2.8 crankshafts

[jaybrand]

just started my 2.8 build .i have machined down my piston skirts and assembled them on 2 litre rods.when i assemble a piston onto the crank and turn the engine over the base of the piston catches on the crank web.i suspect the crank i bought of another zoner is not correct.does anyone no what markings are cast into a 2.8 crank thanks for any help

[ross2009]

is it the eta crank?
and unless youve bored out the block to 86 mm that will be a 2.7
Eta cranks will have either GG or GGG cast into a web meaning cast iron.

[jaybrand]

eta cranks are 2.7 this is a 2.8

[ross2009]

the pistons are hitting caz you should put them on the 325 i rods not the 320 rods there shorter

[ross2009]

i dont believe they eva made a 2.8 crank not in a m20 you can make a 2.8 but with the eta crank custom pistons with eta rods and was bored to 86 mm to make a 2.8

[march109]

Ross what are you talking about?

'They' did make a 2.8L crank its the M52B28 crank, and it works!

No the 325i rods arn't shorter, the E30 325i rods are 135mm the E30 320i rods are 130mm.

Sounds like you have a crank from an M52TUB28 though. It can still be used, I suspect you'll have to aggresivly modify the piston skirts.

[ross2009]

'They' did make a 2.8L crank its the M52B28 crank, and it works!

No the 325i rods arn't shorter, the E30 325i rods are 135mm the E30 320i rods are 130mm.

well for give me if im wrong is this not a m20 thread ???
and you goit me wrong i said you need to use the 325i rods not the 320 rods
read it properly first before you cast judgement

[march109]

'They' did make a 2.8L crank its the M52B28 crank, and it works!

No the 325i rods arn't shorter, the E30 325i rods are 135mm the E30 320i rods are 130mm.

well for give me if im wrong is this not a m20 thread ???
and you goit me wrong i said you need to use the 325i rods not the 320 rods

Yes an M20 STROKER thread, its a tried and tested recipe! Its also what the OP is talking about.

OP is using the correct 130mm rods. (from the E30 M20B20 320i or 320i SE to avoid any further confusion).

Once again its because I suspect the OP has the TU or 'double vanos' crank with larger webs from the M52TUB28 engine rather than the easier M52B28 engine.

[jaybrand]

yhats what i suspected just wondered if anyone had any numbers so i can make doubley sure .my crank has two wood rough keys on the nose if that gives any clues

[march109]

Sorry mate I've never seen both side by side, so couldn't tell you.

Theres usually a part number cast onto a web though opposite end to the nose, post it up someone (usually a 24valve deviant) will know.

[Phatz]

I just thought I'd let you know that I'm also building a 2.8 M20. I'm using 2 litre rods (130mm) and later 325i pistons and I'm still facing the prospect of having to shave about 5-6mm from the piston skirts.

I'm told that earlier 325i pistons are longer and will need a lot more milling off from the skirts than later ones, although my later ones are still fouling the webs.

Chances are I also have an M52TUB28 crank (I've never been able to find out for sure) but I intend to use it still. Shaving a little from the piston skirts is apparntly not a big deal. Maybe you have early "long skirt" pistons?

[march109]

I've seen both pistons side by side and never ever noticed a difference. However with the double vanos crank you'll be shaving either type (if two types do exist).

12valve is the winner boys.

[jaybrand]

im useing early pistons and have taken 14mm off as per the wiki thread .will try a bit more. i am useing 89 320 rods ,89 325 block,and 86 high comp pistons .thanks for the help

[Phatz]

Andrew Everetts 'E30 Restoration Bible' has a good write up on 2.8 builds, thats where I got my info from. Good all round E30 read too.

[march109]

Andrew Everetts 'E30 Restoration Bible' has a good write up on 2.8 builds, thats where I got my info from. Good all round E30 read too.

Thats where my block came from.

[Phatz]

Andrew Everetts 'E30 Restoration Bible' has a good write up on 2.8 builds, thats where I got my info from. Good all round E30 read too.

Thats where my block came from.

You got your block from Andyboy?

[march109]

Andrew Everetts 'E30 Restoration Bible' has a good write up on 2.8 builds, thats where I got my info from. Good all round E30 read too.

Thats where my block came from.

You got your block from Andyboy?

Nah, bought the car from E30Adam, he bought the one that was built for the book, now thats history!

I just cooked the head, so have some work to do befre its back on the road.

[Phatz]

Ah I see. He writes in the book that it was quite an engine. Apparently it broke traction in the first 3 gears in the dry!

Do you mind me asking what the spec is on that M20 now mate?

[march109]

Well spec at the moment is that the head is off and junk so pretty basic! It was;

M20 2.8L block (M52B28 crank, 320i rods, 325i slugs all as per normal)
272 degree Schrick Camshaft
E36 328i MAF
Custom Management
Custom Scorpian Exhaust

Will have the standard head repaired to sell on because I have something better to go on there.

Spec will be:
2.8L block (M52B28 crank, 320i rods, 325i slugs all as per normal)
Billet flywheel
Alpina spec head
272 degree Schrick Camshaft
BTB3 6 Branch manifold
E36 328i MAF
Custom Management
Custom Scorpian Exhaust

Though I have more pressing engine issues at the moment, and no money to do anything.

