CR24v Custom M52B30 FTW. New Exhaust, New gearbox and Fan.

[Dezzy]

1100kg mine I reckon. No aircon or any of that amp nonsence.

Bring on the S50 donks Dan I say.

[Jhonno]

Those S50's are just overrated anchors, not a patch on an iS's handling characteristics

Molested M50's FTW

S50 FTW

[bss325i]

Those S50's are just overrated anchors, not a patch on an iS's handling characteristics

Says the man with an iron block.

[Simon13]

so......are S50 B30 slugs bigger than the normal 84mm then to get upto nearly 3.0 litres?

[Dezzy]

so......are S50 B30 slugs bigger than the normal 84mm then to get upto nearly 3.0 litres?

M52 2.8 crank
S50 86mm pistons

2.926cc

[DanThe]

Those S50's are just overrated anchors, not a patch on an iS's handling characteristics

Says the man with an iron block.

S50's weight is all up top, my donk is under 20kg heavier than an M20

[Simon13]

and the rods? 135mm M52 jobbies? And the block looks to be bored out M50 one. M50 head on this with 2.5 inlet?!

How are you going about getting it running properly ECU wise?

[Dezzy]

It's standard M52 crank and rods, bored out M50 block, decked by 0.5mm, standard head (new oil seals) and shrick cams. M50 inlet with big bore throttle body and uniQ piggyback management. Compression should be 11.1

[bss325i]

Standard M50 head or M52 head?

[Dezzy]

Standard M50 head or M52 head?

Early none vanous M50 head.

[Simon13]

Why no vanos? how come you decked the block? Is there adjustment in the cam sprockets to allow for it or something?

[Dezzy]

None vanos because it an early M50 motor, 0.5mm off the block to increese comp ratio, there is ajustment in the chain sprockets yes.

Why the grilling do you fancy building one? If you do you will need custom
little end bushes making.

[Simon13]

its not a grilling i'm just interested in it so i have to ask these questions! Little end bushes no problem my old man makes these sorts of things for his race bikes so these shouldn't be a problem

[Dezzy]

In fairness it wasnt a problem in the end. £20 a bush made from Phosphor bronze. I enquired first to see if I could get any off shelf item. No go. Rang mahle and was told they make custom bushes out of bronze, they can do it but would be cheeper to get it done local.

I started out with Lee's (E30beemerlad) old M50 out of the touring.
It was unknown milage so I stripped it. It look really clean inside but I wanted something abit special.
I loved Dan's chromie and wanted a simular engine myself. I might add he has been a star with help research etc. I think I am the first to build this spec M50?

Block was bored from 84-86mm leaving 5mm between borers.
Then I checked the height for top of piston on tdc to block top. Dan worked out that I wanted 3mm including gasket thinkness for 11.1 c/r.
Turn's out the block needed .5 off it to achieve this.
Then bottom end was ballanced including crank, rods, clutch cover and lightened M20 flywheel.
Then I fit M52 crank. Then S50 pistons with M52 rods.
I am using a 6 paddle clutch.
New oil seals in the head and bob's old shrick cams.
I am using M52 exhaust manifold with standard twin e30 325 exhaust.
Inlet is M50 and enlarge M50 throttle body standard M50 airbox too
Instead of using M50 psteering pump, altinator and oilfilter housing I am using M52 mainly because I am a tart.


This is by no means the easiest way to get B25 up to B30 I bet but it my way and unless I am mistaken I am first to do it.

I get the head back tomorrow as my mate is sticking oil seals in as he works for BMW and can use there head table.

Think that's it apart from the hole thing will be ran by uniQ which I am hoping to find someone to live map

[DanThe]

Have you finished bolting the bottom end together yet you tart!

[Jhonno]

You are the 1st I believe.. It will be a monster when done. What is the spec on the cams?

[Dezzy]

Have you finished bolting the bottom end together yet you tart!

Would you believe no. Customers with fooking flat and bald Tyres grrr. I have the new rod bolts ran up. Just twitching about torquing them. Tomorrow I promise.

[Dezzy]

You are the 1st I believe.. It will be a monster when done. What is the spec on the cams?

Lee did tell but I can't remember Dan do you know if not ask bob for me mate please.

[bss325i]

Thats an impressive spec!

What head gasket are you using?

[DanThe]

He has an S52 gasket Barry, I cant remember the cam specs but they turned Bobs M50 into a real screamer

[Dezzy]

As Dan said S52 American M3 gasket, part number 11121405106.
Luckly they are exactly the same as M50 with 86mm bores.

[Simon13]

My opinion re exhaust is that a M20 2.5 exhaust isn't good enough for your spec and will cost you power. The pipes are way too small 44mm. e30 Alpina/e30 M3's used 50mm.

But the Alpina exhaust on my 328 e36 is 55mm I'm no exhaust engineer but a bigger bore will get the back pressure down and let it rev better at higher RPM's

[billgatese30]

but too big of a bore on n/a engines can also loose you torque low down I believe as the scavenge effect isn't as effective.

[Dezzy]

I may look into the exhaust at a later date. I chose to stick with standard mainly to keep it looking sleeper.
Maybe remove the middle boxes and use E36 backbox?

Cheers for all the advice guys.

[DanThe]

Soon as I can I will get mine on a dyno, ive got an M3 system to fit so will dyno it again after

[Dezzy]

You would have wouldn't you grrr.

Would be good to know what sort of gains the m3 exhaust makes.

I have a full m52 exhaust to bastadise so could use the bbox off that with the larger dua pipes and still have a standardish looking system.

[Dezzy]

On the exhaust topic, one of our customers who specializes in vw conversions (20v turbo golfs etc) always uses
http://www.aas-exhausts.co.uk/

They are based in Newcastle and says they are amazing. They can tune exhaust note to my taste, make anything including manifolds and out of stainless or titainium.

If I was to get them to make me a manifold back system with twin middle box's and a twin in twin out rear box in the same style as origonal, with twin diagonal tail pipes to look factory, what size bores should I go for?

I was thinking twin 52mm would be about right?

Chris you ever herd of A A S? They are from up your way ish?

[DanThe]

50mm is plenty IMO, and a standard size so would be better priced

[Dezzy]

2" mate. Ok will look into it.

You get that envolope?

[Dezzy]

Slight progress today. Everything is torqued down. Oil pump and E34 oil pick up pipe fitted. New oil seals fitted to the end plate and flywheel seal. All old gaskets removed. Faces cleaned ready for the sump to go on tomorrow. End plate gaskets, do they need gasket seal or can I just use greese?

Tomorrow hopefully I will have this biatch ready for the head to go on. Getting a pan handle just thinking about it.

[E30BeemerLad]

good work mate

What's the plan once the engine is built? Are you gonna finish the 4dr first or start the chromie molestation?

[Dezzy]

Yes mate. The moredoor is getting worked too. I if can drag my arse out of bed tomorrow it might be running.

Then it's just interior and rear shocks and brake's. Mot soon then run that while I molest the chrome cart. Then it will be for sale and I will hopefully pay some of my debt

[DanThe]

Gaskets should be fitted dry, you only need gasket sealer on the joins to the chain cover and rear oil seal carrier

[Dezzy]

I was ment to be working but managed to do a little bit today. Just need the head now and we will be there there abouts

Bottom end all torqued down, fitted oil pump and E34 pickup pipe.



Cam chain cover and flywheel seal.





Sump fitted too





I know it just looks like a normal M50 block and its been seen 100 times but finally getting somewhere





Just need the head on now and we are in business

[Jhonno]

Come on.. Chop chop..