Tunnel ram on sbc

[curves]

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[curves]

I've been thinking about getting a bravo donor boat,and wondering if tunnelram like this would work on 9.1 compression 350?I've never seen ram like this,seems
might mix the gas air better than regelar tunnel.I know on blowers,and stuff like that you need lower compression,as low as 8.1.wonder if the same as tunnel ram.
I got alpha donor,but would 1.50 be enough and break?

 

[curves]

because this guy has 90's 350 for 100,and thinking about building it up,just hear can't plain out with tunnel ram,and bigger cam.sure look wild though.

 

[Gimme Fuel]

That is a cross ram manifold. It would not work well in your boat unless you are planning on spinning 7000+ rpm. Won't make much low end torque at all but a bit more than a short runner tunnel ram, but that is still designed to move a ton more air than a 9:1 350 would use so port velocity would be slow. That would be used for a serious drag/race motor.

 

[Old Navy]

You should get it! That would be awesome! Your boat, however,
would be much slower and run bad.

 

[Jimway]

Hey Curves. Look up a Chrysler cross ram manifold from the early sixties. Notice the length of the manifold runners. You would be going for something like that in a marine application built to run up around 4500 rpm. Also notice the hp ratings and top speeds of these Chryslers. They still had some serious low end grunt.

 

[curves]

ok thanks,just haven't seen one before,was curious.looked different,would almost look like too motors.too bad i can't build 383,or 400.i always wondered how them tunnel rams would do with q-jets on them,i allways see them with like 2 450's.

 

[curves]

Hey Curves. Look up a Chrysler cross ram manifold from the early sixties. Notice the length of the manifold runners. You would be going for something like that in a marine application built to run up around 4500 rpm. Also notice the hp ratings and top speeds of these Chryslers. They still had some serious low end grunt.

I've seen the cross ram on the dz302.but that one has them side by side.still not bad for like 400 if there was a way to make it work,and make some linkage.also boats are wierd,from what i read bigger cc chambers give more low end torque,but lowers compression.I've been seeing these tunnel rams on you tube,but there motors built.on sbc too not just the big blocks,wonder if there using 4blade props.

 

[Jimway]

Q jets work fine and can be be adjusted for a variety of applications. The application is the key. The proper sizing of the carburetor is most important. There would be no need to mount a 1080 cfm on a motor that realistically needs 500 cfm based on engine displacement and actual rpm. Seen a lot of that over the years. A stock 350 can and will run well with a 390 cfm on it.

 

[karzrus]

Looks cool but that's it

There is a reason why old crap like that never really caught on or lasted in any motor sport.

Today, it is even more useless as you can now get one big tuneable carb that will make more power for less money then that set up would cost to make work.
I'd put efi on a boat, way before I'd mess with that.

 

[Jimway]

Kars has a good point on fuel injection. The other morning, 17 degrees here, I cold started two different trucks. One, an old International pickup, and two, a mid nineties Ford pickup. On the International, you have to pull the choke, then push it in part way to adjust the fast idle, then fool with it for quite a while as the carb ices up, turns white with ice on the lower exterior, and tries to stall out. A twist of the key on that big fuel injected Ford, about two revolutions of the crankshaft, and it fires right up and settles down to an idle within moments. No icing, no drama. Three blocks down the road, you could already feel some warm air from the vents. What a change we have seen in trucks in our lifetime. And the evolution of fuel injection. Although, what a sight to see when raising the engine hatch on your Checkmate to reveal a 413 Wedge with a cross ram. 400 hp and 500 ft lbs of torque, and the unmistakable sound of a big block upon fire up.

 

[fast94persuader]

A good buddy of mine built a Ford model a rat rod. The motor was a left over 327 out of a stock car. He put a cross ram on it and reved it to 8000 rpm+. It had two 450 cfm holleys. On a whim he decided to try a tunnel ram. The motor picked up almost 20 hp at the wheels and the et at the drag strip dropped by a half second. Same motor same carbs. Cross rams are cool to look at, a bitch to tune, but don't make much power. In a road racing 302 z28, they keep rpms high while providing an intake that doesn't require a big Cowl scoop, or a hole in your hood. A single plane intake and a single double pumper will out run a cross ram no questions asked. Most likely it would out run a tunnel ram with old school carbs on most small blocks. Just my two cents. I'd hang on the wall or save it for a project that doesn't require max hp and torque.

 

[boatman4021]

A good buddy of mine built a Ford model a rat rod. The motor was a left over 327 out of a stock car. He put a cross ram on it and reved it to 8000 rpm+. It had two 450 cfm holleys. On a whim he decided to try a tunnel ram. The motor picked up almost 20 hp at the wheels and the et at the drag strip dropped by a half second. Same motor same carbs. Cross rams are cool to look at, a bitch to tune, but don't make much power. In a road racing 302 z28, they keep rpms high while providing an intake that doesn't require a big Cowl scoop, or a hole in your hood. A single plane intake and a single double pumper will out run a cross ram no questions asked. Most likely it would out run a tunnel ram with old school carbs on most small blocks. Just my two cents. I'd hang on the wall or save it for a project that doesn't require max hp and torque.

20HP was good for half a second gain? I must be doing something wrong.

 

[curves]

Yeah i believe all that,just a 2barrel carb would probaly have more power.well untill 5,000 rpm's.good info here.I didn't buy it.I bid like 350 on it,if i win it,probaly could resale later on to a sucker like me for more.

 

[ezstriper]

those were horrible intakes, why never caught on...very peaky power curves and needed lots RPM to work at all...they work great as conversation pieces in a "car guys" basement

 

[curves]

yeah i hope guy don't lower his reserve,think i bid 375.

 

[fast94persuader]

20HP was good for half a second gain? I must be doing something wrong.

We're talking rear wheel hp...

2200 pound car...

Went from 12.50s to 12.00s...
It made a lot more torque too and the motor just plain ran better.

It's like making a timing adjustment...the car was just way happier.

 

[wired]

There is a reason why old crap like that never really caught on or lasted in any motor sport.

Today, it is even more useless as you can now get one big tuneable carb that will make more power for less money then that set up would cost to make work.
I'd put efi on a boat, way before I'd mess with that.

True. It was crap when i twas new and its still crap.