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Discussion Starter #1
Under what circumstances would the following be optimal on a jet boat:

Short dual plane (performer)

Tall Dual plane (Perf. RPM)

Air Gap

Short single plane (eddy torker)

Twisted short single plane (torker 2-0 with the carb rotated about 30°)
 

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Discussion Starter #3 (Edited)
Yeah...I'm bored today. :D

Actually, it seems as if the shorty single plane manifolds are advertised to work up to the same RPM range as the tall dual planes, but they aren't advertised as starting to work until a higher RPM range....which seems kinda stupid to me. How can a long runner dual plane work almost the same as a super short runner single plane? I'm sure the answer is, "it can't", but since edelbrock still sells em, along with plenty of others, I'm sure there's a reason behind it. I'm looking for that reason.

BTW, the motor is a 9:1ish oval port 468 BBC w/ about a .520 lift 218° @ .050 flat hydro cam in it. It had a single carb tunnel ram on it with a cobbled together vac sec. carb that didn't work for shit, among other problems. I bought the boat as a bit of project (cuz I need another one of those:D) and realized it's been a while since I played with stockers, so I dunno what to do.
 

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Maybe the short intake was built for hood clearence on car apps. But I think a single plane works best on a jet boat app. due to RPM jets cruise in from 2750and up in RPM! I also run a Weiand Stelth that was to help with rear deck clearence! WT:)devil JMO!

Single plane intakes work better in upper RPM!
 

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Okay Ill play.
I would use the perfomer rpm air gap with a dominator and a big spacer. Or a tunnell ram with 660's to 5000rpm. Any higher you would need dominators and a sheetmetal intake, Im guessing a spread port head would work to 6000rpm.:)grn
 

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Discussion Starter #6 (Edited)
Okay Ill play.
I would use the perfomer rpm air gap with a dominator and a big spacer. Or a tunnell ram with 660's to 5000rpm. Any higher you would need dominators and a sheetmetal intake, Im guessing a spread port head would work to 6000rpm.:)grn
Good idea...I'm putting in a daycruiser and plan to run in the 10 second class..


PS: You've been hanging out with Quickjet too much.
 

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Good idea...I'm putting in a daycruiser and plan to run in the 10 second class..


PS: You've been hanging out with Quickjet too much.
hil:)hil:)hil:)hil:) WT:)devil
 

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So you have a goal in mind. I think youll find the advice I gave would put your daycruiser well past the 10 second class. You might be a runner for the 7.70 class that jets can run in now.
So whats your goal or should we keep playing.
 

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Discussion Starter #9
I'll beat up on the 7.70 class with my southwind. The cruiser is for the 10 second class. I'm not one of those guys that sets unrealistic goals.
 

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Okay Ill play.
I would use the perfomer rpm air gap with a dominator and a big spacer. Or a tunnell ram with 660's to 5000rpm. Any higher you would need dominators and a sheetmetal intake, Im guessing a spread port head would work to 6000rpm.:)grn
Please don't tell my 454 that! It spins to 6k and wants more but my CAST bottom end wont take to much of that! The air gap with a small dominator would be a better choice for that deal. M
 

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Good idea...I'm putting in a daycruiser and plan to run in the 10 second class..


PS: You've been hanging out with Quickjet too much.
People dont "Hang Out" with me, they mearly follow....
 

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Thats what I like to hear. Honesty with your goals. Dont tell anybody else about the secret combination of dual plane intakes, oval port heads and suburban take outs motors. :))THumbsUp
 

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Yeah...I'm bored today. :D

Actually, it seems as if the shorty single plane manifolds are advertised to work up to the same RPM range as the tall dual planes, but they aren't advertised as starting to work until a higher RPM range....which seems kinda stupid to me. How can a long runner dual plane work almost the same as a super short runner single plane? I'm sure the answer is, "it can't", but since edelbrock still sells em, along with plenty of others, I'm sure there's a reason behind it. I'm looking for that reason.

BTW, the motor is a 9:1ish oval port 468 BBC w/ about a .520 lift 218° @ .050 flat hydro cam in it. It had a single carb tunnel ram on it with a cobbled together vac sec. carb that didn't work for shit, among other problems. I bought the boat as a bit of project (cuz I need another one of those:D) and realized it's been a while since I played with stockers, so I dunno what to do.
The motor you are working with doesn't make any power so either of the intakes you listed will work or not work all in the same fashion. You will notice no difference between any of them.
 

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Discussion Starter #15
The motor you are working with doesn't make any power so either of the intakes you listed will work or not work all in the same fashion. You will notice no difference between any of them.
It'll still whoop on your 396
 

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Yeah...I'm bored today. :D

BTW, the motor is a 9:1ish oval port 468 BBC w/ about a .520 lift 218° @ .050 flat hydro cam in it. It had a single carb tunnel ram on it with a cobbled together vac sec. carb that didn't work for shit, among other problems. I bought the boat as a bit of project (cuz I need another one of those:D) and realized it's been a while since I played with stockers, so I dunno what to do.
No biggie with that cam. Air gap or regular RPM version. A regular Performer will probably be down only 10-15 hp with that. So, you have many choices including above and Weiand Air Strike, Street Warrior, older Stealth, Action Plus etc,etc. I believe, but don't know for sure, Summit's dual plane intakes are from Weiand - http://www.summitracing.com/search/Part-Type/Intake-Manifolds-Carbureted/Intake-Style/Dual-plane/Make/CHEVROLET/Engine-Size/7-4L-454/?keyword=summit+intake+manifold

If you get a non airgap type intake I would use intake gaskets that block off the exhaust ports and use a Canton (or etc) lifter valley plate.
 
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