Converter Question/Recommendation

[Orange Bird]

Hi,

I am ready to get back into my 70 RR restoration as I have finished a resto for funds to keep my project going. I have moth balled a 440 6 Pack - fresh rebuild - and I am ready to turn on the $ faucet again. I am considering a Hughes 3K stall 11" converter. New rebuilt 727 w/ extra clutch and shift kit (good for 750+HP I'm told). Car is going to be a grocery getter and stoplight car but built for "you want it you have to take it".

440 6 Pack
flat tappet 545 lift Comp Cam
410 rear
BFG 275 rear
10.5 Compression
Alum Head
Std valve train

I am in Paint Section an about page 25 (70 RR Restoration Process) by now and hoping to pull to the front again once I get back into my own project wit updated pics.

[Kern Dog]

Where is the question?
I think that you may have a blooper with describing the converter. An 11 inch converter will not have a 3000 rpm stall rating. If it really is 11 inches, (NOT at the starter ring) the stall is not likely to be higher that 2400 rpms. To get to a 3000 stall, the converter body needs to be 10" or smaller. My converter is 9 3/4" and stalls at about 2800. this is in the 493 in my Charger with the MP '509 cam.
I think you made a great choice with that Comp cam. I ran two of them back when they had a bad batch that flattened lobes prematurely. Those cams ran great until they failed. Don't worry though. They say that they have improved their products. I intend to switch back to the XE285 cam later this year.

[Orange Bird]

I guess it was more a recommendation/suggestion I was looking for people to weigh in with their options and experience.

I also found a thread here that someone recommended a Turbo Action converter.

I like to hear you were happy with the cam, I hope they have since fixed the issue.

Thanks

[firefighter3931]

With that cam i'd be looking towards a 10in converter from either Dynamic or Turbo Action 



Ron

[Orange Bird]

Thanks. I appreciate the interest and help. I was looking at some of the descriptions from Jegs and there are 2 different converters. 1 is an 11" converter and they describe a 440 w a range of 3200-3500 RPM (#17801) and a 10" converter w a range of 3000-3400 RPM (#17805ST). Is the 11" really not able to make the higher or rated stall? I just don't want to shoot myself in the foot.

[firefighter3931]

Stall as advertyised allways falls into a range....the more torque you make the higher it will stall assuming the same converter is being used behind different engine builds. 

That Comp xe285hl is a healthy cam geared towards top end power. Peak torque will be 3500-3800 so you need to size the converter accordingly. An 11inch unit will have difficulty reaching the required stall speed and still maintain efficiency at lower engine speeds. I'd call Paul at Turbo Action or Sean at Dynamic and see what they say. Dynamic likes to push their 9.5in street/strip converter which is a fantastic piece but it might be a bit too much for your needs, inmo.


Ron

[c00nhunterjoe]

My vote goes to the 10 inch, 3k stall as well. Be sure to get a decent trans cooler, especially if its a stoplight bandit

[Orange Bird]

I understand a little more and a little confused at the same time. I was sizing the cam spec (2500 - 6K) to the converter at the point where it was working at the front edge of the cam RPM range. I did not consider the peak torque range of the cam and now understand the taller stall speed. That said, what confuses me is the spec of the converter (understanding alot depends on the power in front). The Jegs website specs the 11" converter at a higher RPM rating than the 10" unit. I read/hear the  smaller converters have a higher rating given torque in front but the writup speaks to the contrary, at least as I understand it.

I dont want to pull from a stoplight sounding like I'm wound tighter than a top in a normal acceleration with a higher stall (like I'm riding a clutch). Some is OK. I don't want to kill my tranny either with heat. My other RR pulls away nicely and shifts like you know something is there but not bad. Stab the throttle, it hesitates while it winds up and uncorks then shifts like someone is helping you along with a sledge hammer. Its a  440 (a "3k" stall) Its a standard rebuild from 25 years ago with lower compression and about a 480 lift. I like what it does.

I want this build to be about the same with more kick - pull away relatively normal but have it come alive when needed.

Looks like I too will lean toward the 100 given the specs I am reading but will call TA tomorrow. They did not answer when I called

[flyinlow]

I would think a stock converter would work fine except for idle and drive engagement harshness with that build. ( don't know what your idle speed is) Your grocery getter with 275 BFG's should already be turning the tires into smoke at will. A higher stall converter would make it worse and generate more heat. Or are you talking about using slicks on the street?

[Orange Bird]

No slicks. I am concerned a little about the heat. I may drop down to a 2800-3200 range if I can find one close. I may be some under my power band but since I am not racing with the thing I would think it will have enough power to pull through the engagement of the motor at a lower RPM as FireFighter mentions.

[John_Kunkel]

People in the converter business only use stall speed as a selling point because that's what most people understand but, in reality, there is no such thing as a 2500 converter or a 3000 converter, etc. regardless of what the box says.

Your best bet is to contact the converter manufacturer of your choice and give them your wants/needs; converters with the same stall speed can be built "loose" or "tight" depending on your driveability needs.

[Orange Bird]

Yes, there is alot to it and I have taken the advice here. Turbo Action 10" converter on order. Paul at TA called me back on his day off today. Hell of a nice guy and helped me out tremendously. He even spent time bringing me up to speed on how things were calculated specific to my combination. I will recommend Turbo based on my experience. Thanks for all the input