727 Rebuild and Torque converter questions

[Coronet67guy]

So once my 74 is out of the body shop the tranny is next in line. Some specs - Erson Cam with a 1800-4800 rpm range, so needing something in the 2300 stall area.
Motor is the numbers matching 400HP with just some slight upgrades. Intake and exhaust manifolds are original. Estimated highway RPM at cruise speed is around 2900, based on 3.23 ratio. (Car isn't here so not sure on the ratio, if it's a 2.76 that cruise rpm is around 2500)

I'm looking at a couple different Tork Masters. 2000 or 2400. My understanding is these things stall about 300 rpm higher behind a big block, so maybe the 2000 is best? It has a range of 1900-2100. The 2400 has a range 2300-2500. Seems if that one actually stalled above that and I had 2.76 gears I would have a converter not stalling under cruise RPM. Would u suggest another brand converters? Which of the previous options would you use in the rebuild?

Any other tips? I'll have a local shop doing the rebuild but I'm supplying the kit. Considering the CRT Street kit, mainly a stock kit I believe except the Alto red eagle clutches. Also will get a TF-1 Transgo. The TF-2 seems like overkill.

Thanks and happy holidays!

 

[Curiousyellow71]

A 400 isn't going to be a big torque maker at 2k it's not likely to stall any higher then the rating. A 440 could stall higher. I am not a fan of the b&m brand converters but for the step over stock stalls mentioned they probably would be ok. I would maybe consider Hughes converter. For a better converter I would do a Lupo Dynamic. I think you will like a 2500 stall with a 400. A 2200 would be the minimum converter I'd consider.

Shift kits....usually the next level shift kits they crank the tranny pressure up higher and higher. If the front pump has wear it will struggle to build pressure at high pressure settings. but if you are not cranking up the pressure to race levels...you can often get by reusing your old pump. But your tranny will only be as good as the pressure the pump is capable of making. Maybe your shop puts new pumps in there rebuilds and it's a mute point?

 

[Coronet67guy]

A 400 isn't going to be a big torque maker at 2k it's not likely to stall any higher then the rating. A 440 could stall higher. I am not a fan of the b&m brand converters but for the step over stock stalls mentioned they probably would be ok. I would maybe consider Hughes converter. For a better converter I would do a Lupo Dynamic. I think you will like a 2500 stall with a 400. A 2200 would be the minimum converter I'd consider.

Shift kits....usually the next level shift kits they crank the tranny pressure up higher and higher. If the front pump has wear it will struggle to build pressure at high pressure settings. but if you are not cranking up the pressure to race levels...you can often get by reusing your old pump. But your tranny will only be as good as the pressure the pump is capable of making. Maybe your shop puts new pumps in there rebuilds and it's a mute point?

Will for sure ask about the front pump. I believe that's the main issue with the tranny now is the lack of pressure. I believe your saying that if the front pump isn't producing good pressure a shift kit won't help me much.

 

[Curiousyellow71]

Pressure could be escaping in other places as well. If it slips when it's cold and gets better when it's hot the sealing rings may be damaged from the pump to the front drum. A shift kit can help even with a pump that has wear...but at a certain point you are right ....the shift kit is as only as good as the pressure the transmission is capable of building.

I dont really think you will have much trouble with finding a torque converter that will work...but it's a area that you tend to get what you pay for...and cheaper is not necessarily a good thing. But Imo most torque converter issues occur when you are talking higher stall speeds like 3k or more. The last converter I bought was custom from dynamic. I certainly would recommend them...vs the one size fits all mail order converters. It is a little more money. But I bought a stall converter that was junk once and I would rather have a converter expert help me then learn the hard way.....again. Lol

 

[Coronet67guy]

Pressure could be escaping in other places as well. If it slips when it's cold and gets better when it's hot the sealing rings may be damaged from the pump to the front drum. A shift kit can help even with a pump that has wear...but at a certain point you are right ....the shift kit is as only as good as the pressure the transmission is capable of building.

I dont really think you will have much trouble with finding a torque converter that will work...but it's a area that you tend to get what you pay for...and cheaper is not necessarily a good thing. But Imo most torque converter issues occur when you are talking higher stall speeds like 3k or more. The last converter I bought was custom from dynamic. I certainly would recommend them...vs the one size fits all mail order converters. It is a little more money. But I bought a stall converter that was junk once and I would rather have a converter expert help me then learn the hard way.....again. Lol

Thanks for the input. I did find the 2000 stall and 2500 stall from Hughes. If I don't have to buy the required flex plate that I had to buy with the B&M they actually come out to a little less money. I did talk to JEGS, they looked at cam lift and some other factors and recommended the 2000 stall. I think I'll at least step up to the Hughes, just still torn between the 2000 or 2500 stall. I don't have an issue with paying up for a custom one but lowest stall speed I saw for one for my car was 2800-3800. These seem to be more for the high performance/race transmissions.

