700R4 torque converter questions..... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Smokintire70 · 09-22-2016, 05:27 PM

Some one told me a 700r4 does not use a torque converter. I have also have heard that they do use one. If one could specify whether they do or don't that would be sweet. I want to put a cam (272 or 292 Comp hyd roller ) in my ramjet 350. Thanks guys.

LongBox · 09-22-2016, 07:06 PM

the 700R4 does use a TQ. Think of it as a TH 350, with an overdrive gear, and a lock up torque converter.

Low69CST · 09-22-2016, 09:12 PM

Without the lock up feature OD is pointless. The rpms will be below the stall level and the converter will allow slippage.

hugger6933 · 09-22-2016, 09:14 PM

Yep does have a converter. My thinking is on the cam is the cam gonna play nice with the ramjets electronics? I thought they were non-programmable.

Bigdav160 · 09-22-2016, 09:18 PM

I would think a little more stall in the converter is warranted with those cams. The lockup feature can be done without electronic control if the controller won't handle it.

davepl · 09-23-2016, 12:25 PM

It does have a TC, normally a lockup unit in factory config. For a 292 cam, you might need/want a looser converter.

Smokintire70 · 09-23-2016, 06:25 PM

Quote:

Originally Posted by davepl

It does have a TC, normally a lockup unit in factory config. For a 292 cam, you might need/want a looser converter.

What is a lockup? Does it lock the engine and transmission at a certain rpm?

leftybass209 · 09-23-2016, 07:35 PM

Since you don't know much about the overdrive transmissions, you should go to bowtie overdrives website and do a lot of research. Putting an OD trans in a vehicle without understanding what's going on can result in a vehicle that runs like crap, a transmission that will burn up, or most likely both.

You have to consider cam spec, rear gears, RPMS for stall, 1st gear ratio, throttle valve connection, driveshaft length, transmission crossmember.... it's not a bolt and go affair 99% of the time.

leftybass209 · 09-23-2016, 07:37 PM

The show Trucks! Once installed a 700r4 behind a 6 in a 49 chevy, you may want to search for info on that as well.

davepl · 09-24-2016, 01:29 PM

Quote:

Originally Posted by Smokintire70

What is a lockup? Does it lock the engine and transmission at a certain rpm?

Yep. Strategy varies by model, but in most cases they won't lock up unless the transmission is in D and you're at a certain output speed. And there's usually integration with the brake switch so that it unlocks whenever you touch the brakes.

Ideally you'd never feel or know it's doing it, but it helps for mileage as there's then no slip, as opposed to just a little.

09-22-2016, 05:27 PM	#1
Smokintire70 Registered User Join Date: Jul 2016 Location: Santa Rosa California Posts: 52	700R4 torque converter questions..... Some one told me a 700r4 does not use a torque converter. I have also have heard that they do use one. If one could specify whether they do or don't that would be sweet. I want to put a cam (272 or 292 Comp hyd roller ) in my ramjet 350. Thanks guys.

09-22-2016, 07:06 PM	#2
LongBox Registered User Join Date: Sep 2016 Location: Vancouver BC Posts: 784	Re: 700R4 torque converter questions..... the 700R4 does use a TQ. Think of it as a TH 350, with an overdrive gear, and a lock up torque converter. __________________ Rick -69 GMC 910 Long Box, 350 -98 Chev Silverado 1500, 350 Vortec 4L60e -08 Mustang GT Convertible

09-22-2016, 09:12 PM	#3
Low69CST Registered User Join Date: May 2000 Location: Frankfort, Kentucky, USA Posts: 2,163	Re: 700R4 torque converter questions..... Without the lock up feature OD is pointless. The rpms will be below the stall level and the converter will allow slippage. __________________ '69 CST Short fleetside Lowered, 400 small block, 700R4, 4 wheel disc brakes, front sway bar & rear camaro sway bar (in progress) '87 V10 4x4 Short Fleetside Quad Suspension and Dual Tanks

09-22-2016, 09:14 PM	#4
hugger6933 Registered User Join Date: Oct 2008 Location: Marianna Arkansas Posts: 7,280	Re: 700R4 torque converter questions..... Yep does have a converter. My thinking is on the cam is the cam gonna play nice with the ramjets electronics? I thought they were non-programmable.

09-22-2016, 09:18 PM	#5
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: 700R4 torque converter questions..... I would think a little more stall in the converter is warranted with those cams. The lockup feature can be done without electronic control if the controller won't handle it. __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe

09-23-2016, 12:25 PM	#6
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: 700R4 torque converter questions..... It does have a TC, normally a lockup unit in factory config. For a 292 cam, you might need/want a looser converter. __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

09-23-2016, 07:35 PM	#8
leftybass209 Registered User Join Date: Feb 2011 Location: Modesto, CA Posts: 2,189	Re: 700R4 torque converter questions..... Since you don't know much about the overdrive transmissions, you should go to bowtie overdrives website and do a lot of research. Putting an OD trans in a vehicle without understanding what's going on can result in a vehicle that runs like crap, a transmission that will burn up, or most likely both. You have to consider cam spec, rear gears, RPMS for stall, 1st gear ratio, throttle valve connection, driveshaft length, transmission crossmember.... it's not a bolt and go affair 99% of the time.

09-23-2016, 07:37 PM	#9
leftybass209 Registered User Join Date: Feb 2011 Location: Modesto, CA Posts: 2,189	Re: 700R4 torque converter questions..... The show Trucks! Once installed a 700r4 behind a 6 in a 49 chevy, you may want to search for info on that as well.



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