M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Swaps, Turbos, Buildups => Topic started by: shortblock on January 14, 2014, 09:14:56 PM

Title: 318is 1991 with m42b18 worth swapping a m50??
Post by: shortblock on January 14, 2014, 09:14:56 PM
hi, i just bought my first bmw yesterday and i was thinking of swapping a m50b25 in it.
From what i've read most swaps were done with on e30 with m20 engine
and damn, i cant believe the part list required to do this swap...(i only had subarus so far and parts from 93 to 07 were extremely swappable)
Would the m50 worth the time, money and headache spend on it??
im looking for around 170~180 hp, would the m42 give me this extra go??
thanks, im from canada and my english isn't that great sorry
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: bmwman91 on January 14, 2014, 11:28:53 PM
I don't think anyone ever really puts an M20 into an M42 car these days...tons of effort for minimal gain. The M50 is probably a better overall value for doing the swap since it makes more power and is more efficient. There are kits and solid documentation for that swap. Honestly though, your easiest bet is to just sell the 318iS and buy an E30 325i/iS if you want to quickly and easily get a 6-cylinder. The 318iS is getting sort of rare since everyone used them for swaps for a long time and it is sort of a shame to rip their guts out. The 325 is probably easier to do the M50 swap with anyway since you can reuse a lot of the driveline parts.
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: thebrelon on January 15, 2014, 02:45:21 AM
you'll never get 170/180hp out of a M42 for anything close to a M50/M52 swap moneywise.

I would also say that M50B25 is not the best engine to swap, I would consider a M52B28 instead as you can still get more HP out of the stock engine fairly easily if the need arise.
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: MrPhatBob on January 15, 2014, 04:56:10 AM
The only reason, as I see it, to not swap to a M50 or M52 is if you're going to compete in the car.  A lot of classes are based on engine size, so you'd be out of the sub 2000cc classes and up into the high capacity classes where you may be underpowered.

In any other case you'd be best to follow the golden rule: There's no substitute for Cubic Inches.
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: DesktopDave on January 15, 2014, 07:23:20 PM
hi, i just bought my first bmw yesterday and i was thinking of swapping a m50b25 in it.
From what i've read most swaps were done with on e30 with m20 engine
and damn, i cant believe the part list required to do this swap...(i only had subarus so far and parts from 93 to 07 were extremely swappable)
Would the m50 worth the time, money and headache spend on it??
im looking for around 170~180 hp, would the m42 give me this extra go??
thanks, im from canada and my english isn't that great sorry

Congratulations on joining the 'club! I'd stick with the M42, of course. The 318iS is gaining in value, and a swap would murder your resale price. An M42 isn't really all that far behind a stock M20 in terms of power, especially given a few little mods. The longer inline-6 motors tend to ruin the happy balance of the 318iS...one reason they're so special is that they're one of the best-feeling BMWs to drive.

But if you're looking to do a cheap & fun E30 swap, sell off the 318iS and find an '88 325 with a 5-speed (the so-called 'Super Eta'). Drop in a 325i top end/harness/173 DME. The resulting hybrid motor is nicknamed the '327i.' With a chip you'll see an easy 180hp (MarkD has one IIRC). Some claim over 200hp with a good tune. You can also find that motor in an '88 528e. The diving board E30s are a bargain, and the Eta will always lag behind the rest of the E30 flock in value (M10 318i excluded), but they're basically the exact same car. I'll bet you could get the whole swap done for under $1000 or so. Just describing this all to you makes me what to try it. I know where one is right now, LOL.

If you desperately wanted to swap something into your 318iS, the best "bang for the buck" candidate in an E30 is likely an M52 from a late 90's 528i. It has the oil sump at the front of the motor, thus will fit the E30 subframe. But you're right about the parts list...it's long and pricey.

I've had a few Subies myself, always admired the way they were put together. Their commitment to interchangeability and servicing is rare in the automotive world. IMHO, all the times I've been to Canada...I've noted your Canadian "English" is better than our American "English."
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: shortblock on January 15, 2014, 07:27:14 PM
you'll never get 170/180hp out of a M42 for anything close to a M50/M52 swap moneywise.

