Tunnel ram 440

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you have a lean missfire. make sure you have the vacuum secondary diaphams tied together. stock jetting for now. stock squirter. used the green pump cam in both carbs, set thier clearance at .016" with the throttles wide open. for some reason this set up works on several of the motors i have built using tr, even with different size carbs. please give it a try.
 
Thanks! What about the power valve issue it has 65 power valves in each carb. I've seen people go down a couple sizes due to the lack of vacum that a tunnel ram and big duration carb draw.
 
Cam's too big if it's the 680591. There is no 68051 I can find.
However, it should still run.
On the carbs, connect the vacuum pods. Does your carb linkage open the carbs (front and rear, not primary/secondary) 1:1 or is it staged? Also, on the power valves... you need a vacuum gage, and take a reading on manifold vacuum level in gear, at idle. Once you know that number, post it.
 
what about a progressive linkage. I assume this is a street engine. Dumping 8 barrels of fuel with 1200 cfm into a motor thats warmed over isnt going to cut it.
 
I thought that's what the vacume secondary carbs were good for taking what the engine needs. I know double pumpers would dump all 4 barrels all the time. I'm thinking the power valves need to be swapped I'm guessing the motor isn't pulling enough vacume for the 6.5s. I know with some adjustments I can get it to kick ***, and with the help of all you, thanks so far everyone
 
Yes, cam is WAY TOO big. My impression is the "9.5:1" might be a little less unless the engine was blueprinted. That cam wants a minimum 10 and would really prefer 10.5+. So it will have a very low vacuum signal, plus, you have two carbs with two idle circuits that are feeding it. So the idle mixture will be hard to get close anyway. There's just not much signal to pull fuel through the carbs at idle. What I meant by progressive is the primaries of both carbs. Teh secondaries are controlled by the airflow through the carbs, which is why you hav eto give them a single vacuum signal... that's why you have to tee them together. If they are not Tee'd, they may open at slightly diffrent rates, which can cause issues during the transitions in the carbs because its the airflow throught hem that pulls them open. If that airflow isnt steady, niether can the secondary actuation. But, first things first... You should have an idle vacuum level around 2-3" at BEST. What I would suggest would be to get a couple 1.5s and stick them in them. Once things are cleaned up and the idle is better, then take a reading and expect to need to replace them with something slightly higher. I'm sure you are right, the power valve circuits are dumping fuel into it as it is.

PS - these are the vacuum pod covers you need to tie them together...
http://www.summitracing.com/parts/HLY-20-28/
 
Thanx! I actually bought those pod kits but have yet to install them. I'll buy powervalves today and install those pod kits and tie them together and report back asap.
 
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