E30 M3 minor rust repair (few finished pic's)

[x-works]

the chamber is now exactly full of fluid........



and when we checked the graduations on the burette we could see exactly
how much fluid it took to fill the chamber. And hey presto, you now have the volume of
one combustion chamber.
(Now that was some fancy shit wasn't it? While I'd love to take the credit for thinking up this
stuff myself, I have to thank Jake over on S14.net for that method. The way I used to do it
took a lot longer and was a lot messier.)
One little thing to be careful of before we go on is about reading the burette.
When you fill it up originally the fluid doesn't lie flat in the tube, but rather
curves up at the edges. You need to be sure your reading the level either from the
top of the "curve" or the bottom when you fill it and the same again when checking how much has come
out afterwards.........



the test is done 3 times on each chamber and then an average reading taken for
each for each to avoid fu*k ups, sorry, "inaccuracies", making sure the chamber is totally
dried out between each test..........



One other thing thats worth keeping an eye on while doing this
is the fact that you shouldn't see any fluid leaking past the valves and out the ports
during any of this. If you do, you need to check your valve's and their seats, as, if
they just been freshly cut and lapped in, then they should be sealing against
any fluid leaking past......



With all the combustion chambers checked, the average figures came out
at:
cylinder 1 - 42.7cc
cylinder 2 - 43.0cc
cylinder 3 - 43.0cc
cylinder 4 - 42.8cc

Only a difference of 0.3cc between chambers.
Now a normal person would be happy with this as most cylinder head tech
articles advise balancing to within 0.5cc. But, if you've been reading this thread
long enough you already know whats coming next.

The "drip" beside the 1 euro coin below is an example of what 0.3cc volume looks like,
this is roughly what I'd to remove from two of the chambers to get all three balanced to
43.0cc.......



head surface gets masked up with some heavy foil tape to protect it from
any c*ck-eyed blows from the Dremel grinder...........



some old valves are loosely fitted to protect the freshly cut valve seats from damage
and the areas to be "buffed" get shaded a nice shade of blue.......



head is set up at a comfortable angle to work the Dremel......



and then the blue areas are lightly ground with a 120 grit disc.....



before being finished with 400grit.......



a few hours grinding and remeasuring had all four chambers reading 43.0cc.....





theres a good chance, even if you lead a long life, that'll you'll never witness a better
example of Obsessive Compulsive Disorder, I'll do well to finish this build without ending
up with a nervous twitch..........



And, thats about all for tonight. Next on the menu is custom pistons and why I chose to
abandon the money tree's and go straight to printing my own counterfeit money.
Till then..............

[darren_mk]

You are a legend Sir!!

Cant wait to read about the piston choice.

Will it be ready for the Big meet in June time?

[Royalratch]

This thread needed a Lightning Bolt as a symbol if it's epic awesomeness.

[Dezzy]

This thread is the best on here!!!

I wish you would stop updating in white.

On my laptop its bad enough. On my iphone its a nightmare

[x-works]

Thanks for the kind words folks, as always, they're much appreciated.

darren_mk
Will it be ready for the Big meet in June?

As much as I'd love to be finished it for the meet, I don't see it making this one.


Dezzy
I wish you would stop updating in white.

I honestly didn't know this was an issue for people, I think it's been in white since
the start. Would people find it easier to view if the text was the default colour?

[Dezzy]

Dezzy
I wish you would stop updating in white.

I honestly didn't know this was an issue for people, I think it's been in white since
the start. Would people find it easier to view if the text was the default colour?

I have been following it from the start mate. It might only be me thats having the problem. I love the updates but wish i could read them easier.

[beemerbird]

White is good. You can filter the awesome (yet indecipherable in my case) knowledge from the general chit chat

[Dezzy]

White is good. You can filter the awesome (yet indecipherable in my case) knowledge from the general chit chat

I agree the updates should be a different colour. Maybe red or blue though. Its hard enough for me to read at the best of times

[beemerbird]

White is good. You can filter the awesome (yet indecipherable in my case) knowledge from the general chit chat

I agree the updates should be a different colour. Maybe red or blue though. Its hard enough for me to read at the best of times

No comment

[kman82]

No stick with White. Looks fine this end and stands out from the rest

[Kedge]

Epic updates as usual! I know your more than likely have told us earlier in the thread but what do you do for a living? The detail your getting into here is mental.

Also what are the rest of you doing to be able to read the white text? I'm with Dezzy on this, can only read it by highlighting it

[Brianmoooore]

The problem is that we have two versions of how the zone is displayed - the old 'fisubice' version, which has a brown background, and the newer 'liteside' version which has a white background.
The 'normal' colour text shows up as an off white on the brown background, and black on the white background.
White text also shows OK on the brown background, but, unsurprisingly, is invisible on the white.

