Tunnel Ram Carb Confusion

[Ironraven]

I'm new to the site and what a wealth of info. I have a BBC 489 with a rpm air gap and 780 quick fuel carb, dnyo out at 600 for torque and 593 for hp, but at 5300 rpm. Great to drive on the street. I would like to push the torque and hp above 6000 closer to 6500 and I was thinking about doing it with a tunnel ram. I was thinking about going Weiand 1981 TR with either 650 eddy's or 650 holley dp. As I stated it's a 489BBC with a Howard cam 237/243 duration and 635/641 lift, Edelbrock E street oval heads, and 10.1CR. It's in a 72 Nova, TKO 600 and 3.73 posi. It has 2 in headers and 3 in exhaust all the way back with H pipe. I'm looking for some guidance on TR's and carb size, no experience, but something I've always wanted. It will mainly be driven on the street. Thanks

[1980RS]

I'm new to the site and what a wealth of info. I have a BBC 489 with a rpm air gap and 780 quick fuel carb, dnyo out at 600 for torque and 593 for hp, but at 5300 rpm. Great to drive on the street. I would like to push the torque and hp above 6000 closer to 6500 and I was thinking about doing it with a tunnel ram. I was thinking about going Weiand 1981 TR with either 650 eddy's or 650 holley dp. As I stated it's a 489BBC with a Howard cam 237/243 duration and 635/641 lift, Edelbrock E street oval heads, and 10.1CR. It's in a 72 Nova, TKO 600 and 3.73 posi. It has 2 in headers and 3 in exhaust all the way back with H pipe. I'm looking for some guidance on TR's and carb size, no experience, but something I've always wanted. It will mainly be driven on the street. Thanks

Welcome, I think you would make less torque with the tunnel ram but more hp. I would not hesitate to run some more carburetor on that 489 in a heartbeat. The easiest and cheapest might be a single plane intake and a bigger carb.

[bigfoot584]

Retard the camshaft 4-5 degrees.

[jeff swisher]

I have seen results of retarded cams and more power up top was not the result.
My results were less power everywhere.

I have ran many tall tunnel-rams I run 600's on sbc 350's and you should look at 750's especially for that large cube BBC.
I prefer the 1407's

[prairiehotrodder]

i think a TR will make more power and torque everywhere. I have one on a 555 BBC and i love it. I'm using a pair of the Holley 750 track warrior carbs. All i did to them was put in smaller idle jets in the metering blocks then they worked great. The TR picked up my car 2 - 2.5 tenths in the quarter over a super victor and a QFT 1050 dominator. I also think 750's will work good right from 454 CID on up to about the 900 hp level with bigger motors.

IMG_2136.JPG

Brian

[Ironraven]

I was considering a single plane, but if I was going to make a change I would do the TR. As far as the 750's, would you be using Holley's or Eddy's? Thanks

[F-BIRD'88]

Either the weiand hi ram or the Edelbrock street tunnel ram
(oval) will make more torque and more power.. You can bump the cam duration up 250 deg ish if you want peaks to occur higher up... There are Howards cam lobes from that same lobe design family, in the 250+ ish range for you...Use at least 2x 750's .. Eddys are fine.
Easy to set up
. Easy driving. It will eat up a single plane.

2x eddy 800 AVS carbs are not too much at all.

If when using holleys on a TRam you ideally want all the venturi equal size. Thus 2X 750 HP's.
Don't under carb it.. A t-ram wants to eat.
Its critical to it making more power and torque.

[PRH]

I would like to push the torque and hp above 6000 closer to 6500

If this is really the goal....... for a 496 with oval port heads....... you’re going to want more duration than 237/243@.050.

Based on the specs you’ve provided, it appears to be a HR cam, which in itself can provide challenges with BBC’s using some of the common “street duty” type HR lifters, when seeking reliable operation in the 6000-6500 range.

My experiences with the “smaller” TR intakes is they usually make more power than many single carb manifolds...... but don’t necessarily make it at any higher of an rpm.

[Ironraven]

I figured duration would come up, but the motor only has about 2500 miles on it, so that will come at a later date. Would a couple Holley 750, 3310's work? I just remembered I had one squirreled away. I was really looking at those 800cfm AVS2, I just wasn't sure if that was a bit over the top. Thanks for all the great info so far.

[F-BIRD'88]

No don't bother with 3310 carbs at all for this.
Use 750 hp style dp holleys or the 800 eddy is a great choice if you want demand secondaries.. Easy tune' easy inline set up.. No, the 800 eddys are not over the top.

[tjs44]

At least a pair of 800s IMO.Tom

[F-BIRD'88]

Another path to more street torque and power is going with the Eddy Dual QUad RPM hi rise manifold + spacers and 2x 750, 2x800 eddy carbs.. Plus the bigger duration 250 ish cam. Not quite as high as a TRam.. The carb spacers kick up the top end to work with the new bigger cam.

[Ironraven]

I did look at that RPM dual quad with eddy 650's, but the gain didn't seem to be there, but your thought is to use 1in open spacer with with a 750 or 800 and the cam change? What in your opinion would be the results if I didn't go with the cam change, but did all the rest? This is good stuff thanks

[F-BIRD'88]

The cam you got is small. A bigger cam will make more power. It all has to work together. The intake may want 2" spacers.. Give it what it wants.

The carb you got on there now is even way too small.

Double it.

[F-BIRD'88]

Howards roller cam 120893-08