rx7jocke

Im in the progress on mounting my 20b in my fc, the thing is i am gonna use a BMW gearbox with mazda bellhousing and move the engine back behind the engine subframe so it sits more like the 13bt.
The space is there so thats no problem, the problem is fabricating the engine mounts
Then i noticed that if i move the engine back 5.5 inches, it drops behind the subframe and steering rack and the 2 threaded holes in the fat iron aligns pefect with the hole in the subframe that the original 13bt engine mount is fastened to.

So my question is if i can use those 2 holes in teh fat housing to mount the engine, or even bolt a metal plate from those holes in the fat iron all teh way back to the big threaded holes in the rear iron and then use that metal plate as the mounting point?

Or does anyone have a better idea?

t-von

iTrader: (8)

It would help if you would post some pics of how its sitting now? Not too many people moving 20b's back within the Fc chassis. I've done the same thing but in an Fd. What kind off BMW tranny you running? I was curious about doing the same but just recently bought a M12 T56 from a CTS-V.

j9fd3s

iTrader: (3)

since the stock mount brackets attach to two irons, i think i would try to keep that.

rx7jocke

i will be using a bmw 6-speed from a fairly new 530d, its rated for 500+ NM of tourqe in stock form and lots of high revving bmw guys running 9s with these boxes year after year with 1000hp and they work well. the fifth gear is 1.0 and 6th 0,84 and 1st to 5th is very close ratio.

Got no decent pics atm but maybe during the weekend i can get some. It sits so far back it needs the oil filter relocated and the tunnel needs a little massage in the engine bay due to the big bmw gearbox

patman

iTrader: (3)

typical way to mount a 3-rotor is to make the engine-side flange span the center iron and rear iron. You can still put your main support adjacent to the center iron, just include some gussets back to the rear iron as well.

rx7jocke

thank you patman you made my day!

misterstyx69

iTrader: (142)

or you can buy these:
13B-RE & 20B Engine Brackets

rx7jocke

well i could but i still have to cut em up, i want the front iron of the 20b to sit where the 13b front iron used to sit, so i can keep the weight balance of the car and the space up front for a proper v-mount. I also need to lower the engine about 1 inch to fit the bmw 6-speed gearbox. this also enhances the handling if the car :-)

SikFC3S

Bump looking forward to seeing some pics of this if you post them

patman

iTrader: (3)

Pretty sure you're going to be cutting a bunch of the firewall away if you want to mount it that far back. I am mounting mine similarly in the FD, and had to remove the firewall and tunnel all the way back behind the e-brake.

rx7jocke

I have only done some initially measures but it seems possible if i just use a hydraulic release bearing (no slave on top of gearbox) and a remote oil filter, sometime this coming week i will do some more testing with the actual engine

Rub20B

Looking forward to a v-mount in the FC. will u use a vented hood?

rx7jocke

I will use a tamon design hood, its vented but not un the best location...if it wont work i will change it

rx7jocke

Yesterday i did a little testfit with my 20b and the stock fc gearbox to mount it the way i want to, moving the engine back 13cm (5,x inches) is totally possible if you use a remote oilfilter and a hydraulic release bearing since the clutch slave cylinder is in a bad spot, the oilpan might need a 5mm massage in the front but not 100% sure. The mazda b2500 gear linkage moves the shifter 5 inches forward so this seems like a nice solution for stock gear box, with the bmw gearbox that is alot bigger the engine also needs to be lowered an inch and a more modded or custom oilpan is needed, but thats still small potatoes when doing a 20b swap, things look promising! Still no pics thou since i was alone in the garage and had to manage both the engine hoist and balancing the engine/gearbox on my own