Avanti- unbearable Interior Heat/lack of ventilation

[wfhenderson]

Thank you, everyone, for your ideas.

Rich- your message just above is very encouraging. If it is possible I will do it. All of you have given me good ideas to try.

Jeff- if you can scan and post the ducting service bulletin that would be great.

Rerun- from my experience, I would never put a duct under the car at the rear. This is a low pressure area that sucks in exhaust gas and smell.

WCP, Measuring, my car sits 17 1/4 from ground to front bumper (compared to 18" as you note) and 22" at the back (compared to 19 5/8 in your specs). I knew my car sat too high in the back but had no idea it was this far out of whack.. I was hoping 1" lowering blocks would be enough but if I am 2 1/2 inches too high I am not sure what I should do....

Tluz- If your car is all apart I would certainly duct the trans tunnel, and put heat insulation matting on the firewall and floor. The front spoiler/air dam sounds like a reasonable idea and a trip to the junkyard and $10 ought to see if that works. I am going to put a shut-off valve in the heater hose, vs. the pipe nipple route. At least the valve can be undone in cold weather.

I really appreciate all the contributions to this thread. I am a new Studebaker owner, and you guys are really something else. I am now far less afraid of my purchase with this kind of community support out there.

[bezhawk]

Later Avantis that I have worked on have an opening in the rear parcel shelf and a vent to the underneath in the front edge of the tire well.
No need to worry about fumes as it it a one way ducted flapper valve (like EVERY modern car on the road). This along with the later above door weather strips makes for a much more water tight and air whistle free ride.
If you do add the trans cooling ducts, make sure that they are installed like the factory did and have the duct in the cowl area higher than the floor of the cowl . Otherwise it will dump water into the vents when it is wet.

[WCP]

I would suggest raising the front end with new HD springs or shims under the springs or both, to increase the 17 1/4" to say 18 1/2". This will give the car a better stance and drop the rear some to possibly 20 1/2". You want a good stream of cool air passing under the vehicle. I suspect the air dam will be counterproductive as it will increase turbulence of hot engine air in the tunnel and under the floor. It will improve air passage thru the radiator but I have always found the Avanti system more that adequate as designed and that isn't your problem. However, it is an easy thing to try. Let us know how that works out. I still think that there is something wrong with the outside air distribution system of your car - something not working properly or some modification that defeats or interferes with cool air entry. After 37 years and possibly several owners, you would be surprised at what alterations and "temporary fixes" you can find in Avantis. If you keep at you will eventually find the answer. I'm still troubled by the fact that you say the heater valve works backwards. That just shouldn't be! Maybe I'm not understanding what you mean by backwards.

[Gunslinger]

When I installed the Saturn air dam under my '70 Avanti, I noticed an immediate 10-15 degree decrease in engine temperature at highway speeds. The air dam does two things...it forces more air up into the radiator and in doing so, decreases air turbulence and drag under the car. The air dam is of course, no value at low speed or sitting and idling in traffic.

It works well enough that when I heard Saturn was being discontinued by GM, I bought another air dam to keep as a spare in case I need it down the road as a replacement.

I've no difference in interior heat...hot is hot, though not particularly uncomfortable unless I drive with the windows sealed like in a rainstorm...then the humidity level goes right up, but the a/c can freeze me out and handles it well.

[Rerun]

Bruce,

Can you shed any light on this?

I think that there is one more issue that deserves discussion. That is "flow through" ventilation. One problem with the Avanti ventilation is that there is nowhere for the air to go. When the vents are opened, the cabin takes on a positive pressure and the result is annoying wind noise at the weatherstripping around the windows. If you open a vent window, the flow is improved, but the noise increases. The lack of "flow through" also negatively affects the operation of the A/C unit.

I have heard rumor that some of the later Avanti models had a duct added to allow air to flow out. IIRC this was under the rear seat. I don't know if this is accurate, and/or what years would have had this feature. Perhaps some of our more learned members could comment on this.

