Torque Converter help!

[Zach079xxx]

Hey guys, my engine I had rebuilt is back in the truck. It's a 350 with a thumpr cam, weiand intake, and holley 600 carb. Sounds great in park but drive kills the engine. Have to power brake it or it'll bog out. Looking at torque converters, the one in it is around 1100 the guy doing the work says, because he built my tranny months ago and he says that a general guess. I'm getting a 2400-2500 stall converter but I have 2 to choose from. What is your opinion on it? Larry says 2500 should be enough, and he says 3000 is an overkill. THANKS

http://www.summitracing.com/parts/hup-gm25/overview/

http://www.summitracing.com/parts/bm...ll-block-gen-i

Let me know ASAP on your views on this. I'm hoping to have it back by friday


Heres my babe!

[chrly1492]

depending on what you plan to use the truck for, you may want to replace your converter. On the other hand if that is a new carb to you, or that engine combination, you may want to go to tune your accelerator pump first on the Holley. With my combo (pretty mild street with vortec heads, 10:1 compression)
I had to go to a #40 on the squirter, and change to a 50cc accelerator pump to get rid of the bog...runs great now..just a suggestion, unless you need to pull the tranny anyway..good luck with your project..

[Zach079xxx]

My builder says it needs the stall converter. The engine is tuned and timed perfect. This guy is like no other man I know. Crazy custom builds and very skilled. He is going to charge 400 to swap cams which I'm NOT doing. The cam is staying just need a stall converter he said he'll swap converters cheaper than cam. I mean really what's the difference if any of you guys ran a stall converter. I read the reviews but I can't decide

[Zach079xxx]

Went with the b & m. 280$ with next day air and a fuel filter I needed!

[SkinnyG]

My cam is 231°@050, 108LSA. I went with the Hughes GM25 (2500 stall) and I'm very pleased.

The truck is my daily driver, and it flat sucked with the stock converter and this cam.

In my research, there was nothing special about my motor that would need anything other than an off-the-shelf cam. B&M had quite a number of hit-or-miss reviews. Some raved awesome, some ranted they blew up. Hughes seemed to have more favourable reviews.

You will likely want a 2500. Hughes said my cam really wanted a 3000, but since this is my daily and I don't race it, they recommended the 2500.

All the converter companies I spoke with also said the converter is going to need deeper gears, in the neighbourhood of 3.55, 3.73 or more. I just recently switched to 3.73

[SkinnyG]

Oh. I see you already chose. You'll be fine with that one.

[Zach079xxx]

Mine isn't a daily driver but I want it to be able to be! I'll drive around daily but not to school. I drive my car to school twice a week. My trucks for fun really hope I made the right choice. I looked at Hughes and even summits brand. I guess I'll learn, there's no way of learning until you try it. But thanks for the reply, I'll keep that in mind. By the way, I have 3.08 gears :| fingers crossed!

Originally Posted by SkinnyG

Oh. I see you already chose. You'll be fine with that one.

[SkinnyG]

I had 3.08 gears for the past year and a half. They will work, but it's not the best for your cam, and harder on the converter.

[Zach079xxx]

I know it, I would love to swap it out but my wallet, well actually what wallet now?! Lmao just pray to the good lord that this converter will make my truck drive able. Today my mechanic had to hold the brake and gas pretty hard or it would shut off. Saddens me and scares me! If this converter doesn't solve it I can't afford another fix right now. Dang

Originally Posted by SkinnyG

I had 3.08 gears for the past year and a half. They will work, but it's not the best for your cam, and harder on the converter.

[SkinnyG]

The converter will fix that. With the stock converter at a traffic light, I needed to hold the brake with my left foot to keep it stopped, and keep nudging the gas with my right foot to keep it running. With the 2500 stall, it drives like a normal vehicle.

[cadillac_al]

Does the engine ever come alive, like after 3k rpm? A 350 that can't burn a tire would be pretty depressing. I hope the converter will crutch it along.

[geezer#99]

Originally Posted by cadillac_al

Does the engine ever come alive, like after 3k rpm? A 350 that can't burn a tire would be pretty depressing. I hope the converter will crutch it along.

A crutch is right!
Likely won't even chirp a tire!!

[SkinnyG]

It's not so much a crutch - with a lumpy cam, the engine doesn't make enough power at idle to overcome the fluid friction inside the converter. A "looser" converter doesn't restrict the engine as much, allowing it to operate properly. Think of it more as a "properly matched" converter, vs. a "crutch."

When you get on the gas, the looser converter will allow the engine to overpower the fluid enough to get the engine rpm up into it's power band (so to speak) a lot faster. Well, ok, that's more of a crutch. But....

The lumpy cam might not be making decent power until 2500rpm or so, so you'll want to have deep enough gears to get that engine operating in a rev range sooner, where it is happy. Not a crutch, but "properly matched" gears.

It all comes down to building a "properly matched" engine for the vehicle. And a lumpy cam isn't usually the best - but I wouldn't change mine for the world!

[Chaplain]

Good discussion.

[Zach079xxx]

I appreciate all you guys voicing your opinion. I will let you all know how it goes. Surely will be posting a video so you can see & hear that thumpr!

[geezer#99]

It is a 'crutch'!
It'll only allow it to maybe not quit when put in gear is all.
It won't cure how it runs or wants to run.
JMHO.

[Zach079xxx]

It dies once put in gear. Stall of 2500 should fix it.. That's my only problem. That and I over nighted the converter my guy said & it's not right. He ordered one from somewhere else so I just wasted a lot on fees and time. Starting to get aggravated at my build but I'm not allowing it to get to me! :|