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Before anyone says "search" for this. I have read several archived threads already. My question is if you were going to build a 454 for street use with a tunnel ram, how would you do it. By this I mean what heads, cam, manifold, carbs? This will be for a 64 with manual trans so rear gear input would help too. Thanks.
 

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I think if you want to run a tunnel ram on the street keep the carbs smaller like 500-600 cfm (per carb) and get the smallest plenum manifold possible. Gearing I would say 4.10 or better maybe 3.73 at the least. Cam will need to be fairly big maybe in the 240 or so at .050 range. Hydraulic roller would be a good idea. The problem is for the street you want drivability and more low and mid range whereas the tunnel ram is really for high rpm. The problem is the cam probably needs to be really big (bigger than what I said) which in turn would make the car have no low end and idle like crap. That being said with the technology they have today a single 4 barrel on the street is the way to go, but the tunnel ram does look nice and is somewhat unique today on the street. Not to say you can not get it to work but there is a balance.
 

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On the heads some good flowing oval ports would be interesting but I am not sure if they make tunnels rams in oval ports. Most of them are square ports I think. The idea is here is to keep air velocity up so you don't have a wet dishrag driving this thing up to 4,500 rpm.
 

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Why not a pair of 450 holleys and just a mild cam and 3.73 gears? Keep the cam street able, maybe not going for the last horsepower but keep it drivable.
I did a single quad tunnel ram on a sb400 with a 625 Carter. 3.08 th400 stock stall converter and it was perfectly driveable. Jim
 

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Tunnel rams work on the street just fine.
Opinions vary on carb sizing.
On a mild/med. built 454 I would run 600cfm carbs with vacuum secondary's. (yes vacuum secondary's)
You just need to connect the vacuum diaphragms together for balanced operation.
Something along this line. https://www.summitracing.com/parts/cmb-03-0183/overview/make/chevrolet


As for gears that depends on tire size, cam, intended usage etc..
 

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Can be a good street set up, a friend ran a mild SBC (383) with a tunnel ram as a daily driver. Claimed it was as good or better than any single carb set up he ever ran. Rode in the car a few times and it was not lacking for throttle response had good low speed behavior.

I think it would be a sweet set up with dual Fitech or Sniper (when/if they release a duel system) injection. Old school looks with modern livability.
 

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One of these days I will drop this 454 into something,thinking about a building a Grumpy 68 Camaro clone.
Has 063 ovals with 2.19/1.88 valves,small dome pistons,233/[email protected] 110 LSA hyd. roller. Carbs are 1850-2 Holley 600
Motor ran real strong with an RPM intake/750 dpl. pumper in a 4000 lb. car..should be fun with this set up in a lighter car.
 

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Like said, TR's can work just fine on the street. Most modern engines these days have very long runner intakes that are just laid over to fit under the hood. I think the ultimate 454 setup would be a good set of oval port heads and an Edelbrock 7115 street tunnel ram with a pair of sideways mounted 750 dp's and a good hyd. roller. That could be one bad SOB.:thumbsup:

One of the biggest misconceptions in the performance world is that tunnel rams are for high rpm and nothing could be further from the truth. Long runners with the right cross section can be more streetable and make better torque at lower rpm, have better power curves throughout the rpm range and make more total power than just about any single carb intake on the market.
 

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Yes, but the new cars have fuel injection which can be a lovely thing when tuned correctly. On my C6 Z06 I have the MSD LS7 intake and the ports are pretty big and the tube is fairly long like 8 or 9 inches, so yes it is a tunnel ram sideways and it has a good size plenum underneath with the injectors just before the heads. I will post a photo of the MSD without the top below.
 

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Yes, but the new cars have fuel injection which can be a lovely thing when tuned correctly. On my C6 Z06 I have the MSD LS7 intake and the ports are pretty big and the tube is fairly long like 8 or 9 inches, so yes it is a tunnel ram sideways and it has a good size plenum underneath with the injectors just before the heads. I will post a photo of the MSD without the top below.
EFI isn't what makes the long runners in modern engines work so well. I've had plenty of TR's on the street and an 820hp 467 that had a TR and (2) 1050's in a drag boat. That motor would have been very drivable on the street. A pair of well tuned, properly built carbs will run as well as any efi. Carb technology has come a long way in the last ten years. I'm not taking away form the versatility of EFI, just saying you really don't have to give up anything with carbs on a TR on the street.
 

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I hope to find out someday, I bought a oval port dual quad tunnel ram 2 600 holley's the vacuum secondary balance housings and a NOS accell distributor to put on my 439. I even bought a LM-2 from Innovative Motorsports for tuning. I really want a old big block crossram for grins. I have a victor ram for a small block that has the linkage and carbs/filters but someone put the vacuum secondary 600's on sideways!
 

