)
.700"-366/279
.800"-369/284


I want to keep High TQ numbers but down low with maybe a flat TQ curve. Will only see above 5,000 RPM at the track.. Will get driven 2 or more times a week. Cam is supposed to be 2,000 RPM to 6,500 RPM.. Transmission will probably be a 4L80E and the truck is just shy of 3900#.

We can port any intake to get more flow and even if minor welding is needed.. I was thinking mAybe an old Holley Street/STrip Dom?? Victor 2R or Torker 2R. That Eddie C454 looks like a performer 2.0 But not sure what kinda flow you can get out of any of them.



So

Dual Plane or Single ?
Suggestions?

[CHEVY760]

Originally Posted by dually502

Well combo is as follows.
496 BBC
11.1:1 Compression
ProComp 320cc castings (manley valve train)
Solid Flat tappet cam
(SPecs below)
ADV Dur: 287/295 Duration: 252/260
Valve Lift w/1.8 RR: .653/.678 Cam lift: .363/.377 Lash .022
Lobe center: 108 Intake Centerline: 104
TDC Overlap:40 Intake open/close: 22/50 Exhaust Open/Close:18/62

1 Head ported with 2.25/1.88 valves and flow tested on 4.400 Bore.

Its just the bowl reworked.
Intake runners are still restricted at Intake surface to bowl. I need to set it up to an Intake and port match it. Then i can finish opening up the runner and Hopefully get more flow out of them. The exhaust walls looks like it might be too thin to get anymore out of it. I am still comfortable with them but anymore would make me nervous.

.100"-79/69
.200"-174/139
.300"-246/185
.400"-299/210
.500"-333/243
.600"-358/261
.650"-364/269 (As requested per cam lift)
.700"-366/279
.800"-369/284


I want to keep High TQ numbers but down low with maybe a flat TQ curve. Will only see above 5,000 RPM at the track.. Will get driven 2 or more times a week. Cam is supposed to be 2,000 RPM to 6,500 RPM.. Transmission will probably be a 4L80E and the truck is just shy of 3900#.

We can port any intake to get more flow and even if minor welding is needed.. I was thinking mAybe an old Holley Street/STrip Dom?? Victor 2R or Torker 2R. That Eddie C454 looks like a performer 2.0 But not sure what kinda flow you can get out of any of them.



So

Dual Plane or Single ?
Suggestions?

this a 496 in a book i have the cam is a comp cam xe274 hr-12 hyd roller--with 3 different heads it made 600tq they used a edelbrock rpm air gap duel plane intake 850 carb

[AutoGear]

Whats your intended purpose? what is this going in?

My first guess would be a dual-plane; Edelbrock RPM Performer 2.0 or what-have-you. However, if you're going to run this thing all day at 5000rpm and higher, you might be in line for a singleplane or even one of those high-zoot sheetmetal intakes

[dually502]

Its going to be mostly street. 4000# truck. 4L80 Trans.. 1 weekend a month at the track.

On the bench I have a single plane Victor with Dominator carb flange and I also have access to a RPM Air gap for pretty cheap...

[Bowtie man]

I would go the Air Gap for the low end grunt an the upper end will still be good. With anything bigger it will be mid an upper.

[35WINDOW]

Personally, I think you are the stage where an Air Gap is running out of breath (not enough port volume)-my vote would be a Victor Jr.-

[dually502]

Originally Posted by 35WINDOW

Personally, I think you are the stage where an Air Gap is running out of breath (not enough port volume)-my vote would be a Victor Jr.-

Thats how I have been looking at it.. I wish i could find the flow number on the BBC Air GAp intake. Then I would have a general Idea of the amount of work needed to port it for enough flow to support the heads & cam.

A BBC Performer 2-R flows 287 CFM MAx flow with porting 363 CFM

Found those numbers from a reputable Porter..

This is what my intake flowed.
My single plane Victor Jr. (Style) intake flows 388 CFM out of the box but can flow up to 480 CFM ported..

I was under the impression a RPM Air-GAp outflows the Performer 2, out of the box.

[dually502]

I brain farted here guys.

My last 2 BBC's had the RPM Air-Gap.

A 468 short block that was replaced with a Stock short block 502 we reused the 781 heads, reused the same 288H cam, And reused the RPM Air-Gap..... It wasnt a major difference in power but TQ was increased dramatically.. The 468 tuckered out about 4800 and the 502 about 5400.. Yeah that 502 had alot more seat of the pants feel but It had horrible street manners so I didnt drive it too much. I contribute it all to carb issues..

I thought I had used a Performer intake on those motors. Makes me think..

[35WINDOW]

Since you have both, why not try them (assuming I am correct that you have both)? The weight of your Truck suggests the Air Gap, and the Cam /Heads suggest the Victor Jr.

I was looking for an Article that I had recently read where they tested the Air Gap against the Performer (my recollection is they were a virtual dead-heat)-I didn't find it, but I did find this, (it doesn't help my theory however):

http://www.hotrod.com/techarticles/1...o/viewall.html

[dually502]

Thanks 35window.

I seen that HotRod article were they tested all the Eddie BBC intakes. I wish they had put up some flow numbers, maybe that would have given more insight to the power differences between all the intakes..

I found this. Its a milder cam, lower CR and 781 heads but the short block is identical.

http://www.youtube.com/watch?v=uJI5E..._order&list=UL

I dont have a Air-Gap but can get one for less then $100.. I assume the RPM Air-Gap was the cream of the crop for dual plane intakes?

[35WINDOW]

It sure has it's supporters, no doubt, and I think it is merited. There is a guy, however, who makes big power with BBC's, and his name is Mark Jones (owns a Business called vortecpro- http://www.vortecproperformance.com/ .

He insists that the Weind Stealth has much more plenum volume than the Air Gap-must be something to it as he makes big power with stock parts-sorry to muddy the water-

[dually502]

Originally Posted by 35WINDOW

It sure has it's supporters, no doubt, and I think it is merited. There is a guy, however, who makes big power with BBC's, and his name is Mark Jones (owns a Business called vortecpro- http://www.vortecproperformance.com/ .

He insists that the Weind Stealth has much more plenum volume than the Air Gap-must be something to it as he makes big power with stock parts-sorry to muddy the water-

Thats exactly the kind of info I was looking for. Thanks