[Gunslinger]

I don't know anything about a duct added in later cars to help with ventilation. If so, it was later in production than my '70, which at that time was still essentially all leftover Studebaker parts outside of the engine as it was built. If Avanti Motors installed a modified ventilation system, I would suspect it happened when they went to the GM chassis in the post-'85 cars where they could use the GM system.

I've not even seen an Avanti that has holes drilled in the engine bay to allow hot air to escape. I know they must exist as some have said they have cars with them...just saying I haven't seen one, at least haven't seen one that I recognized as such.

What I generally do is drive with the windows down, wing vents and rear side windows open for continual air movement and ventilation. I try to only drive the car in good weather, but have gotten caught in a few rainstorms...one truly epic downpour accompanied by thunder and lightning of what seemed historic proportions! I only use the a/c sporadically as it does run up engine temperature a bit...nothing unusual for cars of that era.

[DEEPNHOCK]

A techy kind of answer is it creates a better low air pressure area 'behind' the air dam, and that allows more air to pass through the radiator.
The part about using a Saturn item was purely a caso thing at the time (and now)....and a good one.
Knowing that this trick works, a better, bigger, and custom fit air dam could be made from ABS, or another flexible but stiff plastic.....
If some is good, more is better, and too much is just right.
Make it easy for the hot air to get out from underneath, and there will be less of it to heat soak the interior.
Just thinking out loud..
Jeff

When I installed the Saturn air dam under my '70 Avanti, I noticed an immediate 10-15 degree decrease in engine temperature at highway speeds. The air dam does two things...it forces more air up into the radiator and in doing so, decreases air turbulence and drag under the car. The air dam is of course, no value at low speed or sitting and idling in traffic.
<snip>

[sweetolbob]

Originally posted by Gunslinger

I don't know anything about a duct added in later cars to help with ventilation. If so, it was later in production than my '70, which at that time was still essentially all leftover Studebaker parts outside of the engine as it was built. If Avanti Motors installed a modified ventilation system, I would suspect it happened when they went to the GM chassis in the post-'85 cars where they could use the GM system.

Don't know when it started but my 83 has the vent. I recall from my adventures under it that it looked like it could be retrofitted.

Bob

[Gunslinger]

It does sound like it could be retrofitted...get the one way flapper and cut the correct size opening under the seat and snap or rivet it in. My '69 Corvette has them mounted in the rear deck. They're called air valve seals.

[JDP]

okc63avanti - you shouldn't have any problem keeping your car cool. I don't know anything about Dyna-mat, but if you seal up your Avanti properly and everything is working as it was designed to do, then you don't need additional tunnel cooling. I don't understand all the fuss over hot avantis. I always put felt padding under the carpets and ensure that the firewall area on both sides has a full hardboard and fibreglass insulation piece under the toe pads. I use no extra insulation under the stock headliners. I make sure that the kickcowl vents seal outside air and open properly. I very well remember driving my R1 Avanti with A/C home from the Indianapolis national meet in 100F air, and being comfortably cool with my wife and son on board. I recall stopping at a thruway rest area and leaving the car run while we took turns at the washroom. When you opened the door, it felt like a blast furnace in your face 'till the door was closed. On that trip, I had a caliper come free and jam the wheel on I75 coming into Dearborn. It was so hot that the small trolley jack that I carried, sunk into the asphalt on the shoulder of the interstate. My present ride is an R2 with Tremec T5 and no A/C. It is similarly assembled as my former R1. It is quite tolerable to drive as I have done, in 95F air on the thruway. Granted, it would be nicer to have A/C, but at this point, I don't think it is worth the effort to modify the engine bay. I typically travel with a bottle of drinking water leaning against the passenger seat and console carpet, and it stays cool enough to drink on a long trip. The carpets and underpad in my car were supplied by JDP and installed with screws as per factory. It is a mistake to glue them in. I have removed and ruined new installations that were glued in, during subsequent restorations. I don't use heat shields. My exhaust system is as supplied by Don Simmonds with the round SS mufflers, 2" all around. Highway noise is quite acceptable under normal driving conditions and really only gets loud if you "get on it".

