MG Sports Cars

engine swaps and other performance upgrades, plus "factory" and Costello V8s

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Dudster
Bill Dudley
Golden, CO
(13 posts)

Registered:
07/07/2008 09:19PM

Main British Car:
1974 MGB GT Rover 3.9 EFI

Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: Dudster
Date: January 24, 2015 04:58PM

I just received my Gen II mini unit with heat, air and defroster and I thought I would ask for the loan of your expertise before cutting holes in the firewall. It looks like I will need to cut out a rectangle of 8"x17.5", and that I will also need to remove the fan from the unit before installing. I have looked at all the "how is was done" posts, especially those by Dan Masters and Rob Ficalora, and it seems that I will not be able to attach the fan back to the unit but will need to make a duct between the fan and the unit. I'm sure the reason for this will become apparent when I cut the necessary holes in the firewall. I don't have Rob's fiberglass skills but I am sure I can cobble something together. Do I need to reinforce the structure after cutting out so much material?

I had hoped to be able to use the fresh air from the vent above for the system, but after receiving the unit I deemed that idea not feasible. The question now is how do I seal up the hole in the vent so cold air and water can't get in the car? Do I just weld it closed?

The heater air for the feet seems to be too far forward so it hits the leg. Has anyone tried to duct it closer to the feet?

It also seems that the defroster vents will have to be modified or replaced by the vents that come with the system. Any suggestions?

Thanks for your help!

Bill


rficalora
Rob Ficalora
Willis, TX
(2625 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

authors avatar
Re: Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: rficalora
Date: January 24, 2015 10:17PM

Bill, you give me more credit than is due! To make the fiberglass ducting, all i did was make the duct out of cardboard -- what I used was a box about the thickness of a cereal box. I then covered it in aluminum foil & did the fiberglass over that. Fiberglass doesn't stick to the aluminum foil so I just peeled the cardboard away when it cured.

Definitely study the pics of Dan Master's AC install; that's the way to do it. My way was way more work than warranted. I don't recall the details on Dan's car, but when I cut rectangle out of the firewall (the area behind the OEM heater), I did reinforce it. I used some 16 ga in the corners & 3/4" angle around the perimeter on the inboard & outboard edges.

The fan motor gets disconnected from the unit & mouted on the inside of the firwall - fiberglass ducting from it to the Gen II mini. Reason for that is because there the firewall is actually about 3 box sections & I only wanted to cut out the middle one. The outer ones have vertical faces inboard of the hood hinge cutouts & there's not enough room to preserve those if you try to keep the fan motor attached.

Again, I don't know how Dan's car addressed the cold air intake. On mine, I was doing a complete repaint, so I removed the intake grill & welded in a piece of sheet metal to close it off completely.

Haven't had any problem with the heater vents where they are. Warms the cockpit pretty well. I will likely make some simple ducts (fiberglass again as I don't think there are hoses to fit them) to route the air around my stereo whenever I install it. RIght now, the heat would blast the stereo if it were there.

I did modify my defrost vents. If you're repainting the cowl, I'd recommend using the vents that come with the Vintage Air unit. They're smaller but have a bigger opening so will likely flow more air in addition to being easier to hook up. If you decide you want to modify your existing ones, let me know - I think I have some pics of what I did to mine that I can send you. They aren't seen so I didn't take the time to make them pretty. But they are functional.


Dudster
Bill Dudley
Golden, CO
(13 posts)

Registered:
07/07/2008 09:19PM

Main British Car:
1974 MGB GT Rover 3.9 EFI

Re: Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: Dudster
Date: January 25, 2015 11:46AM

Rob,
Thanks for all of your help. I don't see much difference between your approach and Dan's, but maybe it's just that the old eyes aren't as sharp as they used to be. I will close up the air intake. Curtis would have me use it for the engine, but I don't want to build my own plenum for the EFI.

I'll try to use the Vintage Air defroster vents. I noticed your def vents were metal - mine are plastic. Are yours from an earlier car? I guess I could go look in my stock 67B, but I'd have to crawl under the dash :)

How did you mount the fan to the firewall? I only see the one bracket at the top of the fan. I will have to be careful wiring it - it goes against my nature to ground a white wire. I've owned british cars for too long.

Thanks again for your help.

Bill


danmas
Dan Masters
Alcoa, Tennessee
(574 posts)

Registered:
10/28/2007 12:11AM

Main British Car:
1974 MGBGT Ford 302

authors avatar
Re: Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: danmas
Date: January 25, 2015 11:42PM

Bill,

The cowl vent was welded close on mine. Here are some pictures that may be of some help. My car isn't here now, so I can't check into it further for you at the moment.

