M50/52 3.0 Stroker

[Ben 0]

I thought id start a post about this as Im planning

to build an M50 stroker in the coming months.

My goal is to have a High comp N/A M50 engine with S52/S54 power

Im not expecting this but Im aiming for 260+RWHP using OEM BMW parts (besides cams)

If you have any extra info or can correct something I have wrong

by all means add it to the thread cause im sure it will

come in helpful for anyone else thats researching this.

Most of the info I have is for using an M50B25 non vanos

though for the most part it is still applicable to the other

84mm bore M50/52 engines vanos engines.

M54B30 ENGINE SPECS

Pistons.

Bore - 84mm

Comp. Height - 28.32

Valve Recess Depth - .71mm, .76mm

Dish CC (in block) - 17.4cc

Deck to piston @TDC - 3.7mm

Comp. Ratio - Advertised as 10.2:1 in reality its closer to 10:1

Head Gasket

0.76mm (0.030")

Rods

Length - 135mm

Crank

Stroke - 89.6mm

Head

Chamber Vol. - 34cc

M50B25NV

Pistons

Bore - 84mm

Comp. Height - 38.2

Valve Recess Depth - 2.24mm, 2.93mm

Dish CC (in block) - 17.4cc???

Deck to piston @TDC - 1.1mm???

Comp. Ratio - Advertised as 10:1 in reality its closer to 10.1:1

Head Gasket

1.76mm (0.070") Also a 2.05mm available

Rods

Length - 135mm

Crank

Stroke - 75mm

Head

Chamber Vol. - 34cc???

Now with M54 internals used in M50 block with M50 HG I have come to a compression figure

of 9.013:1 based on both engines having the same deck height.

The reason for the low CR compared to the M54 is the M50 HG

is 1mm thicker and this obviously lowers CR radically.

This wont do as I will need a CR of atleast 11.4:1 to reach the desired power target.

So the main problem with this build is finding the correct OEM piston

that will give the desired CR and have deep enough valve recces to

accomodate the M50NV/Custom cams.

EDIT!!!

The M52B28 piston is NOT an option...

Bore - 84mm

Comp. Height - 31.82

Valve Recess Depth - 0.5mm, 2.37mm

Dish CC (in block) - 17.4cc???

Deck to piston @TDC - 0.1mm???

Brings CR to 14.07:1 even with 2.05mm M50 HG

EDIT!!!

Specs I need verified for more solid equations...

M54.

Deck Height

M50.

Deck height, Piston dish cc, Head volume cc, Deck to piston@TDC

M52

Piston dish cc

*Glenn* if you see this aybe you can chime in??

I WILL ADD MORE SPECS AS I FIND THEM!!!

Edited March 1, 2011 by Ben

[thorburn 121]

Glenn might know.

m54b30 crank is the same that is found in the US s52b32 engines.

Is this for a forced induction engine?

Is this your own findings or just a copy of PEI330Ci's info? Just wanting to see if someone else got the same results for the head chamber and piston dish volume

[Ben 0]

Glenn might know.

m54b30 crank is the same that is found in the US s52b32 engines.

Is this for a forced induction engine?

Is this your own findings or just a copy of PEI330Ci's info? Just wanting to see if someone else got the same results for the head chamber and piston dish volume

Na Im wanting high comp N/A I havent added all info yet

This is all from my research but yes PEI330Ci's figures seem to

line up with everything I have found.

[polley 916]

I would use an alloy block, much lighter.

[Ben 0]

I would use an alloy block, much lighter.

Although I do agree I already have an iron block in my car

And in my case saving 20kgs isnt worth the extra money

Ill just take a seat out instead

[Ben 0]

After some thought I think its easiest to shave the block 2.0mm

to get the CR Im after but Im not sure if this is going to be a problem

for the cam chain tensioner to take up the slack.

Does anyone know more about this???

Also can anyone confirm the lift and duration of M50B20NV (320i) cams???

One catalogue Ive read has a listing as 9.7mm@255 OEM replacement

and Ive read in a few other forums that they have a longer duration than B25NV.

Ive been quoted $150+gst for a performance regrind at kelford if the B20 cams arent suitable.

Waiting for them to call back 2mrw about the max they can grind the standard cams.

Whats the max RPM for M50B25NV Head???

(I havent found any consistent figures that Im happy with

though Im feeling 7000rpm should be safe with new parts)

As for the basic engine setup this is what Im hoping to build...

-M50 block (shaved 2.0mm)

-Rebuilt M50 head

-OEM 1.75mm M50 HG

-256/240 or 272/256 cams (re. kelford)

-M54 rods, pistons, crank

-Lightened M20 flywheel

-'Wayney' headers

-3" Exhaust

-M52 Injectors

-Hi Velocity Remap

Using 'Silverfox' M54 as a reference for my expected power output Im wondering if

my initial goal was rather conservative.

Im hoping I could gain an extra 40-50hp on top of the 260whp

If you disagree feel free to tell me im dreaming

This weeks priority..