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So I have been down this road and most folks ( my opinion) repeat what they heard and don't speak from experience and pass really bad information, like a few of these posts, which I read and just shake my head. Specially about carb sizing.

So I went from an rpm intake 750 carb to a tunnel ram and two 600 holley vacuum secondary's, first off, A LOT more low end torque, car laid rubber at higher speeds and 1/4 mile never suffered.

Problem with running two 600 vacuum secondary carbs, they are to small, see if you guys can follow. Not trying to be a jerk, just trying to explain what happens.

The primary's on the 600 holleys are small, the tunnel ram increases velocity, so the signal thru the primary's are so strong that it sucks the secondary diaphram so hard and quick (understanding how vacuum secondary's open on a holley helps here in the visual department) that even a black stiffest spring can not control the opening rate, the secondary's literally slam open under wide open throttle and cause a dead spot.

Now this is under an extreme condition of instant throttle stab. If you just drive it easy/ roll into throttle you never feel the problem.

So the solution was going to 750 vacuum secondary carbs which I did, of course I didn't know it was the solution until I made the change.

So once I went with the 750 carb, I know had control of the secondary's, the air moved slower thru the primary's and I was able to run a weaker spring in the secondary's and was able to fine tune the opening rate, of course with a weak spring I could get the same result as the 600 carbs, but the point here was to be able to control opening rate which I could now with the 750.

So in this testing one could take away, anything smaller than 600 cfm should understand the signal thru such a small opening is just way to strong, to me that's a restriction but going to a 750 gave a big enough hole thru the carb you still had the same general throttle response and never gave up anything.

So to me on my engine if I would go to say 850 carbs that probably be to much because the signal would slow down even more thru the primary's and general sluggishness of the throttle would start to be there. Make sense? Another words you know you would be getting to big.

So why choke the engine with such small carb recommendations? I think folks get to stuck on the total cfm numbers and try to treat two carbs as one in size. Which is wrong, the tunnel ram changes the whole intake velocity aspect, now you have higher velocity rates now you can run bigger carbs with out loosing throttle response and allow for more power.

Give the engine what it wants, don't restrict it because of some old repeated wifes tales.

I did track test my car 600 vs 750 and I gave up no performance value my track times was a tick quicker but of course I didn't keep track of weather, but the over all time didn't change for better or worse, I got control of the carbs using 750's

This was on a 10.2 to oval port head engine with 240/[email protected]" cam using a weiand rectangle port tunnel ram.

Later I switched to 325cc runner heads and gained even more power and drop my e.t.s down, I did try 600 vs 750 again, same result, 750 gave back the control. Thinking velocity would slow down using those huge rect ports, wrong, I had the same issue with the 600's slamming open and I went back to 750 and ran perfect.

So a lot of testing in this post, that debunks a lot of the same old same old everyone seems to repeat.......... tunnel ram bad for streets, run 450 carbs, tunnel ram don't work on street cars, tunnel rams...................



So hope this helps
 

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I agree with Steelcomp, carbs have come along way in last 10 years I have a Quickfuel 950 and it works great (much better than the old 4150 from the 1970's). The chassis dyno showed very steady fuel curves from it etc. On the tunnel ram set up, just get the right parts and put on the chassis dyno to get the fine tuning you want on it. Getting the carbs dialed in will be important.
 

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Why not put one of the dual throttle body FI tech kits on it? I think that would work fine on the street without the hassle of getting 2 carbs tuned right.
 

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I too must shake my head on some stuff.
I love tunnel-rams on the street.
Lot more velocity .. but I like tall runners and a very tall plenum.
Those runners are directly under the carb venturies. if you place the carb really close to those you will have an issue with mixture distribution during cruising speeds.. Raise that carb up and give more time and distance for the fuel and air to make the turn into the runners.

450 holleys are a pain it the rear to make work.. no secondary fuel shot.. usually way lean out of the box,, and top end will not be there.

I ran 600 edelbrock performer carbs or the 625 carter afb or the 750 afb.
With those carbs the fuel curve is not really that picky.

Rectangular port on oval heads has worked for many years.

I like the Edelbrock TR2X. for BBC
And for small block the Edelbrock TR1YX with the tall plenum that puts it at 12" tall.

I have ran the T-Rams with small cams like 280H [email protected] and it would out pull the performer RPM intake everywhere.
 

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I ran a TR for years on my nova with a built 355 with no problems, It took a while to get the carbs dialed in but once i got them set up , the car would run its tail off. no loading up, plugs ran nice an clean and it looked killer.

Jim
 
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