Vladislav

Seems as a crime to me

Thanks for clearing me up, Glenn. I knew Mack went to much more massive crank and rods (and other parts) in a inline block but I thought it was when END-673 was made. If it was for Maxidyne it put the ducks in order.

This is interesting to read nowadays since Lanova (at least ED519) had the top revs of 2100 and 2000 when under maximum load. Doesn't look notably (or at all) lower than END-673. The 2nd point END-672 which was still Lanova had an outcome of 160 or so HP. The same figure than the next generation END-673 engine produced using similar displacement. My understanding is the jump from Lanova to Thermodyne (worth to admitt Lanova was also Thermodyne having overhead valves) was more a go from pre-chamber to the single chamber design. The most early automotive diesels utilized pre-chambers. The reason was to make the combustion process "softer" to decrease momental stresses to the engine parts. When the fuel injected into the engine first burns in the pre-chamber and than spreads out into the main chamber (cylinder) the pressure rises slower than if a single "blast" takes place. And seems like early diesels could not withstand hard burning and pre-chamber design prevailed. It also did that in cars up to the recent times. There's another matter (but with the same origin) - pre-chamber allowed a diesel to operate at high RPM's what is actual to a car. At the same time pre-chamber style has its specific disadvantages. First of all it's less fuel efficiency than a single chamber style. The reason is pre-chamber needs extensive cooling being a combustion area. So made sorrounded by cooling passages in the head body. More cooling means more heat remove i.e. energy losses and less fuel efficiency as a follow. The same matter determines difficult cold start. The most pre-chamber diesels had glow plugs. And single chamber ones don't need them. Also there's a tendency of the cylinder head to get heat cracks. It's also a generic problem. One of the main principals of designing a heat stressed part is shape symmetry. When the material expands it gets symmetrical stresses being symmetricaly shaped. And the very existance of a pre-chamber in a cylinder head makes it asymmetrical. As a result about every head off a Lanova is cracked. And quite a seldom case for END or Maxidyne/Econodyne.

The thread turned out as an interesting discussion and I heave read it whole to this point but still don't see the answer to the matter of ability realizing the Maxidyne concept. I understand the lower RPM torque rise was done by fuel and turbo settings. That's fine, Ok, the engine would pull at 1000RPM. But to me it's nothing else but extreme lugging. You add fuel and add air to burn it out and the engine pulls. But I can't figure out how the crank and the block withstanded those high stresses and a similar made Thermodyne could not? Or Mack engeneers just used the actual sturdiness of the components which could work for Maxidyne but just were not stressed up really much in Thermodyne version?

That oil pressure point makes sence to me. Actually what would you worry about lugging an engine? I think combustion process goes quite well at 1000RPM (sure not 100RPM). To me the trouble seems as insufficient oil pressure at low revs. There could be effect of high stess applied to cylinder walls or the crank group. But seems more a matter of the torque itself, not dependant to the revs. If oil pressure have meaning there must be different capacity pumps used in Maxidyne engines or a different pump drive ratio. It's easy to recognize and I belive must be a well known fact. I just never concerned it so far.

Mine had a crawl through opening. The boot was held with a steel strip attached by self cutting screws put through it all over the opening. Both to the cab and sleeper walls.

Funny thing you can fit a wheel of any modern American truck onto this hub and it would fit right up. Ok, it woulf fit correct if it's a stud piloted style.

Lanova used common valves. At least factory description of the engine design doesn't describe anything extraordinar. There was a point on the material used for valve lifting rods which had about zero temperature expansion but I don't remember any valves especiality. Unfortunately no comments on"rees" valves too. Welcome to the site!

The chassis looks nice! Glad to see you're making good progress during the years. Is the engine a kind of 2nd generation AC engine? i know they were of cylinders and a head cast as one part. And yours looks newer.

Very nice! Looks like just a few steps to go and she's ready for the show season!

Welcome to the forum! The truck looks very promising. Vlad

It seemed to me from working on 1945 Mack chassis they primered brown all or the most of separate parts. And when the chassis was rivited together and different brackets and attachments put on they painted it all over into the final color. With cooper tubing etc already in place. So all those hidden marks you discovered seem used as the factory internal id's. Pre-assembly markings or part numbers. No matter Mack stamped the rails or a vendor they should be id'ed coming onto the assembly line. Interesting, thanks for sharing.

Happy New 2022!

They are sexy. And seamless.

Nice truck! Welcome to the forum and keep on progress! Vlad

Looks like a R/Superliner floor panel to me. But could be for a U/DM, I'm not almost sure at the moment. The difference is the threadle valve hole location so not difficult for visual check. These things have value since tend to rot. Someone was even looking for one on here a few moons back. I'd grab it for some bucks if have less headache with shipping.

https://www.bigmacktrucks.com/topic/66390-hatcity-rip/

Cool looking dog! Welcome to BMT!

Also a question is which model your truck is. If it's CH or CX (if a Mack) they have straight rails front to rear and you are able to order a full length newly made channels. Much more job removing the engine and the cab but you would get a truck with chassis of the same or even higher performance than it was originally leaving the factory. Older Macks with "fashioned" front end of the rails don't allow such approach so welding turns out as about the only option. The rails themself aren't extremely expensive. But the amount of job may differ.

To me it's difficult to forget them

Many were also hot riveted in the early days

It's possible someone already rebuilt your chassis in the past and used rails which didn't mutch the size well enough. If the issue was done by rust the shelves of the rails must be slightly bent relating to the horizont. If so I would try to forse them down into the normal position hitting by sledgehammer along the edge or using hydraulic what's more preferrably.

Sounds like impressive job done and a lot of new experience. Glad you got it fixed. Also thanks for mentioning all those underwater stones involved.

Yup. As said above.