My M20 2.8 Build -BUILT!

[goosiegander]

I want to get building a 2.8 m20!

i have a spare b20 block that is to be bored to 84mm and rehoned,

a 240lb/ft clutch,
a spare recon 885 cylinder head,
all the ancillerys from the b25 currently in the car,

in the process of scoping out a 2.8 crank...
What are the issues relating to the year of manufacture re: vanos?

in terms of management can i chip my b20 ecu instead of the b25? -have one spare...

planning on a 272 camshaft from ireland engineering
-apparently there is no need for a vernier pully as its machined for the standard pully

Inlet manifold
-was pondering a set of throttle bodies with m30 injectors any recommendations?
will there be management issues running with itb's?

loads of other things to consider but thats it for the moment

Cheers all, Chris

[march109]

The vanos cranks will fit the block but need the block to be machined first. The non vanos crank fits with no mods.

You just need to replace the chip in your ecu for one designed for the extra throw of the 2.8 crank Ant can supply this (IIRC) so you can run on your current management.

Correct no need for the vernier pulley.

Throttle bodies will require aftermarket management, and m30 injectors are probably over kill unless you have some other mods planned, from what Ant was saying in another thread the otherday M20 injectors are good to 210-220 BHP, running motronic management, and not mentioning 6 branch of BBTB you would probably be within that.

All your questions have been answered in more deatail in several other threads, I will try find some links for you.

I could be persuaded to part with one of my spare cranks, PM me for price, also its non vanos which is a bonus, sale price is less than I paid!

[march109]

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

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

Another 2.8 Build:
http://www.e30zone.net/modules.php?name ... 78&start=0

[goosiegander]

pm sent!

i do want to go for itb's maybe not straight away but it just appeals soo damn much lol!

have the 6 branch on already,

i have read and enjoyed the other 2 2.8 threads that were running over the last few weeks/months they kicked arse and are quite inspiring

really aiming to get as much out as possible without going too crazy if that makes sense,
MS the answer to this problem you reckon?
Oakey's itb's look amazing!

[march109]

YHPM too. And another on its way because I forgot something!

[Brianmoooore]

The vanos cranks will fit the block but need the block to be machined first. The non vanos crank fits with no mods.

You'll spend a long time looking for a M52 non vanos engine! I think this should read single vanos and double vanos (Tu)

[goosiegander]

lol cheers,

er on the subject of box's my getrag from the 2 litre is spare and was in good order at the time of the first swap, is it worth fitting it with a 3.64 diff for the amount of time it may or may not last?
im undecided as my 2.5 box has the worn layshaft rattle

[march109]

Correct, sorry Brian!

[goosiegander]

also the 2 litre block was redlined when i was having the coolant problems waaaaaayyy back, do i need to be worried about the temper of the metal changing?

thanks!

[jaistanley]

One thing that just jumped to mind.. Is the ireland engineering cam machined with the decked block conversions in mind? If the block doesn't need decking for a 2.8 then the cam should be ground for a normal pulley... I'd get a normal cam and probably a vernier to compensate for any variance in manufacture to set the cams' lift at tdc spec to your exact tdc.... Good practice.

HTH

[goosiegander]

It does indeed, Have fired off a couple of emails regarding the tdc problem,
i was under the impression that the 2.8 crank plus 2 litre con rods and post facelift pistons at tdc required the oversized headgasket for safe clearance? as i stands i was only planning on having a clean up shave on the block,

I think i need to read the bible again...

[Andyboy]

A hot cam that doesn't require a vernier eh? That I'd love to see. You will need a vernier pulley no matter what. Just 10 thou off the block face and the cam timing will be out (retarded). The closer the cam and crank are, the more retarded the cam timing is.
Bored out 2 litre blocks are okay but I'd be happier with a good 2.5 block tbh. double vanos cranks just don't fit without a lot of work. Single Vanos cranks just drop straight in.

[jaistanley]

No you need a pulley no matter what. A vernier pulley is one that has an adjustable range. Like vernier gauges I guess.

[goosiegander]

right thats all understood thanks, i'll be looking for a vernier as well then,

Andy can i just pick your brains quickly on the 2 litre getrag box? worth using?

[ed325i]

I have a crank and spacer for sale.

[Andyboy]

The 320i box will be alright as long as you don't really abuse it. If you do, it will just break. I'd imagine the old lyashaft would rattle a bit at low rpm though.

