Which Bay Window trans bell housing accepts a Porsche 912 engine

[Doc_Speed]

Perhaps this has been covered before but the search engine turns up nothing.

I'm looking to find the Bay Window bus Type IV engine bell housing that will accept a 912 engine flywheel. Because the Type IV powered Porsche 914 used a Porsche 901 series transmission, which was used by both the 912 and pre-72 911 it stands to reason that something ought to work.

My goal is to have an engine run stand using a Bay Window bus bell housing. I have heard that an automatic transmission bell housing would work. Would a standard transmission bell housing work? If so, which? Automatic or standard or both? Which year(s)? I believe that the Bay Window switched from the Type I engine to the Type IV engine in 1973?

Because the Type II bell housing has a starter bushing, but 901 Porsche transmissions do not (self-supporting starters) I could also use this same run stand for 356 engine work. Venders sell a starter bushing that has a 6-volt starter ID and a 12-volt starter OD.

Thanks!

[SGKent]

the 912 was a 911 with a type 4 engine. 914-4 used a type 4 engine. 1972 and later North American buses used a type 4 engine. 9172 and later Buses used 3 different flywheel sizes. As I recall, 1700 210 mm, 1800 215 mm, and 2L 228 mm. All the manual trans engines use starters that lack a nose support, the bell housing does that. The starters used are specific to the bell housings because the depth of the flywheel is slightly different between flywheels. The automatics used a starter with a nose that was self supporting. It can be made to work in most manual bell housings.

I believe that the 912 and 914-4 flywheels are the same as earlier bus flywheels. The late GA engine in Europe was a 2L engine. I don't know if it used the cast iron bus flywheel or anything different.

In order to choose a manual bell housing, you will need to know the size of your flywheel. Then use an automatic starter in it or just get the correct starter that goes with the bell housing. A really good place to start is somewhere like Auto Atlanta to look up the part number on your 912 engine year. Then use any of the bus fiches available to compared the flywheel part number. Wish I could help you more.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Doc_Speed]

[dodger tom]

hello doc,

the picture you included in your post about the air cleaners might help folks visualize the engine to which you refer.

dt
_________________
1978 Champaign Edition Westfalia
Would never find the time to keep up another classic air-cooled.

[Wildthings]

I can't answer your question directly, but if you use a bus Type 4 flywheel and its matching clutch and starter then all should be well. The 091 bellhousing and starter would be somewhat of a universal fit and would work with all the bus Type 4 flywheels and clutch combinations.

[aeromech]

Here’s a smoking deal on an engine run stand. I bought the prototype years ago. I went to his house. He’s a Porsche guy and can probably answer your question.

https://www.thesamba.com/vw/classifieds/detail.php?id=2566427


https://zalexindustries.com/

Builder is Tom Perazzo. Great guy

https://www.google.com/search?q=zalex+tom+perazzo&...U4jVQMhgxM
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[Doc_Speed]

[aeromech]

If you want an experts opinion you should email Tom Perazzo. He can answer your question because he builds engine run stands for both VW and Porsche. He’s a mechanical engineer and a Porsche guy. I’m sure he would help you. The email is sales@zalex…

You’ll find the whole address on the link I supplied

BTW, I don’t think I ever suggested changing from a 5 bolt to 8 dowel anything
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[Doc_Speed]

[Wildthings]

[Doc_Speed]

[SGKent]

I think this belongs in the Porsche forum.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Doc_Speed]

[Wildthings]

[Doc_Speed]

[Wildthings]

[Doc_Speed]

[Doc_Speed]

Here are photos of the 912 engine, flywheel and an early (901) Porsche 911/912 transmission case. Photo captions are above each photo.

If folks could provide equivalent 001 and 002 Bay Window bell housing measurements, I would really appreciate it! It seems like the 091 bell housing has been ruled out.

1. Porsche 912 engine.

2. 912 flywheel

3. 912 flywheel ring gear diameter: 10 13/16 in (275 mm)

4. Engine case/trans case mating surface to outer edge of ring gear: 1 5/8 in (41 mm)

5. 911/912 (901 or 902) transmission case (no provision for a starter bushing).

6. 911/912 transmission case flywheel area Inner Diameter: 11 in (279 mm)

7. 911/912 transmission case flywheel area depth: 1 7/8 (48 mm)

8. 911/912 trans. starter mounting flange

9. 911/912 trans. starter mounting flange width: 3 in (76 mm)

10. Starter installed SR-17 Porsche equivalent.

11. Starter nose to trans/engine case mating surface: 1 7/16 in (37 mm)

12. 911/912 transmission case bottom engine stud bolting flange

13. 911/912 transmission case bottom engine stud bolting flange width: 2 1/16 in (52 mm)

[Takamotti]

[Doc_Speed]