52 replies to this topic

[Steve TPF]

Will do, but that wouldn't explain why it was turning over happily before.

[Steve TPF]

Nothing I can see.

[greens nice]

i think the counterweights can hit the cam lobes if you have the cam timing ass about face?

[LJ RB30]

Wrong/odd screws/bolts in cam retainer plate catching on a piece of shit casting on the back of the cam gear?

To check simply remove both retainer screw/bolts & turn over motor whilst holding the cam in with your finger.

Just about everything else has been covered!

Do you actually have the motor out with the sump off to see if the crank & rods are fouling or clearing the cam?

Don't remember reading if you have but might have missed that bit.

With No1 piston TDC & both lifters down (valves closed) & crank/rods not hitting anything............................................................................................................................ the only other suggestion is to remove the 12" shifter & 2lb hammer from the block that the previous owner left in there!!

Hope you get it sorted! I'm keen to know the result.

Nothing I can see.

[Steve TPF]

i think the counterweights can hit the cam lobes if you have the cam timing ass about face?

THAT sounds as likely as anything, especially since the counterweights line up with the cam lobes whereas the conrod sits between them. I'll double check that, thanks.

Wrong/odd screws/bolts in cam retainer plate catching on a piece of shit casting on the back of the cam gear?

To check simply remove both retainer screw/bolts & turn over motor whilst holding the cam in with your finger.

Just about everything else has been covered!

Do you actually have the motor out with the sump off to see if the crank & rods are fouling or clearing the cam?

Don't remember reading if you have but might have missed that bit.

Pretty sure I tried without the screws, but worth considering. Engine is still in car, sump on. I dread having to take it out again. But like I said, this engine was cranking over happily with this cam before I removed/replaced it. So it's presumably something I've got wrong. greens nice's suggestion sounds like the most likely, but I have tried several different cam positions and I can't find one where it DOESN'T jam.

My cam timing kit arrived today, but of limited use since I can't get the crank gear off to use a different keyway, and no good at all till I fix the jamming problem.

[Steve TPF]

Initially, just enough to change position, then later, all the way to try and see WTF is going on.

Fuel pump, oil pump and dizzie have been removed, plus all lifters, pushrods and rockers.

[EunUCh]

sounds like that if it was not jamming b4 and that you have taken cam out to fix a problem that as you say you may
have done something,not being an expert on 6cyl engs it sounds like you may have got the timming out.
all i have ever done is line the dots up on crank/cam and turn over by hand to check.
crank gear can be removed by tapping the holes to suit a bolt in crank gear and use a puller to remove,make sure no shit
gets in crankcase when doing this,bit of a prik when its in car,cam gear usually pushes off in a press easily but dunno why
u would want to remove it as it only goes on one way as does the crank gear with exception of adv/rtd options on key,far as i know
the name/number of gear kit faces out,maybe check the dots line up because if there are multiple dots it would be easy to
get em out if they are similar size dots

[Steve TPF]

Rollmaster timing set, straight-cut gears, multiple keyways. Currently set to -6 degrees far as I can tell. IDK why. Only a couple of numbers visible an 1 mark, thanks to excessive hammering dents.

[EunUCh]

i dont know if this is much help but give it a go,i assume the cam gear has 7 keyways cut in it
the middle ketway is usually 0 setting,find the 4th keyway and mark the tooth directly inline with this keyway
now count 5 hollows anticlockwise from this tooth,the fifth hollow should be where timming mark was and line
up with mark on tooth of cam gear,probly easier if u put 4th keyway in 12 o clock position to do this

[Steve TPF]

i dont know if this is much help but give it a go,i assume the cam gear has 7 keyways cut in it
the middle ketway is usually 0 setting,find the 4th keyway and mark the tooth directly inline with this keyway
now count 5 hollows anticlockwise from this tooth,the fifth hollow should be where timming mark was and line
up with mark on tooth of cam gear,probly easier if u put 4th keyway in 12 o clock position to do this

Except I couldn't get the crank cog off with a puller.

Had a similar problem when changing cam timing in an ecotec v6 and turned out to be a cam bearing cam out and jammed the engine then it became a much bigger job to finish.

I can see down the cam journals and the sump, I'm sure I'd notice if it was something like that.

