I dont typically post alot of Race/tech questions, but I am not sure where I am going wrong. I am working on a 68 Hemi crossram with the correct Holleys on it for a 426 Hemi-Dart. I would rather figure this out for myself, but I am not experience with dual quads...so I need some help.

The problem is the car will not want to idle in gear. Will idle great in park (1400), but has to be two footed contantly when put in gear. Idling it up doesnt seem to help.

Details are..12.5 compression, 700 lift solid roller(R290 Cam), pretty much stock heads and valve train, stock crossram, auto car, with a dynamic conv, two holley blue pumps with dual regulators, jetting is close to stock per Direct Connection book. Carbs were rebuilt in past year. Timing is about 32 degrees. Old Mopar Per Dist. MSD 7al and coil. Taylor wires, Plug gap is about .045.

I used the Dvorack machine synchronizer, but the after checking the idle in neutral was pretty close to being right anyhow before using it.

I am sure this combination could be optimized, but I would like diag on the idle condition. Comment, questions would be appreciated...

Justin

I was having the same problem. Similar combo,12.5 comp, .675 lift solid roller. I set total timing at 34 without checking initial. Put the MSD blue springs in, reset total again. Now it will idle at 650 in gear. Hope this helps.

Is your timing Fixed at 32º or is that total? If not what is the curve in the distributor?

Locked out at 32 degrees.. I thought about bumping it up to 34-35 range.

Thanks for the comments guys

Justin

Well a vacuum leak will keep a engine from idling. I agree you need to check timing at idle. That big-ole cam would like lots of initial timing...Probably 20+ deg would be best.
Recheck the timing, and for vacuum leaks and report your findings. Use some Brake Klean, or carb and choke cleaner and spray around the intake mating surfaces and carb base gaskets etc.
But you say "it Wont idle in gear"
Makes me think it will idle in Park?
Stupid questions but how loose is the converter, and large cam like that and a stock converter WONT idle in gear.

Just a little street driving advice for a crossram hemi, dont try to sit at a stop with the motor loping at idle in gear. If your not accelerating or moving, put the car in neutral. Your plugs will thank you for it.

timing idling in neutral is 32 and locked.

i agree a hemi doesnt want to just set in idle for an extended period of time in gear, but i think it should be idle for 10-20 seconds before it wants to load up that bad.

i thought about the vacuum leaks, but wouldnt that show up in neutral as well.

yes it idles well in neutral, but not in gear.

thanks again guys

convertor about 4000 plus stall..

justin

just checked for vacuum leaks and no change.

bumped up timing, and it seemed to like that.

as far as air mixture screws they are pretty dang close.

what makes you think its in the mixture scews out of curiousity?

thanks again justin

If you are on the idle circut with both carbs,the jetting will not effect idle quality.If the floats are too high,it could cause a rich condition that would require a higher idle to stay running.You might have to remove the carbs to verify your in the idle circut and that the "slot" is covered.If not,open the secondary throttle blade with the adjuster only accessable from the bottom, this will allow add'l air flow so the primary blades can be closed and adjust idle screws accordingly.Sometimes,depending on duration of the cam,small holes have to be drilled in the throttle blades.

you are in dayton,, easy fix... go see tony at specialty motorwerkes

937-293-1188

he is on springboro pike rd

If I remember right, you souldn't have to turn the screws much more than 3 turns out. If you do then the problem is somewhere else.
Are you still running the Power Valves? If so what size.
I recomend investing in a Holly Performance tuning book.

hemi-itis...i talked to another gentlemen and he mentioned some of the same stuff you did. but we were wanting to keep the carbs ss/ah legal, so we werent sure you could drill the holes.

jeff (MCH)..yes i thought about that, but i am hard headed and want to do it myself. i trust tony. i just dont learn much if i have someone else do it for me...hence the reason for not wanting to ask the question in the first place.

the power valves i believe are 3.5, but i dont think they are blown because it runs crisp in idle, and not real fat.

thanks for everyones comments..

justin

Justin,how much vacume under the carbs at idle?Also if there is no difference in idle when adjusting idle mixture,your off the idle circut.A vacume gauge would be a very usefull diagnostic tool right about NOW!!

I agree with the vacuum gauge being helpful. However I do not have a port on a crossram or these carbs. I will have to try to make an adapter tomorrow to get one hooked up. Yes the mixture screws will affect idle quality when i move them. I will try to hook up a gauge and see what the deal is tomorrow.

I guess I need to check for vacuum leaks more in depth...and if no prevail, try adjusting secondaries a little to see if the additional air helps.

Thanks

Justin