Moparts

Higher stall converter = smoother idle?

Posted By: larrymopar360

Higher stall converter = smoother idle? - 01/29/20 06:06 PM

Wondering if a higher stall converter would smooth out idle any on my 410 stroker 360? The converter is an 1800 ish which is too low really for my combination I know. My plans are to upgrade someday to a higher stall, like maybe 2500 or so. It's my street driven only Diplomat. What I'm really wondering is if generally speaking, can stall speed effect idle quality? I prefer a smooth idle on this car, but it does have a bit of lope to it. If higher stall speed would smooth idle out, that would be a bonus.

Thanks.
Posted By: a12rag

Re: Higher stall converter = smoother idle? - 01/29/20 07:35 PM

Dont really think stall speed affects idle smoothness . . . . some may know better . . . in my stock 74 Duster360, the stock stall convertor was 2400-2600 RPM . . . . isn't the stall speed supposed to let the engine get into RPM range for making power ??? . . .
Posted By: larrymopar360

Re: Higher stall converter = smoother idle? - 01/29/20 07:51 PM

Originally Posted by a12rag
Dont really think stall speed affects idle smoothness . . . . some may know better . . . in my stock 74 Duster360, the stock stall convertor was 2400-2600 RPM . . . . isn't the stall speed supposed to let the engine get into RPM range for making power ??? . . .
I wouldn't think so, because it should be fully disengaged, but I read something elsewhere that made it seem it was possible.
Posted By: AndyF

Re: Higher stall converter = smoother idle? - 01/29/20 08:21 PM

It can help. Too tight of a stall will really cause problems if you have a race cam. A loose converter will allow the engine to idle without adding any load. If you have a radical cam then it is still going to have a rough idle even if you have nothing attached to the crank. But a tight stall converter will add some extra load at idle which will cause additional problems for a big cam.
Posted By: dOc !

Re: Higher stall converter = smoother idle? - 01/29/20 08:33 PM

Lmop ... think a 904 trans with 274 gear set !
Posted By: tex013

Re: Higher stall converter = smoother idle? - 01/29/20 08:39 PM

yes it will , if you have a hopped up motor .

Tex
Posted By: moparmanjames

Re: Higher stall converter = smoother idle? - 01/29/20 08:42 PM

If its in gear then yes absolutely it helps, much more slippage while stopped in gear than a stock converter.
Posted By: larrymopar360

Re: Higher stall converter = smoother idle? - 01/29/20 09:25 PM

Ok, thanks! Yes, it's definitely a built stroker with some cam giving it a bit of a lopey idle. I don't have the cam specs off top of my head. I had engine built by professional shop. Makes sense, while in gear. Didn't cross my mind. Thanks.

p.s. My invoice only shows "Muscle Motors custom hydraulic roller cam". No specs. I guess it was part of their secret recipe. The valve train is Comp and Crane. KB pistons, balanced Scat crank and Rods, lots of Milodon parts elsewhere (oil pan, water pump, thermostat), edelbrock air gap intake.
Posted By: Dave_J

Re: Higher stall converter = smoother idle? - 01/29/20 10:15 PM

Dead stock 1975 Dart 4 door, 225 Auto, Manual brakes. Had a LS 1800 or less stall. At a stop light in Drive, the RPM was stumbly and it would push the car hard through the brakes even 2 footen it.
Redid the brake drums and shoes, replaced the master cylinder, replaced rubber brake lines. Did not matter.

Finally I pulled the 904 and replaced the converter with a \6 weighted High Stall and put a TransGo shift kit in it . Fixed it. Idle was smoother and I could hold the car with my toes on the peddle.
Posted By: RoadRunnerLuva

Re: Higher stall converter = smoother idle? - 01/30/20 12:19 AM

Originally Posted by larrymopar360
Ok, thanks! Yes, it's definitely a built stroker with some cam giving it a bit of a lopey idle. I don't have the cam specs off top of my head. I had engine built by professional shop. Makes sense, while in gear. Didn't cross my mind. Thanks.

p.s. My invoice only shows "Muscle Motors custom hydraulic roller cam". No specs. I guess it was part of their secret recipe. The valve train is Comp and Crane. KB pistons, balanced Scat crank and Rods, lots of Milodon parts elsewhere (oil pan, water pump, thermostat), edelbrock air gap intake.