I've never had a issue with a Avanti with AC, mostly R2's are the blast furnace.

[wfhenderson]

Gunslinger- what year/model of Saturn am I looking for at the junkyard? Or on eBay?

[Gunslinger]

The Saturn part number is 21031161. It's called a deflector. I don't know what year and model Saturns it fits. Whether that's a Saturn specific part number or a GM part number I don't know. It's a very easy install by bolting it to the radiator support. I used a length of aluminum bar stock to strengthen the installation, but I've seen at least one other Avanti where the owner simply bolted it directly to the radiator support with no bad effects.

Here's a diagram I copied from Bob Johnstone's website on the installation...

[jgrohs]

the forum won't let me post a .pdf larger than 19.5kb. try this link

http://docs.google.com/fileview?id=0B9atw-hET5bzNmM2MDlhMzgtYjA2OC00ODkzLTljYWYtZDcwNDU1MWY0ZTAx&hl=en

Jeff

Rich- your message just above is very encouraging. If it is possible I will do it. All of you have given me good ideas to try.

Jeff- if you can scan and post the ducting service bulletin that would be great.



I really appreciate all the contributions to this thread. I am a new Studebaker owner, and you guys are really something else. I am now far less afraid of my purchase with this kind of community support out there.

[stall]

I drove my 55 Speedster from Hamilton to South Bend for a Int.meet,I smelt flesh burning ! It was my legs,I could have cooked dinner on the transmission hump,my Packard Hawk with the water cooled trans.had the same problem.I believe this problem to be common to all C-K's with automatic trans.The GT I now have still is hot but not as bad as the others mentioned.A 53 K I had with manual trans. was no where near as bad.
After that trip the wife no longer wishes to go on long trips in summer heat,she follows in her air conditioned ride.

My Speedster is Std tranny and is not very hot when driven in the summer. On a related note I own a 64 Corvette Roadster that is unbearable
to drive when ambiant is much above 75F. I ordered new carpet and decided to follow my Vette Forum buddies advice and add a heat / noise barrier. I used about $300 worth of a 5/8 thick composite material underlay. I cannot tell you how pleased I am; Its like a different car, quiet and cool. By the way
it was the drive tunnel that supplied all the Corvette heat.

Happy Trails, Stall

[bige]

I don't open the vents when it's hot. The car is more comfortable when they are closed in very warm weather. After all, if it's 95 out you sill have 95 degree air coming in and that air is also taking the warm air radiating from the floor and swirling it around and I'm surmising that pressure from the air coming in from open windows is keeping some of that warm air down low also.

I had thoughts of plumbing a tee into the trans tunnel cooling hoses and adapting a vent from one of the 'add on air' vendors or from a brand 'X' so I could close off the air flow in the cold weather so I experimented a little and ran a hose from the cowl to just below the dash and wired the hose up so I got air flow up higher. That air was not superheated so I believe there is some heat transfer going on as it goes from the cowl to the lower floor vents. I still may complete the project someday.

Floor and tunnel insulation under the carpet made a huge difference and as long as the engine temps stay under 200 the car is as tolerable as any non A/C car could be in the hot weather. As engine temp rises so does the interior temp so running cool helps big time.

And, I definitely think a heater hose shut off will help. When my fairly new 'reverse working' heater valve exploded and soaked my rug big time I have had the core by passed. Definitely better than when a working valve was installed. After all, hot water will fill the hose going to the valve and that hose extends into the passenger compartment.

ErnieR

One of the road tests of the period said they were most comfortable with the windows raised, the floor vents opened and the rear windows opened. I haven't tried it.

ErnieR