67RModel

I hate to resurrect this oldish thread again. I spent entirely too much time this week on BMT and here its midnight on Saturday and I'm still on it lol. Anyway, I spent a lot of time reading old threads and looking back through the photo albums. What I realized is this place used to be super rowdy and aggressive. I mean there are a lot of threads that are down right nasty and hateful. This was in the 2017 - 2019 timeframe. I have never experienced anything like those threads in my time here. I came in about when all that seemed to be ending in early 2020. I was thinking maybe that hostility drove a lot of guys away. Or if they were not directly involved in the conversations just said screw it and decided to log on anymore and read a bunch of negativity.

He last logged on December 30, 2022...so like a week ago.

OK I got this figured out now thanks to the video @Onyx610 posted and actually having time to sit down and watch it. The video along with some other sources got me all straightened out. Mechanically governed E7s use the LDA system and not the puff limiter system. For those that don't know and want to know here goes: In a cold start scenario the puff limiter system (think E6 and possibly older) is full rack by default. Rack travel becomes limited once you release the spring brakes and air is sent to the injector pump. Once boost pressure is sufficient for full rack the boost pressure overcomes the air pressure supplied by the parking brake valve via the reversing valve that is tapped directly into the intake manifold. Boost pressure and chassis air pressure are always hydraulically "battling" each other in the reversing valve for control of the air cylinder in the injection pump. In a cold start scenario the LDA system is limited rack by default. There is no reversing valve at the intake like the puff limiter system. The LDA system just has a line tapped into the intake and constantly adjusts rack travel based on boost pressure alone. No compressed air is involved. In a cold start scenario limited rack is not desirable so a workaround is needed. That is the purpose of the valve in the first picture a few posts back. It is a Bendix SV-1 Syncro Valve. When you flip the dash switch to "on" for the CAC bypass, tank air (assuming it hasn't all leaked out) is sent to the SV-1 valve as well as to the two cylinders in the bypass duct plumbing. The cylinders simultaneously close the CAC outlet and open the bypass duct allowing warm compressed air to directly enter the intake manifold. The air sent to the SV-1 valve is regulated down to whatever maximum boost pressure is and passed down and connected to the the tee fitting in the intake manifold where the LDA is tapped into. Thus, the LDA is "fooled" into thinking boost is max and full rack is available before you start cranking the starter. Once the truck warms up a little the CAC bypass can be switched off, the air cylinders cycle back to their normal positions, boost air begins passing through the CAC normally, the air going to the SV-1 valve is exhausted, and the LDA goes back to sensing whatever the actual manifold pressure is. Of course it doesn't stop there. Both systems utilize a torque limiting valve if the truck has a Mack transmission. Once running, if the transmission is put into reverse and/or the low forward gear(s) the torque limiting valve is activated. It is piped from its location on the transmission up to the reversing valve (puff limiter) or to the tee where the LDA is tapped into the manifold. Once its activated it dumps the boost pressure to atmosphere that would normally build up in the system and allow full rack travel. By doing this rack travel is limited in both systems to protect the drivetrain in the low and reverse gears. Once the shift rails are moved to select a higher gear the torque limiting valve closes and allows boost pressure to build up and allow for full rack travel in the injection pump. Below is a picture taken out of my E7 book explaining that all fully mechanical E7s made after 1991 have the CAC bypass setup installed by default. I assume the VMAC trucks can electrically advance the timing during cold startup making this system not necessary for them. I will say that I have consistently been able to start my truck down into the low 30s high 20s temperature range without using this system and it fires up very quickly.

Also, I think it technically illegal by National Electric Code to use a standby generator without a transfer switch. Automatic or manual. 

13 minutes ago, Onyx610 said:

It’s called back feeding and it’s also dangerous to the guys working on the power lines. 

I always wondered about that. Would the generator even run with the main open? In theory wouldn't it just stall the generator or not even start to begin with? I mean isn't that the same as trying to power the whole town that has lost power? Or do the transformers no allow the generator power to reach the main wires? I'm pretty weak at understanding electrical and big power....

16 minutes ago, Joey Mack said:

So the tranny line is a torque limiter?

That is my understanding of it. Well at least how the older style puff limiters worked on the E6s. You got full rack on start up (to aid with cold starting). As soon as you released your spring brakes air was sent to the puff limiter until manifold pressure (boost) was sufficient for full rack. Also, If you had a Mack transmission with lolo gears you wouldn't get full rack until the transmission was in forward high range. I'm not sure about this LDA system and why that valve is mounted up off the manifold. The older style puff limiter valve was tapped directly into the manifold.

1 minute ago, Joey Mack said:

Doesn't one of the air lines go to the front of the injection pump?  If so, I believe it actes like a reversing relay, and high boost pressure, operates the Number valve to push the rack back..  if I remember correctly..  it helps to keep from over boosting the engine..  Jojo 

Joey,

Yes. In the second picture the airline painted in gray that goes out the left side of the picture from the manifold goes to the injection pump to limit rack travel before manifold pressure gets high enough to burn all the fuel from fully open rack. The line coming in the bottom of the second picture to the manifold I think comes from the transmission to keep the rack from opening fully until you switch into transmission high range (I have not confirmed this yet though). I'm just wondering now if I should remove that plug I put in and put tank air to it or tank air via the parking brake valve like the old puff limiters were set up. I'm just not sure schematically what the valve in the first picture does or what its "looking for".....

10 hours ago, Onyx610 said:

Start at 10:00 

Thanks. Ill have to dig into it a little more to try and understand how/why that CAC bypass is plumbed into that valve. I assume the valve I am asking about it the LDA valve? Thanks.