Clear out garage

Build decent work bench

Next week..

Buy stuff

Do work

Throw spanner

Edited March 2, 2011 by Ben

[polley 916]

A m50b25nv head will rev to 7000rpm easily.

[thorburn 121]

I think shaving the block 2mm is a bad idea.

Have you looked into using m52b28 pistons to up the compression? Otherwise i'd get some new pistons. While your at it you could bore the block a bit as well. Or if money doesn't allow i'm sure the standard compression will be fine (maybe not for the extra 40-50hp though).

I wouldn't use the NV head. Flows less at higher rpm and is full of heavy parts.

What's involved in the regrind? that seems like a very reasonable price. Do they build up the cam as well?

Max rpm from what i've read is about 7200 on a standard head.You can probably go higher but I wouldn't want to be doing the R n D for that. Then you float your exhaust valves and they smash into the cylinder.

Good luck though. Please show a million pictures of the rebuild.

If you've got any spare m54 parts i'd be interested in them. In particular the head

[BM WORLD 1283]

custom pistons about 900-1000us , make them 86mm and as much compression as you can go maybe 11.5:1 etc

should be good for about 160rwkw (about the same as 3L m3 engine)

[CamB 48]

I think your max power is going to be about what the M3 engine had (280-290hp at the crank) - you'll match it if you can get the compression up, similar cams, revving past 7k AND the headers/intake/head flow enough.

Its a big ask.

[*Glenn* 854]

My info tells me the US Spec runs 86.5mm bore, M50 SV block and M52B28 head with the larger valves and different cams. They use the 328i Siemens system & Maf with different programing. Compression heights are the issue...maybe custom forged pistons. I priced a set of genuine US spec M3 3.2 pistons....$4,000 +Gst. Was in the process of doing all the maths and research on this...but life has got in the way ATM. I've got all mine set up on a cradle here at work to get back onto when I can

These guys should be able to sort the pistons out

http://www.importperformanceparts.net/impo...istons_bmw.html

BTW 2mm of the deck is not wise because of timing components according to my engineer. I would also density test or Xray the block before taking it out from 84mm to 86.5mm if you considered going that far with it

Edited March 2, 2011 by *Glenn*

[polley 916]

I wouldn't use the NV head. Flows less at higher rpm and is full of heavy parts.

Max rpm from what i've read is about 7200 on a standard head.You can probably go higher but I wouldn't want to be doing the R n D for that. Then you float your exhaust valves and they smash into the cylinder.

A swedish dude who builds turbo BMW's has said he revs standard nv heads to 8k without issue.

Tho I have seen a vanos head float exhaust valves into pistons around 8krpm~

The NV heads do have thicker valve stems which makes them heavier, and flow a little less. Tho I am not sure how much difference it is, I think it would be very little.

[thorburn 121]

I've read about swedes and germans pushing higher revs but never seen any evidence. Things also get a little blurry when people hook up 4 cylinder tachos to 6 cylinder cars. The revs read a bit higher then what they are. Hence why you see some videos of guys reving the tacho out to what seems like 9000.

Anyways you need the air to be going in to make any use of the revs so this is all kind of irrelevant without intake and head changes. Will there be any btw?

Glenn that is one hefty price. A quick google search and i've found these http://store.vacmotorsports.com/cp-pistons...-kit-p1918.aspx

[polley 916]

I've read about swedes and germans pushing higher revs but never seen any evidence. Things also get a little blurry when people hook up 4 cylinder tachos to 6 cylinder cars. The revs read a bit higher then what they are. Hence why you see some videos of guys reving the tacho out to what seems like 9000.

[Ben 0]

Just so everyone knows, Im trying to make this build as simple as possible.

I dont want

custom pistons, rods or crank

bore the block

aftermarket cams.

This is pretty much a BMW parts bin build.

I will sacrifice some performance to retain OEM BMW parts

(cam grinds and block/head/piston trimming excluded)

Vanos vs non vanos is a tired arguement

Ive owned my NV for 5 years and Ive never thought it needs more drivability

And anyone else thats driven it has always commented on how they love the way it

delivers power.

Considering this car is a weekend/track day warrior, power under the curve doesnt bother me.

Im using the non vanos head as it has the hottest cams for a non M engine

and I can have them modified for my needs at a fraction of the price of aftermarket cams.

Dollar for dollar the NV head is going to make more power cheaper than a vanos

head which would require custom cams to get to the same duration/lift as mine

At least in my situation its cheaper.

*Disclaimer*

I dont think non vanos is better than vanos!!!

I like to change down a gear and ring it out to make my car go

if you like to chug around at 50km in 5th thats your choice

Edited March 4, 2011 by Ben

[CamB 48]

I can't see how you'll get more than 250hp at the crank (refer US S52 which is basically a hotted up M50). But that's just me.

[Ben 0]

I can't see how you'll get more than 250hp at the crank (refer US S52 which is basically a hotted up M50). But that's just me.

