Guest pyro Posted January 11, 2008 Share Posted January 11, 2008 Friends..........what's the factory rpm stall converter rating for a 1971 th350? I beefed up the engine slightly a few years ago and am going to drop the tranny for some service, and I figured I'd put a new stall converter in while I'm at it. Any recommendations? 500 rpm above stock? I'm probably running 330hp in a sb350 with a cam with a power curve that really lets loose at about 3000rpm, running a 3.42 rear and 27 inch tires. Thanks for any advice. Quote Link to comment Share on other sites More sharing options...
stangeba Posted January 12, 2008 Share Posted January 12, 2008 According to the paperwork (photocopied book) I received from GM of Canada a 1971 350 engine / THM 350 Trans has a stall speed of 2110 RPM. It has a stall ratio of 2.10 (whatever that means) and has a nominal diameter of 11.75 (I assume inches) The 71 Big block with THM400 has the same specs but has a converter diameter of 12.20. Bruce Quote Link to comment Share on other sites More sharing options...
Heckeng Posted January 12, 2008 Share Posted January 12, 2008 Do you know the cam specs? Duration at 0.050"? Quote Link to comment Share on other sites More sharing options...
stangeba Posted January 12, 2008 Share Posted January 12, 2008 Same book: Valve timing (crankshaft degrees) 350 cu in V8 Lobe lift: .2600 Inlet .2733 Exhaust  excluding including ramps ramps Inlet opens BTC 28deg 38deg Closes 72 92 duration 280 310 Exhaust opens BBC 78 88 Closes ATC 30 52 duration 288 320 (All Above @ Zero lash)  Bruce Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted January 12, 2008 Share Posted January 12, 2008 torque converter stall is a double edge sword  the same converter behind two different engines can have different stalls depending on the amount of torque being applied to it so...  more torque=higher stall out of the same converter  ALSO...if the cam you choose doesn't make the torque in the area of the stall, it can lower the stall  so with the larger cam you are choosing, and moving the torque curve in the higher RPM range, I myself would choose one in the 2800-3000 range  you should actually call the torque converter company which you choose, they will want ALL your spec's including car weight, cam, tire diameter, gear ratio, what trans, and even sometimes compression and cylinder heads  a looser (higher stall) can make it feel like "MUSH" on the street, unless you have your foot stuffed into it. you should take all this into consideration BEFORE you even choose your cam Quote Link to comment Share on other sites More sharing options...
Guest pyro Posted January 13, 2008 Share Posted January 13, 2008 Gross Valve Lift 0.462 0.469 Duration At 0.006 Tappet Lift 262 270 Valve Timing At 0.006 Open Close Intake 25 57 Exhaust 69 21 These Specs Are For The Cam Installed At 106 Intake CL Intake Exhaust Duration At 0.05 218 224 Lobe Lift 0.308 0.313 Lobe Separation 110 Â I believe this is the cam, it's been a few years since the motor was built. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted January 13, 2008 Share Posted January 13, 2008 go with a converter in the 2400 range, I thought it was a bigger cam Quote Link to comment Share on other sites More sharing options...
kc8oye Posted January 14, 2008 Share Posted January 14, 2008 my own expierence wiht my TH350.. from the late 80's... my stall is no where near 2100 !!! it's more like 1500.. at least, that's the highest rev's I could get to before the engine overpowered the brakes  my 700r4 stalls around 1000.. it's stupidly low. Quote Link to comment Share on other sites More sharing options...
Guest pyro Posted January 15, 2008 Share Posted January 15, 2008 2100 rpm? Yeah, I thought stock converter was more like 1200-1500, so I was thinking 1700-2000, hmmmmm......... Quote Link to comment Share on other sites More sharing options...
Reaper Posted January 16, 2008 Share Posted January 16, 2008 I think a 2k converter is a good all around converter... unless you start making a bunch of power and get into a lot of track time... Tom My bro has a 2200 ish converter in his camaro with a 700r4 and you can barley tell the difference between that and the stock one... Deffinetly dont want to much converter on the street though... it can become annoying... I have a 3k+ converter in my Monte and with 3.31 gears and a 28 inch tire it does over 3k RPMs on the highway and doesnt accel very well when your already movin... Thats why Im goin to an overdrive trans and will prolly do a little less converter but prolly not to much... Tom Quote Link to comment Share on other sites More sharing options...
502ci Posted January 16, 2008 Share Posted January 16, 2008 A 2100 stall should hold against the brake at about 1600 with a stock motor. (350) This is what my trans guy told me. Â My question is why? Shouldn't that be a 1600 stall? When does the 2100 number come into play? Â Its all voodoo to me. Â The brakes can only hold it back so much...the stall is really what it flashes to when you launch full throttle...my 3000 stall flashes to 4000+ behind my big block but would act differently behind any other motor. Â Bill Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted January 16, 2008 Share Posted January 16, 2008 I have about a 3600-4000 stall, at the track I have a hard time holding it at 2000 rpm, but when you "flash it" it will stall to 4000+ Â Â Quote Link to comment Share on other sites More sharing options...
Heckeng Posted January 16, 2008 Share Posted January 16, 2008 Wow Bill, that's quite a stall! How does it do with the OD on? Can you tell if it heats the transmission up or if it feels like it's slipping much? Quote Link to comment Share on other sites More sharing options...
