6.9 Misfire - getting worse

[SELfor50]

It's not really that they wanna charge heaps.. they just don't wanna touch the Merc cams other than to standard spec. 
Joeb (ozbenz) told me yesterday that it's to do with the material they're made of?!  Something about if they grind up standard ones and change them - then after that they need some crazy type of treatment to harden them again..otherwise they get brittle etc.. but everyone at all the cam places weren't saying that - they just said they didn't know enough to try and modify them.  No balls I say.

Oscar, you can practise on that set of cams you got there already.   Let me know how you go.

probably because they cost 3 grand each to buy new if they get f-cked up

You'd be suprised, but the Right hand camshaft from the classic centre is 363 euros.  I couldn't see the LHS listed.  But realistically - I reckon that's pretty damn good - considering.


I have had a thought yesterday though..  Need to PM someone, but I think I know where I might be able to get a copy of some performance M100 cams.
Stay posted..

[motec6.9]

Hi Cam Wade replyed to my email told me to give them the numbers on the end of cam and they may be able to use standard cam profile to make an improved 1 and yes i you find out where to get cams im in

[oscar]

 

Something about if they grind up standard ones and change them - then after that they need some crazy type of treatment to harden them again..

Yeah, 20 mins on a chargrill then chucked in a bathtub of cold water.  I got it all covered  

Ok serious face now,  I know there was some hardening treatment involved but I thought it was just a heat treatment rather than a surfacing or hardfacing procedure prior to a grind.  But anyway, that's neither here nor there .... where did JG from MBSpares get their track car's M110 cams done? Dya reckon there's any difference between make up of an m100 and m110 cam?

[SELfor50]

Something about if they grind up standard ones and change them - then after that they need some crazy type of treatment to harden them again..

Yeah, 20 mins on a chargrill then chucked in a bathtub of cold water.  I got it all covered  

Ok serious face now,  I know there was some hardening treatment involved but I thought it was just a heat treatment rather than a surfacing or hardfacing procedure prior to a grind.  But anyway, that's neither here nor there .... where did JG from MBSpares get their track car's M110 cams done? Dya reckon there's any difference between make up of an m100 and m110 cam?

I'll send em down for you to sort out O-man.   haha...

Not sure where he got them done, but I think he got a new set (or used will confirm) and then got them re-ground to performance.  Will find out where he got them done.

BUT, that's not really important anymore - cause I've found someone off-sure to do it.  They already have a performance profile, done them for many people and claim they are "race" spec.  288/278  (inlet/exhaust duration).  I'm yet to confirm what lift they will have, and what type of stall converter I'll require.  If the lift doesn't change much then the standard springs might be ok.

I've been advised that even on a 6.9 engine, those figures will make it uber lumpy - oh yeah.

If anyone's interested send me a PM and I can provide more details.  Might work out cheaper if we get a bulk load done.  You will need a pair of cams though - they don't make them from only re-grind original cams. 

Cam.

[motec6.9]

Let us know the price Cam i would like a set Ps NOS being fitted

[SELfor50]

Sorry to revive this once more..

Swapped the cams off the old engine today.

The problem was actually the lifter.  The rocker arm was also shredded.  And the Inlet valve of cylinder 6 had started on the rocker arm too.

After removal of the rocker arm - I just grabbed the pivot ball of the rocker and it pulled straight up - and would not depress at all. 
All the lifters are brand new (look crystal clean) but I guess maybe cause they were sitting for so long?!

Anyway, got a bunch of photos.. just going to have some dinner (cause we just finished) and I'll post the pics up.  Grab a stiff drink, you'll need it when you see the shots of the camshaft. 

Cam.

[TJ 450]

Was it collapsed, or seized at full lift? I'll have to watch out for this. I'll await the pics of the damage. It makes me want to pull the rocker covers off the 6.9 for a look.

Tim

[SELfor50]

Was it collapsed, or seized at full lift? I'll have to watch out for this. I'll await the pics of the damage. It makes me want to pull the rocker covers off the 6.9 for a look.

Tim

Seized at full lift.. and then as I pulled it out little bit by little bit - it wouldn't go back down.. then once I pulled it out completely I tried putting it back in, and it would hardly go in.
Turns out Inlet lifter on Cylinder must also be on the blink, so swapped that too.  The rocker arm on cylinder 6 was also ground.  Come to think of it, I forgot to take a pic of the rocker arms.
Will do that tomorrow also.. for now, here's the other pics of today's work.

Took it for a spin afterwards.. back revving how it should and kicks on.. felt good.  I think I need to wind the mixtures back a bit now, as I wound the fuel up before in an effort to compensate the misfire (it corrected it for a little while, i'm guessing cause it wasn't opening the inlet as much the extra fuel helped minimise the impact..........but yeah), so by the feel of it - I can probably have another play and get it back to how it should be.


Subject


Spares


The old engine must have had new injectors installed, so these will make great spares - removed them all from the old block.


Ian removing the new(old) cams




Removing the New (dead) camshaft


Cleared



Swapped out lifter - compare the difference between the look of the new vs old - you'd think the new ones would've been sweet?  Probably just sitting idle for too long..


Kaput nockenwelle



Shot Lifter


1 More Angle of die kaput nockenwelle


Installing the backup


Burning the oil drips off the exhaust manifolds




Cam.

[s class]

I'm glad you've got it sorted now.  Pity about the new-now-buggered parts. 

[TJ 450]

Who would've thought. It looks like the camshaft got very hot in that area too, by the look of the baked oil.

Maybe some crud got in the lifter and acted as a one-way valve.

Tim

[koan]

The lifter in the picture looks a bit strange, they don't usually extend that far, the crimped on collar prevents that.

Has someone "worked" on it to compensate for a worn cam lobe?

The lifters are hard to compress, even in a vice it takes a lot of force.

Something you have to watch when doing the basic position adjustment, it takes 5 to 10 (or more) minutes for an unloaded lifter to settle back under valve spring pressure.

koan

[SELfor50]

ok.. To clear the confusion. The lifter that is crusted and black, is the replacement lifter off my old engine.
The broken lifter is the one in the pic with the cam.
You're right ken, it shouldn't pop out like that. I'm guessing at was maybe sitting for so long that it's seized at a point?!
Then as it's lifted further it wouldn't go back past that point.
As stated, once I removed the rocker arm, I was suprised I could pull the top out. Guessing the crimped end has buckled and let it past?.
I'm only guessing, cause to be honest I can't determine exactly why a lifter (that looks brand new still!) Can go like that.

Anyway, here now..
So will be sending a second hand set of cams off to the fatherland in about 6 weeks and when they come back I'll be pulling the engine out anyway to do a bunch of work on the bench. At that point I'll double check all lifters, rocker arms, valve springs etc.

As long as the current setup gets me round mount panorama for a couple days- I'll be happy.

Cam

[koan]

So will be sending a second hand set of cams off to the fatherland

Are they going for holiday or have you found somewhere there with the know how to regrind them?

koan

[SELfor50]

Yep 2nd hand set. Found a place who can regrind them modified. Lift is same, but duration is longer.. Good power increase apparently. They said no valve springs are needed either.

[motec6.9]

Hi Cam i will find my old cams and send to you pm your address after Bathurst