Timing An Xu10J4R

[chris 417 mi 27 2 Cars]

Recieved my engine back from rebuilding a few weeks ago and had to time it before fitting as the builder hadnt.

Seems the timing is off as its trying to fire but just won't, are they timed at tdc or ?? Any help would be greatly appreciated

[petert 550]

Cam timing? The pins should align as per this pic. A third pin goes through the harmonic balancer, which is "supposed" to lock the crank at 90º BTDC. However, as the pin hole is the outer part of the pulley, and this rotates with age, it's position can not be trusted, unless it's new.

[dcc 855]

I used an 8v lower pulley to time the bottom end with the head.

[chris 417 mi 27 2 Cars]

Well timing in general tbh as it has a 2.0 diesel crank in ( of unknown origin) and the marks weren't seeming to make sense.

[petert 550]

The only true way to verify is check the lift @ TDC on an inlet cam bucket with a dial indicator. However, slip an 8V balancer on as suggested. It will probably slip again when you remove it to fit the 16V balancer. So how would you know if it's correct? A better method is to use an 8V timing indicator as I suggest here: http://www.taylor-eng.com/xu9j4/finding_tdc.html

Then rotate back 15 teeth. This will be 90º BTDC where the pin should normally fit in the harmonic balancer.

[welshpug 1,622]

the pin hole should be 70 degrees from the woodruff key

 

or with the pulley off, the woodruff slot should be pointing directly at the rear face of the block, inline with the upped alloy end plate bolts (not the pair for the cover)

[hothatch 2]

Make sure cylinder 1 (French number 4) is at tdc an cylinder 4 (French number 1) valves are on the rock. That way you won't be far off and your marks should line up.

 

[welshpug 1,622]

XU engines do not lock at TDC!

[Richie-Van-GTi 70 2 Cars]

I will be helping chris this weekend, (well supervising since I cant work for a while). Liking the sound of Peters method, set TDC and go back 15 teeth for 90 degree BTDC. We originally timed it with the pin in back of flywheel method but it seems to be a touch out of time somewhere. It has low compression and has been know to fire with the inlet open resulting in a nice flame out the throttle bodies.

[welshpug 1,622]

there are no holes in an XU flywheel for locking/timing purposes, the XUD, DW, TU and EW, have that.

[Richie-Van-GTi 70 2 Cars]

Dont want to question your extensive knowledge and experience but the block is drilled for the timing and the flywheel definaley has the timing holes on the back. Also I have definatley timed xu10's with the flywheel before as my old 205 had one in. My flywheel came from a 2.0 8v 306 IIRC, not sure on the one in Chris's. Its had a lot of engines and parts over the years. Maybe I was lucky with mine at it married up to the 2.1 crank in terms of timing and unlucky with Chris's. Although as he said the crank is of unknown origin!!

[welshpug 1,622]

its the same block casting as an XUD, hence the hole

[Richie-Van-GTi 70 2 Cars]

would expalin it then , main concern is the flywheel / crank combo being right for the 90 degree BTDC trick to work. Worst case I suppose is measure the stroke to calculate 90 degree's. Although if its 90 degrees on the crank then isnt it just a case of all pistons level, same as a few other pug/cit engines?

[welshpug 1,622]

crank will be the same timing as the dowel hole for the flywheel is in the same place.

[chris 417 mi 27 2 Cars]

quick update, with richies supervision we slackened the belt off and retimed it at 90deg BTDC as explained earlier in this thread and she fired up and sounds good , bit of tidying do do followed by an MOT then unfortunately will be put for sale as cicrumstances have changed dramatically since i first sent this engine off for rebuilding.