rhinoo

34 minutes ago, BOBWhite said:

Tread lightly when tuning an E6 especially a 2 valve. 

I did tune my e7 and it’s a powerhouse now. I am leery about anyone else driving it though because in those long pulls I have to lift up on the accelerator a little or it egt’s get a little warm. Does the 2 valve let it heat up even more?

8 minutes ago, JoeH said:

11 liter, not 10.  Don't be fooled by its size, Mack rated their HP at the wheels, not at the flywheel.  So a 350 Mack should make more power than another brand 350.  I haven't driven an E6-350, but it should pull well. Only turn it up if you're the only one that's going to drive it, and don't do much. They're incredible engines for their size, and Mack maxed them out at the perfect power vs durability ratio. If you tip more towards the power then you'll lose durability.

Ok. 11 liter sounds better than 10.. is there any way to tell if it’s a two valve without removing the valve covers? It does have a 13spd behind it so that will help 

Just now, rhinoo said:

Guy found the engine tag. It’s says E6-350R… I’m a little bummed because the e7 in my dump truck is impressive with stage 2 injectors and a big turbo but I talked to Brad at Rochester and he said we can still make it run good but a 10 liter engine just seems awfully small to get a whole lot out of. 

I was gonna add a pic of the tag but I can’t figure it out. 😆

19 hours ago, rhinoo said:

Guy found the engine tag. It’s says E6-350R… I’m a little bummed because the e7 in my dump truck is impressive with stage 2 injectors and a big turbo but I talked to Brad at Rochester and he said we can still make it run good but a 10 liter engine just seems awfully small to get a whole lot out of. 

5 minutes ago, rhinoo said:

Looking at buying an 688st and the guy said his father in law had a rebuilt e7 engine into the truck. Was wondering if anyone can identify the engine off of a couple pics I got. I have an e7 in a Rd dump truck but haven’t been around an E6. Thanks 

Looking at buying an 688st and the guy said his father in law had a rebuilt e7 engine into the truck. Was wondering if anyone can identify the engine off of a couple pics I got. I have an e7 in a Rd dump truck but haven’t been around an E6. Thanks 

3 hours ago, MACKS said:

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

Mack didn’t have one and was $250 and said it was on back order. Fans spins but has some resistance. I am replacing the O-ring on the power steering pump and all the hoses this morning, when I get it back running again I will mess with the fan a little.

1 hour ago, Joey Mack said:

so after about 15 minutes or so, does it NOT disengage?  and then kinda come in and out as you drive?  

Na, it’s noisy as hell about all the time it seems. I think if I rev motor up to a high rpm it may let up some but rarely ever notice it not being loud while driving. If they are only $100, I will for sure pick a new one up tomorrow. I will also go ahead and blow the radiator out good while I’m at it. That teacher was actually a pretty good one. One of the most caring teachers I ever had. He probably only told me that and not the other students cause he knew I wasn’t dumb enough to chop my fingers off but it was definitely one I never forgot. Lol..  I guess I was wondering more if that was even a factory option on that fan or if someone had done a cheap fix on it but sounds like that’s what they put on them. I’ve been running it on the farm for over a year and still running strong after y’all helped me get some bigger injectors and some more fuel to a bigger turbo someone had installed on it before I bought it.  That 350 now will easily push my brothers 425hp c12 in a t800 over any hill when we run together. Thanks for the help.  

Got a 98’ Rd688s with an e7-350 and the engine cooling fan seems to run too much. I own several semis and they all are air operated but this motor has a fan drive type fan on it. Im not sure if this is even correct or not? I assume it works off of a thermostat built in to front of the drive? I can turn it with engine off but has some resistance to it. It looks like it had been replaced recently. I can start it up at 20 degrees and it will be running wide open. Any help is appreciated. 

I was on here a while back and had bought a truck with an upgraded s-400 turbo which had terrible turbo lag. I added bigger injectors and made a few tweaks to the pump. Truck runs great now but egt’s are a little warm. 1050 degrees behind turbo @ 36-37 pounds of boost. If I’m driving it and get in a long pull I can let out of throttle and get it to drop down but at some point one of my lead foot drivers will be in it so I’m thinking I need to cool it down. My question is, if I get rid of the 4” exhaust will that help or do I need to back fuel down a little? I really like how it’s running and hate to defuel it. 

4 hours ago, Joey Mack said:

well, that makes it even easier..  jojo

Thanks for yalls help again. Found a couple exhaust valves that were a little tight but not bad. I think it should be ready for them big loads now. 😁

46 minutes ago, Joey Mack said:

ok.. you have an E-7...  the exk on them was .028"  the engine brake is set based on the turbo you have.. widen the picture so we can see the whole plate and get the number off the turbo tag..  probably an S400 SO41  schwitzer.... jojo

No brake unfortunately. 

Ok, finally found the marks. I guess someone put a clutch in at some point and installed the pressure plate bolts in those holes. I was looking at the empty holes. I also just noticed my valve cover stated specs of .016 and .028

8 hours ago, theakerstwo said:

Poat a photo of the bottom of the housing please.

This is not mine but looked the same. That part of housing that sticks out with a hole in it looks same as mine but mine had a steel plug in it. It didn’t seem if it were going to come out easily. 

6 hours ago, Joey Mack said:

yep pretty easy..  The marking are 1&6... 2&5... 3&4.....  it follows the firing order...  'too young,, too old,,, just right!'... 15-36-24.. when the pointer is pointing at 1&6..  look at the #2 exh. rocker. it should be 'rocked'  if so ... you are up on #1, if not , you are up on #6..  easy breezy... jojo

Got under truck this afternoon to try to find the marks on flywheel and pointer. The only think I saw was a part of bell housing that protrudes into the inspection hole. It would be a hole that possibly you look through but it had a metal plug in it and didn’t seem like it was going to come out very easily. But, maybe that’s not even the right thing?

