old school tunnel ram and carbs question

[RichSchmidt]

That was pretty much standard fare back in the 70's.I had the article of Grumpy Jenkin's 70 camaro prostocker from the 1970 issue of Hot Rod,and it mentions how the car was plumbed with"Neoprine" hose,as if this was some kind of state of the art feature at the time.The trick record holding prostock fuel system consisted of some 5/8" metal home heating tubes soldered into the top of the tank with rubber hoses running to 2 Carter fuel pumps,the same kind you could buy for $9 at the local parts store at the time,and the engine compartment fuel lines were all done with hardware store grade brass fittings and rubber hose.This was state of the art back then.This could also be why the Grumps Monza burned to the ground so fast a few years later,but the fancy fuel systems we know today wouldnt be around for years to come.

The real tuth about most supercars was way too sugar coated.Most of these highly valued supercars had sledge hammer adjustments done to fit oversized tires,and exhaust systems,and you have to remember that these super valueable Motion supercars were about as pleasant to drive on the street every day as having a prostock race car with mufflers.That is what made them so valuable,the race car mystique.In reality,they were hard to drive tempermantal beasts that were broken down more then they were running,or at least that was the case of you actually drove yours the way they were intended to be driven.Most of them were either found burned alongside the road because their owners grew tired of their beastly ways,or were converted to full on race cars and evolved off the streets.Thats just how it was.The fact was that the Motion car wasnt anything that the average kid couldnt have built for half the price at the time in his back yard with hand tools.In reality, even the winningest of prostock cars from that era would be nothing more then a bunch of cobbled together parts that wouldnt pass saftey inspection at even the most backwoods track in rebel country today.Back then,they were record hold state of the art race cars.

[hvychev]

Hmmmmm.....very well said IMO.

[JoeG]

Yeah---Weren't those Very times---

[Plowman]

I've come into this thread a little late, but wanted to add a few of my thoughts.

I've run several 1850 carbs with both tunnel and x-ram intakes. I've found that street driving required me to restrict the liquid line in the metering block. Since the 600 carb was factory tuned to provide idle- we'll say for 8 cyl. in this case, multiple carbs will then be very rich at idle- beyond the adjustment of the idle mixture screws. With this done, the 1850's can be tuned with conventional methods to run very well on the street. I'm willing to discuss this more if anyone is interested.

As for the vacuum secondaries, needing to be changed I’ll have to disagree. Although tunnel ram does lower the engine vacuum, the secondaries operate off of venturi vacuum. They are completely tunable on tunnel ram. I also think they help in making a tunnel ram engine more streetable because they only open X amount from the venture signal. Mechanical secondaries can give too much CFM too easily.

I actually like the look of sideways mounted carbs. When/If you remove the jet plate and add a secondary metering block to an 1850 carb (to allow standard jet changes) you can no longer mount the carbs inline. Sideways mounting also helps with fuel slosh.

Plugs do tend to foul with multiple carbs due to fuel puddling in the intake, but a vintage MSD 7A will remedy that. I’m sure any hot ignition system today would work as well- I just like the old MSD 7 before they went to the 7AL.

[musclcar]

when you say "restricting the liquid line " are you talking about lowering the fuel pressure down to control flooding by adding a pressure regulator ?? .also the secondaries will work correctly without the vacum line connecting them together

[whitetop]

The only other problem I don't like about running the carbs sideways is you have to cut an extra wide hole on the hood the clear the carbs and linkage. The extra large hole looks odd when the hood is closed (or open for that matter).
From your first thread it sounds like you want to make the car period correct. I would say only 5 out of every 100 street cars ran the carbs sideways. You can do what you want.

In terms of the vacuum secondaries There was a huge differnce when I ran the balance tube kit...for the better.

[427TJ]

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The only other problem I don't like about running the carbs sideways is you have to cut an extra wide hole on the hood the clear the carbs and linkage.

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Leave the hood off and chrome the hood hinges and springs. Then drive around with the hood hinges in the "open" position. Anyone remember that? A noisy gear drive adds to the impact. Suddenly it's 1979.

[budnate]

[ QUOTE ]
[ QUOTE ]
The only other problem I don't like about running the carbs sideways is you have to cut an extra wide hole on the hood the clear the carbs and linkage.

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Leave the hood off and chrome the hood hinges and springs. Then drive around with the hood hinges in the "open" position. Anyone remember that? A noisy gear drive adds to the impact. Suddenly it's 1979.

[/ QUOTE ]

[Plowman]

Unfortunately, I was in the ER and just got released. I thought about this thread while I was in there and I'm glad to reply. The liquid line in the metering block is set up for 8 cylinders, so by having 2 1850s on there, there will be enough liquid to feed 16 cylinders. By restricting the metering blocks to only feed 4 cylinders each, you have 8 cylinders being fed and idle will not be super rich-very streetable.
The vacuum secondardies will work fine by themselves. They are adjustable by changing the springs in them.
If you have more questions, maybe I could post a picture of them.

[budnate]

a question..when we buy these so called matched tunnel ram holleys with the kit like from Summit are they not metered correctly..I was getting a good handle on this until the last few posts...

Thnx Bud