holley carbs

[creepingcharlie]

looking for some help with engine idle. I have a 366 bbc with a mild cam. I think around 282/535 or so. the intake is wieand tunnel ram with 850 Holley. The problem I have is trying to set idle and timing. the adjustment in the metering blocks don't seem to help with get the idle stay level. I was told to change the power valves to a smaller size and it would help in the tuning. what else is there to do or check to maybe get it right or close. thanks advance for any info.

[Blown 472]

http://www.holley.com/TechService/Library.asp

[SmokinLowriderSS]

And each is going to give you fits.
First, you've got a damn big carb sitting on top of 360 inches. Airflow at idle and throttle response are going to be nightmares. That carb might be OK at 7,000 RPM, not at less.
Seccondly, you have 1 carb, sitting on top center of a tunnel ram, which wil cause rich mixtures in the center 4 runners, and lean ones in the end 4 runners. This happens at all RPM, not just idle.
Third, TR's are normally a very high RPM design, needing 6 to 8,000 RPM for good mixture velocity to prevent fuel dropout and puddling which happens at lower RPM.
To get the single 850 on the TR atop the 366 to work right, you're gonna put a LOT of work into adjustments.
You'd be much better served by something 650CFM class, on a single or high-perf dual-plane manifold, but that'll cost you at minimum 10 blingMPH (30 on e-bay).
The power valve change will do NOTHING unless they are leaking at idle. Intake vacume should hold them CLOSED at idle. What is your idle vaccume? Power valve size should be aprox 1/2 that (10" vac install a 5.0 PV to start with, 13", install a 6.5 PV)

[SmokinLowriderSS]

If you are dead set on the TR, get a pair of the smallest 4-barrels you can find (I think Holley is 450's). You are still WAY overcarbed, and likely down on power from a proper single 4v setup, but your mixture and in-carb velocity problems should be minimized.
Some4times folks arround here have a set they are tired of having on a shelf in the garage.

[Cheap Thrills]

And each is going to give you fits.
First, you've got a damn big carb sitting on top of 360 inches. Airflow at idle and throttle response are going to be nightmares. That carb might be OK at 7,000 RPM, not at less.
Seccondly, you have 1 carb, sitting on top center of a tunnel ram, which wil cause rich mixtures in the center 4 runners, and lean ones in the end 4 runners. This happens at all RPM, not just idle.
Third, TR's are normally a very high RPM design, needing 6 to 8,000 RPM for good mixture velocity to prevent fuel dropout and puddling which happens at lower RPM.
To get the single 850 on the TR atop the 366 to work right, you're gonna put a LOT of work into adjustments.
You'd be much better served by something 650CFM class, on a single or high-perf dual-plane manifold, but that'll cost you at minimum 10 blingMPH (30 on e-bay).
The power valve change will do NOTHING unless they are leaking at idle. Intake vacume should hold them CLOSED at idle. What is your idle vaccume? Power valve size should be aprox 1/2 that (10" vac install a 5.0 PV to start with, 13", install a 6.5 PV)
Agreed, That's a hell of a carb and intake. Great for WOT conditions. Absolutely useless for pleasure boating.
650cfm double pumper and a mild intake such as the Edelbrock performer or torquer, Air Gap ect. would be more suitable. Tunnels aren't made to idle.
Good Luck
C.T. :wink:

[creepingcharlie]

I have a 650 dp, do guys think that carb would be a better fit? I know the intake is made for high rpms but thats what it came with. I really don't want to throw a bunch of money at this motor. Just trying to get it to run good for one or two summers or entail I have some money and time to build up a 454.

[YeLLowBoaT]

a 650 would help some, but it does not really matter what you have on top as the intake is KILLLING your motor. For less then $100 you can pick up a used intake at a swap meet or a little more on ebay. take that intake and put the 650 on it and you will do just fine.

[roostwear]

All the chat about the carb size, intake, and power valve is fine and all, but as far as I know (and if it's Chevy, not much), when is a 366 a BIG BLOCK? A hundred cubes or so is gonna matter......

