TheSamba.com :: View topic - Cooling a mid-engine type3. Looking for ducting options.

Fri Oct 07, 2005 8:52 pm

Ok I know if I don't like how VW built them from the factory find somthing else to cut up! That is not an option, I like the look of the notch and want it air cooled as well.

What I am thinking about doing is building more or less a tube frame that will bolt up like a stock pan but be set up for mid-engine. It will have a 2.0L type 4 engine with efi-turbo, bolted to a 914 5spd (better shifter location for mid-engine than my 911 901 5spd). I have the skill's, tool's and now the shop to do it so I am ready to start colecting parts and ideas. I aready have the front and rear suspention figured out so now it is time for engine cooling.

The first idea is to re-direct the stock vents at the back window to a new plenum that will feed the engine ducting.

Second would be to fabricate side scoops like what is used on some of the later 911's for brake ducting. This will allow the stock rear window vents to be used to cool the additional oil cooler and the turbo inter-cooler.

Third thought would be to route air from the front of the car thru a new center tunnel. I could fabricate an intake vent where the horn grill is located. This would keep more of a stock look from the out side and still keep the rear vents for other cooling items. This would also add in cooling as speed is picked up due to it being pushed into the tunnel.

So just how much air do the stock vents really see from air floowing over them? Does the engine pull all the air in or is it pushed from out side conditions?

Any thoughts on this idea?

Thanks for any input!
Kevin

Fri Oct 07, 2005 11:42 pm

For what it's worth...if you took all the money you'd spend building this car you could easily buy a nice, presentable Porsche 914 :wink: It's mid-engined with a TIV :D

I would recommend you look to a 914 TIV engine as it's tin is set up for mid-engine use. All of the VW-based engines of that type are for tail-draggers (rear-engined) and thus the cool air tin work is 180º different. You'll need to find a way for cool air to get ducted into the pulley fan and duct the waste engine cooling air away from the engine and induction.

Sat Oct 08, 2005 5:28 am

I'm by no means as good the mechanic as you when it comes to fabricating but do you still have the heating channels in the car? You could open them at the bottom of the car or the front wheel wells as intake ports (thus still keeping a stock look) and the channels would take in a good amount of cool"ground air" to help out.

John
65 square S (weezer)

Just try and pimp my ride, biotch!

Sat Oct 08, 2005 6:41 am

Air_Cooled_Nut~ You are right I could build a 914 but then it is just a 914! I had a Notch Way back in high school but did not have the money or skill to build anything out of it and now I do. Still I like the look of a Notch better then the 914's. Also I like to build things that are chalenging and not just built from replacement or bolt on parts.
From what I remember don't the 914's cool from the top just behind the window? I am still planning on ducting air right into the front duct. I would like to keep the engine cover area simular to how the rear trunk looks as far as height. This will leave me with a god amount of room inside of the car unlike the 914's. My neighbor has one and I will be doing some free work on it for him and alot of inspection for myself.

6T5 square I have thought about the chanels but the diameter of air you can get thru them would not be enough and I still need to have an out side pick-up duct to get air into them. I have thought about building a scoop up front where the spare tire tin is. With the tin removed their is alot of space to work if I were to duct the air frm just below that area and into a center tunnel. The problem is I will have this car fairly low and I would be worried about scraping. If I do a front air intake I will wnat it to be just below the bumper at the front of the car. This would not be real visible if you were not trying to find it.

Thanks for the input, these are the kind of ideas I am looking for to bounce ideas off of.

Kevin

Sat Oct 08, 2005 8:55 am

If you are using a T-4 style engine as a mid engine, then the air intake is at the FRONT of the engine. If you are wanting a sleeper, just some slight ducting from under the car should give you a ram effect. As for exhausting the air, use the 914 tin work, and it will exhaust where you need it, towards the back. You could put your hot muffler clear to the back like 914 did.

Sat Oct 08, 2005 2:32 pm

Yes, the engine cooling air comes from above and front, and exits below and behind. The upper and lower halves are separated by tin and, of course, body.

I can appreciate the challenge aspect of what you want to do. I would recommend you nestle down in the ShopTalk forum.

Sun Oct 09, 2005 11:24 pm

i run my cooling air from under the car... drove it 400 miles round trip this summer with no ill effects. i used a very temp idea for th trip (4 inch flex tubing) but this winter i will build the permanent set up. the four 4" tubes provided more than ample cooling air to the engine.

Mon Oct 10, 2005 5:41 am

Right under the car was another thought I just was not sure once the car is lowered how much air still went under! Russ I would set the muffler in the very back since their wil still be quite a bit of room along side the trany. Also the turbo would be right behind the bell housing like on some of the 914 set up's I have come across.

Kevin