[fierosum]

I have a SBC/700R4 in my 4300LBS hot rod with a 2000 stall converter. While highway cruising the rpms on the engine are around 1600 - 1800. I have a toggle switch to lock the tc and works great. Pardon my lack of understanding on this, but is the transmission slipping and generating excessive heat? No oil temp gauge. What's your thoughts on this?
Thank you in advance.

[cobalt327]

Originally Posted by fierosum

I have a SBC/700R4 in my 4300LBS hot rod with a 2000 stall converter. While highway cruising the rpms on the engine are around 1600 - 1800. I have a toggle switch to lock the tc and works great. Pardon my lack of understanding on this, but is the transmission slipping and generating excessive heat? No oil temp gauge. What's your thoughts on this?
Thank you in advance.

When the torque converter (TC) is locked there is no slippage adding to the heat generated by the transmission. When the TC is unlocked there will be some additional slippage (and heat) involved.

If the vehicle is driven at a steady light throttle cruise speed the slippage when unlocked will be less than when the vehicle is under a load (heavy throttle/strong engine, off-roading, towing, hills, etc.). It is best to unlock the TC under high load conditions.

It is always advisable to use an auxiliary tranny cooler. Fit as much cooler as you have room and budget for. Adding a deep pan can increase ATF change intervals but may not do all that much for cooling- either way it's not a replacement for an auxiliary cooler.

[JohnTN]

Your rpm sound about right, but it really depends on the tire size and rear gear ratio.

You should see about a 200 rpm drop when you toggle the transmission to lockup.

John

[fierosum]

I have a TCI Max Cool 4" x 11" x 3/4" mounted up front, behind the grille with about 5" space between it and the rad. Most of the time the engine temp hovers around 195*F. As soon as I hit town I unlock the TC and never tow. Rarely I have hills or climbs around Ontario or Michigan.

So I guess I'm good, but I'm planning to stick an oil temp gauge somewhere in the future. Best scenario would be to get a deeper one with a bung already in the pan.

Thanks for the replies.

[JohnTN]

I thought it was best to only have something like 1/2 inch space between the radiator and any aux cooler. This ensures the fan pulls air through the aux cooler.

John

[fierosum]

That makes sense, but my fan is a pusher. I also plan to have one of those finned cylindrical aluminum mounted somewhere under the car close to the frame and away from any exhaust.