[Dezzy]

^^^ That's why I could read it before. Once I changed the back ground I have struggled. I never twigged.

[dn808e2]

can it all be reprinted onto paper , and how much it will ruffly cost

[darren_mk]

The problem is that we have two versions of how the zone is displayed - the old 'fisubice' version, which has a brown background, and the newer 'liteside' version which has a white background.
The 'normal' colour text shows up as an off white on the brown background, and black on the white background.
White text also shows OK on the brown background, but, unsurprisingly, is invisible on the white.

Thats why i switched back to brown 'fisubice' version, as i couldnt read the updates on this thread!

[kman82]

Oh I see, different colour backgrounds. I have on several occasions looked back over the thread to see how a suspension strut goes together for example and the different colour text is really useful to make x-works posts stand out.

It has been said before but I seriously think x-works should consider publishing this when finished! I for one would buy a copy

[x-works]

I spent a while there this morning trying out the two different colours of
background and I can see the issues the white text is causing some of you,
unfortunately, there doesn't seem to be any simple solution. When I tried the
different colour options available for post fonts I couldn't come up with one
that works well on both colour backgrounds.
So for the time being all I can suggest is viewing the posts with the brown background.
Although it's inconvenient it is only 3 clicks of the mouse to switch.
If anybody has an easier solution I'd gladly listen.

I know your more than likely have told us earlier in the thread but what do you do for a living?

Served my apprenticeship as a HGV mechanic and have worked ever since on these.......

It has been said before but I seriously think x-works should consider publishing this when finished

can it all be reprinted onto paper , and how much it will ruffly cost

Hope to try and offer a full version on a DVD when the finale comes should folk want it.

[Dezzy]

Mate just keep the updates coming. Now I know it's the background it's easy solved.

[x-works]

Chapter 52: Custom Pistons and the road to financial ruin.
In this exciting episode we'll be revealing the closely guarded secrets of how to f*ck up a
custom piston order, quickly followed with a "how to" guide on using a kitchen bread knife
to remove a kidney with a view to selling it on ebay.
But, before we get to that, it's probably best we deal with question of why we wanted custom
pistons in the first place. Below is a picture of a Mahle standard piston for the S14 M3 engine.
If you should happen to wander in to your local dealer with a pot of gold large enough,
four of these little carefully machined slugs of aluminium can be obtained...........



So, why didn't I use these? Three main reasons really, increase the valve relief's,
changing the engine's compression ratio, and reducing piston weight, and of course not forgetting the most
important of all, my seemingly unavoidable irritating habit of complicating everything.

Valve relief's.
Due to the design of the S14 engine, the valves come in quite close proximity
to the top of the pistons while the engine is running and as such the top of the
piston has 4 little valve relief notches cut out of it to avoid any disastrous contact
between the two..........



When running standard diameter valves and standard lift camshafts all this works
as it was designed too. However, when (like I am) you change to oversize valves and
higher lift camshafts, these relief's cut in to the top of the standard pistons are usually
insufficient to offer the proper clearance any more. The Schrick 284 degree inlet and 276 degree
cams being used in this build can be considered relatively mild in the large scope of whats available
out there for this engine, and as such seem to be right on the border of being usable with standard
valve relief's.
As a guide Schrick recommend a minimum of 1.5mm clearance between valve and piston at their
tightest point. I'm not 100% sure that you'd run into trouble if you were just running the higher lift cams
mentioned with standard diameter valves. Some folk report no issues with running them,
while others report problems when the valve to piston clearance is measured upon assembly.
What is probably clear from that is you should at least take the time to measure the clearance when assembling,
as the "f*ck it, it'll be grand" approach could end up being expensive down the line should the pistons and
valves take a notion that they'd both like to occupy the same space at the same time.

I had no such worries however as when you add in the larger valves I'm running I was pretty confident that
the end result would be mass suicide should I have tried to use the standard pistons.
So, reason number 1 for custom pistons = larger valve relief's.

Raising the compression ratio.
In the last section we touched briefly on the subject of compression
ratio when we balanced the volumes of the combustion chambers in the cylinder head.
The piston, or more precisely, the top of the piston, has a dish in it (coloured red below).
With a custom piston you can alter the volume of this dish and as such change the compression
ratio of the engine............



I find myself ideally suited to offer a simple explanation of what compression ratio is,
as I haven't half a f*cking clue myself. But, since that small fact hasn't seemed to stop me
anywhere else in this thread I shall now continue the fine tradition.
Static Compression Ratio, at it's simplest, is the ratio of all the volume in the chamber
when the piston is at the bottom of it's stroke (all the area you see as green below).........



compared to the volume of what it all gets squashed into when the piston
comes to the top of it's stroke........