Wonder why they didn't give camshaft specs for your engine that YOU PAID FOR....makes no sense?? Their outta business now...unless you have the builders phone #??
Posted By: larrymopar360

Re: Higher stall converter = smoother idle? - 01/30/20 12:29 AM

Originally Posted by RoadRunnerLuva
Originally Posted by larrymopar360
Ok, thanks! Yes, it's definitely a built stroker with some cam giving it a bit of a lopey idle. I don't have the cam specs off top of my head. I had engine built by professional shop. Makes sense, while in gear. Didn't cross my mind. Thanks.

p.s. My invoice only shows "Muscle Motors custom hydraulic roller cam". No specs. I guess it was part of their secret recipe. The valve train is Comp and Crane. KB pistons, balanced Scat crank and Rods, lots of Milodon parts elsewhere (oil pan, water pump, thermostat), edelbrock air gap intake.


Wonder why they didn't give camshaft specs for your engine that YOU PAID FOR....makes no sense?? Their outta business now...unless you have the builders phone #??
I believe they are out of business. That's what I heard. I have no reason to call really. Cam specs really don't mean that much to me. It was a total package I was looking for. I explained what I was looking for, and got that. The phone number on the invoice is 517-482-4900. I researched a bunch prior, and their reputation was very good, and I'm very happy with the engine and it's performance.
Posted By: jbc426

Re: Higher stall converter = smoother idle? - 01/31/20 05:04 PM

I run a healthy hydraulic roller in my 408 Magnum with an automatic transmission. I used Precision of New Hampton to build a custom 3800 rpm stall, lock-up converter to match my combination. They nailed it. It wasn't cheap, but I learned you get what you pay for with converters if you use a reputable shop.

My car lopes pretty good at idle in neutral or in gear. I would have issues at idle if it were not for the higher stall converter. As it is, there is barely a change in idle speed when I put it in gear. The modern converter is so efficient, I only gain 300 to 400 rpm when I unlock the converter in 4th.
Posted By: larrymopar360

Re: Higher stall converter = smoother idle? - 01/31/20 10:59 PM

My converter is a TCI along with the 727. I know some are down on TCI stuff, but I've been fortunate. I had TCI converter and 727 in my last crate 360 car and it was flawless through 70,000 miles, when I sold it. It's supposed to be basically a stock Mopar muscle car stall speed. 2200 ish I believe. That's what it feels like too. I know I need a higher stall to really take advantage of this engine too.
Posted By: Bad340fish

Re: Higher stall converter = smoother idle? - 02/01/20 01:23 PM

I would go with something in the 3000 range 9 or 10 inch converter. It will idle smoother in gear and drive better around town. You will also get a great response when you smash the loud pedal.

My car is mostly race car but I have driven it all over the country with an 8" 4500 and later a 4800 converter. I think even a stock 340 would benefit from a 3000 stall converter.
Posted By: larrymopar360

Re: Higher stall converter = smoother idle? - 02/01/20 05:10 PM

I do like the sound of something around 3000 rpm and not higher for street use, though I have not had anything higher than 2200, I don't want to go too high and have regrets.

Thanks for all info.
Posted By: dOc !

Re: Higher stall converter = smoother idle? - 02/01/20 08:01 PM

SOUNDS LIKE to me you need a Newport boat instead of this stall speed headache... xmaseek

Me thimks you’ll never rEgReT THAT ! up



Posted By: Diplomat360

Re: Higher stall converter = smoother idle? - 02/12/20 10:10 PM

Yeah, the higer stall will un-load the motor at lower RPM, so at idle you'd get that more docile behaviour...but why would you want that!!!??? scope

Ha ha..on a serious note, not that I'm trying to peddle my wares here, but I still have my old 2800 stall converter that I had in my coupe prior to the move to the 4K 9.5" piece. That was the original custom built converter which was just not enough stall for the combo I put together. Drop me a note if you're interested...
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