[Blown 472]

If you are dead set on the TR, get a pair of the smallest 4-barrels you can find (I think Holley is 450's). You are still WAY overcarbed, and likely down on power from a proper single 4v setup, but your mixture and in-carb velocity problems should be minimized.
Some4times folks arround here have a set they are tired of having on a shelf in the garage.
WAY overcarbed? what size carb would you use on a 416 small block mopar, street strip car that runs on pump gas?
One more for ya, what size carb for a 340 mopar, street car on pump gas, both cars have automatic trannys.
Btw, ditch the single carb tunnel ram, they dont work, pick up a nice dual plane intake like a stealth and try the 850 on it, if you dont like it put the 650 on it.

[creepingcharlie]

All the chat about the carb size, intake, and power valve is fine and all, but as far as I know (and if it's Chevy, not much), when is a 366 a BIG BLOCK? A hundred cubes or so is gonna matter......
its the motor gm buts in the topkick truck in the nineties. If I remember correctly it has 3.50 or 3.75 bore and the same stroke as a 427 in a 454 block. small cubes in a big block.

[steelcomp]

WAY overcarbed? what size carb would you use on a 416 small block mopar, street strip car that runs on pump gas?
One more for ya, what size carb for a 340 mopar, street car on pump gas, both cars have automatic trannys.
Btw, ditch the single carb tunnel ram, they dont work, pick up a nice dual plane intake like a stealth and try the 850 on it, if you dont like it put the 650 on it.Dude, you don't know any more about what you're talking about than he does, so give it a rest.

[396_WAYS_TO_SPIT]

How many rpm's does this motor spin??? :idea: :idea:

[396_WAYS_TO_SPIT]

366 cubes x 5000 rpms = 1830000/3456 = 529.51cfm @ 100% Ve
I say run a 600cfm holley on a weiand stealth or a edelbrock performer and you will be happier! Keep the tram and 850 for another project. When you find another 850, change the tram top and now you have a good setup for a larger motor for the future;)
_SPitter

[cfm]

If your idle mixture screws don't seem to have an effect your t-blades are probably past the transfer slots. You need to correct this if the case. Best bet is to spend $20 on 'How to Tune/Modify Holley Carbs' found at your local or online bookstore like Barnes and Noble or etc.
Initial timing should probably be somewhere between 16-18° . You will have to play with this to see what gives best idle manners. Once this is done, change your advance mechanism so total stays the same as before, assuming that was done correctly.
======================
BTW:
You did not give us much of an idea what is wrong with your idle.
Always make sure their is good compression in all cylinders, no vacuum leaks, cracked/worn/improper plugs, and so on and so forth.

[Blown 472]

Dude, you don't know any more about what you're talking about than he does, so give it a rest.
OH thats right you are the great engine builder and tuner. Sorry oh great one.

[SmokinLowriderSS]

WAY overcarbed? what size carb would you use on a 416 small block mopar, street strip car that runs on pump gas?
One more for ya, what size carb for a 340 mopar, street car on pump gas, both cars have automatic trannys.
Whatever this may have to do with Charlie's 366, I sure as hell wouldn't run an 850 on them, unless you are turning them 8-grand, let alone on a TR, let alone on a single 4v plate on top of the TR.
Both would run fine with a 650.
You are excused now blown.

[Blown 472]

Whatever this may have to do with Charlie's 366, I sure as hell wouldn't run an 850 on them, unless you are turning them 8-grand, let alone on a TR, let alone on a single 4v plate on top of the TR.
Both would run fine with a 650.
You are excused now blown.
Answer the questions, both you and supercomp.

[SmokinLowriderSS]

I did, your reading comprehension is too low to register it tho.

[creepingcharlie]

[QUOTE=cfm;2558300]BTW:
You did not give us much of an idea what is wrong with your idle.
the problem is that the idle revs up and down and eventually loads up and dies. I check the plugs and they are black. That tells me there to mush fuel. When trying to time it the mark jumps all over the place so I try to set as good as I can. I know now that the comb is way off. So now I will be looking for a different intake for it and puting the 650 on and going from there, unless you think that I can get this combo to work.

[Blown 472]

BTW:
You did not give us much of an idea what is wrong with your idle.
the problem is that the idle revs up and down and eventually loads up and dies. I check the plugs and they are black. That tells me there to mush fuel. When trying to time it the mark jumps all over the place so I try to set as good as I can. I know now that the comb is way off. So now I will be looking for a different intake for it and puting the 650 on and going from there, unless you think that I can get this combo to work.
Make sure you dont have a broken spring or something in your dizzy that is making the mark jump around. Get a different intake you will be much happier, also make sure you dont have a blown power valve or something else that might be dumping fuel.