[EunUCh]

they not easy to get off,i assume you used a puller with tangs that go behind the gear,i have used that type
of puller to get em off,try getting some weight on the puller as if you were pulling it off,get it tight
then give bolt on the puller a bit of a smack with a hammer,you might have to have a couple of goes at it.
if that does not work you will have to get a tap and thread the holes in the gear and use a difrent puller.

[fenz]

Might want to warm the crank gear with oxy or good heat gun to expand it a tad and then try using the puller.

(If gear has got hammer marks on it track down the culprit and insert hammer in apropriate orafice.)


All of the above mentioned ideas will be a whole lot easier with the motor out.

Good luck (let every one know how you go with that hammer hehe....)

[Steve TPF]

they not easy to get off,i assume you used a puller with tangs that go behind the gear,i have used that type
of puller to get em off,try getting some weight on the puller as if you were pulling it off,get it tight
then give bolt on the puller a bit of a smack with a hammer,you might have to have a couple of goes at it.
if that does not work you will have to get a tap and thread the holes in the gear and use a difrent puller.

The holes are already tapped, I used a harmonic balancer puller that bolted to the cog. No joy.

This thread is going nowhere.

As soon as someone suggests a remedy the OP either doesnt bother trying or just says "no its not that"

Get us a bloody photo.

As I have already stated, no camera or phone, or I would be happy to give you one. What do you mean "The OP doesn't bother trying?" I tried fitting the camshaft by counting the teeth, as suggested. The engine jammed. I din't try reversing the dizzie because a: I tried that previously while trying to start the car, b: I verified (by removing the rocker cover) that the valve timing was reversed, and c: the dizzie has now been removed, and cannot possibly be jamming the engine. I have looked down the cam journals, sump, and cam follower holes for foreign objects. I can't see any, neither does anything scrape, rattle or jam when the camshaft is removed. If the conrods were hitting the camshaft itself the engine would not have turned over before. I have checked for foreign matter in the crank cog, and for damaged gears. So what makes you think I'm not trying?

Currently I'm leaning toward green's nice's suggestion that the counterweights may be contacting the lobes. oldjohnno's brilliantly logical idea of using some masking tape sounds like the best way to confirm this. It will have to wait till tomorrow though.

BTW, can you define "decent puller?" Mine 's now stripped the thread on the main shaft. In any case, I've managed to spot a couple of numbers and one mark among the dents, so the cog isn't on backward.

[EunUCh]

back to square 1 orig. post,problem 2,who fitted the gear to crank,if it is so damaged and it wont come off with
puller and it jams in same place maybe the crank gear is so bruised that it has distorted the gear,find a spot where the
gears have a bit of backlash(no oil on gears makes it easier,clean em with a bit of petrol)
and then turn it over stedy and check that you still have backlash as you turn it over
if you dont have backlash all the way and it feels like its getting tight crank gear is fkt from hammering lessons

[rodomo]

You have new gears don't you?
Relieve the old gear with a 1mm angle grinder blade.
This pic is for harmonic balancer but you'll get the idea?
Once split, it will pry off with a screw driver.

Attached Files

•  timing+gear.jpg   38.05K   1 downloads

Edited by rodomo, 17 June 2011 - 08:21 PM.

[EunUCh]

yep,looks like you gonna have to bite the bullet and just destroy the gear
sometimes you just gotta do what you dont wanna do,saves a lot of frustration
in the end and you end up gettin it fixed,if it was someone elses fk up dont go back,
if it was your fk up,learn from it as a lot of us have in the past,and still learning.
if you intend on fitting new gears on your own,heat up crank gear with gas and have suitable
drift that clears snout of crank and tap on,it dont need to red hot,just no discolouration.eg.not blue

[76lxhatch]

The Repco etc style of "harmonic balancer puller" is useless and will bend and strip the thread. You want a good quality cross-block puller with fine thread and it needs to be bolted hard against the gear - it'll come off.

[Steve TPF]

My puller did bolt to the cog, but possibly i could find a better one.

Meanwhile, having wrapped tape around the camshaft as suggested, I can see a scrape mark on the tape at the #6 conrod position. So it seems oldjohnno was right, the cam is slightly out of round. Evidently the previous owner found the one spot where it didn't jam.

seems to me i need to get the camshaft ground with a relief groove.

[Steve TPF]

Alas, no die grinder. I have a bench grinder though. Thanks for the help, it looks like we've found the problem.