# turbo m42b18



## toyosupr (Nov 16, 2003)

hey i was looking into buying a 318is older 92-93 and maybe turboing it.
i seen the engine has forged rods and a iron block. are the pistons forged? i couldnt find that any where. If you could lead me in the right direction for info on turboing a m42 engine id be thankful. i tried to search but its not working or something liekthat. thanks again


----------



## toyosupr (Nov 16, 2003)

all iv found so far is one that was 170kw or 227hp but i dont know anything else about it


----------



## andy_thomas (Oct 7, 2002)

toyosupr said:


> hey i was looking into buying a 318is older 92-93 and maybe turboing it.
> i seen the engine has forged rods and a iron block. are the pistons forged? i couldnt find that any where. If you could lead me in the right direction for info on turboing a m42 engine id be thankful. i tried to search but its not working or something liekthat. thanks again


Yes, the crank in the M42 engine is forged, and the bock is iron.

The M42 compression ratio is quite high (10.5:1) so a proper turbocharger installation will require the use of lower pistons, to reduce the C/R, unless you stick to a low boost.

I have heard that supercharging the M42 has been more successful - don't know why, I would have thought that supercharging with a low-ish boost would have been less efficient than a turbo.


----------



## toyosupr (Nov 16, 2003)

ya, iv seen its 10:1 but even at that boosting 10-11psi would be work with good tunning. if more was wanted getting a thickerhead gasket will lower the compression a bit. but then the pistons become a problem. i dont think those are forged. Is the m42 a closed deck engine? (id think it is). a supercharger would be fun, with the tq the engine already provides the sc only make that all teh better. iv got a supercharger on my b16 in a crx and it doesnt have traction in 1st or 2nd. What charger was on the m42/318i you speak of the roots or a centrifical? 

websites would be cool if anyone has them?!?


----------



## DKJBama330ci (Dec 22, 2001)

Your best bet would be to try the forced induction forum at www.bimmerforums.com. There seem to be a lot of guys over there who really know their stuff when it comes to forced induction.

Later,
DKJ


----------



## toyosupr (Nov 16, 2003)

ill try it out. thanks


----------

