My M20 B28 build, 200+ bhp/tq now bits to deal with it

[stonesie]

Well with today being a nice day I decided to make a start on my Rebuild of the Ebay purchase, Advertised as a early B25 out of a 87 touring it turned out to be a later engine with a 88 date stamp on it and 3 snapped exhaust studs

So far i have followed the wiki guide to dismantling the head and it all looks ok in there, no cracks visible and no real ware on anything, not even the rockers so they may be cleaned and re-used

My cameras dead as a dodo so pics will be on here tomorrow, after work tomorrow the heads off to a local head shop, they do good work for reasonable money, the last head i had them re-condition came to £87 (VW 8v head for my old scirocco).

I think this one could run to a bit more than that though

[ricey46]

Sounds good mate, is this for the 2.8 build??

[stonesie]

Yep, if i can find a crank then it will become a 2.8.

I am thinking of leaving it badged as a 320 though, or maybe a 316 should be good for the local boy racers...

There are a lot of things to decide along the way but i think it will be fun

[stonesie]

Well it went off to Headmasters today, I didn't get any pics though as by the time I got home I had 20 minuets to get it there before they closed for the day.

The man say's it looks a good one, nice and flat according to his straight edge and no corrosion in the main waterways , he was not quite so enthusiastic about being asked to remove all the exhaust studs though (don't blame him on that one) Should be back by the weekend

On another note, What is the best way of cleaning the block and alloy part's?
I have had a search and theres a few different methods mentioned...

[blingsta]

i think most people would just use Gunk spray mate and give it a good rinse to wash of all the crap.. then some high temp spray in black !!

[stonesie]

Well no physical work so far and no call from Headmasters, theyre very busy and i made the mistake of telling them that there was no rush

I have been refreshing old knowledge and re-learning how to calculate compression ratios ect and have figured out that simply adding the B28 crank with B20 rods will raise the static compression from 8.8:1 to 9.3:1.
That figure will be refined once i know how much meat theyve had to remove from the head face, but it's got me thinking, it will mainly be running on LPG which is pretty high octane (107 iirc) so would it be worth raising it to a nice round figure of 10:1? it would require a total skim of 0.78 mm so take whatever they take off the head away from that and you have the figure to deck the block by. That would also mean that both faces were as close to perfection as possible.

I have my eye on a sequential LPG kit form a jeep cherokee but is it necessary? or will the single point kit i have now be fine for running a cammed, high comp 2.8?

[daimlerman]

Sounds like you will be a buyer of that Miller ajustable multi map device we were talking about a few weeks ago! Map for LPG,map for petrol,map for 'er indoors...

[stonesie]

Sounds like a plan, I am seriously considering megasquirt so i think I'm going to have to ring Ant and bombard him with silly questions would be rude not to let him recomend and supply a catcam while I was at it.

I might have to come down there and put it up against your 2.7, I've read a few times on here that theres nothing between the two capacitys

[daimlerman]

Will you be built and installed for the end of May? Rolling road day in Scun thorpe...taking both mine...

[stonesie]

Sadly not, im takeing mine as a 320 and want to try for 2 runs to compare it on gas and petrol

A couple of weeks after i have 2 weeks off work so the main lump of work will be happening then, maby 3 days to swap lumps as I have to liberate the conrods from the B20 before I can do much to the B28, im going to get all the prep done so it should go smoothly... fingers crossed.

[daimlerman]

Sadly not, im takeing mine as a 320 and want to try for 2 runs to compare it on gas and petrol

A couple of weeks after i have 2 weeks off work so the main lump of work will be happening then, maby 3 days to swap lumps as I have to liberate the conrods from the B20 before I can do much to the B28, im going to get all the prep done so it should go smoothly... fingers crossed.

Never mind,at least seeing my 2.7 strut it's stuff will be inspiration! And a target to beat...