When I've got the controls set to "floor," the heat comes out the bottom vents right where I want it on my feet. That's a real plus in the summer when the AC is on to cool my feet, as that area gets quite warm in the summer.
100_5279.JPG
100_5281.JPG
100_5283.JPG
100_5288.JPG


rficalora
Rob Ficalora
Willis, TX
(2625 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

authors avatar
Re: Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: rficalora
Date: January 26, 2015 12:34AM

Quote:
I'll try to use the Vintage Air defroster vents. I noticed your def vents were metal - mine are plastic. Are yours from an earlier car?

Yes. I converted my car to the '67 and earlier metal dash. Also grafted in the cowl panel from a metal dash car when I did that so I had the defrost vents from that car.


74ls1tr6
Calvin Grannis
Elk Grove,CA
(1150 posts)

Registered:
11/10/2007 10:05AM

Main British Car:
74 TR6 / 71 MGB GT TR6/Ls1 71 MGB GT/Ls1

authors avatar
Re: Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: 74ls1tr6
Date: January 26, 2015 12:38AM

Since my car is disassembled, I will take some close up photo's of what I did, which is very close to what Dan's car had done. You will install the system with the fan assembly off the unit from the engine compartment ( the hole you will cut). After the system is in place you can put the fan assembly back on the system(only 3 screws). There is an area that you have to reshape behind the fan assembly on the firewall. It is real close to the hood bracket.

Soon I will post some photo's of that area and modification that need to be done.

Calvin


danmas
Dan Masters
Alcoa, Tennessee
(574 posts)

Registered:
10/28/2007 12:11AM

Main British Car:
1974 MGBGT Ford 302

authors avatar
Re: Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: danmas
Date: January 26, 2015 01:16PM

Quote:
You will install the system with the fan assembly off the unit from the engine compartment ( the hole you will cut). After the system is in place you can put the fan assembly back on the system(only 3 screws)

That's the way I remember it on my car also, but it's been a long time and I didn't trust my memory. Hopefully, I'll have my car back soon and I can refresh my memory (my car repairs are finished and now I'm waiting for a chance to go get it - snow free roads, availability of co-driver, schedule conflicts, etc.)



74ls1tr6
Calvin Grannis
Elk Grove,CA
(1150 posts)

Registered:
11/10/2007 10:05AM

Main British Car:
74 TR6 / 71 MGB GT TR6/Ls1 71 MGB GT/Ls1

authors avatar
Re: Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: 74ls1tr6
Date: January 26, 2015 02:37PM

Bill,

Here is some photo's with everything out of the dash and bare.

This photo is looking in from the engine compartment. The big hole is cut out. The bottom sheet metal needs to be squared at the bottom by the steering column. This way the Mini II can be tight to this wall in the corner.
2015-01-26 10.52.32.jpg

A photo of the hole size. You will notice the shelf is flat so Mini is down from the vent. The Mini will sit on this shelf.
2015-01-26 10.52.39.jpg

This photo show where the relief cut has been made for the AC connections, and heater lines. This is on the passenger side.
2015-01-26 10.52.46.jpg

This is the relief cut that needs to be done for the fan area. This photo has been taken from the passenger side inside the car. Just make sure your hood bracket has full movement when welding the metal back in, a BFH works well bending to shape for this area before welding.
2015-01-26 10.53.09.jpg

Here is all Dan's photo's from his build at different angle's, just look through this tread.......[www.advanceautowire.com]


74ls1tr6
Calvin Grannis
Elk Grove,CA
(1150 posts)

Registered:
11/10/2007 10:05AM

Main British Car:
74 TR6 / 71 MGB GT TR6/Ls1 71 MGB GT/Ls1

authors avatar
Re: Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: 74ls1tr6
Date: January 26, 2015 02:46PM

Here is a little more focused photo of the relieved area.
2015-01-26 10.53.13.jpg

A little different angle.
2015-01-26 10.53.22.jpg

A good shot of how much is relieved in the hood hinge area. I may need to add some metal back into this area for strength from the shelf, and tie back into the under dash. Just need to make sure the lines can be attached.
2015-01-26 10.54.24.jpg

This photo was taken looking into the hood hinge hole from the engine compartment.
2015-01-26 10.56.08.jpg
\
Let me know if you need a different angle photo?

Calvin



Edited 1 time(s). Last edit at 01/26/2015 02:56PM by 74ls1tr6.


Dudster
Bill Dudley
Golden, CO
(13 posts)

Registered:
07/07/2008 09:19PM

Main British Car:
1974 MGB GT Rover 3.9 EFI

Re: Vintage Air Gen II mini in 74 MGB GT - installation questions
Posted by: Dudster
Date: January 26, 2015 10:18PM

Thank you all for your comments and pictures. If I can't get it together with help and pictures I should quit MG's and buy a Yugo. I plan to cut the hole in the firewall and begin installation later this week. I would start tomorrow but it is supposed to be 68 degrees here (Golden, CO) tomorrow and I plan to get in a round of golf! I am playing with other MG owners so there will be come car talk involved. I hope any of you in the eastern blizzard's path can keep you, your families and your cars at home and out of harms way.

Thanks again for your help. You guys are great!


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