mrsmackpaul

Joey it is the day the first fleet pulled up at Sydney cove to build this place we now call Australia And independence day for Australia was January 1st 1901 Paul

Happy Australia day to to the greatest country on earth

Great stuff Paul

Fjh I guess 2 or 3 thou isnt a lot So with this in mind it wouldn't take much I guess not a lot is needed for worn components or bad adjustment to have a big impact And I guess correct adjusment at the very least is needed and as you suggest maybe even a bit closer I do have some rocker cover gaskets and the other gaskets needed to drop the covers off What I lack is time, but I do wanna try and get Dynatard working correctly before bunging the Jacob's kit on And Joey I guess the best way to prove what happens with no fuel is wheb driving along one day, pull the stop on the motor I can tell you from experience, if you loose prime when driving there is no real noticable change, I just sort of coast along quietly Paul

Nice and warm here as well, well over 100 f yesterday and a much nicer 87 f today Paul

I think most of us are starting to understand how the Dynatard actually works and why it is so limited with amount of retardation And why the timing of the cam could have a huge impact, even just a few degrees on the effectiveness of Dynatard And also why if your rocker gear has done millions of miles and is a little worn, why thus can have such a big impact on the Dynatard as well The little lash adjuster ram has to respond fully and instantly to get the most amount of compression out of the cylinder at the absolute precise time I think this also explains why some people reckon they are okay, but most don't as once things are worn slightly the result would be very different Yes they still make the noise, but effectiveness is so much less Paul

As far as I am aware, in Australia all E7 Macks came with engine brake and a Jacobs exhaust brake as standard from the Mack Australia factory It may not of been all but it at the very least it was most I guess to me this points to even Mack acknowledging just how crap their engine brakes were compared to everything else into the 90's and beyond Yes Geoff, the science was good on Dynatard but the execution left a little to be desired And then you add a couple of million miles of use into the mix and worn parts etc and things really are not in Dynatards favor Paul

Jo Jo I reckon your spot on And our expectations have changed as well We were just happy to have any sort of engine braking once, now with modern engine brakes to compare to, anything from 40 or 50 years ago seems hopeless Paul

I dunno if this is 100% correct Yeah I know in the standard parts department this is correct However on racing type motor for a car you can dial in the cam shaft to make sure it is exactly correct The use of off set keys to shift the cam slightly is used Can this be done with a Mack motor ? I dunno, I guess it probably could be Why would this be important ? well I guess if the cam is slightly retarded it would mean the exhaust valve is opening to late Would this be a real issue ? I dunno, but clearly there are really good and really really bad Dynatards Something or a combination of things have to be slightly out and combined make a big difference To me the weakest part of the design has to be the rockers that from memory have no O ring to seal the oil in there, this would mean little to no retardation as the hydraulic lash adjuster would struggle to fill with oil and expand If this happens the retardation would be at the wrong time Anyway, just some thoughts Paul

Yep, the world's a mess Paul

Yes I am

I think the issue is there is so many spots for oil to leak in the rocker gear and the oil pressure is say 60 psi at best, once the rocker gear is worn a bit oil can easily leak out the rocker shafts This means the little ram in the lash adjuster never gets its full oil pressure Also timing must be critical as the lobe change is tiny Paul

That's hardly what I call a lump, but for the sake of keeping the peace you can call it a lump 😆 Paul

There is no second hump on a dynatard cam They look almost the same as a non dynatard cam When dynatard is off the exhaust doesn't follow the cam because it can't The exhaust valve is shut and as such it can't travel any further When dynatard is on, the effective push rod length has increased and as such the valve must follow the cam and the exhaust opens just before TDC If we think about the dynatard and all the bits that need to work and be reasonably oil tight and in good working order it is little wonder that there are lots of issues with them as they age Reducing the valve clearance would help as the effective travel needed is reduced to achieve a good result Having said all of the above I feel timing is also critical, as is good mechanical clearances on the rockers gear The little piston in the lash adjuster can't extend fully if it can't be supplied with oil under pressure There's a lot to getting dynatard working fully, more than most of us understand Paul

I think parts still available in Australia Paul

What a good watch that was Unfortunately for the human race, the places we like to live mother nature also likes to burn and flood A lotta good old gear shown there Thanks for sharing Paul

Sorry I own nothing like this, I think ? Got a Matchbox or Corgie or maybe it's Dinky R model and another Im not sure at all what model it is except R model Paul

Paul, don't hold back now tell us how you really feel You need to feel free to share here, have a look for Swishmans thread on Gay Volvo's Farcanel they are either loved or loathed Paul

The cone part of the bearing and the roller part are available in lots of combinations generally So if the outer cone is loose dont dispare as usually different cones of greater out side diameter are available to match the inner bearing You will need a decent bearing retailer that actually knows what they are doing to do this Then get the hub machined out to suit the new cone Or you can weld the hub up and machine it back out to suit, it will be I, imagine cast steel, not cast iron, if it's cast iron machine it out and shrink a sleeve with liquid nitrogen and drop it in, then machine it out to correct size, it will be as good as new No matter which way you choose this isn't a big problem to solve Paul

Yes, happy birthday Hope your having a wow of a time, been a while since we heard from you, to busy having fun I guess Paul

Some lads just getting on with it, not much of that these days in Australia sadly Lot's of high vis clothing and plenty knob heads giving directions that don't know their ass from their elbow Paul

Yes it does, very strange by U.S. standards I guess Mercedes Benz, Man, Leyland, Deutz and probably a lot more And yes on highway high speed jobs Paul

But like many European planetary gears on hubs This allowed for a small diff center Some blokes went to great expense to change ratios only to find it exactly the same The final drive ratio eas in the hub, not the diff center

MAN trucks were like that, German built Paul