502ci Posted January 16, 2008 Share Posted January 16, 2008 Wow Bill, that's quite a stall! How does it do with the OD on? Can you tell if it heats the transmission up or if it feels like it's slipping much? Â A 3000 stall is what I had ordered with my tranny...now the company who built it didn't use any of the hi-performance parts I ordered for it so it is possible that the converter is wrong also...possibly oversized...I'm not sure, but it was definately a no name brand they listed and if I could go back in time what I know now I would have ordered a name brand. Â Only feels like it is slipping when I first start it (we had that conversation before) but when it warms up you can barely tell it has that big of a stall...you can blip the throttle a bit when idling through a parking lot to maybe 2000+ and the car won't jump forward and can actually give the illusion to a bystander standing there that my car might have a clutch set-up. Â Using those calculators available on-line my converter is slipping like 1 to 2 percent more than it should be at 60 mph. I still have no tranny temp. gauge so I'm not sure what it is running at, but I do have a large tranny cooler in front with a large fan on it, I do not run the lines through the radiator, in fact I ordered the Be Cool one without them. I never noticed that it was hot or smelled anything funny. Â At any speed if I hammer it the rpm's jump to 4000+ which is just below my torque peak for my motor, I'll admit (and brag) my car pulls extremely hard at any speed, at 60 mph in overdrive (remember my car is locked in overdrive with the gear vendors at that point) my TH400 kicks in the passing gear and just starts pulling...I can make my passengers eyes get real wide at that point... ... Â Bill Quote Link to comment Share on other sites More sharing options...
680HPStroker Posted January 16, 2008 Share Posted January 16, 2008 Opinions vary, but I'd call a torque converter manufacturer that has a solid reputation and get someone on the phone who will go over your combo and sell you a converter with the correct stall for your application. IMHO off the shelf converters lead to dissapointments. Quote Link to comment Share on other sites More sharing options...
dbreese Posted January 17, 2008 Share Posted January 17, 2008 +1 Greg  Call any good converter company and speak with one of the tech guys. Tell'em what ya have and what your going to use it for. A few companies that come to mind are ATI, Edge, and Coan. I've been running a Coan Pro Street 11" with a 3000 stall. Footbrakes to 2000 ( Although I launch @ a lower rpm ) and flashes to 3100. It drives on the street just fine and cruises down the hwy with out a problem. Works well with my combo.  David Quote Link to comment Share on other sites More sharing options...
Reaper Posted January 18, 2008 Share Posted January 18, 2008 How much of a difference you think the diameter of the converter would make? Say an 11" converter or a 9" converter... I know a bigger converter keeps the heat down better but also takes away alittle more power/responce... Anyone know how much of a difference it is? Im looking at converters right now for the 4L80 and Im thinkin either an 11" or so converter with a little higher stall.. about 3300 or so... or a 9.5" converter with a little lower stall... about 2800 or so... What are your thoughts on this along with the thought on stall speed... Tom Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted January 18, 2008 Share Posted January 18, 2008 I would talk to the converter company that you are thinking of buying from Quote Link to comment Share on other sites More sharing options...
Heckeng Posted January 19, 2008 Share Posted January 19, 2008 Reaper, it may be hard to find converters like you're talking about. As diameter decreases, generally the stall goes up and they tend to get looser. The guys at ATI claim that a 10" converter is a better design than an 11" because an 11" converter is some sort of mix and match of parts while a 10" uses things that are made to work well together. I don't know, but you should definitely talk to a good company and let them tell you what they would recommend. Quote Link to comment Share on other sites More sharing options...
Reaper Posted January 19, 2008 Share Posted January 19, 2008 I talked to a guy last night from a company I got the converter for my 4x4 and he suggested a 10" converter... To run a turbo the converter I need is $1000.00 sucks.. So basically Im upto about 2k for the trans rebuild and then 1k for the converter. I hate spending money like this... Trans better hold up! Tom Quote Link to comment Share on other sites More sharing options...
680HPStroker Posted January 22, 2008 Share Posted January 22, 2008 If anyone who is building a hot rod hates to spend money on it they should consider another hobby. Anything other than stock is a money pit. You always get what you pay for. Ask anyone who cut corners in the past. I'm sure if they are being 100% honest they regreted it. I know I am and won't do it anymore. So just dig a hole, shart shoveling in money, and get a match. You have to love it because these cars will never give you a 100% return on your investment if you sell it. That is any builds that are other than stock unless you find someone who just has to have your car and is willing to pay for it. Have fun and enjoy and pass it on to the next generation. Quote Link to comment Share on other sites More sharing options...
Reaper Posted January 23, 2008 Share Posted January 23, 2008 Im not saying I wont spend the money and I know it has to get spent... Just saying it sucks that everything is so much money I just turned 26 I have no kids, no wife and renting an apartment and buying a house is the last thing on my mind so I have a little money, but it sucks to spend so much at one time... I just got done paying a couple grand to get it going and now I gotta spend another couple grand again. I will gladly pay it versus not being able to drive my car and I will gladly pay more to make it faster I just gripe about it to talk I guess... Quote Link to comment Share on other sites More sharing options...
Guest pyro Posted March 1, 2008 Share Posted March 1, 2008 Okey dokey.........if you want prompt, reliable, educated information, don't go to TCI. Finally settled with PATC which eagerly gave me precise, informative, and accurate information for both speedometer gears and torque converters. TCI not only gave improper information (no 9 drive gear ever produced for a 71 TH350), but after 2 requests for a torque converter recommendation, I got nothing. PATC. I went with a 2000 converter and an 8-20 speedometer combo. Ya'll have a nice day now. Quote Link to comment Share on other sites More sharing options...
BigDan Posted March 3, 2008 Share Posted March 3, 2008 $3,000 for a built tranny is a great deal  I spent over $5,000 for the tranny in my Dodge Cummins.   Quote Link to comment Share on other sites More sharing options...
kc8oye Posted March 3, 2008 Share Posted March 3, 2008 3g's for a trans? ouch.. the trans shop by my house is talkin $600 to rebuild my 700r4 including a new 2400rpm stall converter. Â Quote Link to comment Share on other sites More sharing options...
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