[stonesie]

I've checked my dates and the rr day is in the middle of my 2 weeks off... That's a conundrum, dare i put a fresh build on the rollers or make the rollers the final flurry of the B20

I've decided to put a wanted up for a set of b20 rods so i can get the thing built, nevermind waiting to pull my existing block to bits, they can go up for sale and don't take up much room

[daimlerman]

Difficult call,I would be nervous about running a freshly built motor up to 6000rpm as well... if you can get a few miles on it and change the oil and you are happy with the way it runs then maybe...you coming to Darrington on the 17th?

[stonesie]

I will be, Wouldn't mind a nose about your engine bay to help me decide a few of the finishing touches

[stonesie]

Well the head is back and looking good to me, it needed 5 exhaust studs drilling out, all 6 exhaust guides and a good clean up, pressure test and skim (6 thou/0.15mm)






Excuse the phone pics, the proper camera still won't hold charge

[stonesie]

Parts have started arriving, well 1 anyway, the lightened flywheel from Hongkongfuey...




I could say it was well packaged but that dosent cover it, took me 5 minuits to get into the thing

I've also be scouring this site for recomendations of what to use to clean it all up and fianlly came across the link to auto express.

http://www.autoexpress.co.uk/products/p ... clean.html

That won this years test, so i googled it and most of the reviews said that it was better than gunk, which i have tried and was not impressed with + the smell lingered for days. I have ordered 2 litres of the comma stuff and will see how it goes

[stonesie]

MORE BITS!

Today I got my Engine stand, that was assembled in double quick time in true bloke fashion... The instructions are still in the bag now.


The crank also arrived courtesy of Dips, It looks well labelled, fragile, heavy, do not drop. It's all there and it still looks like this....


Hmmmmm, will unpack it tomorrow.


With the lump on the stand I set about it and soon had it looking a bit bare, the marks in the bores that I had passed off as 'a bit of muck' turned out to be some scoring (arse) thankfully it's not deep and should be taken care of by a hone.



The pistons should also clean up with no problems I think... It's worth a try.




The bottom end shells were all ok, this is the worst of them but I will probably replace them.

[Ant]

Those pistons are VERY worn on the thrust side

I'd not be re-using them as is for defo

if you must, then use a B20 block, and get the pistons machined down so they are perfectly round, then bore the block and gap the rings to suit the new size, 83.98std, I'd suggest 83.96 as a starting point, dont forget they'll need around 14mm off the skirts to clear the crank @ BDC too.

and please replace ALL the shells and the OIL PUMP, anything less is madness !!

[stonesie]

This low mileage, high comp engine (bah, ebay sellers) i bought it turning out to be a bit of a lemon, I think you will be getting a call tomorrow Ant to help me decide whats best, wouldn't have a spair set of pistons lying about would you?

[stonesie]

Little more progress, Block, crank and pistons are now at the local machine shop and they will get every thing measured up and hone the bores, they said that they would not try to remove the marks from the pistons because they're not suposed to be perfectly round... That goes against what i have been told by Ant, and i know who has a proven record with these engines


They are also making my spacer out of the M52 pully hub and modifying the washer... I hope to hear from them early next week.

[stonesie]

Not much progress but a question about injectors, although it will mainly be running on LPG it will still be run on petrol for 'play time' which will include a run or 3 up the 1/4 mile at York

How much can the standard B25 injectors deal with?

Would i be better finding a set of rover 1.4 injectors? I think ive read on here that on a M42 they can handle 200 ish, so 50 bhp/pot should (in my un-educated mind in these matters) be good for 300bhp so they will be farely un-stressed by the demands my 2.8 will make.

Whatever gets fitted, they will be sent away for Ultrasonic cleaning first.

[StuBeeDoo]

Those pistons look the same as the 2.3 ones that caused me to call time on the project.
Find some more Dude.

[stonesie]

I have another engine arriving tomorrow or friday, this supplier is more trusted so the machine shop have been asked to put it to one side but continue with measuring and polishing the crank.

Ah well, at least i will have a spare head... Just incase

[bss325i]

...they said that they would not try to remove the marks from the pistons because they're not suposed to be perfectly round...

