Evo3 engine blueprints

thanks. those were 8500 rpm shifts, but I backed off near the top of 4th gear/begin of 5th as it was a bit faster than the speed limit there :). for some reason is doesnt sound in real life like it does on the video. its louder and more intense.  everything always looks slow on video too, even if you are doing 200 kmh, it looks slow.  Im going to experiment with a remote cam soon, perhaps it will look faster if the cam is closer to the pavement :))

for a passenger ride you are welcome if you are ever at the Ring.

John

I was out today and did a short little acceleration video:

john.gmstech.de/video/airbox4.wmv

it was against the sun so a bit dark.

John

Thanks Uwe and John!

I know the crank has to come out, and it will as soon as my new one arrives. As 215dmx said before - just right for turbocharging!

If it wasn't a sport evo, then maybe that is what I would have done. But it 'aint, so like you say Uwe, that crank has to come out, and wrapped around the head of the owner who rebuilt it or L&C who supplied it in the first place. It may have better effect if it were tossed through thier showroom window!  JOKE!

I'll do a compression test and dyno the car next week, and post the results on here. I can only give kw/bhp power at road wheel figures though.

SHEPSM3 wrote: 2.25mm down the bore? Is this because the 2.5 piston is 0.75mm shorter from the centre of the gudgeon pin to the crown of the piston than the 2.3 piston? Also I thought bore sizes between the two were different too??

that assumes a 2.3 piston was installed which I dont believe it is as you have a 95.0 mm bore? so I think you have a 95.0 mm piston in there. 

yes to your CR question.  it is a rule of thumb.  It is probably not accurate if you deviate by a large amount from the intended CR. e.g. if you used 8:1 instead of 10.5:1, or 14:1 insteado of 10.5:1

for a given engine, there is an optimal location of the main "peak pressure pulse" which occurs after initial combustion. This is located some degrees after TDC  ideally near where there is maximum mechanical advantage.   The air-fuel mixture burns at an exponential rate in time.  This depends on the type of gas/octane, cylinder pressure and temperature  AND rpm.  so your ignition advance is just the amount needed to start the fuel mixture burning early enough so that the main pressure pulse reaches the piston somewhere near maximum mechanical advantage.  If cylinder pressure and temperature are disregarded for the moment, the burn-rate of the fuel is mostly contant, so as RPM goes up we have less and less time to burn the fuel, therefore we have to increase ignition advance. Now when we open the throttles & the cams are online, we will increase the amount of air-fuel mixture that is then compressed resulting in higher cylinder pressure. To accomodate this, we have to reduce the ignition advance, as the mixture under higher pressure will burn faster. This way you again have the peak pressure pulse somewhere near maximum mechanical advantage on the piston.  Intake temperature and cylinder head temperature also have an effect. Generally, we'd like to keep things cooler. e.g. have your water temperature near 80C for max power, have cold spark plugs to pull as much heat out of the cylinder head as possible, etc. Compression ratios lead to change in efficiency and local temperature (as well as a shift in the by products-->emmissions).

Point of all this is that there is more to it than simply increasing compression ratio... many factors that ultimately may or may not lead to a power increase

John

UweM3 wrote: You kidding me! I am sorry but actually the piston is 2.25mm down, not 1.5 I still don't believe this has happened. OMG!

It has happened! I can't believe its happened either. I only wished I knew about the nut/bolt thing before I bought the car. The engine numbers are certainly correct though and don't look as though they have been messed with. Part number of crank fitted is 11 21 1 310 618 which I am sure its a 2.3 crank. It couldn't be a 2.0 crank surely?  I am sure though that the owner who rebuilt the engine had no intention of fitting the wrong crank, and I suspect it was the supplying dealer who got it wrong and the owner was none the wiser? Trust me, I want the correct parts in my engine!

2.25mm down the bore? Is this because the 2.5 piston is 0.75mm shorter from the centre of the gudgeon pin to the crown of the piston than the 2.3 piston? Also I thought bore sizes between the two were different too??

You would have to drive the car (and your welcome to) to believe how well it does actually go considering how far down thebore the pistons are from where they should be. Its only on light to 3/4 throttle where it feels as though its holding back. I was going to get the chip ignition timing advanced up 4-5 degrees throughout in an attempt to make the engine livelier. Pointless now I am changine the crank for the right one anyway. 

Hey Uwe, I just plugged the numbers into a little calculation program I have.  So I may have made a mistake.  But, I assumed all things are the same, just the crank changes.  Not comparing to a 2.3l setup with 2.3l pistons. so for the comparo: the rods are 144.0 mm in both cases.  the piston is the same 95.0 e3 piston in both cases.  so if we have case a) 84 mm crank and case b) 87 mm crank, the piston in case a) should be 1.5 further down the bore compared to case b), right?

thanks for posting the schematic.  where did you get the block deck measurements from?  218 and 218.25 mm?

just an observation: in the e3 piston with compression height 30.75 mm and dish depth 0.75 mm, my piston if machined flat (e.g. no dome) would have 30.66 compression height and no dish.

John