M20 2.8 build - 328iX

[tomson]

The spacer that is needed to fit the M52 2.8 crank into the M20 block, what is it machined from please, is it a part from the M52 lump ?

[march109]

oooh you building one?

I just gave a machine shop the specs and they made it up, actually I just dropped in the block and crank and left them to measure it too.

[tomson]

oooh you building one?

I just gave a machine shop the specs and they made it up, actually I just dropped in the block and crank and left them to measure it too.

Im seriously thinking about it

Could you get another made or was this ages ago?

[march109]

twas a while ago, any decent machine shop should be able to do it, or contact someone building one now and get two made, though I would prefer it to be made to the tolerances of the crank you are matching to the block don't know if it makes any difference but can't hurt.

[tomson]

Yes, I would tend to agree with that. Do you know what is is machined from?

[march109]

sorry nope, left it up to the experts to sort.

[Brianmoooore]

It's made by machining the front off the chain sprocket from the M52 crank.

[DanThe]

Isnt it the front pulley thats used?

Thats what I get asked for anyway

[tomson]

Isnt it the front pulley thats used?

Thats what I get asked for anyway

Got a spare Dan?

[Brianmoooore]

Isnt it the front pulley thats used?

Thats what I get asked for anyway

Fingers not typing what the brain is thinking! Yes, the seal is machined from the front pulley, as that's what it's part of, not the chain sprocket.

[tomson]

Isnt it the front pulley thats used?

Thats what I get asked for anyway

Fingers not typing what the brain is thinking! Yes, the seal is machined from the front pulley, as that's what it's part of, not the chain sprocket.

Good so the front pulley is needed, I'll check if the vendor still has this

Is the crank bolt specific to the M52? I cant imagine one new from BMW is a lot anyhow.....?

[ed325i]

[daimlerman]

We could do with having that drawing in Hoshy's wiki thingy for future reference.Perhaps the OP could keep us all informed of his progress,please.

[tomson]

We could do with having that drawing in Hoshy's wiki thingy for future reference.Perhaps the OP could keep us all informed of his progress,please.

Certainly sir, although is something (else ) that I'm toying with atm

[hoshy]

Ok - we already have "building a 2.8 page" Can we maybe get some info in it? I've put that pic up already.. I assume the copyright owner is happy with this as it's already been posted in the public domain.

http://www.e30zone.net/e30zonewiki/inde ... ding_a_2.8

[march109]

M20B28 crank oil seal
M20B28 further resources
M20B28 technical

ect ect....

As long asits linked and has text tosearch through it will be indexed and found properly.

[tomson]

After reading the threads about the 2 most recent M20B28 builds it appears there are different types of M52B28 cranks, some need the pistons shaving, others dont.

I have sourced a crank and the vendor said this -

"The engine is a '96 M52 with nikasil liners. It ran smooth enough but burned too much oil and was down on power. I found a complete donor so swapped the engine and gearbox to make my car a manual at the same time. The engine was replaced under warrenty, I'll look to see exactly when, I know it was early on though as they fitted another nikasil block"

Anyone got any idea's which crank this may be ? ?

[march109]

most likely it is the non-TU and hence single vanos, ie one which doesn't need the block or piston mods.

[tomson]

It is from a single vanos donk, so that means just fit it straight in with no decking to the block/shaving of piston skirts?

[march109]

It is from a single vanos donk, so that means just fit it straight in with no decking to the block/shaving of piston skirts?

correct.

[tomson]

It is from a single vanos donk, so that means just fit it straight in with no decking to the block/shaving of piston skirts?

correct.

Happy days, I'm going to build this then.

The iX will be getting a fresh 2.8 with M5 ITB's etc etc

[beardymat]

It is from a single vanos donk, so that means just fit it straight in with no decking to the block/shaving of piston skirts?

well if youre being pedantic there is a slight difference in piston height at tdc as iirc the throw is 8mm longer but the rods are 5mm shorter so it leaves the piston slightly short. i have a freshly built 2.8 on an engine stand which was built alongside templ8e30`s and we both had the blocks decked as it seemed to make sense not only on the compression ratio front but also to get a nice new flat face on the block`ian also spoke about squish and other nonsense i am totally oblivious to

looking forward to getting the thing in now, need to know more about the M5 throttle boddies too so dont keep it to yourself

[tomson]

It is from a single vanos donk, so that means just fit it straight in with no decking to the block/shaving of piston skirts?

well if youre being pedantic there is a slight difference in piston height at tdc as iirc the throw is 8mm longer but the rods are 5mm shorter so it leaves the piston slightly short. i have a freshly built 2.8 on an engine stand which was built alongside templ8e30`s and we both had the blocks decked as it seemed to make sense not only on the compression ratio front but also to get a nice new flat face on the block`ian also spoke about squish and other nonsense i am totally oblivious to

looking forward to getting the thing in now, need to know more about the M5 throttle boddies too so dont keep it to yourself

Right, I did kind of have in the back of my mind the block would need a slight shave for optimum CR/power. I have a very good engine shop in Bristol who I know the owner personally and have been using them for over 10 rears so I get looked after very well. I will probably just give them all the bits and get them to build up the bottom end doing whatever they think is necessary. I will build the head up and run it in then off to Circuit Motors to get the ITB's on and remapped

Need to make a decision if to have any headwork done, this is something I know little about, I hear Bexley's do a good job ?

These are the ITB's

http://www.e30zone.net/modules.php?name ... highlight=

[Beavy_OZ]

Can I interject and ask whether the block will need to be decked/shaved if you use the higher comp 2.5 pistons? I am one phone call away from sending my B23 to be bored to fit 84mm pistons and an 84mm crank *grin*

[tomson]

Can I interject and ask whether the block will need to be decked/shaved if you use the higher comp 2.5 pistons? I am one phone call away from sending my B23 to be bored to fit 84mm pistons and an 84mm crank *grin*

See beardymatt's post above, yes I believe it will very slightly although its not essential from what I've read. The way I see is do it properly 1st time, I'm going to have a 2litre block bored out to 84mm so essentially I'll have a brand new block so far as wear to the bores goes.

I am using the early high compression slugs also......

[tomson]

This is going ahead now, I recieved the crank this morning

I know I need to use 130mm rods of which I have plenty in amongst my scrap but are the M52 one's better, does anyone know? I think they are a tad lighter no?

[tim_s]

sorry to crash the thread, but what engine builder you on about tomson?

[tomson]

Padfields Tim, by Temple Meads station....

[beardymat]

i seem to remember the m52 rods being the longer type as it uses different pistons instead of shorter rods. Danthe has a lot of experience with these so should be able to confirm.

My engine still isnt in

[Andyboy]

24v rods are all the long type, even 2 litres.

[tomson]

24v rods are all the long type, even 2 litres.

Thanks Andy