If the volume of the green area in the top picture were 300 cubic centimetres (cc) and the volume
of the area it all gets squashed into in the second picture was 30cc, then you'd have a
compression ratio of 300 : 30 or simplified down, 10 : 1.
As a very general rule of thumb, the tighter you pack that volume when the piston squashes it,
the bigger the bang you'll get, thus, the higher the compression ratio the better the power output
from the engine. Everything thing else being equal, an engine with 11 : 1 compression ratio will
normally produce more power than an engine with 10 : 1 and so on.

So, just wack up the compression ratio and we're good to go? Well, unfortunately it's not quite
that simple. When you reduce the space that the piston squeezes all the mixture into, the fuel/air
mixture obviously now gets compressed a lot more. The side effect of this is the more you compress
the mixture the hotter it gets. If you go too high with the compression ratio, and compress the mixture too
much, the temperature in here gets so high it can spontaneously explode before the spark plug even
has a chance to light the fire.
At this stage your into the wonderful world of detonation (also known as "knock"), the results of which,
if severe enough, can destroy engines in seconds.
So, the trick seems to be, raise the compression ratio as high as you can to reap the rewards of bigger
horse power, while trying not to go too high where the dreaded detonation becomes an issue.

If you look at the (fantastically detailed) diagram below you can see the area the mixture gets squashed into
is made up of the combustion chamber in the cylinder head,
some of the head gasket volume(the brown bit)
and then the dish in the piston makes up the final piece of space.......



By making the dish in the piston smaller we can reduce the space the mixture gets squashed into,
and, as such, compress it a little tighter which will raise the compression ratio.
But before we could start figuring out what volume dish we wanted in our new pistons
we first had a few decisions to make.

[x-works]

This engine is being built to power a day to day road car as opposed to a "balls to the wall" all out race motor.
And as such I've decided to shoot for a compression ratio of 11 : 1, which should be well enough inside the
"safe zone" that detonation won't become an issue, but still provide a little bump in hp over the 10.5 :1 compression
ratio the engine originally left the factory with.

So with the target set at 11 : 1 the first thing we needed to do was find out what compression ratio the standard
pistons would give us, and then hopefully from this we could figure out what modifications to make to the new pistons
to arrive at 11 : 1.
To do this we first need to know the volume of that dish on top of the standard piston,
so the piston is assembled onto a conrod and instead of fitting a piston ring
we use some rubber o-rings to seal the piston in the bore..........







then the piston and rod are fitted into the cylinder and bolted up to the crank.......



As we're going to be using fluid to measure the volume of the dish in the piston crown
the next step is the same as what was done on the cylinder head earlier. Get it all 100% level.........







with everything level the next step was to drop the piston down the bore a known
amount. To do this we set up a dial gauge and zero it on the deck surface of the
block...........



Then move the needle onto the raised circumference of the piston (not in the dish),
and rotate the crank till the piston drops down 3.00mm from the surface of the deck.........



From our bore measurements taken earlier we know that the diameter of the bore is
exactly 3.6950" or 93.85mm, so now we can figure out the exact volume of the space
between the top of the piston and the surface of the deck (the red area below)..........



using the formula for the volume of a cylinder, pi x radius squared x height, the volume
of the red area in the diagram above comes out at 20.7cc.
So what the hell did we do all that crap for?
Well when we fill up the hole with fluid in a minute, we now know that it takes exactly
20.7cc to fill up the red area and anything over this must be the volume of the dish in
the piston..........



So, with the nail rig in place to indicate when the holes full, the burette is again filled
and the tap opened........



When the fluid reached the tip of the nail, the tap was shut and we read off how much
fluid it took to fill the hole. Which was 29.3 cc. So subtracting the 20.7cc (red area) from earlier
the 8.6cc we're left with is the volume of the dish in the piston.

With this info and a few more little measurements we could now figure out what the compression
ratio would be with these standard pistons fitted. I'm not going to get into the formula's and
calculations end of working out the compression ratio here, as, well, it's boring. And with porn only
ever a click of a mouse away I reckon there'd be an echo in here after a short while.
What I will say before we move on though is I came across a great bit of software to help
with the calculations if you ever find yourself doing something similar. Its by a crowd called
Performance Trends and is downloadable here http://performancetrends.com/download.htm#crc

[x-works]

After doing all the calculations we found that, if fitted, the standard pistons would have given this
engine a compression ratio of 10.5 : 1 , and after flogging the last few remaining brain cells I have to
within an inch of their life, I then managed to figure out that the new pistons would require a dish of
of just 7.5cc to raise the compression ratio to 11.0 : 1 . By this stage we'd finalised all the dimensions
for the new pistons, and were ready to place the order. We had decided to go with JE Pistons and instead
of going straight to JE themselves with the order we were going to use one of their agents as the price was
going to work out much the same and it gave us the opportunity to have a second set of eye's, as it were,
to look over the spec's and make sure they'd result in what we wanted.