[Phatz]

Well spec at the moment is that the head is off and junk so pretty basic! It was;

M20 2.8L block (M52B28 crank, 320i rods, 325i slugs all as per normal)
272 degree Schrick Camshaft
E36 328i MAF
Custom Management
Custom Scorpian Exhaust

Will have the standard head repaired to sell on because I have something better to go on there.

Spec will be:
2.8L block (M52B28 crank, 320i rods, 325i slugs all as per normal)
Billet flywheel
Alpina spec head
272 degree Schrick Camshaft
BTB3 6 Branch manifold
E36 328i MAF
Custom Management
Custom Scorpian Exhaust

Though I have more pressing engine issues at the moment, and no money to do anything.

Blimey, that sounds like one serious M20!

As far as I know, an uprated cam and mapped ECU are a given for these stroker lumps, but how did you find the E36 MAF compared to normal E30 setup? Much difference? Any issues?

Reason I ask is that eventually I will be building my engine (once the car itself is sorted!) and I'm just trying to decide on spec. I was thinking of:

2.8 with 2 litre rods and 325 pistons
Possible a 272 Cat Cam
BBTB
Remapped ECU once it's all run in

Fairly mild spec but I'm just after an M20 that is a bit quicker than standard really. May add a stainless exhaust and possibly BTB fannymould at a later date.

[march109]

Never drove it or anyother 2.8 M20 without a MAF so I couldn't compare, it picks up well but that could be down to anything, it really was a great engine,I was gutted when she gave up the ghost.

[Phatz]

Did you ever get it on the rollers before it died?

[march109]

Yup but thats a thorny issue, was at Fritz which read high, made 220bhp on the same day and same rollers IS's were putting down stock power. But it did out pull a 24valve 328i engined E30.

Before that in different stages of tuning it was dyno'd at anything between 198bhp and 210bhp.

I have all the paper work still, makes up quite an interesting history so I won't let it die.

[E30_Crazy]

I have been looking at doing a stroker for a while now. 325i S/S 6 branch (3 into 1) manifold. Scorpion Exhaust. Getting a center silencer delete done this week. When ever I can borrow my friends truck, I gotta run back up north to the guy I bought the car from and pick up a port/polish head. It has german supersport suspension and 17" alpina reps. Was also looking at getting a chip. Heard Speedtouch was good?

Not to highjack, but any suggestions would be appreciated,

thanks,

---Kaleb

[toby]

I don't know if Speedtouch does a 2.8 chip but Ant at A-Tech definitely does.

[goosiegander]

My spec is:
2 ltr block bored out to 84mm,
2 ltr rods,
Facelift (Low compression) 325 pistons,
Single vanos 2.8 crank,
Standard 885 headcasting,
hot-tuning 6 branch,
One of Ian's BBTB's
285/285 degree catcam,
A-tech MAF conversion including mapping of motronic 1.3 to suit,
No clashing issues, standard head gasket used.

Before the MAF conversion it put out 196bhp on gash injectors, i'd consider mine to be a fairly sensible build and i still have the option of strapping on a charger at a later date should the urge take me.

I'd seriously consider giving Ant a call/email if you want a chip or mapping

[jaybrand]

been playing with different pistons trying to get clearance on the crank but its still catching on the crank webs just before tdc.can see on wiki the s52 /m54 crank is longer stroke anybody no what conrods they use with the above crank?. it says they use stock 325 pistons to give 3.0 litres but doesnt give what rods to use. i lathed one piston down to the bottom of the gudgeon pin boss approx 18mm but it still catches. any ideas

[E30_Crazy]

IIRC, I read somewhere that you use 320 conrods... They are shorter, giving the clearance...? IIRC the 325 conrods are 135mm and the 320 conrods are 130mm.

Again, this is all from memory, not me looking it up. The wiki I'm sure explains it.

[jaybrand]

im useing 320 rods at mo.tryed early and late pistons. but still catching,part number on crank is 1439413 any ideas what crank this is from

[E30_Crazy]

No idea, sorry. All the parts catalogs and at schmiedmanns I checked say that "1439413 " is not a long enough number...

[clarko74]

I've got a single vanos M52B28 crank sitting under my desk, here are all the numbers/refs that are on it:





Might be of some help...

[e21Jason]

A S50/52/54 crank will not work in an m20 unless you are talking about the US spec m3 cranks

Jason

[HairyScreech]

i think he is thinking of the m54b30 crank.

the simple way to tell is just measure the stroke of the crank, bung it in with a piston and rod, turn it over and measure the stroke, if your getting 84mm stroke then its a 2.8 crank.

i should be getting my 2.8 TU crank in the next couple of days so i can post the numbers from that on here.

my best suggestion for a tu crank is to use the 135 rods and a modified piston. which im working on atm.

[eta]

Some of the M52 cranks require the piston skirts to be modified I think. The single vanos ones I believe give the best clearance for the pistons and the crank case. I am sure the wiki article explains all this though. The M54B30 crank can be used in an M20 but apparantly you have to attack the crank case witha grinder to get it to clear everything. Pistons will be custom though. Metric Mechanic do this build so its possible

[HairyScreech]

the single vanos is a normal m52, the dual vanos is m52TU, what is said above is correct, the webbs are larger on the TU crank.