Too much Carb for a 318?

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Cameron1038

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I'm pretty sure I know the answer to this, but I am (like most of us I think) trying to save a buck.

I was planning on a 650 eddy for this build, but I have (in parts) a holley 750 DP.

The build is

318 w/ 360 heads.

forged aluminum pistons that put it at right about 9.8 to 1.

isky cam .485 lift, 280 dur, 232 dur .050, LC 108

M1 single plane intake

doug's headers.

So, is a 750 DP too much?
Pretty sure it is, just wanted some feedback.

Thanks!
 
maybe a little.it could be tuned to work.whats the rest of the combo like?gears,automatic or stick?
 
I agree with you 340-8. I would like to see a 650 vac. sec. carb and maybe a dual plane intake on this combo especially if you have an auto and not much convertor or rear gear. I always thought it is better to jet up a smaller carb than jet down a bigger one.(to a certain point) Keep the velocity up.
 
I dont have a stall converter picked out yet, but it is going in a 73 swinger with a 727 and 3.55 gears.
 
A 750 can work fine, though, I'm with the guys on this one. More gear would be nicer, but if your staying with 3.55's, look for a higher stall converter, with advice from a pro on the matter.
 
Well, I do plan on staying with the 3.55s, any advise on which converter to go with?

650 with vac. sec. sounds good to me. I might go with a dual plane eventually, but the M1 is sitting on top of the motor now.
 
No advise from me on the verter. I'd contact a pro shop for best results.
 
Cameron1038 said:
Well, I do plan on staying with the 3.55s, any advise on which converter to go with?

650 with vac. sec. sounds good to me. I might go with a dual plane eventually, but the M1 is sitting on top of the motor now.
Click to expand...
the isky cam you have is a 280 mega.with that cam id go with a 2500 + converter.you could gain a little velocity/low end by modifying your manifold with a plenum stuffer called a "turtle".do a search for brodix turtle.i think summit may even carry them.
 
I was curious about the cam. Here's what Isky recommends:

280-MEGA High performance use/bracket racing. Lopey idle. 2500 Stall. 9.5-10.5:1 compr. 3.90-4.11 axle ratio. Up to 780 CFM Carb. RPM-Range (2500-6800) Valve Lift (.485 .485) Valve Lash hot (.000 .000) ADV Duration (280 280) .050 Duration (232 232) LC 108

This cam changes the whole equation.
I would say the M1 would work with this cam. The rpm range for the manifold is 2600-6600 rpm. which is pretty well matched with the cam. This combo would also be great with a bigger cube motor. It definitely needs converter and gears.
 
Well, the 750 is to big. I would go with a 650 cfm. to start. On the calculations for your engines displacemnt, it shows you should have at least 598 CFM. To go to a bigger carb, I would run the car down the track and see if you are pulling a negative on a vacuum gage through the line. If you are, you can go to next bigger size carb and tune it from there.
 
Hey Cam, what would you like to do with your car? Drag race? A nice running street car? It looks like we're all thinking maximum horsepower here. You may not want that.
 
This car will probably see the strip at least a few times, but no, mostly a street car.

Thanks everyone for the advise, I am fairly new to the game.

Toolmanmike, that was my thinking when I built this engine, I like high reving engines.

I want to stick with the 3.55s, and probably a 2500 stall. I am going to try to loose weight wherever possible.
 
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