'Silverfox' is getting more than that on a standard M54b30 with locked vanos.

I want to use a higher CR, much more aggressive cams, a full exhaust, bigger injectors and higher rpm

(possibly a lighter flywheel also).

If my budget allows ill try to balance everything and lighten and knife edge the crank.

I cant find a flow chart for M50NV vs S50US heads but guys in USA are getting 300+whp

on there "hotted up" M50s with similar setups (cams, CR, zorst, etc).

Im not saying thats what Ill get but its still motivating.

If it ends up being quite peaky powerband Ill just put a auto diff in the back

so it stays in the rpm range

[E30-323ti 66]

I cant find a flow chart for M50NV vs S50US heads but guys in USA are getting 300+whp

on there "hotted up" M50s with similar setups (cams, CR, zorst, etc).

Are you sure about that..... Might pay to double check.

The norm. seems to be ~270-280rwhp, thats with some decent cams (Sunbelt) on a tuned S52B32US.

BMWCCA IP class engines.

Example 1

NB comments re: fully Built S52B32US ~300rwhp

I recall another thread re: WHP of a Euro E36 M3 on here even, and a video of one on the dyno, it put out 187rwkw (~250rwhp) stock, I don't think a BMW parts bin M50B30 with regrind cams and no tuning is going to come up that high (well above what is essentially going to be a S50B30US), even ignoring the area under the curve benefits.

[CamB 48]

Last I saw the one Silver Fox did was about 220hp atw (which is, to be fair, probably over 270hp at the crank and pretty good going). That'll be a full race exhaust though.

http://www.bimmersport.co.nz/forums/index....60&start=60

I'm not saying you can't do it, just that it won't be easy. The S50 Brent is selling will be cheaper...

(edit) Don't forget 3.2 is 6.8% biggerer, so you could roughly deduct that for a 3 litre rather than a 3.2.

Edited March 6, 2011 by CamB

[kerry 10]

i have a m52tu with m50 cams and m3 throttles, im pulling 242RWHP. still got heaps of torque also so any 3.0 stroker has to be good with a good tune etc. good luck.

[Ben 0]

E30-323ti - Ill employ gavin to tune it and cams, regrinds or aftermarket, are going to do the same job

as long as I can sort lash but more on that further down.

CamB - Its cheaper for me to build a B30 by a huge margin and it would be rebuilt as well.

Silverfox's setup is relatively standard, this is a quote from a PM he sent me...

"has standard cams, but with the vanos removed, so they have to be locked off. It is about a 40k engine other than that, no other mods, uses m52 steel std headers, and yes, full m50 loom , ecu, intake etc. Has a full remap courtesy of Gavin at Hi Velocity as well. There are a few other small things you have to do such as modifying the cam sensor wheel, although, going in an E36 does make the bottom end easier.

Only revving to 6500, and m50 injectors, the torque would blow you away, more than factory."

Im taking ^that^ and adding as much as I can to it.

After a long phone call to kelford cams we have come to a conclusion on the max duration

on an M50NV cam without going to a full hard face weld and grind.

Also using the above as a baseline we came up with a conservative

figure for what power could be expected

Cams - +15-20%

CR increase - +20-25bhp

Exhaust - +7rwhp/10bhp min.(according to wayneys dyno figures)

If we say baseline tuned M54B30 is 270hp and use lowest figures for power increase

270+15%+20+10=340.5-15%(drivetrain)

=289.425whp conservative estimate

I still feel thats an optimistic figure

Id be happy with 270rwhp which is s50b32 territory for under 1/2 the price.

[CamB 48]

It doesn't work that way - you'll get more hp from the cams **if** you increase the c/r, not in addition to. Arguably same with the exhaust, unless the std exhaust (and intake - a different issue) isn't a restriction on uprated cams. To put it another way, if you want the 15% on the cams you may *need* to increase c/r, change headers and modify intake. They don't add.

If you do reach that power goal, you'll need new injectors, the remap, all the parts including cams - sounds to me like $000s - maybe not $6500 but you could sell your M50 to cover some of it.

(edit - and the one David (silverfox) did was 220rwhp, so start there - I guessed a higher conversion factor for Gavin's dyno as my 2002 only made 102rwhp, so surely its a big factor, lol).

Edited March 7, 2011 by CamB

[CamB 48]

By the way, I'll be delighted if you can get there - will be awesome :D A situation I'd be happy to wrong in.

[Silver Fox 43]

Hi Ben, I also doubt you can just add all those bits up on top of each other, they are all dependent on each other and need to be in the right ratios to work properly.

I'd love to see what you can get and would also have gone this way if the engine we used hadn't turned up.

My guess would be in the 250 region for rwhp, but let us know what you do, that's what the forum is for, keeps us all interested.

[Jacko 2154]

^ +1 Watching with interest, I wants me a 3 litre twin cam e30

Edited March 7, 2011 by Jacko