More Tunnel Ram talk

General engine tech -- Drag Racing to Circle Track

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MadBill
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Re: More Tunnel Ram talk

Post by MadBill » Mon Feb 05, 2018 6:55 pm

I was going to mention, vacuum carbs generally need some spring tuning, and it's a ton easier with quick change covers.

I hooked up micro-switches to the secondaries of the 600 CFM Holleys on my ~ 475 HP 350 SBC with a factory cross ram and they didn't reach full opening until 7,000 RPM in third. I didn't get a chance to change springs, but a borrowed pair of 650 DPs felt like they added 50 HP..
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Re: More Tunnel Ram talk

Post by Casper393W » Mon Feb 05, 2018 8:11 pm

I have to agree but in the defense of VS carbs....I have found that depending on the application... A VS carb can be made to perform nearly as well as a DP carb. On my setup I know that I have enough converter to run DP carbs...In fact I am trying to find a nice of center squirters to try when we Dyno the engine....I don't know if I will be lucky enough but I hope someone has some they will part with...

So if anyone has any 4224 Holley Carbs they want to part with let me know!

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Re: More Tunnel Ram talk

Post by Casper393W » Mon Feb 05, 2018 9:54 pm

I still don't see any guess on power numbers from this combo....
Surely you have a guess! Lol

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Re: More Tunnel Ram talk

Post by 427dart » Mon Feb 05, 2018 10:43 pm

On the VS type Holley carbs.....seems I can't think of a slow 426 Race Hemi that ran them!

With my dual 650 VS setup I use the weak White spring without the check ball. In place of the ball is a bushing with a sized hole that gives me the opening rate I like. With the weak spring you have to make sure there is no slop in the secondary linkage or vac. pull at cruise can slightly crack open the secondaries raising the idle speed.

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Re: More Tunnel Ram talk

Post by statsystems » Mon Feb 05, 2018 11:24 pm

427dart wrote:
Mon Feb 05, 2018 10:43 pm
On the VS type Holley carbs.....seems I can't think of a slow 426 Race Hemi that ran them!

With my dual 650 VS setup I use the weak White spring without the check ball. In place of the ball is a bushing with a sized hole that gives me the opening rate I like. With the weak spring you have to make sure there is no slop in the secondary linkage or vac. pull at cruise can slightly crack open the secondaries raising the idle speed.

The hemi guys run them because they have to.

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Re: More Tunnel Ram talk

Post by F-BIRD'88 » Tue Feb 06, 2018 3:38 am

A VS carb can be made to perform nearly as well as a DP carb

Not on a tunnel ram or any 2x4 application unless the vehicle acceleration ratio is very very slow. A TR wants to eat and leave with all 8 throttles WIDE OPEN.
(The AFB-AVS(2) carbs are nice on street deals) But 2x750HP body (holley or Proform body kit) DP's will get er done. You can build your own with components better than you can buy.
You end up with better streetability than the 660's and often more power too.
it will certainly for sure run fine with 2x600 VS holley carbs but for max perf......

Especially on that new style Hi Ram. It is going to want to eat.
It will be cam hungry too.

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Re: More Tunnel Ram talk

Post by F-BIRD'88 » Tue Feb 06, 2018 3:59 am

I don't know why the off shore intake/head manufacturers are not reacting to the Dual Quad market (dual plane hi rise and Tunnel Ram) and "short ram" for 2x4 Blow thru applications and for the Aftermarket Windsor family cars.
Even on SBC's the dual plane manifolds are way under sized for the big inch/big aftermarket cylinder head street cars

I wish someone would make a 2x4 carb box for blow thru. Edelbrock should jump on this because they will get to sell 2 new carbs or twin EFI to each buyer too.

As far as the factory look you need to forget about the (Holley) carbs appearance and concentrate on making a custom built Dual Quad carb air cleaner that looks retro yet is very functional too. When the air cleaner/shaker Hood scoop is on you don't see the carbs.

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Re: More Tunnel Ram talk

Post by 427dart » Tue Feb 06, 2018 9:25 am

F-BIRD'88 wrote:
Tue Feb 06, 2018 3:59 am
I don't know why the off shore intake/head manufacturers are not reacting to the Dual Quad market (dual plane hi rise and Tunnel Ram) and "short ram" for 2x4 Blow thru applications and for the Aftermarket Windsor family cars.
Even on SBC's the dual plane manifolds are way under sized for the big inch/big aftermarket cylinder head street cars

I wish someone would make a 2x4 carb box for blow thru. Edelbrock should jump on this because they will get to sell 2 new carbs or twin EFI to each buyer too.

As far as the factory look you need to forget about the (Holley) carbs appearance and concentrate on making a custom built Dual Quad carb air cleaner that looks retro yet is very functional too. When the air cleaner/shaker Hood scoop is on you don't see the carbs.
I put this filter base plate on when I want the "retro" look,seal out the hot air and look at those Holleys!
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Re: More Tunnel Ram talk

Post by RD_Racing » Tue Feb 06, 2018 10:35 am

I just finished putting this 406 together and trying out some new custom built Quickfuel VS 600 carbs with finger adjustable secondary opening rates. Its 10 degrees here so it will be a while before I can actually road/track test it but so far im impressed, it fired right up and went directly into a 1200rpm idle, something I wasn't able to do with the Holley 450's and Holley 600's no mater how much tuning I did..

Image

Image

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Re: More Tunnel Ram talk

Post by Casper393W » Tue Feb 06, 2018 2:56 pm

Hey 427dart do you have a part number on those Aircleaners?

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Re: More Tunnel Ram talk

Post by Speedbump » Tue Feb 06, 2018 3:49 pm

That air filter/base plate idea is REALLY slick! Nice to see some of THAT on this forum.
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Re: More Tunnel Ram talk

Post by prairiehotrodder » Tue Feb 06, 2018 4:41 pm

my 540 BBC with freshly installed Weiand Tunnel ram and a pair of Holley 750 track warrior carbs.
IMG_2136.JPG
Seems tunnel rams are coming back into style !
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Re: More Tunnel Ram talk

Post by 427dart » Tue Feb 06, 2018 8:23 pm

Casper393W wrote:
Tue Feb 06, 2018 2:56 pm
Hey 427dart do you have a part number on those Aircleaners?
The filter lids were bought with cheap paper elements from Pep Boys and I got the KN filters # E-3340

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Re: More Tunnel Ram talk

Post by 427dart » Tue Feb 06, 2018 8:27 pm

Speedbump wrote:
Tue Feb 06, 2018 3:49 pm
That air filter/base plate idea is REALLY slick! Nice to see some of THAT on this forum.
Thanks! I switch out the filter setup every so often and put that one on during the cruise nights sometimes.

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Re: More Tunnel Ram talk

Post by 427dart » Tue Feb 06, 2018 8:33 pm

Here you go...on the way to a cruise in with the transparent hot rod filter setup. You can see them peaking out the cowl opening.
https://youtu.be/FeyUXc_CFBI

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