[goosiegander]

Thanks for that Andy, ed325i have crank sorted now thanks

[goosiegander]

Andy, something else occured to me, could you explain why a 2.5 block re-honed would be preferable to a 2 litre block bored to 84mm?

The cost of me doing this is hardly anything and its easier to use the 2litre lump thats spare instead of sourcing another b25...

[ed325i]

instead of sourcing another b25...

I have a good 2.5 block you can have if you pick it up.

[goosiegander]

Much appreciated dude! hmmm, just thinking if i have appropriate means of transporting it, what size vehicle would i be looking at to move said lump?

[ed325i]

Its only the block so it would go in the boot of an e30.

[Beavy_OZ]

any progress on this?

[reggid]

A hot cam that doesn't require a vernier eh? That I'd love to see. You will need a vernier pulley no matter what. Just 10 thou off the block face and the cam timing will be out (retarded). The closer the cam and crank are, the more retarded the cam timing is.
Bored out 2 litre blocks are okay but I'd be happier with a good 2.5 block tbh. double vanos cranks just don't fit without a lot of work. Single Vanos cranks just drop straight in.

+1

The catcam cam i just got required 20* crank advance (10* on vernier) to get the intake and exhaust lift at TDC about the same at 4-5mm. With no advance it was about 2mm int /6mm exh which would have smash the pistons had i not checked. i believe it is a misgrind since it was supposed to be about 2.75mm int /2.05mm exh with no advance or retard, i won't use it of course.

[goosiegander]

Right im cracking on with this now, the bits are at the machine shop.

spacer being made up
block being bored to 84.00 mm
low compression pistons on order -cheers theo!

no decking of the block rqd

some more questions if i may...

Which cam profile do i use for decient drivability? dont want all the power at the top end...

with standard bores and cylinder height what do i need to ideally do about clearance?
(is it the 325e h-gasket for safety as described by Andyboy)
...and how will the clearence affect comp ratio?
...again is it something to worry about?
...ps will it be low enough for a supercharger at a later date?

that was bit of a rambling mess lol! -hopefully someone has an idea or two

I really appreciate the imput chaps,

pps Gareth that crank was perfect -link to your feedback?

Cheers guys, Chris

[reggid]

if you want to go FI (by the sounds of it you do) then use a stockish cam, otherwise a 284/272 or lower schrick will be quite torquey with a 2.8 bottom end and a catcam of similar duration will offer a bit more topend if you want a proper NA build. Whatever you do decide if its to be NA or FI otherwise the build will be less than ideal for either

[BadDave]

I've inquired about the CR on this a while back and it turns out to be "about" 9.3-9.4:1 depending on how much of a skim there is on the head/block

You'd probably be ok witht the charger if you don't run too much boost

I've already been discussing the option of decking B25 pistons to drop the CR a bit to make it nearer stock M20B25 with the intention of turbocharging in mind

HTH

[goosiegander]

It does indeed help, thanks dave and reggid.

With a mind to supercharging, i dont want a lot of boost, i want to be able to build a decient 2.8 and not worry about rebuilding the internals again in order to strap Ant's charger.

Surely there is a middle of the road option for a cam thats going to be ok for the na and later sensible charged option?

[BadDave]

If you build it with FI in mind rather than"it's just going to N.A for now" then it'll save you having to do certain things twice, like welded water jackets in the head,uprated head bolts or ARP stud and nut conversion etc

[maggspower]

I think the thing you need to do is realy have a think and decide what you realy want, a build that will be suitable for both n/a and f/i will be compremised at best. You also say you dont want much boost, it sounds like you want a bit of every thing.

I have found the key to building engines is to be specific about their charecter, tree stump pulling torque, high reving nut case, low pressure turbo, or boost monster

focus on what you want from the engine, manufactures make engines that are compremised, and we always want to change them dont we

If you pin point what you want yor engine to do, and do it, you will be much happier with the out come i think

cheers maggs

[goosiegander]

Bottom end built and ready... Hooray!




but what is this bit for?

[goosiegander]

and yes i know the mount is on upside-down, wasn't me

[goosiegander]

anyone?

[JazzMan]

err not sure, what does the other side look like?

[carannc]

There as something similar in my gasket set. I never used it

[goosiegander]

well the order has been placed for the catcam and engine management chip from Ant.

For those of you interested this is the friendly local machine shop that has been doing the hard work

http://www.cylinderheadsdirect.com/

well worth a look...