7 minutes ago, fjh said:

Strange But Nice! Your getting the boost of a stock 427 a little under a 460 37 - 40 ! Good job! You can bump a thousand for a bit and not hurt anything as long as the boost doesn't start falling off to much !

I ordered a set of valve cover gaskets for it since they are seeping a little. I figured I will go ahead and run the over head while covers are off. Does .016 and .024 sound right for that engine? Definitely harder to find info on these motors vs cat or cummins. I briefly looked for a pointer on front cover at the damper and saw a piece of casting that could be a pointer possibly but wasn’t sure. 

Just wanted to update on the truck:

I had ordered a set of stage 2 injectors from Rochester diesel and was wanting to fix the fuel pressure issue first but after not much luck figuring it out I decided to go ahead and change them out. After getting them installed and took the truck on a test drive my fuel pressure problem was fixed. Went to 20psi just off idle and 40psi at wot. Under a load it would hold around 26psi.. doesn’t really make sense but that’s the result. I adjusted the cog wheel in the governor and removed all of the lag. I am impressed with how it is running now. Pulling hills in 2 gears higher than previously. Egt’s are a little warmer than what I would prefer but I think it will be ok if i keep an eye on it. 35psi boost and egt goes to 1000 in a long pull for usually no longer than 20 seconds. Does that sound ok or too hot?

1 minute ago, br549 said:

Truck built 2/24/98 E-7350 Mechanical engine   1996 EPA

So, what’s there is possibly original it sounds like. I did notice the tag on valve cover said 1998.. I just removed that plastic line on intake that goes to diaphragm and sucked hard on it and it held a vacuum. Someone mentioned a different gauge so I guess I will check that too. That is a Matco gauge I’ve had for years but won’t hurt to eliminate that. Under load with boost pressure the fuel drops to almost 10 pounds according to the gauge I have on it. I just wonder why according to the diagram that Mack sent it appears to be missing that over flow valve? 

Just now, rhinoo said:

Vin# 037403…thanks

Just now, rhinoo said:

Vin# 037403…thanks 

Rd688s

 

14 minutes ago, br549 said:

What is the model and last 6 of the VIN, i will ck and see what it came out with.  If your only complaint is the lag, I seen truck with that fuel pressure give no problem if it dont go lower under a load.  If you want it to get rid of the lag, you need to ck the line and diaphgram I talked about in an earlier post.  If it is OK I  would pull the plug on top of the governor and you can adjust the pick up when you mash the pedal, it will get rid of the lag.   it will give the fuel faster, but will put out a little bit of smoke.

Vin# 037403…thanks 

Just now, rhinoo said:

I called Mack earlier and asked them about the return side fittings. I could tell me and him were describing something different so I asked for a diagram of the pump. A transplant like you mentioned would make sense because according to my serial number it shows in the diagram it should have and overflow valve plumbed in coming out of the injection pump. I guess possibly someone removed it or this motor did not come in this truck and has a different return system on it. In the diagram (cb) is called an overflow valve. 

2 hours ago, fjh said:

that is a manual pump and that drainback system is what was normally used on VMAC pumps how ever doesnt mean it can't be used on the manual pump! The T style is what I would think should have been on there! 

I called Mack earlier and asked them about the return side fittings. I could tell me and him were describing something different so I asked for a diagram of the pump. A transplant like you mentioned would make sense because according to my serial number it shows in the diagram it should have and overflow valve plumbed in coming out of the injection pump. I guess possibly someone removed it or this motor did not come in this truck and has a different return system on it. In the diagram (cb) is called an overflow valve. 

12 minutes ago, rhinoo said:

So, I connected lift pump directly to a bucket of fuel and still had same low pressures. Went and picked up a new lift pump at Mack today. Slapped it on and same exact pressures. I was looking at return system today wondering if something isn’t going on with that. Looked in fuel tank while truck was running and seems like a rather large steam of fuel is returning. Where the return line comes off the injection pump there is a fitting with a restrictor hole to limit return I’m guessing. On the fuel tank side of that restrictor hole is a tee fitting that has a 1/4” or so rubber line that runs over to the back side of the injection pump and connects to a port. Not exactly sure what that is but any chance I could have an issue with something here? Could that small hole be worn to a bigger size?  

On 12/7/2021 at 4:45 PM, Vmac3 said:

Yes are absolutely correct, but we already have low fuel pressure to begin with. The poster already mentioned that they checked all basics. So I don't see as to why the poster would have to check it under load to reconfirm that there is low fuel pressure. The only other thing is to bypass the complete fuel system and run the fuel system in a bucket straight from the transfer pump. If the pressure doesn't go up then we can confirm that the lift pump is defective.

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So, I connected lift pump directly to a bucket of fuel and still had same low pressures. Went and picked up a new lift pump at Mack today. Slapped it on and same exact pressures. I was looking at return system today wondering if something isn’t going on with that. Looked in fuel tank while truck was running and seems like a rather large steam of fuel is returning. Where the return line comes off the injection pump there is a fitting with a restrictor hole to limit return I’m guessing. On the fuel tank side of that restrictor hole is a tee fitting that has a 1/4” or so rubber line that runs over to the back side of the injection pump and connects to a port. Not exactly sure what that is but any chance I could have an issue with something here? Could that small hole be worn to a bigger size?