Daul quad 360 questions

[5th_Ave_Sleeper]

I now have the 5th Ave running with the tunnel ram and twin holley's. Now I have a few Q's
1. Do tunnel ram's always take alot of cranking to get the engine to start?
2. What is the smallest jet size I can put in these things. both are 600's with 49's in the primaries and plates in the back.
3. should i go with 50cc acc pumps?
The engine has a really bad flat spot off idle. when I accelerate, the car falls lat on its face, then roars to life and spins the tires. And is blowing alot of black smoke. all four idle adj screws are all the way in.
This is going to be an on-going problem i think.
5th

[amxauto-x]

And you drive that on the street?

[6 packin]

1200 cfm is alot of fuel for a engine that would run best on half the fuel. You can get vacum pods quick change spring covers that link the two secondaries togather. Sound like you need a hevier spring in there?? This combo will be tough to tune on a 440, being a 360 and all. It can be done though. Try changing the squiters too. You dont need the 50cc pumps. Run as much intial timing as it can stand and still crank when hot. I would trade them for some 350cfm carbs and mechanical seconds.

Good luck

[DEMON SIZZLER]

Too much carburation=not enough head flow=not enough cam/compression; so the carbs will tend to be 'rich' since again the air flow is really low because the engine cannot pull enough air through the carbs. Jetting down usually will not help but mabe two 390 cfm Holleys will work. You will probably find that the carbs will run slightly better with no air cleaners, DAVID.

[dwc43]

I'd use two 430 cfm holley's that were made for this set up anyways. That's 860 cfm total and only 60 more than the stock 800 cfm thermoquad that came on it any way.

[fastmopars .inc]

hmm, that was basically all the problems that everyone listed would happen when you first said you wanted to put a tunnel ram on a mild 360 and run it on the street!

i think your stuck with it until you put a decent intake on it. you will gain torque where you sorely need it, and save money on gas.
think about this.

[1972roadrunner]

hey, to each his own right? 5th, how about some updated pictures!! this i gotta see!! have you cut your hood yet, or are you runnin without it??

i would do somthin to try and lean it out a little. when you say "plates in the back", do you mean your blocking the secondary butterflies?

hey, one thing that could possibly help, is a higher stall torque converter (for launch anyhow ).

good luck man, keep me updated!

[dwc43]

By the way the extra cranking is due to flooding from the big carbs. Be careful, 'cause one back fire on a t ram car will make a nasty fire. Seen it happen before. So you might wont to get that 1200 set up off of there and get the two 430's for a total 860 that should be much safer and drivable.

[5th_Ave_Sleeper]

I will start looking for some 430's. in the mean time, ill keep messing with the a/p cams and squirters. by the way the heads are heaviley ported and comp ratio is a "high" 10.5 to 1
5th

[dwc43]

That's good to know. Just might work with the right carbs. I only have one 430 that came off my old 4x4. Not sure if I can part with it yet. Wont du you much good with out a mte either though.

[Slingshot383]

The 600's will work just fine, you just need to get the tune up. First, tunnel rams have different vacuum/pressure spikes than a single or dual plane intake. Pull the powervalves and install powervalve plugs. Second, make sure that no more than .040" of any of the transfer slots are exposed, either on the primary or secondary throttle blades. What you want is the same amount of the transfer slot exposed in each throttle bore, so you may have to open up the secondaries and close down the primaries. If these carbs are vacuum secondariy carbs, you do want to get the balance kit for the secondary vacuum pods. You will want to put in #40 - #45 accelerator squiters, and the 50cc pump kits might be needed. You will want a pretty quick advance curve in the distributor, and will have to time for total timing at around 3000 rpm, and let idle timing fall where it will. After doing this, it should idle with the idle screws fairly close to 1 1/4 turns out.

[5th_Ave_Sleeper]

thanks slingshot, my next question was going to be about the power valves and a vacuum reading.
What is this balance kit you speak of? does it connect the two vac pods so they open at the same rate/time?
5th

[Madman Stephan]

...my Challenger usually starts up right away unless it's fairly cold outside. I have two 625 CFM AFB's on top of an Offenhauser tunnel ram for the 360. I don't have any chokes on these units, don't really need them. And yes, tuning them is a pain, I'm always looking for tips and tricks to help out.

[wallyghs]

5th! Get us some pics! I'm getting ready to setup my 9" phord for my M Body... motor should be *finally* done by the end of the summer...
Still not sure if I want to go as serious as you have... I like to look of the tunnel rams and I'm willing to put up with a lot... but I can barely get my single carb motors running right!
Good luck gettin the sleeper running.

[1972roadrunner]

Originally posted by wallyghs

Good luck gettin the sleeper running.

sleeper? i'm not so sure it's a sleeper any more with big tires on the back, the back jacked up, and a TUNNEL RAM stickin out of the hood...

[Slingshot383]

Like I said, between the cam and the tunnel ram, powervalves are a thing of the past. Just jet accordingly. Yes, the balance kit is the pair of vacuum pod caps and vacuum line that goes between them.

[5th_Ave_Sleeper]

I will put 45 size jet's in the primaries, and power valve plugs tomorrow.
I should probly go with heavy secondary springs too eh?
*** Stupid holley question***
which vac port do i use for the vac advance dist? the one under the front bowl, or the one off the side of the metering block?
5th
PS Im workin on gettin some pics
5th

[1972roadrunner]

i have mine under the front bowl. since you have two holley's, are you going to put a T and use both? or just the one?

good luck man!