140 PG clarification

[junkyardkustoms]

Hello everyone, I have a question (big surprise). I've been trying to read everything I can about mating a Power Glide to a 140, but I get some conflicting information. So I'm looking for some clarification from you Corvair Gurus. My '65 140 has a PG swapped into it. What EXACTLY needs to be changed in order for these two to run in harmony?

1- Is it necessary that I swap in a 95hp camshaft? I've read both Yes and No, but would prefer not to if it can be avoided. If not, anyone have a spare laying about?
2- Do I need a different Governor for the Transmission? Which one?
3- Is it actually beneficial to adjust the TV cable? How much?
4- Anything else need done?

[cnicol]

The engine modifications weren't there from the start but were countermeasures to overcome doggy acceleration.

The 95hp cam provided more low end torque but started to run out of breath and lay down at 4000 RPM, right when the secondaries really wanted to get to work, so... the cam timing was retarded using a special timing gear on the crankshaft. This modification RAISED the RPM range of that flaccid cam to better match the flow characteristics of the heads and carburetors.

If you are satisfied with the "off the line" performance of your car (some engines are better than others), you don't need to change anything on the engine.

The transmission modifications (valve body, governor, and maybe the torque converter (there's some controversy on that bit) match the trans to the engine's character. Valve body has higher pressure to allow tight shifting at higher throttle openings, the governor shifts from low to high at much higher rpm (this is a biggie), and the TC is supposed to have a slightly higher stall speed. Of these three, the governor is most needed and this alone does more than everything else. 140 PG governors are virtually impossible to find but CORSA recently punished a How-To that detailed how to convert a standard governor into a 140-spec governor.

[cnicol]

One more thing... Corvairs don't have a TV cable, it's a rod and its adjustment mostly affects the road speed where the transmission shifts. It's beneficial to crowd that to the upper limit to allow the engine to run to higher RPM before shifting.

[junkyardkustoms]

I think I saw that write up on modifying the governor. Didn't look too difficult. Sounds like if I do that and a adjust the shift points, I might be able to get around doing the cam. Any ideas on what my timing should be set to if I don't have that special retarded timing gear? (And yes, I chuckled as I wrote that)

[cnicol]

Timing on the PG 140 (339 distributor) is the same as timing on an MT 140 (330 distributor). Both call for 18-degrees initial. With today's fuel, you might not be able to get that high without pinging.

[bbodie52]

The chart below will let you see the comparison in advance curves, as well as the initial timing settings...

Left-click the image with mouse to enlarge for better viewing...

[junkyardkustoms]

But isn't that with the different cam gear? So if it is supposed to be 18° with the appropriate cam gear that retards timing by 3° (or whatever it is), wouldn't I want to set it to 15° to compensate for having the incorrect gear? Or am I looking at this wrong?

[junkyardkustoms]

Actually, I suppose that wouldn't help. Because the gear would only change the cam timing in relation to the crank.

[junkyardkustoms]

One more thing... Corvairs don't have a TV cable, it's a rod and its adjustment mostly affects the road speed where the transmission shifts. It's beneficial to crowd that to the upper limit to allow the engine to run to higher RPM before shifting.

How do I adjust this rod? Is there any specific measurements?

[notched]

One more thing... Corvairs don't have a TV cable, it's a rod and its adjustment mostly affects the road speed where the transmission shifts. It's beneficial to crowd that to the upper limit to allow the engine to run to higher RPM before shifting.

How do I adjust this rod? Is there any specific measurements?

The complete adjustment procedure is in the 1965 service manual on page 7-31. You should really have a GM service manual if you do not already have one.

[bbodie52]

Many of the available Corvair Powerglide technical references can be found posted at this Corvair Forum link...

CORVAIR POWERGLIDE AUTOMATIC TRANSMISSION SERVICE GUIDE
viewtopic.php?f=225&t=5760

[cnicol]

One more thing... Corvairs don't have a TV cable, it's a rod and its adjustment mostly affects the road speed where the transmission shifts. It's beneficial to crowd that to the upper limit to allow the engine to run to higher RPM before shifting.

How do I adjust this rod? Is there any specific measurements?

As Brad stated, the procedure is in the '65 manual and it begins on 7-32 but there it refers you to page 6-6; where its labeled as item #10. The adjustment is made in the engine compartment and it's changed by disconnecting and rotating the threaded swivel that connects the main throttle rod to the carburetor cross shaft.

The original specs are on page 7-55 but since the modifications (countermeasures) for 140PG performance came after the book was printed, you have to look elsewhere for 140 info. (I've seen it but can't find it)