WETTE VETTE

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!!
Craig

dlbCheckmate

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

Cord

iTrader: (2)

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

WETTE VETTE

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.
Craig

dlbCheckmate

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 ?

KAAMA

iTrader: (1)

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!!!


Just kiddin' ya bro. Iget to mess with you cuz I know you! 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.

WETTE VETTE

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

Plum_Crazy

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

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

tomcat

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?

cobra marty

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