[p4msi1]

I didn't want to cut the super 400 hood so I fabbed an aluminum intake low enough to clear it, which it does barely. I am wondering if the top is too close to the top of the runner entry, they are 3/4" down from the top. The new engine is 535 with tiger heads and my victor was not even close to fitting. Maybe I can cut the top off and use 2-4 barrel set up? That would probably make for a smoother entry being right over the port entry. I also made up the water crossover to try and match the intake. I tried to route the water line behind the altenator but that could not work and I did not like the way the radiator hose went in front of the intake so I rolled some alum tubing and welded it on the the crossover. The engine was just fired up and does run well with no tuning yet. I drove it about 1/2 hour and throttle response is good with such large ports. I think Dave Wilcox said they flow about 440 or 450 cfm, he ported them. If I could get some of you experienced intake builders to critique the design, just remember that's all the height you get. I will do dyno testing later.

[p4msi1]

I got alot of people asking for photos of the super 400 hood so I sent them.

Steve

[Daniel Barton]

Steve, the few things that I see that would concern me are the plenum size looks small, the entry angle looks like it would not match the angle of the port in the head, the runner in the manifold appears to be straight and not tapered and I usually like to have at least 5/8 of material around the port at the entry in the plenum before any kind of wall is there. The runner also looks quite short. I understand that you are dealing with room constraints but those are the things that pop out at me from the couple of pics you posted. Hope some of this was some help to you. Dan

[p4msi1]

Dan, Thank you for the response ! If I open the plenum it will shorten the runners. If I widen the plenum I might be able to correct the port entry angle but still have short runners. My time is very limited so I decided to not do a fat radius at runner entry. I was trying to just get the motor running. It took me about 26 hours to build the intake and crossover. I can always cut the top off and correct it, at least on 3 sides of each port or just build another one with the runners separated and tapered. Now that the car is running I could take my time with it. Would 2 carbs help fuel distribution on a low profile manifold as this.

Steve

[Daniel Barton]

Steve I honestly cant answer you about running 2 fours on that particular intake and its affect on fuel distribution, the plenum is so shallow that I think that the fuel will be bouncing off the floor of the plenum. I would really be pushing for you to change hoods so you can get a better intake on it... The size of the plenum and it being shallow as well as the entry angle and lack of taper in the runner are what concern me the most I guess. The quality of your work looks good, it is the area constraints that make it near impossible to do a sheetmetal intake well. Good luck, Dan

[twinturrbo406]

Originally Posted by p4msi1

I didn't want to cut the super 400 hood so I fabbed an aluminum intake low enough to clear it, which it does barely. I am wondering if the top is too close to the top of the runner entry, they are 3/4" down from the top. The new engine is 535 with tiger heads and my victor was not even close to fitting. Maybe I can cut the top off and use 2-4 barrel set up? That would probably make for a smoother entry being right over the port entry. I also made up the water crossover to try and match the intake. I tried to route the water line behind the altenator but that could not work and I did not like the way the radiator hose went in front of the intake so I rolled some alum tubing and welded it on the the crossover. The engine was just fired up and does run well with no tuning yet. I drove it about 1/2 hour and throttle response is good with such large ports. I think Dave Wilcox said they flow about 440 or 450 cfm, he ported them. If I could get some of you experienced intake builders to critique the design, just remember that's all the height you get. I will do dyno testing later.

... i agree with Dan, but if it were me, i'd change the runner/faceplate flange to a .500 thick piece on both sides, the flange that connects the runners to the plenum section, basically what the carb see's entering the runners ... this way you can shape the entry into the runners by hand to a nice radius, or if you have access to a mill you can machine the radius on the flanges and flap/wheel it smooth, then weld it together ...
... what those corners will do is trick the air/fuel mass into reacting as if the runners had less CSA at the runner entry then they actually do, because the air/fuel mass can not make that dead corner, so it over runs the corners on all 4 sides and enters the runners more in the middle of it instead of using all the CSA that is actually there ... hence behaving as if there were less CSA ...
... i would also split each runner/pair apart from each other about .750-.800 so you can let them have some kind of radius between them, then if you are able or willing, i'd aim the runner/pair at the carb bores slighty ... to help minimize the the hard turn for the end runners ...
... as for changing the carbs, i would run AndersonPortDevelopment Split Dominators of the correct sizes, but linkage might not be something you want to deal with, if so, you can run one of my EXT Dominators, just depends on what direction you want to go ... the pics below are of one the Proto-Type EXT Dominators we used for testing, i have many colors to choose from also, if that matters, i like the Titanium color myself, which is what the center billet body is coated with ...
... as for the taper, or lack of it in your case, you'll want to be careful with that as you do not have much runner length to play with and it may be very sensative to too much taper, i do feel it would respond from having taper, but the tough question will be how much will it tolerate before it starts moving the power band way up, what is the runner length you have now ?? ...
... but i do realize you want to keep that hood, but i would recommend changing it in favor of a taller one , at high rpm that setup could be a real problem ...

[slowbird]

Bill's thats a cool carb you design that?

[twinturrbo406]

Originally Posted by slowbird

Bill's thats a cool carb you design that?

... most of my involvement with the EXT system is with the calibrations and plenum/spacers, we are currently working on an "Anti-Reversion" spacer for it for further testing, the EXT has shown promising results thus far ...

[Jim Robertson]

Built the intake in the pics with similar self-imposed constraints of the hood line. In my case I was trying to stay under the shaker of a 71 T/A. Manifold size looks very similar with small shallow plenum, single dominator and flat top. In a back to back test on our dyno this manifold was down about 3.5 percent from a ported Victor and 1" spacer (which would not fit under the hood line either.) We ended up running the Victor and 1" in the car with a different hood.