 

[Curiousyellow71]

Thanks for the input. I did find the 2000 stall and 2500 stall from Hughes. If I don't have to buy the required flex plate that I had to buy with the B&M they actually come out to a little less money. I did talk to JEGS, they looked at cam lift and some other factors and recommended the 2000 stall. I think I'll at least step up to the Hughes, just still torn between the 2000 or 2500 stall. I don't have an issue with paying up for a custom one but lowest stall speed I saw for one for my car was 2800-3800. These seem to be more for the high performance/race transmissions.

A good tranny place will have enough experience to build it as tight as you want and likely get it really close to what you want. But nothing wrong with the direction you mentioned. They put 2200s in most of the old pickups and seldom do you here of people complaining of them stalling 2 high. If you think have 3.23...I would do 2500. If you have higher...its a judgement call depends on your driving.

 

[33 IMP]

I would get the 2500, your 400 will probably make 50-100 more hp at 2500, compared to 2000. Worlds of difference on take-off, and still not slipping at freeway speeds.

See Hughes tutorial on stall speed at : "ep 5 torque converters 101, what is stall speed?" on you tube. You will probably learn something, i sure did.

For reference, ive got a 3500+stall in my 440 runner, and a 4500 stall 9" converter in my 440 62 savoy. I did once buy a cheap "3500" converter, stalled 4500 behind a 440 street car and slipped constantly. Utter piece of s#!t.

 

[wyrmrider]

Transgo was near my shop
I have TF-2 in everything should be fine
have you run the stock converter with the erson cam? is stock converter a hp?
earsons are milder than they look- they use the SAE .006 at the valve which is for a mopar .004
at the lifter- like a crane do you have the part number?
a 268 mopar has much more seat duration than a 268 erson more like a 280 earson
you need to estimate the new stall torque to what you have now
If you had a magnum cam there may not be much difference
I'd put it together with the stock converter and do a stall test and drive it for awhile to see how far you have to change
BTW erson cams from the Super Shop era are designed for the backyard instller and leave a lot of mid range on the table- for "come back" and lob failure prevention reasons

 

[451Mopar]

I'm not sure why Trans-Go sells the TF-1 kit? Maybe is was supposed to be less expensive?
The TF-2 lets you make the same adjustments as the TF-1, but includes a few more parts if you want even firmer shifts. If they cost the same, you get a bit more with the TF-2 kit, but you can configure it to be just like the TF-1.

 

[Coronet67guy]

I'm not sure why Trans-Go sells the TF-1 kit? Maybe is was supposed to be less expensive?
The TF-2 lets you make the same adjustments as the TF-1, but includes a few more parts if you want even firmer shifts. If they cost the same, you get a bit more with the TF-2 kit, but you can configure it to be just like the TF-1.

Funny thing the TF-2 is actually 2 bucks cheaper than the TF-1 on Summit. I guess I'm going with the TF-2 then. It just says "full race shifts" where as the TF-1 seems more for street. That's why I was a little confused over which one to get.

 

[Coronet67guy]

Transgo was near my shop
I have TF-2 in everything should be fine
have you run the stock converter with the erson cam? is stock converter a hp?
earsons are milder than they look- they use the SAE .006 at the valve which is for a mopar .004
at the lifter- like a crane do you have the part number?
a 268 mopar has much more seat duration than a 268 erson more like a 280 earson
you need to estimate the new stall torque to what you have now
If you had a magnum cam there may not be much difference
I'd put it together with the stock converter and do a stall test and drive it for awhile to see how far you have to change
BTW erson cams from the Super Shop era are designed for the backyard instller and leave a lot of mid range on the table- for "come back" and lob failure prevention reasons

Hello. I have no clue as to the stock converter. I assume it's the original one since the tranny is but if rebuilt in the past that wouldn't be the case. I was told the stock one would of had about a 1600 stall.

Erson Cam is E 410322. Cam sheet shows 284 duration. .472 valve lift. 220 duration at .050 tappet rise. Has a 1800-4800 rpm range.

As for putting it back together with the stock converter I didn't think that was even an option due to likely contamination in the old converter. Plus since I'm paying someone to pull and install it would get expensive to keep pulling it out again to change the converter.

 

[Curiousyellow71]

I would do the upgrade of the torque converter like your planning. I don't think I'd be worried about your cam 2 much since your are only talking a step over stock stall. Most of the shift kits we used to put in where b&m transpack kits where you can do heavy duty/street/race out of the same kit. B&M had a basic shift kit 2 like transgo and IMO it was kind of silly to purchase to save 15 bucks and loose nice shifting features.

 

[wyrmrider]

ok the earson has a rather long seat duration for the lift and .050 but they wear well
B&M used to have cnverters built to their specs by Continental Torque Converter in Inglewood CA , who did excellent work, but the Owner Died and they are gone
No idea who is doing B&M work now
you might want to get a converter closer to home
suggestions anyone

 

[Curiousyellow71]

I've seen B&m marketed under the Holley brand. I don't have a clue who builds there converters. I've seen quite a few complaints about b&m converter issues and unhappy customers. A converter is not much fun to switch out...so I have my reservations as far as recommending one. I always liked their shift kits though. Continental had a good reputation for a long time.

 

[wyrmrider]

If you read between the lines I'd ask around and go elsewhere
Wonder what happened to Continentals Chris- he was the best