7 hours ago, DM800guy said:

Did you sell them?

No. I still have them. Have a few interested parties but nobody has shown up yet to get them......

You are pretty much SOL. They have been obsolete for several years. Pretty much your only option is to source some used ones from a salvage yard or change the axle to something with normal wheel ends and brakes. This has been brought up many times on here. Below is a link to the most recent thread I could find on the matter. I always wondered about calling a parts place in France. Presumably there would be a lot more of these trucks over there since they are just rebadged Renaults and imported from France. Maybe they are not obsolete over there yet if you can determine the model number they were sold over there as. Just a thought if you can speak the language.

Ok I try to always follow up on threads I start. Anyway I got to working on removing this system from my truck. I started with removing the switch, indicator lamp and associated air plumbing in the cab. What I’m a little stumped on is what the valve in the first picture is? I will preface that question with how the switch was plumbed behind the dash. There is a large maybe 5/8” airline coming from I assume the air tank into a tee. Out of one branch of the tee goes to the air gauge. The other branch went to the switch. If the switch was turned “on” air would be sent to the valve in the first picture. The line went into a tee that was on the back of this valve and out of the other branch of that tee a line went to the cylinders on the bay pass duct. You can see there is a 3/8” plug in the back where the tee used to be. There is also a line going from this mystery valve to what I think is the aneroid (spelling?) valve on the intake manifold for the puff limiter in the second picture. The left and right sides of the valve in question are just dumping to atmosphere. Is it a quick release valve for when you flip the switch to “off” and/or when the manifold pressure gets high enough to dump the air on the puff limiter? 

I think Joe Biden is from Scranton and Fetterman is originally from Reading, PA.

And yes the CS clones that are here in the sates go by many names, Metro, Field Marshall, DES, GTS, Powerline, and many others. From my understanding the "brand" is more or less the assembler and/or exporter. I think there are many workshops in Pune, India that assemble them for anybody and everybody with little to no difference between them. They are just copies of the original CS Listers manufactured in Dursley England. 

1 hour ago, mrsmackpaul said:

I wonder how it goes with the drum (barrel) of water for cooling in places that get bellow freezing for long periods

I plan to use a thermosiphon radiator off of an old John Deere LUC power unit with a cooling fan driven off the engine flywheels. The cooling fan will blow across the radiator much like a vehicle's cooling system. It will take some trial and error / testing once I have it up and running to see what kind of load I can keep cool and for how long. I don't think it will be a problem with a 6kW load, which is all my generator head can supply. I believe the LUC engine was rated at 16hp so I should have plenty of cooling with its radiator in this application. Of course I will be using a 50/50 glycol / water mix to prevent freezing. 

I was going to say since its a single axle not too much weight there. Truck will weight 12,000 pounds max but probably less. Only thing to look at on trailer is the tires and hub oil. If the tires are not overly dry rotted and weather checked I would load the B61 on it and pull it home with a truck you know will make the trip. With 8 tires on the trailer and a relatively light load I wouldn't loose much if any sleep over using the trailer to haul the truck as is. If you drive the B61 straight onto the trailer most of the weight will be on your towing trucks 5th wheel anyway.

2 hours ago, mowerman said:

 OK I think I was damn lucky to get this one down loaded enjoy fellas it’s not much…. Bob

You gotta get it finished by June of 2027. I just got the latest ATHS magazine the other day and they are saying the national convention show for 2027 is going to be in Reno, NV. June 10-12…..right in your back yard

1 hour ago, Hayseed said:

That will last forever & a day..!!!
I've Got a 1926 Lister Petrol Motor (The Crankcase,Flywheels ect Look Indentical to That) That I drive My Sawbench with & cut All our Firewood with..!

Ahhh the perks of being a British colony. Old lister engines probably everywhere down there. Sadly they were never really common here. Then India cloned them. The quality of the the clones is shotty at best. They need completely torn down, and cleaned of casting sand and reassembled before they can be run. Our EPA banned the importing of them a while back and you don’t hardly see any at all now. Some people try to sneak them in as “air compressors” with the injection pump removed but I think the customs people are wise to that now. They are certainly a unique engine. If you know then you know…..

I was behind an electric Ford lightning at a stop light the other day. The chassis looks crazy. The back suspension are these insanely large aluminum A arms and there is a CV shaft going to each wheel end. No conventional differential and solid rear axle. It seemed like it sat a lot higher than a regular f150 but I’m not sure. 

I see Bob's DM playing peekaboo behind the house 👁️‍🗨️. What a little tease...lol

13 minutes ago, MACKS said:

See if u can easily spin the fan when the truck is cold..

Should you be able to or should it be locked up when cold and not running?

I thought ethering an ASET engine was like the biggest NO-NO in the book? I have a friend who used to own a large fleet of E7s and ASETs. One of his trucks was far away from home and had to get towed into a shop. The shop was a one man real old school operation and the old timer had never worked on anything that new at time. He used ether on it and it wiped out something in the head. Something in the valve train is ceramic or ceramic coated and you can't use ether on them? I can't remember. Maybe I'm wrong on that so correct me if so.

If your getting good fuel up to the head ether the computer isn't allowing the injectors to operate because it isn't satisfied or there is not enough compression to ignite diesel. When you crank it without ether will it start to smoke at all out of the exhaust? No smoke no fuel?

I love living in an area where there is actually 4 distinct seasons, however, winter is my least favorite. The first snow or two are nice but after that I'm really done with it and can't stand it. I despise the cold the most. Once it gets cold out I light a coal fire and pretty much hibernate inside until mid March. I think we hit -8 and they said it felt like -30 with the wind. Today its supposed to be 51 and sunny.