1150 dominator Questions

[Bob Alberty Jr.]

More questions about the same carburator,

It is an older 7320 without adjustable air bleeds, I bought new throttle blades from Chuck Nuyten, but they didnt want to discuss the carb because it is "only a two circuit"

My questions, if it idles through the pits, and is wide open against a chip on the tranzbrake, why would there be any need in an intermediate circuit?

Also, box stock jetting is 95 sqared, I currently have 100 squared in it, and it wants more. What are your opinions about putting power valves in the carb (the motor only pulls 4.5" at idle) say 8.5's so that they are always open, and lowering the main jets so I can get back some adjustability out of it as 100 jets are the biggest I own,or can you buy 100+ jet sizes, all I have found is the alky jets up around 130, and read somewhere that the alky jets were a different thread pitch? Or have I got something screwed up to need someting so far away from the factory jetting? I am running Sunoco 110 gasoline (110 octane) at 7.5 lbs of fuel pressure.

I set the throttle blades with a feeler guage to get them the same, then adjust front and rear idle speed screws the same, to keep it squared, and the four corner air fuel needles I keep sqared, all the way in then out about 1 1/2 rounds is where they are now for the highest vacume reading.

[Tom Goldman]

Bob,Check the size of the main circuit air bleeds, they should be .028". ....If they are larger, it will lean the carb. ........Also,you havn't said much about the engine....The relativly low octane fuel you are using brings up the question of the engine being over carburated...........If the engine /cam head combination does not produce enough air flow at the booster,the resulting poor signal will not pull adaquate fuel thru the booster. .....I've usually found this to be the case when jetting changes are 3-5 jet sizes above stock,and the car still shows lean. ..........Tom

[Bob Alberty Jr.]

Thanks for the reply Tom,

The motor belongs to my sponsor, and it was bought 3rd person, It was all new, we did pull the pan looked at the bearings etc... but we only know what we were told about it. I will dissasemble it this winter to check, but what we have been told about it and the person is a reliable source, he has nice pieces.,before they freshened it he has using it for a nitrous streetcar shootout deal

477 big block chevrolet

10.2 compression,

Comp Cams http://www.compcams.com/Cam_Specs/Ca...?csid=551&sb=2.

Edelbrock heads http://www.edelbrock.com/automotive_...erf_rpm1.shtml

I didnt get the cam card till last week, had been setting the valves at .028, have since re-set them at the specs Comp calls for,.022 .024, made no differance in e.t.

Ignition is an MSD 6al,2 step,blaster coil,msd magnetic pick-up distributor at 36 degrees,(locked), running autolight 3935 gapped at .035

Staging it on a 4800 chip, shifts at 2.75 seconds into the run which is 6800, goes through the lights (1/4) at 7400, powerglide trans 1.76 low, 4.88 rear gear pulling 14x32's car weighs 3250 with me in it, runs 10.30's to 10.20's depending on the weather.

Personaly,I think the motor is lazy,it's consistant,but doesnt have the hit I think it should have say if you tried to do a chirp. Maybe Im just remebering my small block.

I will bring my guage pins home tommorrow from work and check the air bleeds.

[Rich Biebel]

That carb is too big for the motor specs you list and that is why it is lazy.....A 10-1 477 that runs 10.30 will go faster with a smaller carb. A 1050 would be about the maximum carb I would try to use on that engine/car combo.

[Tom Goldman]

I'd try an 850 on that motor. .Not enough compression,or rpm to justify anything larger. .........Probably would work if it was still on nitrous,but way to big without it...........Like Rich said ,It'll probably pick up a bunch of ET with a smaller carb..........Tom

[Floyd Staggs]

How about on a 10 3/4 to one 540 with .714, .714 cam etc? Is the 1150 to big? That's what I'm using.
4000 lb pickup, pump gas, 10.72 @ 122 best.

[Tom Goldman]

Floyd, I'd bet your short times ,probably up to the 660' would pick up considerably. ......I've seen guys use way to big a carb and have success,but I've also seen many who struggled with the problem Bob is having. .....Bottom line is you have to try different carbs to see which is best for your combo..........A while back,.I tried a 1050 on our S/ST AMC Spirit which has a very healthy 401 in it. 13 TO 1, big roller ,ect .....It picked up about 1 mph ,but lost over 2 tenths in ET! , compared to a good 850 carb. ......Tom