M42 Stroker+Turbo+ecu stock

[tm02rmn]

Hello,i am planning to build very soon,in maximum 1 week starting from today a m42 stroked and turboed! I am an automechanic,i work as a mechanic since i was 13 years old and now i am 31.I run a small autogarage ,where with my partner,we make maintenaces,rebuilding engines,etc.He is a honda fan for live....We have turboed a lot of hondas.The reason for this post is that for BMW i don t know how can i stroke this m42 engine and have a good compression ratio for 1.2-1.5 bar of boost.Like a ideea i have a lot of friends with  bmw dismantling garages,so i can get a big variety of parts to combine,i say that because recently i have builded an e30 with 2.0 short block,2.5 head,and 2.8 crank,rods and pistons,run on 0.7 bar managment by vems and makes 380hp..dyno at exelixis romania,so i was thinking that for this engine i can combine a crank from i think i read somewhere 2.0l d 136hp?and what con rods and pistons,cause i want to stroke but i want a lower cr too.As with the management,the only problem with stock ecu is that i don t have a map sensor,but i can remap my ecu with tuner pro and moates ostrich 2.0 emulator,and i think i will mount afm in front of the turbine and recalibrate...i have a garett tb03 with 0,52 ar on cold side and 0,48 ar on hot side.I look for 300hp+...i have heard a lot of storyes about m42 internals.....are forged or not?


Please excuse my bad english!

[Darky]

Hello and welcome
Please don't be sorry that your 2 nd language is nearly as good as my my only language. I have enough issues!l lol

The only internal part that is cast for these engines is the m44 crankshaft. All else are forged.

A list of the internals that will get you around the 8.5:1 ratio roughly.Stroked
M47d20 crankshaft 11212247514
M52 connecting rods 22 mm pin
86 mm S50 US 22 mm pin or S50 euro 21 mm pin machined out to 22 mm

Note a lot of people just use the m42 crankshaft easier to get and stroking not really required with that sort of boost. Still bore it out to 86 mm though. Because you can!

Hope this helps Rohan

[tm02rmn]

So,the only problem will be this m power pistons,cause i will never find them at a resonabile cost,in the fact i was thinking that if my m42 internals are forged,it will be ok for boost,but when you say that internals are forged you mean:crankshaft,conrods and pistons too,or only crank and rods?So like i ve said if all are forged then i se no point of using 2.0 d crank,cause i ve seen a lot of them cracked on 136 hp engines,and instead of swapping,isn t much better to custom modify conrods?I know o olad that was working machinistfor conrods all his life,and he told me tha he can shorter my conrods by cutting 0,5mm or so from the long side,and then install the shorter side.tighten at specify torque and machine the interior for bearing.like he is not touching the small half,he is cutting bearing location only into the longer part of conrod,so with this ideea i will not need custim decompressed pistons,causean alternativeforthis was either 2 stock headgaskets,cometic gasket,or cutting about 0,5mm from the top of the piston to lower the compression ratio.butthis was my ideea when i wanted to turbo the stock engine.Now after i was driving that e30 with 20block 2,8 internals and 25 non vanos head turbo.i became crazy.as it is  ..hello i build it from the owner specs,hhe claim to be a f###ing genius but i think that he read somewhere what yo be done,and i said that cause i ve spoked with him adout my ideea.i have told him to calculate engine cfm and turbine efficiencyand he was starting to speak around the subject,he told me that my turbine at 6000rpm will make chokes.but wow this turbine was on b16a2 vtec vti engine,revving up to 10000 rpm,and had full boost from 3500rpm,with internal wastegate actuator.for my bmw i plan to weld an use an extefnal wastegate with spring for 0,5bar and use a custom boost controller to play with wastegate in order to achive what boosti want starting from 0,5.I am planning for over 300hp.Do you know another combo cause that M pistons i will never find them.

[Darky]

Hi

I think you will like this
Honda b18c conrods fit 138 mm long but 21 mm pin. So euro s50 86 mm piston 21 mm pin.
Yes you could use stock internals but compression will be to high for that amount of boost. Standard is 10:1

Maybe m44 Pistons there 22 mm pin and 85 mm diameter compared to 84 mm for m42.

Cheers Rohan

[alex230ro]

Hello,you can keep stock engine,just drop CR .The main problem is the engine managament you need an aftermarket solution.
anyway i've asked a firend and a good M42 turbo setup is around 2000-3000 eur.for all other questions Darky has already answer.

