Mi16 Rebuild Question

[blessed6383 0]

Hi guys just rebuilding my xu9j4 lumps and as the cranks been out is there any way to tell the difference between the compression stroke and firing stroke? just got to fit the timing belt wondered if there is a way to tell rather than having to changewhen its fitted in car?

cheers

[welshpug 1,657]

just pin it all up

[blessed6383 0]

cheers welshpug

 

did pin the bottom pulley on the hole using a 6mm allen key and locked the cams with exhaust bolts 8mm to 6mm,

take it it cant be 360 degrees out then?and the hole in the bottom pulley is for this reason only?

[wicked 103 3 Cars]

Cam pulleys turn at half the speed due to their size and turn 180 degrees while the crank turns 360 degrees..

So in the 'other' cycle of the crank, the pins wouldnt fit in the cam pulleys.

[unariciflocos 49 1 Cars]

360 degrees is a complete revolution, therefore the engine can't be out 360 degrees. As said, just use the locking holes, just as you would when changing the timing belt. The rebuild manual has more than enough information, get it here: http://www.buzzboxx.co.uk/XU9J4_Rebuild_Manual.zip

[blessed6383 0]

when i said 360 degrees out i ment the crank is 180 degrees out as this is possible when timing over engines i've done as with a 4 stroke there is 4 actions to the cycle! suck, squeeze, bang, blow, unlike a 2 stroke engine which only has 2 actions

[smithy 1]

On a 4 stroke the crank does 2 revolutions to one of cams.

If it is pinned the crank cannot be out the cams however could be 180 out if you have only done 1 revolution of the crank.

 

Just pin the top and bottom turn 2 complete revolutions of crank and re pin to check.

 

The 4 stroke cycle is

1 induction,piston going down

2 compression,piston going back up

This is 1 revolution of crank

3 power,piston going down

4,exhaust,piston going back up.

 

2nd revolution of crank

To this complete cycle the cam has revolved once