I would also say that M50B25 is not the best engine to swap, I would consider a M52B28 instead as you can still get more HP out of the stock engine fairly easily if the need arise.

yeah, i thought of this too, are the obd1 to obd2 conversion really complicated?? with vanos and immobilizer wiring added :S
the m50b28 are only obd2 right??
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: shortblock on January 15, 2014, 07:44:08 PM
hi, i just bought my first bmw yesterday and i was thinking of swapping a m50b25 in it.
From what i've read most swaps were done with on e30 with m20 engine
and damn, i cant believe the part list required to do this swap...(i only had subarus so far and parts from 93 to 07 were extremely swappable)
Would the m50 worth the time, money and headache spend on it??
im looking for around 170~180 hp, would the m42 give me this extra go??
thanks, im from canada and my english isn't that great sorry

Congratulations on joining the 'club! I'd stick with the M42, of course. The 318iS is gaining in value, and a swap would murder your resale price. An M42 isn't really all that far behind a stock M20 in terms of power, especially given a few little mods. The longer inline-6 motors tend to ruin the happy balance of the 318iS...one reason they're so special is that they're one of the best-feeling BMWs to drive.

But if you're looking to do a cheap & fun E30 swap, sell off the 318iS and find an '88 325 with a 5-speed (the so-called 'Super Eta'). Drop in a 325i top end/harness/173 DME. The resulting hybrid motor is nicknamed the '327i.' With a chip you'll see an easy 180hp (MarkD has one IIRC). Some claim over 200hp with a good tune. You can also find that motor in an '88 528e. The diving board E30s are a bargain, and the Eta will always lag behind the rest of the E30 flock in value (M10 318i excluded), but they're basically the exact same car. I'll bet you could get the whole swap done for under $1000 or so. Just describing this all to you makes me what to try it. I know where one is right now, LOL.

If you desperately wanted to swap something into your 318iS, the best "bang for the buck" candidate in an E30 is likely an M52 from a late 90's 528i. It has the oil sump at the front of the motor, thus will fit the E30 subframe. But you're right about the parts list...it's long and pricey.

I've had a few Subies myself, always admired the way they were put together. Their commitment to interchangeability and servicing is rare in the automotive world. IMHO, all the times I've been to Canada...I've noted your Canadian "English" is better than our American "English."

yeah ive read of that too (327 hybrids), but yeah im in quebec and there is like none e30 around for sale...there's a couple in ontario but than again, i would need to import the car fix everything =.= and do a inspection to be able to plate it. cars from quebec are sad man, HUGE potholes everywhere, falling concrete from the bridges, huge amount of salt so its really really hard to find old cars in good condition
i wanna stay with this 318is i bought it for 1200$ and it was the cheapest one in the market (there's 5 in the market right now), so yeah i dont mind doing a m5x swap on it
would i be able to reuse some of my parts?? the seller gave me a extra 4.10 welded diff, if i cant keep the drivetrain, would my original transmission crossmember work??
ill post a pic of my engine bay
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: Beeker1972 on January 19, 2014, 12:37:21 AM
I think an E30 M42 to M50 swap would be the easiest, because BMW used the same transmission bell-housing bolt patterns on M42, M44, M50/S50, M52/S52, and M54 Engines.  I think BMW still uses the bell-housing bolt patterns in their modern models, but I could be wrong.  I know Getrag 260/5, Getrag 265 w/ M20 Bell-Housing, Getrag S5D200G, Getrag S5D250G ZF S5D320 ZF S6S 420G, and ZF GS6-37BZ/DZ should bolt up to M20, M42, M44, M50/S50, M52/S52, and M54 Engines.

Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: thebrelon on January 19, 2014, 03:46:30 PM
you'll never get 170/180hp out of a M42 for anything close to a M50/M52 swap moneywise.

