Question on a dual plane intake on a 557

I am putting together a 557 for a 70Torino. It has the factory scj heads that are ported and the cam is a solid flat with 260 and 264 @ .050 and .640 lift. I am running a Blue Thunder dual plane intake with the scj ports and standard holley flange. Going to use a 950 or 1000 cfm carb. My question is what should I do with the center divider on the intake. It is milled down 1 inch right now. Some people are telling me to mill it down all the way for more high rpm HP. The car is 4000lbs with 4speed and 4.11 gears. I mostly am going to show it and run the crap out of it. Maybe a little racing. Also, I am not one of those guys that shift at 5k to save my engine. Most likely it will see 6,500 alot if not more. You guys always have the answers for me. Thanks in advance. Dave W

Couple of questions:

1) Are you hooking this up to a shaker?

2) Are you keeping the dual plane for appearance sake, or can you use a single plane?

One thing is for sure, you do not want to just mill down the center divider.

Dave

Yes I am keeping the shaker. I want the dual plane for stock look. I am going to Mod the shaker fit the carb that sits higher. I have a Torquer II but I did not like the look. I want it to look stock. Dave W

A dual plane intake tends to be very restrictive when compared to a single plane so anything you can do to make that restriction less will help. On a large engine I would most certainly mill down the divider inside of the plenum, down at least to within about 1/2 inch of the floor of the top side runner bottom. I'd use a flow bench to determine the bad runners and give those the most attention. The results will surprise you and I'll bet you'll find that one of the top ones will be the worst probably cyl number 8 with the bottom ones being better.

I did some testing on a 408 Cleveland engine making about 500 horsepower at 6000rpm where we had to use a factory Boss intake for hood clearance(Pantera) and we compared the ported stocker to an out of the box Blue Thunder dual plane and a Strip Dominator and we found less than 10 horsepower difference between mine and the Single plane but the stock Blue Thunder was about 15 horsepower down. Playing with an open spacer helped the Blue Thunder big time as it did the Boss intake.

While different I feel that these trends would also hold true on a larger engine.

DaveMcLain wrote:A dual plane intake tends to be very restrictive when compared to a single plane so anything you can do to make that restriction less will help. On a large engine I would most certainly mill down the divider inside of the plenum, down at least to within about 1/2 inch of the floor of the top side runner bottom. I'd use a flow bench to determine the bad runners and give those the most attention. The results will surprise you and I'll bet you'll find that one of the top ones will be the worst probably cyl number 8 with the bottom ones being better.

I did some testing on a 408 Cleveland engine making about 500 horsepower at 6000rpm where we had to use a factory Boss intake for hood clearance(Pantera) and we compared the ported stocker to an out of the box Blue Thunder dual plane and a Strip Dominator and we found less than 10 horsepower difference between mine and the Single plane but the stock Blue Thunder was about 15 horsepower down. Playing with an open spacer helped the Blue Thunder big time as it did the Boss intake.

While different I feel that these trends would also hold true on a larger engine.

Thats what I have been hearing. But the advice was coming from Chev guys and we all know that what works on a SBC does not work on all engines. Do you think I would be better off with a Torquer II that is a single plane with somewhat smaller ports. I can port the ends to SCJ ports but the whole port is smaller. It would take alot of work but I can putty and mold the outside of the Torquer II with Kevlar Putty and make it look like a dual plane intake. Dave W

badmusclecars wrote:It would take alot of work but I can putty and mold the outside of the Torquer II with Kevlar Putty and make it look like a dual plane intake. Dave W

Boy you are serious aren't you? I'm simply going to paint my Torker II Fomoco blue for the stealth look on my SCJ Torino with shaker. Only hardcore guys will notice.

I feel that without question the Torquer 2 would be better. I've done that sort of stuff to an intake before and it is a lot of work but it can be very effective when trying to fool the competition.

DaveMcLain wrote:I feel that without question the Torquer 2 would be better. I've done that sort of stuff to an intake before and it is a lot of work but it can be very effective when trying to fool the competition.

You have convinced me to go with the Torquer 2. Once I mod the intake everything else will be easier since it is the same height as the factory manifold. Thanks,Dave W