The third pic is what the intake looks like now. We will see if this combination likes two 950HPs and 1" plenum spacer better than the flat top. We have a total of 2.5" of spacers built and will be testing a few sizes to see what this combination likes.

Rattlesnake nearly ruined the party.

[65nss4spdGTO]

I just picked up one of Bill's carbs last week, it was a Christmas gift for my GTO from Hill Performance. I was having issues with my borrowed HP 1000, I put this thing on and it would idle at 950 RPM with a nice throttle response.

Calvin Hill
Hill Performance / Mondello Tech Center
708-250-7420

[BruceWilkie]

These guys know more than me, however, I see a few things.... Dual carbs (if greater overall flow than current carb) should slow the velocity into the plenum plus help distribution.

I also dont like the runner stagger at the plenum... Think I'd try to get them across from each other.(at least closer) Possibly widening them at the same time. Try to get straightest shot from dual carbs.

Also the pics seem to show you might be able to get away with lowering the bottom of the plenum a little bit more. You dont want it too low(flat line across or uphill) though.

Your hood is nice! Gives me the thought that maybe some kind of cross ram intake arrangement might be something to consider.

[60man]

Originally Posted by 65nss4spdGTO

I just picked up one of Bill's carbs last week, it was a Christmas gift for my GTO from Hill Performance. I was having issues with my borrowed HP 1000, I put this thing on and it would idle at 950 RPM with a nice throttle response.

Calvin Hill
Hill Performance / Mondello Tech Center
708-250-7420

Think your getting enoughg fuel to it Calvin ??
Is that some that "5/8" ID #10 push loc ??

[john marcella]

Its sucks when the #1 priority of the design is to make it fit. At that point every part of the manifold is compromised big time.
2 carbs will be better always. But in this case really better, carb way to close to the runner and plenum floor, Better fuel distribution and always better to have the runners under a throttle blade for many reasons.
I see lots of issues but there is not much you can do if you will not cut the hood.
If you can get 2 carbs on it, do it and get them up as high as you can.

PS cut the dam car.LOL

[p4msi1]

TT406, Jim R., Bruce and John Marcella Thanks for the responses. I now have all this technology pouring in that I can apply to the next manifold. I think right now I will simply tune this current design, dyno it, then cut the top off, radius the runner entrys and make a removeable plate for the top so I can go from single to 2 fours and test that.
John, I know you want to cut it up and I would not be opposed to it if there was a scoop that could integrate well with the hood. I would rather cut up the original 400 steel hood. I am also struggling with back halving to car. I didn't struggle this hard deciding to get married, start my business or moving my family from Louisiana to Virginia!

Steve Prudhomme

[p4msi1]

TT406 that is a trick looking carb you have there, never seen anything like it. I'm sure it would help but I think a 2-4 set up may be better in my case. How much are you selling them for? I could toy with the idea of angling the runners toward the center of the plenum where that " extended Venturi" carb you have could be situated over the runners.
Everyone, just realize that this is a pump gas (93 octane)street car that will go to the track about 3-4 times a year maybe more if time allows. If the horsepower is down 3-4% it still may make enough. Looking for at least a 9.80 in the 1/4. I go to the local tracks to run my car and pass out flyers to advertise my chassis dyno. The old combo could drive to the 1/8 mi. track and run high 6's. Now I'm looking for low 6's.I do dyno tuning on carburated cars for a hobbie and a little cash. My real job is metalwork, you can see the press brake and shear in the background.

[twinturrbo406]

Originally Posted by p4msi1

TT406 that is a trick looking carb you have there, never seen anything like it. I'm sure it would help but I think a 2-4 set up may be better in my case. How much are you selling them for? I could toy with the idea of angling the runners toward the center of the plenum where that " extended Venturi" carb you have could be situated over the runners.
Everyone, just realize that this is a pump gas (93 octane)street car that will go to the track about 3-4 times a year maybe more if time allows. If the horsepower is down 3-4% it still may make enough. Looking for at least a 9.80 in the 1/4. I go to the local tracks to run my car and pass out flyers to advertise my chassis dyno. The old combo could drive to the 1/8 mi. track and run high 6's. Now I'm looking for low 6's.I do dyno tuning on carburated cars for a hobbie and a little cash. My real job is metalwork, you can see the press brake and shear in the background.

... you have a really nice bird' by the way, regardless of the intake height, lol ... as for the spread-venturi dominators, i can build them with a range of sizes anywhere from 2.00(1050cfm) up to 2.800(2300cfm) ... for me to give you an acurate price i'll need all of your engine and vehicle details, as this will affect the components that get used in the carb, block type,throttle blades,circuits,boosters and skirts, and obviously calibration, but these carbs are generally a little over 2K ... as they are billets units, lots of spindle time ... maybe i should start a seperate thread, i do not want to hi-jack your thread ...

[p4msi1]

TT406 don't worry about highjacking this thread, it sounds like more people should hear about your carb.

[twinturrbo406]

Originally Posted by p4msi1

TT406 don't worry about highjacking this thread, it sounds like more people should hear about your carb.

... well i appreciate that P4, i do need to start a seperate thread due to the extensive amount of products i sell for fuel systems and carbs, i just thought this spread-venturi might help you ... they are pretty cool to look at though ... a little pricey but it is a full billet carb ... hard to make one of those cheap ... if you dont want to go that route, i'd suggest split-dominators, not too sure i'd go the dual-4 route on pump gas, i can have some options also with the dominator style boosters such as skirt extentions, and circuit and emulsion options too, but you may end up having to experiment with some rough-diffuser type turtles in that intake, it is very close to the carb ... you can try maching some rough steps on the bottom side of the top plate, basically the opposite side of the carb, you may have to make it a .500-.750 top to have the room for the stepped-radius ...