[GofastRacer]

[QUOTE=cfm;2558300]BTW:
You did not give us much of an idea what is wrong with your idle.
the problem is that the idle revs up and down and eventually loads up and dies. I check the plugs and they are black. That tells me there to mush fuel. When trying to time it the mark jumps all over the place so I try to set as good as I can. I know now that the comb is way off. So now I will be looking for a different intake for it and puting the 650 on and going from there, unless you think that I can get this combo to work.
Ok, if all you're looking for is for it to run and not worried about performance so you can save money for a different motor, just use your 650 on your manifold and make sure the carb is in tip top shape. Check the distributer, timing should not be all over the place, have this stuff done if you can't do it yourself. Right now both the carb and distributer needs attention, take care of that and it will run and get you by till you get the motor of your choice done, and save both money and grief!..

[cfm]

[QUOTE=cfm;2558300]BTW:
the problem is that the idle revs up and down and eventually loads up and dies. I check the plugs and they are black. That tells me there to mush fuel. When trying to time it the mark jumps all over the place so I try to set as good as I can. I know now that the comb is way off. So now I will be looking for a different intake for it and puting the 650 on and going from there, unless you think that I can get this combo to work.
I didn't say I like the combo or if it could work (I don't like single carb tunnel ram set-ups. Some run them successfully, but personally I would not do one) since I've never played with a set-up even close to yours.
I'm mearely pretending it's just a motor that somone is trying to make idle/run correctly with what someone has.
==================================
Your timing bouncing around all over the place - do you have a spring/weight type distributor by any chance ? What type do you have ?

[cfm]

WAY overcarbed? what size carb would you use on a 416 small block mopar, street strip car that runs on pump gas?
Not the same but since you are comparing cid's vs type of engine As example: On hot 421cid+ SBC we like to use 1050 Dom's - yes, pump gas and street driven. These bigger Sbc's love big carb's ! Same cid BBC with same HP usually doesn't like the Dom as much.
Figured I'd sidetrack the sidetrack. LOL.
Anyway - let's help this guy out. That's why he's here.

[creepingcharlie]

gofast, the 650 I rebuilt about two years ago and ran once. I am novices at all this so it is probably not tip top.
now as far as the distributor. it is a Mallory dual points converted to unilite. it is a weight and spring advance type. I have check the springs to see if thats the problem but they looked fine. I did notess that they seemed to be a little weak.

[GofastRacer]

Well, maybe time to look into it again maybe??. You may have the wrong springs in the distributer??, since you're a novice at this I would suggest taking it in and put it on a distributer machine and let them adjust the curve on it!..

[Blown 472]

Too lite a spring and the timing will be all over the place, perhaps a nice hei unit might be a better way to go, I think those chivy dizzys are easier to tune then a mallory???

[SmokinLowriderSS]

HEI ius not a bad idea, BUT, the way they switch signals arround, it creates an automatic retard effect that I believe to be about 1* per 1,000 RPM, which is usually not desired. Depends on just how picky you want to be for your maximum timing.
If ther timing is all over the place, the dist needs looked at.
You will need stable base timing to try to get anything else to settle down.
Check with someone elses light first, or check that light on another vehicle, to rule IT out as eratic.

[creepingcharlie]

hei will not clear the t ram I have tried. Im going to take the distributor out and check it out. I going to try and find some info on setting a timing curve in it and give that a shot.

[creepingcharlie]

i found a offenhaeuser dual plan/dual port intake??? and a torker edelbrock intake. what one would be better out of the two? i may be able to get one or the other pretty cheap.

[Blown 472]

i found a offenhaeuser dual plan/dual port intake??? and a torker edelbrock intake. what one would be better out of the two? i may be able to get one or the other pretty cheap.
Get the torker, that dual port is junk

[ibelio]

if it truely a 366 truck eng [tall block] it will take a different intake not standard 396-454

[creepingcharlie]

it is a tall deck block. It has spacer on it. thats one reason I don't wanna waste a bunch of $$$ on it. I have not had the chance to mess with it yet but hopefully soon, its getting hot.