How much more power with a tunnel ram type of intake?
 

Hello,
I am running a NA 598" BB that I built myself. It runs great, but I think a tunnel ram type of intake may make a few more HP. My combo has 10:1 compression with JE pistons, Dart 355 CNC heads with REV valves, solid roller cam 264/270 duration @ .050" on 114 LSA installed on 112 w/ .740"/.730" lift less lash, Jesel rockers, Isky lifters and springs, match ported Dart single plane intake, Nickerson stage 5 1250 (Flows 1475), CMI Sport Tubes, MSD, crossover, etc. The motor is in a small cat and runs very strong up to 6500 RPM. So, with that said what kind of gain would I see going to a tunnel ram type of intake with a couple of stage 5 850's or maybe even some 1050's? I don't care about power development below 4000 RPM. The boat is relatively lite and accelerates like a banshee so the focus is on the big end. WOT operating range will be 6000 to 6500 RPM when I am done getting it propped correctly. Winter is coming and I need something to do!! :D
Craig

Re: How much more power with a tunnel ram type of intake?
 

I would tend to agree, I think you would lose low end, but who cares. Look at the ZUL NA motors, I see tunnel rams :D :D :D

Re: How much more power with a tunnel ram type of intake?
 

Talk to Jim Valenko. He's running an injected tunnel ram.

Re: How much more power with a tunnel ram type of intake?
 

That is what got me thinking. I just wonder if there is 10HP or 30HP+ with the TR? 10HP and I won't mess with it. 30+ HP and I may consider doing something. :rolleyes:
Craig

Re: How much more power with a tunnel ram type of intake?
 

Well, Jim took off the blower and went with the tunnel ram. If I remeber right he's going as fast or faster now. I would think adding the tunnel ram and second carb, or fuel injecton would be worth 30 plus ?

Re: How much more power with a tunnel ram type of intake?
 

No, I am quite positive that Jim lost about 10mph going from the supercharged engine to the naturally aspirated engine.

Vette, you'd gain at least 175hp with a tunnel ram---So go and put one on!!! :D :D :D


Just kiddin' ya bro. Iget to mess with you cuz I know you! :D Anyway, I have always heard about 30hp or so increase as well. A friend of mine from Chicago used to run tunnel rams in his 38' deep V Cougar "SAVAGE" in 1988 on his 598 inch engines too---just before the superchargers began to bleed into the marine world/market. He always kept up with, and liked the good runnin' speed equipment.

Re: How much more power with a tunnel ram type of intake?
 

Well for 30 HP it certainly is worth considering. I think for this fall I am going to focus on getting the boat propped right and I plan on trying a friend's 2" shorty to see what it will do. A single carb is very simple and until I get everything else right it it doesn't make much sense to mess with the motor trying to find a little more. I will be changing lifters and springs after next season, which would be the perfect time to go with a different intake. Still if anyone has opinions or experience with a dual quad tunnel ram compared to my current single dominator please post what you know!!

Thanks,
Craig

Re: How much more power with a tunnel ram type of intake?
 

Wette, check out this article. It's right up your alley.

http://www.carcraft.com/techarticles...ram/index.html

Re: How much more power with a tunnel ram type of intake?
 

The tunnel ram has runners with a longer radius turn, and must be less restrictive to air flow. But it also has better wet flow than a single plane; important for carbs, not for EFI.

JimV is that a Dart tunnel ram?

Re: How much more power with a tunnel ram type of intake?
 

That's the article I remember and the tunnel ram out HP and TQ the single 4 bl from 4000rpm and up.

Re: How much more power with a tunnel ram type of intake?
 

In back to back testng the tunnel ram was worth about 40 HP on a pair of 540's, probably would be more with the larger displacement. Also, as part of the same test we did twin 750's compared to Dominators. Guess which made about 15 more HP at 6000 and 25 ft lbs more at 4000?

This was on an old Edelbrock Victor, I think the Dart is better but never tried it, went to blowers next.

Hint - it was not the dominators

Re: How much more power with a tunnel ram type of intake?
 

WV-
I just built a set of Tunnel Rams and the motors are great.
Plenty of low end for the boat, afterall the top end is where it counts and I think from what I read and heard during the research phase of building around 30hp over Single plane with a Dominator. The custom Intakes may be the best route and run about $2000; I used Holley and have two Weiand that I will try next on another set in a ouple of weeks. The advantage of the Holley was you can use your MSD or Merc ingnition and distributor.
Zul builds a couple of nice T/R motors; and Pfaff where I got my cams has built a few 598's like yours with huge hp #'s if you call Steve out there he can tell you about them.

Re: How much more power with a tunnel ram type of intake?
 

Tom, currently I'm using a Holley Pro Ram. The boat GPS 95. If I was starting fresh I'd problaby use the Dart (longer runners). I had problems with the efi earlier in the season. I installed a single plane dart with a 1050 and lost about 7 mph. Tried a 1250 and narrowed it to 5 mph loss. When I was running the blower GPS 101 and a lot of blowed up drives.

Re: How much more power with a tunnel ram type of intake?
 

565 92 octane hydraulic roller 95mph 1992 27 fountain

Re: How much more power with a tunnel ram type of intake?
 

MBAM,
My guess is the Dominators made more torque and HP than the 750's. From speaking to some other enthusiasts that don't frequent the board it seems there could be as much as 50 HP from the change. I would likely go 1050's. Winter gets pretty boring so this may be happening.
Craig

Re: How much more power with a tunnel ram type of intake?
 

WV,I'm using edlebrock on a 548,it has plenty of low ,mid and 6200 on top w/ a hydraulic roller.The edlebrock is close to the dart except for the top,have to use adaptors to turn 4150's sideways,so I made my own top.I believe T/R's run more consistant in hot humid weather than single carbs.my .02