any tuning ideas? Edelbrock "street" tunnel ram

[wyrmrider]

Not only the price the quality of gas goes bad real quick with that few miles a year
varnish up your valve guides and bend your pushrods- ask me how I know

[dualquad]

I have seen a very similar 355 that ran good with 2 - 450cfm holley t-ram carbs. Surprising throttle response for having NO secondary acc. pump! I'm not saying that the 450s are "better" than the larger carbs, just saying that they can run quite well. I think having the carbs dialed in is more important than their size.JMO

kenny

[F-BIRD'88]

Again this is not a Motor for a T bucket... You could stick 2 2bbls on it and it will run..
But it won't make any power. The problem with tunnel Rams is everybody wants to dummy it down.

[wyrmrider]

Tunnel rams do not dummy down well
best option to sorta dummy down is EFI them
One carb is definitely not the way to even think about

[randy331]

D
This motor should make close to 600hp.

No way.

600 HP/355 cubes = 1.69 HP per cube. Even a tunnel ram ain't gonna make that happen.

The 500 HP rewguy mentioned may be a little optimistic.

Randy

[F-BIRD'88]

1.69x 302 cid = 510hp... not that hard.

500hp From this 355....You will have to dummy it down some . Like little carbs. Little exhaust. etc

[Bob Hollinshead]

tuner, on the 1850's do you drill idle discharge holes in the secondary side to allow the fuel carried over from the primary and adjust it all with the primary mixture screws?

Yes, like the 350-365HP 327 R-2818 and other "585 CFM" Chevy carbs, 350-360HP 396, 390HP 427, some 300HP 327, etc.

Cool, some years ago I rebuilt a 67 327 vette carb that I think was set up like that

[jeff swisher]

I played with tunnel rams for many years and the small carter afb carbs(or edelbrocks) lacked power in the 350" engines compared to the 600 or 625cfm units.

The small carb with ported 1.94-1.50 heads that had 158-175cc runners coupled with a small 280H would still not give the pull above 5000 rpm that the 600+ cfm carbs would.
Fact the small carbs fell way short and nosed over early.

Now as the head gets smaller the carbs can get smaller.
case : 355" with flat tops ..043" piston to head and bowl ported 305 2 barrel heads with a TR1YX tunnel ram 2 600 edelbrock performer carbs.
The heads were ran with the stock valves 1.72-1.50 size.
It ran 12.51 at 111 mph 3200lbs with driver, TH350 2200 stall speed and .456 gears 280H cam 230@.050.

I could disconnect the secondary linkage on both carbs and it felt the same on the street in first and second gear.. 6700 rpm shift point either way.
Now with bigger valve heads that shift point moved up to 7200 rpm.

Now" Same short block as above but change of cam to the 292H 244@ .050" and change the head to a 305HO casting 601.
1.94-1.50 valves this time and same carbs and tunnelram.
Shift point was now 7400-7500 rpm. car ran 11.94 and 116 mph ..
This time when i disconnected the secondary linkage the car would run out of power at 4800 rpm.

So Your heads and your cam will really benefit from the larger carbs..I tried tweaking the secondary air valves to come in different .. but really did not make any difference as the tall tunnel ram had excellent velocity and those carbs are pretty darn good almost as is.

The 11.94 could have been much better if the driver would try different shift points or if the converter would stall more than 2200. the 60 foot was in the 1.6's
This was 91 octane 7-11 fuel with 10% ethanol.
It pulled 12" vacuum.
To make throttle response super snappy I would run the orange power piston spring in the edelbrocks and to those i would add another spring that fit inside of the factory orange one.
Those smaller diameter springs were sourced from ink pens.

I would cover 1/2 of the power piston with the top cover and this way i can see the piston working while the car was running.
Blip the throttle and vacuum drops and the piston needs to instantly jump up.

If it stays down add more spring..If the piston flutters up and down during idle remove spring pressure until it stays down at idle..In gear at idle needs to be checked. (Power Pistons I am talking about are the ones that the primary metering rods are attached to)

Have fun!

Another note. I worked for many hours trying to make the 450 holley's work as well as out of the box 600 edelbrocks.. almost there but not quite.

[bmcdaniel]

http://www.fitechefi.com/default.asp.pg ... ix-PackKit

[kirkwoodken]

The TR/"ram effect" requires a certain sized "chunk" of air to operate. Restricting the air flow with too small of a carb will not deliver the full chunk in the amount of time given.

[psychomotors]

Don't forget the Grumpy Jenkins carb trick of adding 850 dp bases to 660 center squirters. Little more involved than that but supposed to be good stuff according to a buddy that had it done.

[Steve K]

oK, I don't want to hi-jack this thread but I have two cars running tunnel rams and 600 Eddy carbs. One is a 400 SBC with a 242/252 Voodoo HR cam and the other is a 383 with a 250/255 HR Bullet cam. How much power am I leaving on the table with these carbs. Should I be running Holley 750dp's for max power. Both are strong engines and are very streetable.
Thanks Steve

[F-BIRD'88]

Steve, ya the 750 holleys will make more power.. But so will a serious roller cam.

If you don't drag race it what difference does it make...You never use what you got now..
Having xxx horsepower is not like having money in the bank..
You have 0 horsepower until you do work with it.

The 600-750 eddy carbs work great on the street. The air cleaners are important.

The hyd roller girlie cam is the limiting factor anyway..

Enjoy your street ride..
If you want to know what you got dyno it or drag it 1/4 mile mph..tells hp.

You can refine the 600 carbs by fine tuning them.

[Steve K]

Steve, ya the 750 holleys will make more power.. But so will a serious roller cam.

If you don't drag race it what difference does it make...You never use what you got now..
Having xxx horsepower is not like having money in the bank..
You have 0 horsepower until you do work with it.

The 600-750 eddy carbs work great on the street. The air cleaners are important.

The hyd roller girlie cam is the limiting factor anyway..

Enjoy your street ride..
If you want to know what you got dyno it or drag it 1/4 mile mph..tells hp.

You can refine the 600 carbs by fine tuning them.

What?? Are you saying you CAN have too much power for the street...not out here in Paradise LOL

[F-BIRD'88]

Have you refined the tune jetting calibration of the current carbs yet? On the street the air cleaner design function will make a big
difference. Your installed exhaust system function will make a big difference.
Once you have optimized this stuff you can then measure the intake manifold vacuum at max engine output (WOT) and see how much flow restriction the 600's are on your motor, in your car.

It is nice having the functional chokes on this manifold, on the street.
if you had the little holley 450's or the 390's (which neither were designed or intended for use on tunnel rams anyway) then you'd want to look at carb size for More power, if having "More" power is more than a warm fuzzy feeling.
if and once the eddy 600's are properly dialed in on your motor,, you will not likely have "More" drivability with a different or larger carb.

Has the car ever seen the drag strip? How will you ever know?

Do you want more horsepower (to do more real work) or want a more warmer, fuzzy -er feeling?