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Author Topic:   350 cfm carb motor
tweiii
Dirt Roller

Total posts: 10
posted November 19, 2004 12:29 PM  
I know this question has been asked many times, but I don't beliveve the answer is practical to all racers. This is a two part question. We have to run a stock 350 cfm holley 2 bbl carb. We can run a cast iron intake, no high rise or bow tie and do what we want to it with any 1" thick spacer or we can run a weiand spec intake #7547 with a mr. gasket adapter. Any steel heads except bow tie. There is no cubic in rule, no compression rules, and no vacume rule. The only other rules are no roller cams, roller tip rockers only. I know the best engine is a light weight short stroke, but we have a $425 claim. With that they take oil pan to intake includes flywheel and balancer. Due to this most people are building 383's or 400's with about 12 to 1 vortec heads and steel intakes. On an average we spend about 2500 to 3500 to have a motor from oil pan to intake. What do you recomend for this price range. Also there are a few big shows where we will spend 5000 so do you recomend something different for these shows. At the last one I had a 412 with dart 49cc heads and a (spec)alum intake. I would apreciate any help.

tweiii
Dirt Roller

Total posts: 10
posted November 28, 2004 09:25 PM  
Is there any additional info that I need to give or if this exact question has been answered I would realy apreciate any help.
Basicly I am wondering what heads I should use and the motor combo such as 305,350,383,400, and finally what rod lenght to use with the combo. thanks

tweiii
Dirt Roller

Total posts: 10
posted November 28, 2004 09:28 PM  
Sorry but i wanted to add that we have dyno tested 350, 383, and, 400 and the 400 made the most power through the range but they all had different heads and intakes. thank you

racer17j
Dirt Forum Champ
Total posts: 5390
posted November 28, 2004 11:07 PM  
With the 400 talk, which is better 406 or a 377 all parts basically being equal internally. Just a curious question. I never have ran a 377, just wondering.

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juliaferrell
Dirt Freak

Total posts: 370
posted November 29, 2004 10:17 AM  
The most important thing here is rpm range with the 350 carb............small cubes and higher rpms or big cubes at lower rpms. I would run 3.336 stroke and 6.125 rod with 4.155 bore............compression as high as I could get!! About 250 duration and as much lift as possible. Turn about 6500.

tweiii
Dirt Roller

Total posts: 10
posted November 29, 2004 09:31 PM  
quote:
Originally posted by juliaferrell:
The most important thing here is rpm range with the 350 carb............small cubes and higher rpms or big cubes at lower rpms. I would run 3.336 stroke and 6.125 rod with 4.155 bore............compression as high as I could get!! About 250 duration and as much lift as possible. Turn about 6500.

How much would a combo like this cost to build?

Istock66
unregistered Total posts: 10
posted November 30, 2004 04:28 PM           send a private message to tweiii   Edit/Delete Message   Reply w/QuoteBBBBBB
3.336 stroke is a short stroke motor.

It has a steady power but needs rpm.

Youll never reach the potential of that combo with a 350 cfm carb.

I worked with that exact motor combo in a pavement late model, unrestricted carb motor with brezinski cc corrected bowties. It was dynoed and the peak hp and peak torque were at 6800 rpm.
It was a 12000.00 dollar motor or so.

I run a 350 carb and have 406's.

sjakes, a 377 is again a rpm motor, anything will work but the longer stoke motors work better, with the restricted carb. The longer the rod the better, but in our claimer class 5.7 is as long as mines ever getting..

mudd on the tires
Dirt Full Roller

Total posts: 42
posted December 06, 2004 04:12 PM  
weiand spec intake #7547

is this intake cast iron???

Istock66
unregistered Total posts: 42
posted December 06, 2004 05:07 PM           send a private message to mudd on the tires   Edit/Delete Message   Reply w/QuoteBBBBBB
7547-1 alum single plane.

turmoil
Dirt Roller

Total posts: 7
posted December 06, 2004 08:08 PM  
Dont try that short stroke big bore deal. go with a 3.75 stroke with 350 or 400 block. 5.7 rods are ok 6.0 would be better. spend your money on your heads and intake. Trust me dont waste your money on a pavement motor.

speedy2
Dirt Full Roller

Total posts: 54
posted December 17, 2004 09:14 PM  
My OPINION/BEST MOTOR IVE RAN was a 383 stock rod, bone stock double humps w/ 1.94,1.5, and stock 2 BBl intake that had a cam that was a little smaller then the midwest #8. Ran that with the Holley 350 2BBL. That motor got me 4 wins countless top 5's and 6 points out from being track champ. One thing i figured out is put more money in your car then your motors and the speed will come. Just my opinion guys

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted December 18, 2004 11:01 PM  
dave is right
at the indoor go kart races, our open 2 strokes that put out almost three times the power can't keep up with the stock kt100 yamaha's... they just can hook it upa nd go... it doesn't take a big motor just takes a good foot and good setup... and a GOOD Carb on a decent motor will wake any motor up

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