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Smallblock454 · 03-25-2015, 07:10 AM

Well, OK. So, let's see.

We have a 4 stroke Boxer engine. That means we have 3 pairs of pistons that work together like that:

So 1 and 4, 2 and 5, 3 and 6 are pairs.

Let's take a closer look at 1 and 4. So 1 and 4 are allways at the same position and at OT. The difference where we are in the "stroke cyle". So if 1 is at OT and before ignition - all valves closed. 4 has all exhaust valves open and all exhaust gases are out of the cylinder.

So if 1 is at OT all valves closed and you crank the crankshaft 360 degress 4 is at OT all valves closed.

Because we have a 6 cylinder engine, there are 4 clinders left.

First, they work also as pairs. So the same logoc as above. But they work with a different timingcycle because of the crankshaft has a 60 degree offset for each pair.

In combination with the firning order i think now you should be able to make a spreadsheet and note all OT and crankshaft turn degrees for your engine pressure loss test.

Animation: https://youtu.be/JDYHyGNFR5Y

Regards Markus

03-25-2015, 07:10 AM	#13
Smallblock454 Registered User Join Date: Jun 2014 Location: LB, Germany Posts: 1,512	Well, OK. So, let's see. We have a 4 stroke Boxer engine. That means we have 3 pairs of pistons that work together like that: So 1 and 4, 2 and 5, 3 and 6 are pairs. Let's take a closer look at 1 and 4. So 1 and 4 are allways at the same position and at OT. The difference where we are in the "stroke cyle". So if 1 is at OT and before ignition - all valves closed. 4 has all exhaust valves open and all exhaust gases are out of the cylinder. So if 1 is at OT all valves closed and you crank the crankshaft 360 degress 4 is at OT all valves closed. Because we have a 6 cylinder engine, there are 4 clinders left. First, they work also as pairs. So the same logoc as above. But they work with a different timingcycle because of the crankshaft has a 60 degree offset for each pair. In combination with the firning order i think now you should be able to make a spreadsheet and note all OT and crankshaft turn degrees for your engine pressure loss test. Animation: https://youtu.be/JDYHyGNFR5Y Regards Markus Attached Images Last edited by Smallblock454; 03-25-2015 at 07:18 AM.