#40, March '25 update Options

[mb911]

My kind of weekend therapy; Pines #2 rotary- hydraulic mandrel bending

Have the same bender.

Was going to do the GT brackets but just built one that worked exclusively with my mufflers..

[Gint]

WOW

I just saw this thread and quickly scanned a page or two. Of course I'm going to have to read the entire thing.

I'm still looking for just the right place to hang this.

[MATTYLITE]

Here's some quick engine update pics. Still some things left to do, then it's reassembly time!

(IMG:http://www.914world.com/bbs2/uploads_offsite/i.ibb.co-14843-1602375771.1.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i.ibb.co-14843-1602375771.2.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i.ibb.co-14843-1602375772.3.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i.ibb.co-14843-1602375772.4.png)

[rgalla9146]

How much different are the Factory GT headers vs the stock six exchangers?

Very different, they are donor headers borrowed from the 906. Shorter primaries, Long transitional secondaries (via megaphones).
Seems the Zuffenhausen tuners deemed these "Correct" for the duties of a very high compression , big cammed, twin plug, 46 ida webers, 220bhp, 2L , running mostly W-O-T for race circuit; totally too wild for daily street use. 916's on the other hand did use heater boxes, which also included a tap-in-duct (and flex tubing) for heating the aneroid (spl ¿) sensor on the mfi pump. Most m471's (as you know) ran with standard (long primary tube) 9146 HB's.

I actually have a set of the Heat Exchangers for MFI. I used it too.

Please excuse the OT
Clay I recall seeing a NOS MFI heat exchanger for a 6 (right side) on a european site
probably ten years ago. It had a large second chamber for warm-up. Properly
manufactured. Quite unusual.
Is that what you have ?
Perhaps a pic ?
Is the left side different too ?

[mepstein]

How much different are the Factory GT headers vs the stock six exchangers?

Very different, they are donor headers borrowed from the 906. Shorter primaries, Long transitional secondaries (via megaphones).
Seems the Zuffenhausen tuners deemed these "Correct" for the duties of a very high compression , big cammed, twin plug, 46 ida webers, 220bhp, 2L , running mostly W-O-T for race circuit; totally too wild for daily street use. 916's on the other hand did use heater boxes, which also included a tap-in-duct (and flex tubing) for heating the aneroid (spl ¿) sensor on the mfi pump. Most m471's (as you know) ran with standard (long primary tube) 9146 HB's.

I actually have a set of the Heat Exchangers for MFI. I used it too.

Please excuse the OT
Clay I recall seeing a NOS MFI heat exchanger for a 6 (right side) on a european site
probably ten years ago. It had a large second chamber for warm-up. Properly
manufactured. Quite unusual.
Is that what you have ?
Perhaps a pic ?
Is the left side different too ?

I saw a similar pic. Was it on Brutus?

[Maltese Falcon]

O/T>> On a 916 with the 2.4 mfi, the R/ side HB with the small bump + a short 1" dia. (approx) nipple , connects to a mating hose ending at the Aneroid housing of the mfi mechanical pump. I've seen this on the ex-Otis yellow 916, and on my buddy's 2.4 mfi 9146gt.

[Maltese Falcon]

WOW

I just saw this thread and quickly scanned a page or two. Of course I'm going to have to read the entire thing.

I'm still looking for just the right place to hang this.

(IMG:style_emoticons/default/beerchug.gif)

[ClayPerrine]

I actually have a set of the Heat Exchangers for MFI. I used it too.

Please excuse the OT
Clay I recall seeing a NOS MFI heat exchanger for a 6 (right side) on a european site
probably ten years ago. It had a large second chamber for warm-up. Properly
manufactured. Quite unusual.
Is that what you have ?
Perhaps a pic ?
Is the left side different too ?

I will see if I can get up in the attic and take some pictures. They are off the car because the MFI motor is not in it any more.