What are they meant to be then, oval?!

Those pistons have had it.

[carannc]

Yep, when cold anyway

[stonesie]

I stripped a 2nd block today and the pistons are in much better shape... And a different shape...



Thats the worst of the new set compared to one of the first lot.

The worst of the new set, I can feel the marks with my fingernail but theyre not deep, should polish out with nothing more agressive than scotchbrite


And the bore's



Now here's a question, with these pistons having shorter skirts will they still need trimming to clear the crank? I cant do a mock build just yet as the guy who was selling me some 320 rods has vanished.

[sweep]

Buy my complete early 320i engine for £50 for the pistons its on ebay..

[stonesie]

I would pete but im rapidly running out of room, It is suprising how much more storage space an engine takes when it's in bits




27/4 edit.

No work today but I did sort out the all important insurance, with a predicted bhp of 210, Brentacre covered it for a few quid less than last year (129 bhp) with a statement of 'don't worry if it's a few over that'

They only charge for mods that increase the power of the car, suspension, brakes, paint and body mods are all things they need to know about but will not affect the premium... http://www.brentacre.co.uk

[stonesie]

Ok

I need to know if a set of cleaned B25 injectors will cope with my plans

I'm working around a headline figure of 210bhp but want scope for a bit more as a safety margin, even though it will be gas powered most of the time it will be entered for some track days too where it will be driven, hard, on petrol


As for actual progress.......
Ive bought a LUK clutch kit and replaced the center bearing and guibo for the prop... The machine shop are dragging thier heals just slightly

Oh and spent just shy of £450 with A-tech

Ant is a legend

[carannc]

My 2.8 pumps out 209 bhp and 215ftlb torque with std injectors running 13afr no problem.

Makes using std motronic with Ant chip much easier.

[stonesie]

Mini update

Not a lot has happened, got the block back from Arnets and they've done a fine job on it, also got a complete set of Payen gaskets. The price of that headset was eyewatering at over £150 retail

They've still got the crank and not machined the spacer though

No big deal, the rods are still at A-tec waiting for the catcam to come in after ants (well deserved) holiday.


So the last 2 days have been spent changing the rear beam, arms and all the brake pipes under there. The diff was a Ebay bargin 3.64 with shagged bearings and had started to cause a strong vibration at anything above 50mph that came and went at random... im sure it was the diff as i have changed the prop bearing and Guibo too (or artic-disc as BMW call it now)

I didnt take any pics of all the nice painted bits and shiney things going on today but heres some of the old bits comeing off...








The big lump of box section was very useful for persuading the beam bushes out of the chassis in 1 piece

[daimlerman]

If I had seen this before Sunday I would have been down on me hands and knees for a look!

[stonesie]

Well you might have to bring your cars to the doncaster one in the meets section thats comeing up , I got the last bits from Arnets today and got bent over by Stratstone BMW for the oil pump and various other odds and ends (£190 + vat for a center box )

Also had a chat with TinleyTech about my lpg mixer, we concluded that it would not have helped my dyno run at all as its too small, so after explaining about my plans hes sending me one with a 36mm venturi to replace the 26 ish one thats on now... Back out there now to put another coat of hammerite on the block

[StuBeeDoo]

got bent over by Stratstone BMW

Stratstone = Pendragon = tossers!

Also had a chat with TinleyTech about my lpg mixer, we concluded that it would not have helped my dyno run at all as its too small, so after explaining about my plans hes sending me one with a 36mm venturi to replace the 26 ish one thats on now...

26mm???
My 2.7 didn't like revving above 4k with the 36mm mixer. May have been something to do with the other issue I have with the LPG at the moment, but now it will rev although it's still weak at the top-end.

[stonesie]

He says that they fit 36mm venturis to 3.5L range rovers with no ill effects, and that he will exchange it if causes me any problems... those rover V8's are not exactly high on bhp but they still shift some air at full chat so im sure it will be fine, he also said that it biggest they can do that will fit on the inlet of a bosch AFM is 38mm