m52b25 worth it?

[jahnaboi]

Put a deposit with a friend on a 99 323is drivetrain for a very good price. 149k miles, starts and runs perfectly fine. Getting everything including the driveshaft (the car is stick).

My question, is the juice worth the squeeze?

We plan on turning this car into a track/fun car and are looking to boost this in the near future. We were looking forward to having a m52b28 to play with but the craigslist add was worded incorrectly.

I doubt there is much power gains stock vs stock. What you guys think? Get errrrrr done?

Adding s52 cams would be just as applicable as a m52b28 IIRC?

-Jasper

[blunttech]

I wouldnt. M52b28 is so cheap nowadays. Hold out if youre going to boost

[monkeytaco]

There's no replacement for displacement.

[phreshkid]

That's probably one of the worst sentences I've ever read

[nando]

the M52B25 out of the 323 is an extremely choked off version of the M50 family - it only puts down 170bph.

if you did an ODB1 conversion to it you could eliminate most of that factor, but an M52B28 is definitely a better buy.

[jahnaboi]

the M52B25 out of the 323 is an extremely choked off version of the M50 family - it only puts down 170bph.

if you did an ODB1 conversion to it you could eliminate most of that factor, but an M52B28 is definitely a better buy.

We have the obd1 parts already. Everything down to the tee. If a m52b28 was available we would be on it, but at the moment there's none. Guess this will have to do. With obd1 bits + s52 cams, 3.5" hfm/chip/exhaust what do you think this will put out? Over or just about 200whp? Guess we'll have to see.

[SpecM]

it wouldn't be any worse off than an m50b25... once the obdII manifold is junked and a proper exhaust fitted

if you get it at a good price, I say do it. It would pretty much be a m50tu, power-wise

[jahnaboi]

Yea, I figured it would be within the same power range. Top of my head, is the bore 84mm? Same bore size as the b28?

[Leo_328i]

Yeah all the 2.5 and 2.8 engines are 84mm bore.

You guys are very lucky in the states with such cheap engine prices! I'm down here in Australia and a M52 B28 worth buying is worth around $2000+ whilst M50 B25s/M52 B25s are closer to the $1000 mark.

I'm thinking of getting an M52 B25 soon, converting it to OBD1 and sticking it into my 318iS! We're luck that all our M52 motors are the alloy block which is a good 23kg lighter :)

Regarding M50TU B25 vs M52 B25 comparisons, excluding inlet manifold and OBD1/OBD2 differences, the M52 has a revised valvetrain which is lighter and is said to improve running smoothness and fuel economy according to official BMW literature. This includes conical valve springs and smaller lifters.

According to RealOEM, the pistons and rods are the same as M50TU B25.

[jbxblitz]

does the m52b25 come with a forged crank?

[Leo_328i]

No unfortunately, all the 2.5l motors use a cast crank. Its not really that bad a situation though, the rods are the items that are most likely to break and they are forged.

[blck325is]

We have the obd1 parts already. Everything down to the tee. If a m52b28 was available we would be on it, but at the moment there's none. Guess this will have to do. With obd1 bits + s52 cams, 3.5" hfm/chip/exhaust what do you think this will put out? Over or just about 200whp? Guess we'll have to see.

Just got a m52b25, what else can I do after I do all this?

[Sharino]

Is converting a M52B25 to a M52B28 as simple as swapping out the crank or is there more to it?