Mandrewoid

Ohhh yes I know that equipment. Live less than a mile from Quinte Mobile concrete. They've got tons of volumetric mixers. The older ones run a big crank mounted gear pump like a garbage truck, and then use pressure/flow compensating valves, and the newer ones are Allison autos with REPTO. .... Kinda jealous of those new trucks 😂. They have a few international and a few Mack.

What kind of application is that? Mine has a second pump on the front for running aux functions but I have it just pumping oil through the filter and back to tank.

The pump is an Eaton hydrostatic pump. 5.4 cubic inches. 40gpm@1800. But it's a variable displacement pump. The response time would be because the pump has to swing the s wash plate before it starts pumping. Although maybe if I put an air cylinder on it it would move faster than the current 1/8" hydraulic cylinder that activates the control lever. I could put a button on the shifter that would be kinda cool.

Another fun experiment that I'm not sure anyone has ever tried before. You could link up your throttle pedal and a boost sensor to a 1-in airline going to your exhaust manifold on the pre-turbo side. Then when you stomp on the throttle at 900 RPM and have no boost yet. Dump compressed air from your air tanks into the exhaust manifold to light up the turbo faster. If you want to get real fancy you can also stick a fuel injector in the exhaust manifold so when you dump this cold air in then you light it on fire. And you have a jet powered turbocharger for a quarter of a second every time you step on the throttle until boost builds.

I have also toyed with the idea of using my massive live PTO as a hydraulic retarder. All I have to do for that is install a check valve and a 4000 PSI relief valve. It would dump a lot of heat into the oil but at maximum rpm it would give me 150 horsepower of braking force. I never thought of using it as a shift assist though because the delay from hydraulic valve activation to pressure actually building is probably about half of the amount that you'd need to make a good shift anyway. Unless I had the oil always pumping and just threw a directional valve in order to activate the breaking then it would be immediate but if I screw it up I'd end up with 300 gallons of manure on the road. My tanker unloads 6,000 US gallons in one minute and 30 seconds

A guy might be able to get away with 30 PSI of exhaust back pressure. Because that's about the same pressure as your turbine drive pressure under hard loading conditions would be. I have looked for these butterflies before and I've seen them for RV purposes but I've never really seen one that I thought was big enough to use on an e6 Mack?

I like this idea. But I'm also afraid of valve float from exhaust back pressure. I never really thought of it before, but two valves have much more surface areas and fewer valve springs to hold them shut. I'm pretty sure my engine is a 2 valve, I have had the covers off in the past.

It is an EM6-275L for sure. I believe the other one is an EM6-350 but I will definitely check. It only has a 9 speed so my assumption is that it has the same large power band. Especially when I talk to the old owner of that truck and he describes driving it. The 350 had a massive air to air in front of the radiator, and my 275 is a tip-turbine with water to air. I saw on here somewhere that they did make a tip-turbine 350 with water to air. Would that be the same motor internally as mine, or did Mack do crazy things like put different valve springs and pistons in depending on the horsepower designation of the engine? It would make sense to me to keep all that stuff common for ease of manufacture and parts supply... But I know other engine manufacturers did not do that.

I realize this is several years ago, but this is exactly the issue I have with our EM6-275L. The puff limiter is disabled and the fuel plate is adjusted and ground down a little, but still when you hit 1700Rpm, those governor weights pull your fuel rack back because the springs cannot hold it in anymore. In my case I do have an "L" rated engine, which I know was designed for fuel economy, but now in the second life performance matters a lot more. I can't shift gears going uphill because you lose so much speed, by the time you get into gear it's dropped to 900rpm,and the sky turns black.

No this is incorrect. You can set the high idle screw to 2300 rpm all you want, but if you have 1800rpm governor springs, you will only make idle power at 2300rpm. What you can do is put 3000rpm governor springs in and then turn the high idle screw down so you don't exceed 2200 rpm. At that point it will likely behave a little bit like a farm tractor. As soon as the engine rpm drops to 2100, all the horsepower will be available. You won't have to wait to drop down to 1700rpm.

In neutral I've got 1990RPM. Under significant load I've got 1800. My understanding is that the e6-285 has different governor springs than the e6-275L but otherwise should contain identical internals. The low rpm version was designed for fuel savings, which is no longer an important issue for this vehicle. Time savings and performance is worth it for us. The people that do extreme truck pulls with these, are there any of those guys here?

Maxitorque 8 speed. Everything on the truck is factory. It used to be a cement mixer. Just made for local city driving. Now I'm taking it all sorts of off-road up very steep slopes trying to keep my speed and engine rpm up in order to unload my load. Overall GVW is pretty similar to the mixer configuration, because the tank has a very heavy subframe and I've got 5990 USG of manure

You can still adjust the high idle stop. I don't want my engine to actually turn 2800, I just want full fuel all the way to 2200. The notice on the sun visor says it's good for 2300rpm. I'm sure people have pushed that a bit and gotten away with it too. I have found that on an incline of any sort, I can't get above 1700rpm, then when I try to shift I'm down to 900 by the time it gets in gear. Then I'm turning the sky black for 3 minutes before we get some boost and some RPM going. If I could shift at 2000 or 2100 it would be much better for everyone especially the guys behind me. And if I can maintain 2000rpm in field in second gear that would be nice too. The governor springs from my spare motor would be guaranteed not to hurt it, but not sure how much of an improvement it would actually be.

Following on a thought I had in a previous thread. I know a few people with Cummins pickups( same fuel pump as my E6-275L. ) Who have replaced their governor springs with higher RPM springs, and they say it really awakened the truck quite a bit. I know these trucks were made with the L destination for low rpm in order to be more fuel efficient. Fortunately for me in my off-road application the fuel economy is pretty much irrelevant, what matters to me is having the widest possible power band. There are times where I can definitely tell that the pump is de-fueling due to high RPM, but I'm not talking 2000rpm, I'm talking about anything above 1550rpm the engine starts to work less hard. It is my understanding that higher RPM governor springs will help to solve this problem. Obviously I'm not going to go 4000rpm like the truck guys do. But I am thinking perhaps a stock spring from a Cummins would work in the Mack application. Or possibly the spring out of an E6-350, or maybe even just a 285 non-L Does anyone have experience with this? In the Cummins, the fuel pump is mounted with the governor springs on the outside so it is a 10 minute job. On the Mack, it seems to be on the inside, so the fuel pump may have to come off... Looks like the stock Cummins is set to 2800rpm. That should do nicely, as long as I don't actually allow the engine to over-rev

Do you think the mounts will be in different spots too? Drilling new holes in the frame normally wouldn't be a big deal, but my fenders etc are in the way. Perhaps this is why people don't do it. I already have an E6-350 spare engine for parts from a truck I dismantled 😅 but it has a 9 speed unfortunately. I have wondered about stealing the injectors and fuel pump to give me more power. I have already ground my fuel plate in the e6-275 that this truck has. The problem is that it's a 275L so with the low speed governor springs I'm still losing all my power about 1600 rpm on the top side. I'm sure if I had full fuel all the way up to 2100rpm it would be a different beast.