Tunnel Ram & 2 4's
 

Why don't i see this on bigger cubic inch marine engines ? Would this help a 540ci and bigger breathe ? I just need to know . deep

The RPM range for tunnels rams is higher than most boats use...

Every dyno test I've seen shows that tunnel rams are as good as dual plane on the low end and better than single planes on the top. I know Engine Masters magazine did some side by sides and the tunnels worked best overall by a significant margin.

It would be nice to see some real world numbers by our own engine masters . Would there be an advantage only spinning the rpm's to 6,000 ? Thanks

Idle characteristics?

I have a tunnle ram on my 588 ci 14 to 1 engine idle in cold weather can be a little fun works best in upper rpm .

When i built my 588 i went big bore short stroke so i could rpm it to take advantage of the tunnle ram.

Nothing like a big chevy at 6800 rpm sounds cool.

Go to 2012 loto part 1 on you tube we are about the 15th boat running sounds cool.

That's definitely a chest thumper bro !! Nice work . Would you post a pic of your engine ?

We converted tunnel rams to EFI, they make good power. I would think with the right carbs and proper tuning they would work just as well.

I agree i took the boat out the day i left for loto with a fresh engine drove it around for 20 min to break it in did a couple of speed runs with wide band on it to make sure air fuel was ok.
We broke a 100 mph so i new i could step up the record from last year so i did no more tuning that being said it ran ok with out of the box gary williams carbs and would idle around at 1000 rpm .
If you fuel inject it a lot of problems go away.
But to get the real advantage of a tunnel ram be ready to turn some rpm so dont scimp on the valve train.

JimV (Valako) runs a Holley Dominator tunnel ram manifold modified for EFIon his 565 with twin 1000cfm throttle bodies. I believe the dyno was 787HP@6200. And it was not lacking torque. They make power. Last year he tried twin 750 carbs and lost power.

If you go to our race site there is one picture of me putting it in the boat also keep in mind we did this with a old school tunnel ram before loto next year im doing a cam change and a modern tunnel ram then i will put it on the pump and find all the power it might have on tap.

www.michiganmafia.net

I will try to find some pictures of it in boat complete/

Have run the Dart TR's with carbs and with 8-71's and carbs. Idle great and make good power.

reviving an old thread... looking to unleash some more power from my 557's N/A motors,, anyone else running a tunnel ram set up with dual carbs? in the 800hp range? or should I just add a pair of blowers ?

Zul 800 motors are tunnel rams. Not sure of CID

Is it time for mailboxes? I think you should just buy and OL - Christmas is around the corner. :santa:

Tunnels are better theory. In practice, due to class rules, lots of really good 1x4 BBC manifolds get developed. There are fewer tunnel ram options, but with some work they should always end up best.

Dart Tunnel Rams too. :)

Ran Dom - TR's will never make near the power a SC will of course.

Not willing to cut hatches... sunpad is essential , lots of blower options that will fit under hatch, but just don't think it will fit with a any type inner cooler /chiller , obviously a blower would easily exceed my HP goals .. just exploring all my options.. I very confident my hull would respond nicely to an extra 100hp a side

If I was building some bigger power NA engines, I would be doing tunnel ram intakes. For a few reasons.

#1. Fuel Distribution. The individual runners with twin carbs, much better fuel distribution to all 8 cylinders.

#2 . Powerband. Contrary to popular belief, tunnel rams arent just for 7500RPM big blocks. Often, they make more power from 3000-6000rpm, over a single plane.

#3 They simply look cooler IMO, than a single 4 barrel setup.

Some good info here. They had a 540ci, 8.8:1 compression, 271/280 .742/.715 lift cam , Dart 355 cnc heads.

Weiand Team G single plane with dominator = 770HP/663 TQ

Weiand Tunnel Ram, twin 950 carbs = 777HP/681 TQ

Dart Tunnel Ram Twin Dominators= 806HP/694 TQ

Dart Tunnel Ram ported by Wilson = 833HP/712 TQ

The Wilson ported combo is up a solid 50hp at 6000ish rpm, and 30-40ftlbs thruout the midrange. Doesnt look like it gives up anything anywhere to the single plane setup.

Thanks, MT that's the sort of info I was searching for

Mild Thunder - how do I get my hands on one of these Tr's from Wilson and can they be modified for sequential port EFI?
Do I just call them and give them my engine spec's?

Edelbrock makes the Victor Tunnel Ram, with injector bungs, with open top plate.

Intake Manifolds - Chevy - Big-Block - Victor Series - Edelbrock, LLC.


Theres also the Pro-Flo XT intake, which I think is bad ass. Not really a traditional tunnel ram setup , but really cool imo. I think it be a nice top end for a EFI-540-565 build, rather than some lamo single plane with a throttle body on top. Seen enough of those already :faint2:
Intake Manifolds - Chevy - Small-Block - Pro-Flo XT Series - Edelbrock, LLC.

Would be interesting to see that back to back vs MPI and merc racing efi manifolds. Send one to articfriends?

160 additional HP from only an induction system change is impressive. Period.

Supercharge it and be done!

i know you are old like i am but recheck your math!

Guess I should've waited until I had my coffee.

Add in some Elijah Craig or Makers to that coffee:coolcowboy:

I was looking into the option of going to a tunnel ram setup with EFI on my big inch NA motors. I don't think you could realisticly have a better induction setup. The long intake runners of the tunnel ram with fuel curve adjustability of the EFI. I wanted to go to a little different cam profile to try to take advantage of the induction setup then see what the dyno had to say about my idea but found a set of 10-71's I just couldn't pass up. Going with carbs on top for now but eventually I would like to go to an EFI setup on the blowers too. We'll see how things go.

This would be bad azz, with a couple of the Holley billet 1000cfm TB's on top

Intake Manifolds - Chevy - Big-Block - Victor Series - Edelbrock, LLC.

Wish they made that in a tall deck 10.2

Anyone know if the Victor is better than the Dart ? On most 540-600" or so marine engines ?

The guys that did my machine work, told me that they see 30-40hp increase on the dyno with the Super Victor CNC over any other single plane.

:faint2:

thats why hey make intake spacers.

yep. I have a set or two if he needs them

I had my manifold done by Wilson. They are good people to work with. Give them a call I am pretty sure they can do what ever you need.

I hate the looks of spacers.

They kind of look like " hey lets just cobble this together"