Messages

1

Engine + Driveline / Who drive CR 13:1 Je-Pistons?

« on: April 19, 2008, 06:04:36 AM »

I want to know how the higher CR is realized because we have to increase CR to 13.4.
Furthermore I like to know how many millimeters we can lift the valves at upper dead center without touching the piston.

2

Engine + Driveline / Who drive CR 13:1 Je-Pistons?

« on: April 18, 2008, 04:15:18 PM »

Hi guys,

as written in the title, I like to know if anybody use the Je-Pistons with a CR of 13:1 at the M42 engine.
I wrote an email to JePistons but it seem that they are too busy to answer on it.. :mad:

Thx
Torsten

3

Engine + Driveline / ready for E85 fuel

« on: April 13, 2008, 05:15:30 AM »

high compression pistons could be a good idea, too. But I've never seen high comp. pistons for the M42 :confused: because most of the people want to lowering the CR to install a turbo. Good old suction engine tuning seem to become pretty stale in comparison to turbo- or supercharging engines.

4

Engine + Driveline / ready for E85 fuel

« on: April 12, 2008, 05:45:12 AM »

Yes, he removed 2mm of the block, but having installed other rods which were 2mm truncated.

We will removing as much as we can at the block, but have to make sure that the piston will not contact the head gasket. So we need the underhang (is ist the correct english word for?? :confused: )of the piston skirt and the stock block plane.

5

Engine + Driveline / ready for E85 fuel

« on: April 11, 2008, 11:30:42 AM »

Where do I get total seal rings for the M42? I've have looked at totalseal.com but didn't find a kit for the M42. :-(

We have calculated, that he have do decrease the compression space between piston and cylinderhead of 2,4mm.
If we install a very thin headgasket from cometic, we will earn about 0,7mm so we have have to find 1,7mm more to remove.
The valve seats are very close to the head plane. Does anybody know how many mm we can remove from the head without injuring the valve seats? I guess, it's about 5/10mm?!
And does anybody know the maximum machining for the block plane? Maybe we can remove here some material, too.

6

Engine + Driveline / ready for E85 fuel

« on: April 08, 2008, 02:28:20 PM »

Not sure if high compression ratio is harmful to engine itself? It is usually detonation or knock due high CR that causes the problems.

Also, you need to consider dynamic CR in addition to static CR

Yes, you are right. But we have to know to which ratio we can set the compression without starting to knock.

Does anybody have experiences with E85 or does anybody boost his M42? If yes, please post CR, boost and octan-value of the fuel.

7

Engine + Driveline / ready for E85 fuel

« on: April 08, 2008, 02:23:06 PM »

We will do the following points:

-increasing comp. ratio to 13.4:1
-new camshafts with adjusted valve lift to avoid valve crashs.
-bigger injectors
-4 throttle bodys
-rev. limit 8.300 rpm
-lowering flywheel weight
-fine balancing of all rotating parts.
-megasquirt ECU w. Alpha-N control
-4 in 1 exhaust manifold
-2,5" exhaust system
-all gasoline feeded lines will be replaced.

8

Engine + Driveline / ready for E85 fuel

« on: April 06, 2008, 06:07:15 AM »

Hi guys,

I'm from Germany and study mechanical engineering at the university of Karlsruhe in the 6. semestre.

Here we are going to convert a stock M42 engine from a E30 318is running with E85 fuel (85% Bio-Ethanol / 15% gasoline)

Due to E85 has a much higher octan value (104) we like to increase the compression ratio. So we ask ourselfs how much compression the engine can handle without blowing into tons of pieces. We have calculate a value of 13.4 for comp. ratio... but we are not sure if the engine can handle that.

I guess, that several guys here installed a turbo at this engine. Maybe somebody can tell me how much you can boost this stock engine.

Thanks a lot and greetings from Germany!

Torsten