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Author Topic:   Intake too big?
tilley88
Dirt Forum Champ
Total posts: 879
posted April 07, 2005 01:34 PM  
I'm running a 358 on gas, Dorton 4412 carb. Intake is one of those big 'ol Hurricane single planes. My motor seems lazy on take-off, and I'm only turnin' 6300 rpms's. If I switch over to an air-gap dual plane, will that help bottom end and total r's?

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted April 07, 2005 02:31 PM  
yes, it will help the bottom end and will prob turn more rpm because it will pull harder through the midrange.

A. Bighurry
Dirt Full Roller

Total posts: 35
posted April 07, 2005 08:49 PM  
We used a Performer RPM air gap intake and loved it. Great low end and pulled strong all the way through.

wfoondirt
Dirt Forum Champ
Total posts: 505
posted April 08, 2005 07:46 AM  
Why not just put some more gear in it?

Dman
Dirt Freak

Total posts: 270
posted April 08, 2005 08:38 AM  
Could be cam timing. Not all cams are ground straight up.You may need to check the degreeing. You may just have too much camshaft for what you are running. We have run the Hurricane intake on everything from a 327 to a 410 and no problems so I don't think thats it.Let us know when you figure it out.Good Luck!

tilley88
Dirt Forum Champ
Total posts: 879
posted April 08, 2005 10:05 AM  
It's a somewhat small solid vacuum cam. I've run this motor with a cast iron Bowtie intake and turned more rpm's and pulled better vacuum. I'm running a 5.83 gear now, had a 5.43 gear in it. I ran my 750 Holley on the same motor/intake last year and it was lazy, too. When I ran the Dorton 4412 on my 383 w/Bowtie 2 intake(slightly shorter than the Hurricane) I had better throttle response and turned 6800-7000 r's. I just bought a Crosswind air-gap intake, hopefully it'll be here in time for next weekends season opener.

andykmod
Dirt Freak

Total posts: 351
posted April 08, 2005 11:12 AM  
Sound to me like a cam issue, but yes the smaller intake should help with your mid-range power, but not to sure about higher rpm's

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted April 08, 2005 11:49 AM  
Do you have any carb spacers on the big intake. If so I would take them off first, then try the other intake. It might help enough to save you from changing intakes, maybe, maybe not.

If your only turning around 6500 then the dual plane intake will prob work better in most cases. The newer dual planes like the performer rpm work really well and flowgood even to 6500, especially on a 358, if it were a 400 it might be different story. The big single plane intake doesnt keep the air velocity up engough to work well at lower midrange rpms lke your running at. Its the same as going too big on intake runner size on heads. Too big and you kill torque because of the decrese in air velocity. Unless your turning it well past 6500 then the dual plane will create a better torque curve for you. You have already seen the difference between your other intake though so you know what to expect.

tilley88
Dirt Forum Champ
Total posts: 879
posted April 08, 2005 01:07 PM  
No carb spacers except the 2bbl adaptor. Gettin' 'er thru the corners better should help, too, but that's another post(lol)!

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