tunnel ram

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rumblefish360 said:
Sure! But, it is about balance. How many big blocks have you seen run twin 850's on a TR?
If so, what was there engine like that it could actually consume/use 1700 cfm?
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Your could be right that there to large but it's only 1700 cfms at 1.5" of vacuum. But 2 850 would probably be half or less that vacuum level which probably more like 1000 cfms of actual carburation.

Sale all 3 carbs and the old intake and buy the proper sized DP's.
 
Well, since we're making some votes out loud, I vote then OP gets a keg and dancing girls!
LMAO

The pair of 600's ought to carry him pretty good.
 
bOb shingler said:
600vs carbs are fine, don't change them. install them inline, linkage is simple. jets and plates have to be the same. the vacuum cans have to be tied together, holley has the tops for this. buy two spring kits. your motor should pull enough vacuum to require the black spring in both cans. when using the lighter springs should you feel the motor studder it's the cans opening the secondaries to soon and you need to try the next stronger spring. the motor isn't making enough vacuum to pull gas up the emulsion tubes yet and needs to slow the blades down a little. you need to also buy two nozzle cam kits, try the quick green one first, it should be the correct one. the ram likes a very quick shot. your cam is just fine you don't need to change it. you'll find out the coming off a 1000 rpm idle will work real good.
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aaron, just try this to start out.
 
"The problem with a vacuum secondary carb on a tunnel ram is the secondaries don't open until high RPM and sometimes they NEVER open. May as well run a single 4." When I was dynoing my tunnel ram equipped stock stroke 400B the biggest problem was the secondaries would pop open TOO soon and it would BOG badly. This is with a pair of AVS carbs, we ran out of time before completely tuning it out.
 
Edorion said:
"The problem with a vacuum secondary carb on a tunnel ram is the secondaries don't open until high RPM and sometimes they NEVER open. May as well run a single 4." When I was dynoing my tunnel ram equipped stock stroke 400B the biggest problem was the secondaries would pop open TOO soon and it would BOG badly. This is with a pair of AVS carbs, we ran out of time before completely tuning it out.
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did you ever get more time to mess with it?
 
Edorion said:
"The problem with a vacuum secondary carb on a tunnel ram is the secondaries don't open until high RPM and sometimes they NEVER open. May as well run a single 4." When I was dynoing my tunnel ram equipped stock stroke 400B the biggest problem was the secondaries would pop open TOO soon and it would BOG badly. This is with a pair of AVS carbs, we ran out of time before completely tuning it out.
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Not exactly the same.
 
Please, explain the difference, not being sarcastic. We managed to get them so they didn't flop open and BOG, but didn't try any timing or fine tuning of the A/F after that. I don't have the dyno sheet in front of me IIRC it was 35 degrees total timing and around 12.5:1 A/F throughout the range . There were some issues with the headers/mufflers I brought and I'd had a long day, so I called it. The carbs are OE '70 440 that I'd modified for dual feed and removed the choke linkage, but hadn't removed the towers. We were testing them without the velocity stacks mounted. It will be interesting to see how they respond with them. I'd got a broadband for it and should (finally) have the car on the road by years end.
 
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Hello again. Been working on my carbs. 2 holley 600s Added metering blocks to the back. Went with 66 jets on front and 74 in back with no power valve. Problem is since they are inline wanted to use jet extentions in back but they wont let the float drop. Do they make a side hung float for use with jet extentions. Car 60fts in the 1.40s. Do I need them?
 
aaronk785 said:
Hello again. Been working on my carbs. 2 holley 600s Added metering blocks to the back. Went with 66 jets on front and 74 in back with no power valve. Problem is since they are inline wanted to use jet extentions in back but they wont let the float drop. Do they make a side hung float for use with jet extentions. Car 60fts in the 1.40s. Do I need them?
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You don't really need jet extensions on those bowls, but they are never a bad thing. Not sure if they are even make floats for extensions with that bowl.

You absolutely need power valves in the front. From your post, I can't tell if you have a PV in the front but you need it. By the jet split, you are jetted like you have the PV's in the front.

So the carbs actually fit on the intake end to end with metering blocks on th secondaries??? Better for you if they do.
 
Yes. Power valve in front. I will tie the cans together and start there. Carbs fit on with a 1/2in. to spare. Ill skip the jet extentions and give it a try in the spring on test and tune night. I have spring kits and pump cams and an assortment of squirters. Thanks to all.
 
aaronk785 said:
Yes. Power valve in front. I will tie the cans together and start there. Carbs fit on with a 1/2in. to spare. Ill skip the jet extentions and give it a try in the spring on test and tune night. I have spring kits and pump cams and an assortment of squirters. Thanks to all.
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Cool.

Keep us posted.

Always like any TR deal.
 
Buy 2 Holley 6109's if you go to 750s. They are tunnel ram specific. I had a set on my hemi for a bit, they ran really well and had great throttle response and idle.
 
Hello all. I got my car started after some head aches. Pressure regulator went bad and some leaks but nothing serious. Car ran very rich and the power valves would not stay closed because of low vacuum. I expected this because all I had were 6.5 pv . I ordered some 4.5s to try. My question is can I just block the front power valves and square jet the carbs. This is a race only car. Streetability not a concern at all. There are no pvs in the rear of carbs just 74 jets. Thanks.
 
I square jetted mine with no power valves, these were 750 's, custom built by Quickfuel for a tunnel ram, literally just bolted them on and they ran perfect. No bog, car ran 9.80's at 136mph. Normally ran 10.00 flat with a single Dominator before switching to the tunnel ram. The TR even ran nicer on the street, only complaint was the fuel consumption.

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ProSport said:
I square jetted mine with no pwer valves, these were 750 's, custom built by Quickfuel for a tunnel ram, literally just bolted them on and they ran perfect. No bog, car ran 9.80's at 136mph. Normally ran 10.00 flat with a single Dominator before switching to the tunnel ram. The TR even ran nicer on the street, only complaint was the fuel consumption.

View attachment 1715003439
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If it wasn't getting enough fuel mileage, you probably could have tightened up the T slot restricters a bit. That's where most of the cruise fuel comes from.
 
I didn't want to change anything on it since it ran perfect at the track and clean plugs on the street. A combo like that is gonna consume some fuel either way.
 
Awesome weather today. Started my car today after adjusting the carbs some. I have the front blades to where the t-slot is square. The back blades or 3/4 turn open. Ive been chasing the idle. I can get it set and its good for a couple minutes. then it leans out. So I turn the idle mixture screws out and idle comes back. After a couple minutes it goes pig rich. So I turn them back again and same thing. Back and forth like this. And either way its pig rich of idle. It will clear out at 2500 rpm in 10 seconds or so. I tried to open the back more and close the front and readjust but cant fined the right spot. No power valves. Its not pulling though the boosters of idle so I don't think that's the problem. If I whack it its very crisp. If I go at it slow it sounds like crap and loads up for a while. Suggestions please. Thanks. I'm starting to think vacuum leak.
 
You need power valves in the primary.

You need to open the idle air bleed .004-.006 and work from there.

You may have to make the idle feed resticter smaller by .004-.005 as well.
 
Thanks YR. Ill give it a try. Just tried it with no pv didn't make any difference. I will put them back in. It is frustrating but that's how you learn. Buddy bolted on bone stock 600s on his tunnel ram and it runs and idles great. But he has more compression and less cam so probably more vacuum helps him out.
 
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