The left heat exchanger is no different than a stock six HE. What I figure is Porsche started making the MFI HEs for the 916 program. When it got cancelled, then just put them into the spares for the 914-6 and sold them.

[sixnotfour]

(IMG:style_emoticons/default/beerchug.gif) Armando has the pic.

[Cairo94507]

Wowzer! I have never seen one of those heat exchangers. MFI in a 6 would be cool. (IMG:style_emoticons/default/beerchug.gif)

[ClayPerrine]

Wowzer! I have never seen one of those heat exchangers. MFI in a 6 would be cool. (IMG:style_emoticons/default/beerchug.gif)

BTDT. It is really cool. And a b1tch to live with on a daily basis.

[rgalla9146]

Is that an additional (1") nipple on the far right ?
Is that a perforated area on the right side of the added chamber ?
Very interesting.

[horizontally-opposed]

…MFI in a 6 would be cool. (IMG:style_emoticons/default/beerchug.gif)

BTDT. It is really cool.

Indeed. Most fun 914 I have driven was a 2.2S with MFI and short gears in a 901, which brought more smiles than a 916 did with a 2.4S with MFI and a 915.

And a b1tch to live with on a daily basis.

Do dish…

[raynekat]

Wowzer! I have never seen one of those heat exchangers. MFI in a 6 would be cool. (IMG:style_emoticons/default/beerchug.gif)

Oh how soon we forget......





I've got a 2.7 MFI in my 914 using Ben's bigger heat exchangers.
The shop that did the install added a nipple to supply the warm air to the MFI pump so that it leans out when the engine gets up to operating temp.

It starts easily and is perfectly fine on the street.
The "only" downside is that MFI runs on the rich side, so fuel mileage isn't so hot.

[rgalla9146]

Wowzer! I have never seen one of those heat exchangers. MFI in a 6 would be cool. (IMG:style_emoticons/default/beerchug.gif)

Oh how soon we forget......

I've got a 2.7 MFI in my 914 using Ben's bigger heat exchangers.
The shop that did the install added a nipple to supply the warm air to the MFI pump so that it leans out when the engine gets up to operating temp.

It starts easily and is perfectly fine on the street.
The "only" downside is that MFI runs on the rich side, so fuel mileage isn't so hot.

That is perfect ! Beautiful !
The heat exchanger looks to have two features that MFI normally requires.
The larger nipple for cold start and the smaller one to air filter intake.

[Sway Bar]

As mentioned the nipple on the right is for supplying heat to the cold start solenoid on the mfi pump which is a thermostat with a bunch of expanding washers that move the main rack within the pump to lean out or of course enrichen when cold.

The middle chamber will be your regular cabin heat.

The left preheat chamber supplies warm air to the MFI 'flapper box' which preheats the combustion chamber and also has a built in thermostat to close the flapper and supply fresher cool air in for combustion. In most warm air areas people remove this and/or even remove the cold start solenoid.

I love MFI...if in great order it runs awesome, sound even better and has great throttle response...its a 50 plus year old analog computer. I find mileage really good but because of that great throttle none of us drive it for mileage (IMG:style_emoticons/default/biggrin.gif)

[Sway Bar]

Is that an additional (1") nipple on the far right ?
Is that a perforated area on the right side of the added chamber ?
Very interesting.

The perforated screen is to allow air to come in and be heated since that chamber connects to essentially the combustion chamber during cold operation.

[Maltese Falcon]

New 9146-gt (FIA style) headers , makes it easier for the engine dyno guy to set a/F ratios. These are now a regular MSDS production part. Just dropped off at the Ceramic coating contractor. Originals are in storage, easy to swap out.

[horizontally-opposed]

New 9146-gt (FIA style) headers , made easier for the engine dyno guy to set a/F ratios. These are now a regular MSDS production part. Just dropped off at the Ceramic coating contractor. Originals are in storage, easy to swap out.

Now, that's pretty awesome. (IMG:style_emoticons/default/smilie_pokal.gif)

[pete000]

Interesting HE, I never knew about those !