Let's talk Carb's !

[bartlett]

I'm planing a carb/fuel system upgrade this year. Right now I run a 750 vac sec holley and a single n20 kit with the fuel supply run off a mec pump for everything and it works perfect and never goes lean on any full throttle passes. ( I run on board digital air/fuel )

I feel Im leaving some Hp on the table and also not running the ideal fuel supply.

Im also on the edge with 11.1 comp pistons and zero deck.

last year I did see a couple of times where fuel soak started to get me on hot days in traffic... It would just start to get ruff and doggy.

My motor .. Fe stroker, 11:1,294s cam,Eddy heads,fpa headers,Rpm intake,street driven,3,500 stall c6,3:70 gears,100-200 shot, et streets, full weight car.

The car likes to be Hot ... It gets to temp Imo very fast ... 1 mile of driving its upto temp. 190ish and will NOT run cooler no matter what I do and runs 200's down the highway on hot days and stays 200 after that. Granted it does not ever over heat. it just likes 200 ! lol ... and 200 is ok in my book ...


So fuel ! Im on the fence ! I'm dizzy with ideas.  one side of me is thinking a bolt on efi. like fast or msd. My racer side is thinking of switching to E85 to run a little cooler and twist in some more timing. Then on the other side I'm thinking a 850 mec and a return system.

In the perfect world Im looking for 50hp more from the motor. I think im leaving that on the table with the vac 750 carb..   

what do you think ?

[My427stang]

I think you will be hard pressed to get 50 horsepower, but there is likely something in there.  I like the idea of an 850 and was right with you until you said 50 hp, that's a big number

My opinion is that it will take more money to get as much as you want, especially with a 434.  What you did with the juice already is the smartest way IMHO and keep in mind, it is providing oxygen so the carb is probably not an issue at WOT

That being said, I think the car would be very happy with an 850, I think a modern EFI would make it very fun to drive and well mannered.  However, I think if you want more power, there are a couple of more expensive routes to take. A couple of examples, but there are many

- work the heads and intake and your bigger carb idea
- work the heads and to a victor, lash it as tight as you can
- work the heads/intake and add cam and gear
- add more nitrous

BTW I really like that car, and I remember your careful build when you did it, it's reliability and performance shows how good your work was.

[machoneman]

What CID is your stroker? Perhaps Jay's dyno testing can supply an answer to whether your carb is too small. Yet, I doubt any carb alone can give you an additional 50 hp. That and a well-tuned 750 vac Holley should give excellent street manners. Can you beg/borrow/steal an 850 for some seat-of-the pants testing?

On the heat issue, what size crank and pump pulleys do you run? Sometimes a larger pump pulley will slow down coolant flow and actually improve heat transfer. Another thought is to temporarily dump the t-stat for some testing and install a hand-made aluminum plate (ala' Moroso) and see if a restriction in the current stat's hole size is limiting free coolant flow.

http://www.summitracing.com/parts/mor-63440

[bartlett]

yea 50 Hp might be grabbing a little to high. But ya gotta have goals right ? I think I'm going to order a victor intake and get to work on that. And do some research on a 850 carb.   

[bsprowl]

How about trying a Holley 3BBL - either 950 or 1030 CFM? 

I'll loan you either if you'll pay shipping both ways.

Bob

[bartlett]

3 barrel ! wow,havent even seen one in a long long time ! That a great offer Bob,but I think im leaning to efi. Im not sure witch one yet ... I like the idea of timing control for nos .