Euro 316 subframe

[Polski Drywer]

Hi there. I'm in Poland and want to do a 24V swap into a clean 316 that has a dinky m40 engine in it. Does anyone know if the 316s, 318s and 325's had similar subframe?

[moatilliatta]

The only subframe that I can think is different are the ones with the mount for the damper on manual steering cars. But geometry should be similar.

[Polski Drywer]

The only subframe that I can think is different are the ones with the mount for the damper on manual steering cars. But geometry should be similar.

Thank you very much!

[82eye]

Hi there. I'm in Poland and want to do a 24V swap into a clean 316 that has a dinky m40 engine in it. Does anyone know if the 316s, 318s and 325's had similar subframe?

the m10 and m40 e30's share the same subframe. all m20's and the m42 share a different subframe.

m10 and m40 sub is 31111126427

m42 and m20 sub is 31111130707. early m20 subs are 31111126428.


you will probably need to swap subs or modify the existing one. subs and mounts have often been modified for engine swaps. i'm not sure about anything specific to your needs though. we never got the m40 version where i am.

[roguetoaster]

Haven't checked parts diagrams, but can see no reason why an M40 and M42 car would use different surfaces. To add oidentical. believe M42 and M20 subframes are idential, but think by extension that M40 ones may be the same as well.

[82eye]

Haven't checked parts diagrams, but can see no reason why an M40 and M42 car would use different surfaces. To add oidentical. believe M42 and M20 subframes are idential, but think by extension that M40 ones may be the same as well.

the m40 is a single overhead cam as opposed to double for all other m4x variants. the m40 uses the same bottom as the e30 m10 and same motor mounts. which is why it shares the subframe. it is also belted like the m20, as opposed to chained for all dohc m4x variants.

the mounts and sub changed with the addition of dual cams. the bottom was still m10. i'm at a loss to explain the change, as the m20 remained belted for it's entire run. i would speculate it was to make the subs for the m42, m20, and s14 the same. the s14 also uses an m10 based bottom and dual cams.


edit : i checked and the s14 m3 uses its own mounts and subframe. different from all others so i am corrected there. oddly an s14 drops on to an e21 m10 sub and will bolt to the tranny in an e21 like it lives there.

i'm not really sure whats going on with the m10 / m40 - m42 / m20 subs. i could be a euro vs n/a market difference as the m40 never came here.

[moatilliatta]

S14 subframes I think have reinforcement on the engine mount platforms.

[Polski Drywer]

the m10 and m40 e30's share the same subframe. all m20's and the m42 share a different subframe.

m10 and m40 sub is 31111126427

m42 and m20 sub is 31111130707. early m20 subs are 31111126428.


you will probably need to swap subs or modify the existing one. subs and mounts have often been modified for engine swaps. i'm not sure about anything specific to your needs though. we never got the m40 version where i am.

Thank you. Interesting, because I want to join the n52 craze but will have to make my own measurements and compare with the other guys. Perhaps I need to dig harder to see what m10 guys have done for 24v swaps.

[roguetoaster]

the m40 is a single overhead cam as opposed to double for all other m4x variants. the m40 uses the same bottom as the e30 m10 and same motor mounts. which is why it shares the subframe. it is also belted like the m20, as opposed to chained for all dohc m4x variants.

the mounts and sub changed with the addition of dual cams. the bottom was still m10.

While they have different cylinder heads/timing setups the M40 and M42 share what is effectively the same block, albeit not completely identical. They also share the same gearbox. Thinking about it more, the only real difference is that the M40 uses solid mounts, whereas the M42 uses hydraulic units.

[82eye]

While they have different cylinder heads/timing setups the M40 and M42 share what is effectively the same block, albeit not completely identical. They also share the same gearbox. Thinking about it more, the only real difference is that the M40 uses solid mounts, whereas the M42 uses hydraulic units.

i know that m10 subs can be modified fairly simply to accept an m20 for an engine swap in an e21, so they can't be too far different in that chassis. it does need welding. i would have to imagine e30 front subs would be pretty close to each other as well. maybe not exact, but probably close enough to be able to make it work.

[KI4UJO]

m10 subframes are essentially identical, minus the mount for the engine mounting dampener on the right side. Both of the ones I have (84 and 85 build date) also have two sets of steering rack mounting holes to accommodate the steering dampener mounting on the rear of manual racks, as noted above. I can say from personal experience that a 24v powerplant will clear an m10 subframe - currently have an m54 in mine

[82eye]

m10 subframes are essentially identical, minus the mount for the engine mounting dampener on the right side. Both of the ones I have (84 and 85 build date) also have two sets of steering rack mounting holes to accommodate the steering dampener mounting on the rear of manual racks, as noted above. I can say from personal experience that a 24v powerplant will clear an m10 subframe - currently have an m54 in mine

i vote engine swap all the m10's ...

[lukeADE335i]

Or turbo them - the M10 block handled 1500hp in F1 qualifying trim



M10s aren’t a bad engine - in 2.0L injected trim (approx. 130hp) they’re pretty sprightly as a manual and lighter than the M20. They just need a shorter diff in them to liven them up as early e30s had a 3.64, which isn’t exactly short. A 3.9 or 4.10 would go well.

[82eye]

Or turbo them - the M10 block handled 1500hp in F1 qualifying trim



M10s aren’t a bad engine - in 2.0L injected trim (approx. 130hp) they’re pretty sprightly as a manual and lighter than the M20. They just need a shorter diff in them to liven them up as early e30s had a 3.64, which isn’t exactly short. A 3.9 or 4.10 would go well.

there was a lot attached to that block to make it happen. the s14 and m4x are also m10 bottoms. iirc it was the first winning f1 turbo as well. there's all sorts of urban legends about it from how they used ex taxi blocks to stories of them literally pissing on the blocks for some stupid reason.

my e21 had both the m10 and the 3.90. not so bad but i'll stay with the m20 and my e30 now thanks. .

[Jaxx_]

i vote engine swap all the m10's ...

Totally! Who wants 50/50 weight distribution, anyway?

please send any unwanted M10s to me and I'll keep them