Jump to content

Transmission tunnel cooling

Billy Shears

Recommended Posts

I put a Tremec 5 speed in my 1963 Avanti, following the example of sbca96, and I have been quite happy with it so far, until yesterday, after about 40 minutes of driving, when suddenly the damn thing wouldn't go into gear at all. I'm going to sort that out, but it got me thinking about another issue that I've been wanting to address. As many Avanti owners know, heat is our archenemy. When any part of the cooling system starts to get out of order, Avantis will show a tendency to overheat sooner than most cars. Fortunately, I've never had this problem, and my car shows no such tendency. But even when everything is working well, Avantis can be warm cars to ride in, and the A/C (if your car has one), can struggle to keep the interior cool. Even in Avantis that don't tend to overheat, the inside of the engine compartment gets quite warm, and Avanti IIs had four vent holes in the inside of the engine compartment on either side, to vent out some of this heat. (the 1975 Avanti II I used to own had these.) This hot engine bay means the seals in the firewall need to be good, or some of that heat gets into the passenger compartment.

Another source of heat can be the transmission tunnel. The shifter lever on my Avanti II could get noticeably warm after driving the car a while, and some owners have said theirs could get almost too hot to touch, though mine never got that hot. I don't know if excessive heat is a contributing factor to the transmission problems I am currently having, but it just might be, and there's no doubt that keeping that area cooler will prolong transmission life. And cooling the transmission should also mean reducing another source of heat that gets radiated into the cabin, and should thus make the car pleasanter to drive in warm weather. Later Avantis and all Avanti IIs had an extra cowl vent at the base of the "gunsite" bulge that was used to duct cool air into the transmission tunnel. My Studebaker, being a 1963, does not have this extra vent, yet I have heard of people venting air into the transmission tunnel on '63 cars. Details of this, however, are hard to come by. Bob Johnstone's site doesn't say more than "Early Studebaker Avantis didn't even have a grill at the base of the windshield. These were added as the first run progressed and things got improved on.. So you may not have the capability of tapping the fresh air intake there, but you can be innovative and get it from somewhere else. It is very effective." This isnt' terribly helpful. Has anyone here done this. If so, where did you tap the fresh air, and how much improvement have you noticed?

Link to comment
Share on other sites

Interesting. No such problems as yet in my '79. Temp gauge never gets above 180*, and the interior is comfortable so far.

The fresh air floor vents and the quarter windows do a great job of venting out the heat.

I am thinking that with so many owners, in efforts to increase performance, changing engines, transmissions, etc,,

the increased heat generated by these changes far outweighs the inherent design parameters of the original engine/trans combinations.

The increase has no where to go but into the interior as the engine compartment simply can't vent the heat increased adequately.

Modern engines and increased performances generate a great deal more heat than "back in the day".

This problem isn't specific to Avanti's, but plagues most other cars with increased performance upgrades.

Some much more than others.

Packaging space fills up quickly when constricted by design parameters.

Lets face it, these cars were designed in the early '60's with smaller engines with much less horsepower. The designers never could

imagine these cars being viable well into 40+ year range, especially with the plethora of options now available.

Perhaps, offered simply as a simple solution, a shallow "air scoop" of sorts could be fabricated and mounted under the car to the floor-pan

to get additional air movement across the transmission to help cooling. But then that heat needs to be controlled.

Dynamat on the entire floor pan under the carpet seems to help according to those who have done so.

On my '79, I have fabricated a full width front air dam, wheel opening to wheel opening, with the center section under the radiator

directing additional air through the radiator.

I blocked of the area behind the grill so as much air as possible is directed across the radiator. The side pieces of my air dam/splitter

divert air around to the wheel openings creating, hopefully, a somewhat lower pressure area under the front of the car that so far has helped extract

heat out from under the heat generating source. Seems to be working so far.

Even with the original shag carpet glued directly to the floor pan, no padding, backing, or heat barrier, the heat through the floors

and trans tunnel is not an issue.

My '79 has no such air vent holes under the hood. I have thought of fabricating a louvered exhaust panel but have yet to do so.


Link to comment
Share on other sites

I don't recall any tunnel ducting on either my 74 or 83 but if there is something I can put the 83 in the air and get a few pictures.

I doubt the temperature had anything to do with the trans issue as most newer cars run 200+ deg and there's generally not a lot of venting underneath them either.

As a thought, is the clutch dragging? Bob

Link to comment
Share on other sites

I installed louvered vents (that look something like '64 Avanti floor vent grills) in the R&L inner fender skirts on my '83. I made sure they were removable for spark plug access....which is kind of a side bonus!

Link to comment
Share on other sites

I installed louvered vents (that look something like '64 Avanti floor vent grills) in the R&L inner fender skirts on my '83. I made sure they were removable for spark plug access....which is kind of a side bonus!

Great idea but it didn't happen without pictures :)

Link to comment
Share on other sites

  • 3 months later...

Did you get this Transmission Tunnel Cooling Kit sorted out? Many years ago I got a complete kit from Avanti Motors and installed it in my early Avanti. No added grille work in the "gun sight", just a couple of holes under the larger cowl grille about in the center of the car. A flange bolted from the underside, a couple of 1-1/2" flex hoses (1358968) about 3-feet long running inside the center console, terminating near the shifter. Metal bracket inside the cowl grille, covering the adapter flanges to deflect direct water. Fairly simple installation, if I remember.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...