I would also say that M50B25 is not the best engine to swap, I would consider a M52B28 instead as you can still get more HP out of the stock engine fairly easily if the need arise.

yeah, i thought of this too, are the obd1 to obd2 conversion really complicated?? with vanos and immobilizer wiring added :S
the m50b28 are only obd2 right??

there are company selling kits and it doesn't sound more complicated than the swap itself. Vanos and EWS are not an issued, they can either be deleted or taken advantage of...
wouldn't say for sure that M52 are OBD2 only but it doesn't sound wrong to me.
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: Beeker1972 on January 19, 2014, 09:34:25 PM
Well just look for an E34 525i made between 1991 and 1992 the M50s in those cars have no vanos system.  If you like vanos any E34 525i made between 1993 to 1995 will work fine for wiring harnesses, oil pan, and oil pump pickup.  Retro fitting back to OBD1 is pretty easy if you find a M52B28, M54B30, and S52B32NA just use wiring harnesses, oil pan, oil pump pickup, and the rest of the engine accessories from an E34 525 made between 1991 thru 1995 for E30 chassis 3 series.



you'll never get 170/180hp out of a M42 for anything close to a M50/M52 swap moneywise.

I would also say that M50B25 is not the best engine to swap, I would consider a M52B28 instead as you can still get more HP out of the stock engine fairly easily if the need arise.

yeah, i thought of this too, are the obd1 to obd2 conversion really complicated?? with vanos and immobilizer wiring added :S
the m50b28 are only obd2 right??

there are company selling kits and it doesn't sound more complicated than the swap itself. Vanos and EWS are not an issued, they can either be deleted or taken advantage of...
wouldn't say for sure that M52 are OBD2 only but it doesn't sound wrong to me.
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: Beeker1972 on January 19, 2014, 10:37:43 PM
I have a 1991 318i 4 door and If I was going to do m42 to m5x/s5x swap I would use the engine stuff from an E34 525i Manual model years between 1991 thru 1992.  Find a stripped long block of a m54 that has not been overheated, a close ratio ZF S5D320 from a M52 powered BMW, 3.25 to 1 LSD from a M30 powered E28, find a m20b25 powered E30 rear diff cover.  The only problem I see is the drive-shaft.  I don't know taking off the Getrag S5D200G output flange and putting it on the back ZF S5D320, and taking off the u joint flange from the small diff and putting it on the larger diff from m30 powered e28 would work.  I don't know the flex disc could handle the increase in power though.  I don't know if Revshift makes an aluminum/poly flex discs for M42 powered E30s.

I think I will eventually find a E30 M20/E28 M20-M30 4.10 to 1 LSD, a close ratio ZF S5D320 from a M52 powered BMW, and try to keep the current drive-shaft, because it has been replace by Beyer Motorworks they rebuild BMW drive-shafts that are rebuild-able.  I think I want to build a 2.0 or 2.1 forced induced M42 for the car.  Metric Mechanic makes M42 crate engines that are 9k screamers, but who has 10 grand to shell out for one of those engines.
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: shortblock on January 20, 2014, 08:12:58 PM
wow!! thanks for the info guys  8)
yeah, its going to be a low budget dailydrive, so nothing crazy
ill swap in a 525i e34 and quick question i know there's alot of brake servo that fit in there
but what would be the easiest one to find?? i saw 944, old school golf??, 325ix and stuff like these
and i also saw people deleting the booster O__O, wouldn't the brake system loose alot of its braking power??
cant wait till spring so i can do the swap!!! :(
Title: Re: 318is 1991 with m42b18 worth swapping a m50??
Post by: Beeker1972 on January 21, 2014, 11:32:15 PM
I know some people put the hydraulic assist braking system from the M30 powered E23s, late E24s, E28s, and E32s because it's a more powerful brake system than vacuum assist, but there could be lots a custom fabrication to do that swap.  I agree with Desktop Dave try to keep a M42 in the car, and go to a salvage yard and get another M42 to build up.

wow!! thanks for the info guys  8)
yeah, its going to be a low budget dailydrive, so nothing crazy
ill swap in a 525i e34 and quick question i know there's alot of brake servo that fit in there
but what would be the easiest one to find?? i saw 944, old school golf??, 325ix and stuff like these
and i also saw people deleting the booster O__O, wouldn't the brake system loose alot of its braking power??
cant wait till spring so i can do the swap!!! :(