So just to recap, standard pistons look like this..........



new pistons would look fairly similar as the only adjustments being made were the
valve cut outs being deepened and enlarged a little and the dish in the piston being
made a little shallower. So, the order was placed and we waited for the pistons to
arrive so the build could continue.
Eventually the package arrived, and just like a little kid does at christmas the box was ripped
asunder to get a first look at those four little expensive aluminium pots of goodness........



The essence of the moment can be neatly summed up in one short word,
BOLLOCKS.

Jesus H f*cking Christ, what the hell are these? There's a f*cking pyramid in
the middle of me new pistons. The valve relief's were deep enough to house
a small family of elephants, with weight disorders. In short, the pistons were
totally useless to me........



I'm not going to go into details here of what happened as the outcome is still ongoing,
all I will say is that there was a monumental cock up and it wasn't at my end.
The end result of all this at the time was I was severely out of pocket
and severely pissed off with the whole build.

I closed the door on the garage that evening and didn't return to it for quite a while.

[CHR1S1990]

I'm not going to get into the formula's and
calculations end of working out the compression ratio here, as, well, it's boring. And with porn only
ever a click of a mouse away I reckon there'd be an echo in here after a short while.
What I will say before we move on though is I came across a great bit of software to help
with the calculations if you ever find yourself doing something similar. Its by a crowd called
Performance Trends and is downloadable here http://performancetrends.com/download.htm#crc

I must be very boring, as i was actually hoping youd go into the depth of your calculation

never mind, software downloaded

sorry to hear about the pistons!

[CaesarBob]

Entertaining and informative ... we need more installments!

[darren_mk]

Ahh mann.... what happened - don't just leave it there!!!!

[gooner1]

How the feck could someone get those Pistons so wrong Even i half understood
what you required them to be. Surely it's not as simple as getting
concave and convex confused, is it

[Royalratch]

I hope you bury your Irish charm and manners and let fly with some venom over the phone - otherwise they'll take another 6 months to get you sorted for the correct ones.

Bummer dude!

[jessy]

really Good work..........

[tim_s]

I take it TEP are the agents in question?

[e301988325i]

However, when (like I am) you change to oversize valves and
higher lift camshafts, these relief's cut in to the top of the standard pistons are usually
insufficient to offer the proper clearance any more. The Schrick 284 degree inlet and 276 degree
cams being used in this build can be considered relatively mild in the large scope of whats available
out there for this engine.

The pistons are merely gods way of telling you to go for WILD cams.

I'm not going to get into the formula's and
calculations end of working out the compression ratio here, as, well, it's boring. And with porn only
ever a click of a mouse away I reckon there'd be an echo in here after a short while.
What I will say before we move on though is I came across a great bit of software to help
with the calculations if you ever find yourself doing something similar. Its by a crowd called
Performance Trends and is downloadable here http://performancetrends.com/download.htm#crc

I must be very boring, as i was actually hoping youd go into the depth of your calculation

never mind, software downloaded

sorry to hear about the pistons!

+1

Awesome thread!

[Morat]

Awesome work! And before a witch hunt is started I am the one who changed the text colour back to default. If it causes offense to xworks I'm happy to change it back......I only did it so I could read the text on my phone.
Good luck with the money trees!

[GeoffBob]

I just followed a link posted by Gooner1 here where Sebastian35 seems to have a similar problem.

Honestly, that is an appauling mess they made of those pistons X-works. I do hope that JE sort them out for you and that all is resolved. Excellent work you are doing BTW.

Regards
Geoff

[Sebastian35]

I just followed a link posted by Gooner1 here where Sebastian35 seems to have a similar problem.

Honestly, that is an appauling mess they made of those pistons X-works. I do hope that JE sort them out for you and that all is resolved. Excellent work you are doing BTW.

Regards
Geoff

Yes I have an issue with Top End but I was sweet talked into using mine with bad results!
Now I have to buy more. I am very pissed at the time it will take to get new ones more so then waste of money! Some say I should have just stuck a new standard motor in but that would be to easy....This is something I can point out to the

[Jon_Bmw]

Christ, I was just about to order some for an e34 m5 3.8 from Topend... Perhaps i'll wait a bit to see what the result was.

X works, if you already have the result as I am sure you post up stuff that you have done around 3 months ago, please could you PM me.

[corkie]

as usual epic stuff