[Darky]

HI again
Here's the easiest rather than all that hard work, thicker metal head gasket!
Cheers Rohan

[tm02rmn]

A headgasket from cometics isn t what i am looking about!I want to modify internals somehow,and keep stock headgasket and headbolts new oem,no arp.I was thinking to drop compression ratio to 9.0.1,I have an option to buy forged conrods,forged pistons,arp,acl bearings,but...stock hondas bearings are way better then acl,and about forged pistons wiseco and je conrods ,about1000e,i drived the car for 2000km,with a safe map,exchange oil Eneos,i had the engine limited to 3500 rpm from soft during this 2000km,then remapped and i ve been to drag racing 1/4 mile,first run at 1,2 bar,9.0.1 -11,27sec,second run boom broken pistons and 1 conrod bent,i ve tooked the car to garage,buyed 4 stock pistons,the cheaper i found,about 50e with rings(all4),pistons for 1,8 and putted in 1,6 along with the stock conrods and used oem bearings,same map for the soft,runing for about a year and no problem,so...i understand what forged means,and i understand the ideea of arp's but how strong is the material compared to stock headbolt material?!I read somewhere that some japanese car,doesn like arp,and cometics,and they are back to stock,because head was starting to blow and arp did not make the job that are created for. So like an ideea i want to adjust some old oem parts,because when bmw made that m10 turbo for formula one they said thay the block was 200000km,and it is the best way,because if it was to crack,it hab already been.So i need someone who is good at calculation and combos to tell me,if i keep it stock,how much i have to short the conrods to drop it to 9.0.1(is good this cr?)

[tm02rmn]

Or keep my crank and conrod stock,if they are forged like everyone says about m42,and adapt pistons from some turbo engine like audi 1.8  turbo or so,here in my city it is a guy with m42 that is faster then 1jz at 1/4 mile,and that guy have money for new forhed parts,if i tell you that he have audi 18t injectors wich are 315cc or so,and he cut them,and moded to makr 600cc at 3 bar,do you belive?i did nt but i be searched the oem number on internet and injectors are fron 18 t,so he habe some combo in engine,but doesn t wanna to share the info.like the ones who know to tune motronic.and activate eeprom and make a map for ecu to have both afm or maf and map,he told me that i even have 2 map sensor,one for intake boost,and one to see outside atmospheric pressure to calculate ...but he doesn t want to share. So i will try and see,but i want to build something that theoretical have chance to work,because even with math i will habe a lot of work,bit without math is better to stay off.I want my 18 16 v to beat 1,6 16v honda,both turbo,honda turbo on stock engine with 10.0.1 or 10.5.1 not shure but run with t3t4 china ,0.9 bar

[Tgoode318]

i should have posted this earlier but didnt.. Darky is right! On top of that you need to upgrade all of your bolts etc arp is one option. The stock bolts are incredible weak you can almost strip them by hand. who ever told you not to upgrade to arp is just trying to make money off you

[Darky]

Hi

Tgood 318 +1 thanks

M44 head gasket is 86 mm stock. Yes fits m42, but may need an additional holes depending on who made it.
Don't know why your against metal head gaskets, I think there a must for a boosted engine. Particularly at that level of boost. We use to have to w ring and copper wire things, now it's just so easy.

Yes you could use other Pistons but you will need to calculate a lot of things to get the desired compression ratio. Compression height etc
Then you can select the rods and Pistons.
Saying that just using b18c conrods will drop compression by roughly 1.5. But a lot of maths and measuring and volume calculating/measuring is required. To do this u need them in front of you!

Safe to say as far as ecu goes there are a few people who could tune it, using the existing ecu. But I'd go aftermarket at that level. 1.2 atm is a lot. 2.2 times the amount of air we are breathing.

Remember though intercoolers are your friend and are a must, bigger better, biggest best. That's what generally makes or breaks turbo engines. You must get the heat out of the air!
Otherwise it will self destruct.

Cheers Rohan

[tm02rmn]

A friend of mine have 4 honda b18 forges with arp,new,he told me that he doesn t know if it will match my crankshaft bearings,and another man in my town that make custom hand made headgaskets,he claim that he made for bugatti,maseratti,but when i asked him ig he made for na or fi engines he said that he doesnt know,but he guarantee that if block and head are straightened that will ne no problem with his headgasket,is not metalic in The middle,some material armed,but it have metal plates on top and bottom from 0,20-0,25mm,he can make it from 1,2mm up to 2,4mm,with fire metal rings for the bore,he said that not single one was bad since 16 years that he is in this job,but.....is very is to say anything....doesn t cost you to much to speak!So i plan to turbo stock engine,make the manifold,al The pipes etc,i ce heard that i can run 10 psi,and after that buy all internals forges,arp for crank,conross and head,and a standalone,to make,but gor now is the problem with my turbo,i can t find a decent place to install,on top,i have problem wuth downpipe cause i have to lift het to much as the downpipe to cross yhe top cover but the it is a problem with the hood,i tink yhat u will install her between head and sump,please tell me all the pipes must have the same lenght?do i need to know something for the collector?or i can just cut the old manifild and weld a flange?

[tm02rmn]

Sorry for gramatical,i write from smartphone ,and i have big fingers,i will corect from laptop when i will arive at Home.

[Darky]

Hi

B18c are the right width and diameter for the bottom.
Just a 1mm smaller at the piston pin.

Forced induction engines don't require equal length exhaust pipes it's just nice to have!
Tuned turbo manifolds are very hard with a block tilted on the exhaust by 30 degrees.

Thicker head gasket is just one idea, b18c rods are another.
But goto a larger bore either way, upto 86 mm for forced induction is the safe bet.

Cheers Rohan