jeffs

As far as you guys know, will I have any clearance problems with a Speed Demon + Performer RPM, or RPM Air fitting under the stock 1978 hood?

Alwyn678

Should be no problem......I got a performer and an edelbrock....and it fits fine..Is the demon any taller?? I am pretty sure it will work

Red73

This fits under my 73 stock hood.

ylose

from my understanding....if you want to use the conventional air cleaner the
RPM intakes won't fit with the carb and air cleaner... RPM intake is considered a highrise intake.

but you can do as the above pic and use a pro-flow to allow better clearances..

otherwise you will need to stick with the performer air gap (performer is a low rise intake)....as it isnt a high rise....

gkull

You list a Team-G in your profile. If it fit's anything shorter surely would. Are you running the team G now?

jeffs

Yes, I run a Team G with a Holley now. I have about 1/4 in. clearance with the stock air cleaner.

gkull

Dumb question #2. What are you trying to accomplish with a manifold change?

Red73

Just curious, why are you looking to change?

jeffs

gkull, Red73,

I would like to get better off-idle throttle response up to 4000 rpm. You would hope with my engine I could beat these 320 hp camaros. Not so.
I also have to run very rich now to keep a slight stumble out at off-idle. I was hoping a dual plane and the Demon would help fix this as well as let me pass emmisions without a carb tweak each time. This may not be a factor, but my heads have 320cc runners and I was hoping to also maybe counter a possible "lack of intake velocity" problem.

I was putting 3.73 gears in this winter to help get the engine up into the higher rpm range quicker.

Any thoughts from you guys would be appreciated.

Jeffs

Tim H

Your off idle stumble is either the squiters or you need a 50cc front pump on the carb,also sometimes take off is so good that gas comes out the vent tubes and drowns the carb. Try connecting the vent tubes with a piece of rubber hose with a hole cut in the middle on the top.
Don't change the intake,try a 750 double pumper with the jets and power valves mated to your combination.
I have very good luck with my 650 DP.

yellow 72

This is off your subject in question but if your talking about a stumble just as the throttle is cracked and not a wot bog, I chased the same thing for months.
I have a disscontinued Holley 4010 600 dp that did this from day 1 out of the box. Changed squirters, squirter cams, timing etc. and nothin' helped.
Finally talked to a Holley tech and he suggested opening up the idle feed restrictors and BINGO instant throttle response. I've had a lot of people tell me this carb would never perform well. Not true you just have beat on it with the right hammer :smash: :lol: and find the person with the right answers :yesnod:

gkull

I'll assume that you ment Pro-1 230 cc. They use a Fel-pro 1206 gasket size. You can't go to a smaller intake runner size. I gave it hell trying to fit both a Stealth and an RPM to 230+ cc runners. So I went back to my single plane.

How manifolds get a tuned ram effect over a certian rpm range is: The port clear down to the valve has to continually get smaller. so as the A/F mix is heading for the cylinder it's speed increases and causes cylinder overfilling for a ram effect. If your manifold port is smaller than your head port the speed decreases and the fuel will drop out of suspension. Jetting becomes a nightmare and it will never really run right.

A 406 should kick some butt. You really just need to set up the 750. get a vacuum gauge and set the idle and then bigger squirters and play with the cam colors to maybe bring in the squirt faster.

jeffs

gkull,

I am going to find out the model # of my manifold. I know they had to build up alu on the manifold so it would match up to the big head ports. This makes me feel that I should research the port size of the manifold. Also, if they did not port match the manifold to the 230cc Pro 1 head ports, (just built up alu to cover ports) I could have the condition you describe. That is, restriction at the entrance to the head, then expanding back out to 230cc once in the head.

I thought I had the Team G # 7525 w/EGR. I will check.

What manifold do you have, and what size head runners?
thanks for the info.

Jeff

nunus79

I planned on installing that 7525 manifold in a couple of weeks. Its matched to a 1256 gasket. Big jump from 1256 intake to 1206 heads.

Did you try running the #7460/7461 spacer w/plenum divider plate?

jeffs

nunus79,

I have not tried the plentum divider. I needed to put a thermal spacer under the carb to keep the carb cool. This only left me with 1/4 in space between the stock air cleaner and the hood. There is not room at this time.

I have never port matched a manifold to heads so I do not know through experience if this big difference between port sizes lends itself to a successfull port job (keeping in mind gkull's idea of a funnel shape to the valve).

Any thought are appreciated.

Jeff

gkull

http://www.weiand.com/HiOctn/ProdLin...AMSM/7532.html

You have to use a dropped air cleaner. I have a 3X14 K&N

This is a big pic 600K It shows my 825 race demon and 1/2 inch wood spacer. Crane stud girdle required with solid roller cam. Ask Nunus. He came to Reno a couple of months ago and it's a nice street motor.
http://temp.corvetteforum.net/c3/gkull/stuggirdle.jpg



[Modified by gkull, 10:19 PM 11/16/2001]

nunus79

Jeff
I rode in, no, I held on to dear life in Gkull's ride. Throttle response whether it be just moving along from traffic light to traffic light or from a roll was incredibily smooth and powerful. The motor never missed a beat, no stumble, no nothing. That was enough to convince me that single planes can be your friend. :D

Vette's hood clearance conditions surely forces one to be creative, doesn't it. I'm going to try running my Qjet on the 7525. Wish me luck. :seeya

Red73

George, Are there vacumn ports with this manifold that I can't see in the picture? Rod
http://www.weiand.com/HiOctn/ProdLin...MSM/f7532.html


[Modified by Red73, 8:14 AM 11/17/2001]