Transmission height for custom engine mount

[I'mThatGuy]

Hey Guys, I'm resurecting a 79 targa widebody, and I bought the chassis as a non roller with no powertrain, now ive got trailing arms trans and an engine hanging, so I was wondering if somone could give me a measurement from the bottom of the diff housing to the garage floor on a stock us ride height 911 with a 915 trans I'm making the rear mount plate this week so I am trying to get the location as close to stock as possible.
Thanks Guys

[boyt911sc]

Originally Posted by I'mThatGuy

Hey Guys, I'm resurecting a 79 targa widebody, and I bought the chassis as a non roller with no powertrain, now ive got trailing arms trans and an engine hanging, so I was wondering if somone could give me a measurement from the bottom of the diff housing to the garage floor on a stock us ride height 911 with a 915 trans I'm making the rear mount plate this week so I am trying to get the location as close to stock as possible.
Thanks Guys

Why can't you use the OEM transmission bracket instead of fabricating a new one? The transmission bracket is available and cheap to obtain. Why make one? Just wondering.

Tony

[I'mThatGuy]

not the trans side I have that mount as a stock piece for now, it'll be custom made for high power output. I'm have a honda K24/a2 turbo in it, I dont have the porshce engine mount and nor do I have one that isn't a 930 with the 4 speed that I'd be allowed to crawl under, Basically I am making the plate to use the factory engine mount locations ontop of making custom side mounts and I need to have it at the right angle to make the mounts.

[boyt911sc]

So you need the clearance of a 915 transmission housing from the garage floor? I have a '78 SC sitting the garage. Let me know if we are on the same page.

Tony

[I'mThatGuy]

Affirmative that is exactly what I'm looking for, thank you. And when you do it if you could measure the wheel arch height on both door sills so I can compensate for wheel differences in dimension..... Thanks.

[cole930]

That Guy !!!!!

I'm an old 930 guy and recently converted my stock exhaust system to
a set of factory 934 headers and a center mount turbo. This required the
fabrication of a new engine mounting truss.

The first advice I have is start by installing the trans and engine and
block it in the desired location. Take measurments from an existing
car so you know, when you block it up it is in the same location as a
standard engine / trans install.

Mock up the new truss using the four mounting studs on the front of
the engine and the two truss end mounts on the chassis.

Added some pics, hope they might be of help to you.
















Hope these help some.

Cole

[I'mThatGuy]

Yeah thanks that does help, Im going off brand engine wise as I bought just the carcass of a car, that's why I asked about the measurements so I can in theory double check my current blocking before I make the truss mount

[I'mThatGuy]

Any chance I can get those measured today anyone? trans case to the ground, and door sills to the floor hopefully in a garage, I just have time today is all, thanks
-Keith

[pete3799]

Be right back......

[pete3799]

Okay
My rear is sitting at 24" (225's on 16 inch wheels) floor to top of wheel arch.
After a few attempts I was able to find a socket and short extension combo I could use to measure the gap and came up with 4 -11/16" floor to the bottom of the tranny at the rib where the trans. serial number is located.
Hope that helps.

[boyt911sc]

Originally Posted by I'mThatGuy

Any chance I can get those measured today anyone? trans case to the ground, and door sills to the floor hopefully in a garage, I just have time today is all, thanks
-Keith

Keith,

Measurement taken from a '78 SC with fender height at 24.5" four corners with 16" Fuch wheels: The vertical distance from floor to the transmission case rib over the first fin from end side = 225 mm.

I used a wooden stick and trim it to fit the clearance between floor and transmission. The wooden stick was set below the filler cap and exactly sitting by the 1st. cooling fin (counting from the rear end.)

Tony

Edit: Ignore the numbers!!! My car is sitting on wooden planks and will do a re-measurement.

[pete3799]

Note:
My car is way below stock us ride height.

[boyt911sc]

Originally Posted by boyt911sc

Keith,

Measurement taken from a '78 SC with fender height at 24.5" four corners with 16" Fuch wheels: The vertical distance from floor to the transmission case rib over the first fin from end side = 225 mm.

I used a wooden stick and trim it to fit the clearance between floor and transmission. The wooden stick was set below the filler cap and exactly sitting by the 1st. cooling fin (counting from the rear end.)

Tony

Edit: Ignore the numbers!!! My car is sitting on wooden planks and will do a re-measurement.

Keith,

Using Pete's reference point (flat area with trans.#), I did a second measurement and got 4-15/16". I have not checked my tire pressures but with 32°F temperature, the reading would be lower than before. The correct tire pressures for my would probably have negligible difference in height measurement. So my measurement is aprrox. 5".

Tony