M925a2 Power Surge

[Jbulach]

Booooo!!!
Yep, pretty sure theres a process for chroming just about everything, or at least chrome like! Vroom, vroom...

 

[red]

All this talk of chrome has me thinking of the latest Mad Max movie, Fury Road haha.

 

[someoldmoose]

No need to "chrome" aluminum. Polish it out and have it clear anodized (Durabrite like Alcoa wheels). Will outshine and outlast any chrome plating out there because it's the full depth of the material, not just a few millionths of an inch.

Gimpyrobb, thank you for reminding me of my long forgotten past. Raging Slab ! Yessssss

Jbulach, have you seen the vid of that Double Dozen running ? Complete insanity, so of course I LOVE it !

 

[74M35A2]

More Raging Slab, just kidding. I'm moving the turbo to the same location where it is up high on the 8.3L. So, off with this exhaust manifold, and I 'll need to clock both housings on the turbo. The turbine housing has a locating pin to the center section, but that can easily be re-drilled. That is to prevent rotation between the turbine housing and center section (CHRA) since the VGT vanes will cause a rotational force. The turbo oil amd coolant lines will be easy to replace with longer ones.

Also a pic of the 24 valve configuration looking into the exhaust port.

 

[Another Ahab]

More Raging Slab, just kidding. I'm moving the turbo to the same location where it is up high on the 8.3L. So, off with this exhaust manifold, and I 'll need to clock both housings on the turbo.

View attachment 684403

I don't know as much as I should, but you're saying the turbo will locate like literally on top of the block somewhere, or off to the side (off the manifold), somewhere?

 

[Buffalobwana]

I wish I knew about half of the things you do about engines. I'd be so cool. Well, I'd be so able to do more work on my own engine.

 

[WillWagner]

I don't know as much as I should, but you're saying the turbo will locate like literally on top of the block somewhere, or off to the side (off the manifold), somewhere?

It just means the manifold that the engine came with mounts the turbo in what is called the low mount, rear out, LMRO, position. He wants to locate it to 1 of 2 positions, high mount rear out, HMRO or center mount rear out MMRO. HMRO will have the turbo mount flange facing up and the MMRO will have the mount flange at almost straight out.

examples....

 

[74M35A2]

Yep yep, thanks. High or low rear just makes it harder to bend exhaust 90, though there are ways to do it. Low rear as it is now may hit the heater core box. Going for high-center mount, which is where the stock 8.3L is. Still learning, looks like some manifolds have round ports (like mine), and some have a "peanut" port shape to them. Pics below are of the config I want, and the manifold I think I need. This locates the turbo mount between cylinders 3-4, and at an upper angle, vs downward angle it is now.

 

[WillWagner]

HMRO. look at the jpeg I posted. At the bottom, it shows the related options. Those are for the plumbing, like the drain line and coolant plumbing. Remember how to look them up on QSOL?

 

[74M35A2]

Yep, thanks. Got the turbo apart. No locating pin for the turbine housing. So, easy to re-clock it for the position I want. Just line up the vanes and we're golden. Here is a couple of shots of the VGT. Next post will be how it actuates. I did not know until I played with it. Simpler than expected.

 

[74M35A2]

OK, so the pneumatic cylinder is spring loaded one way. When air is applied, it pushes up the collar which all the vanes are located. This is really called a nozzle. These vanes are cut with 2 different patterns in them. Depending on how the pattern aligns with the turbine wheel fins affects the where the exhaust gas hits on the blade, and the angle. The turbo also has a speed sensor on it which is monitored by the ECM to help control this. It is variable position, the ECM monitors intake boost pressure and adjusts the VGT until target boost is reached. This is their first gen VGT. Next/current gen is electric motor actuated, no air cylinder.

2 pics below are VGT in both positions:

 

[74M35A2]

I wish I knew about half of the things you do about engines. I'd be so cool. Well, I'd be so able to do more work on my own engine.

Thanks, but, I really just guess my way through it and put on a good show. I wish I knew less about engines, and more about other things in life that matter more, but oh well, this is what we've got, so it is what it is.

 

[74M35A2]

Here is some grid heater action, just shoved my phone in the intake and clicked it:

 

[someoldmoose]

74M35A2,You will LOOOOOVE that variable turbo. I drove a Single-set for years. Great fun trying to cross intersections. The lag was terrific. Would finally spool up and "rocket launch" me right about the time Soccer Mom was getting ready to blow the horn and flip me off. 'Cept she'd a hadda put down either her phone or her latte' to do both. Those remind me more of a Roots type supercharger with almost instantaneous boost that just builds and builds, also holds boost better while shifting (since you went the manual route) Didn't look back through posts, does that engine have an engine brake ?

 

[Elijah95]

Really jealous of this build :drooling: I have a spare HE431VGT air actuated turbo nearly brand new if anyone wants it for a small fee


1974 AM General M109A3 w/Deuce Bed, White LDT, Whistler C, and soft top

 

[74M35A2]

Thanks. I'm looking forward to some of the toys via this modernization.

This particular ISL does not have an engine brake. It came from an expensive RV, and I don't think that group enjoys excessive noise. It did have an exhaust brake on it though. Factory mounted and controlled. The ISL can be had with a engine compression (Jake) brake, but not this one in particular. I know a lot of people like them, but brakes on an M939 are outstandingly strong anyway. I'm looking more for the go than the stop, or noise.

 

[74M35A2]

There is a factory block mounted coolant filter available. Yummy.

 

[someoldmoose]

Roger on the brake sitrep. The coolant filter is an awesome add-on too. I am soooooo envious. I would love to do something similar in the future. ISX12 with the automated ​Eaton is my dream combo.

 

[74M35A2]

New/used exhaust manifold arrived in one day. Nice place. Lowest prices, part came cleaned and painted. Puts the turbo about where it currently is on the 8.3L, just slightly further away from the block, but should be fine. Remaining engine homework will be to flip the oil pan to front sump, change the pickup tube accordingly, and ditch the Allison to mate the Road Ranger 13 to it, then the truck goes under the knife for the transplant. I hope to simply re-use my existing 8.3L flywheel housing as to not disturb the rear mounts and starter position. If I have to move them in the end, then it is what it is.

 

[red]

Make sure to check the clearance on that tubing for the lower radiator hose and that filter mount on the passenger side of the engine. With the engine offset to that side of the truck it can create clearance issues, common problem with those that have swapped in more powerful 855 series engines. Might not be a problem with this swap but should be easy to verify before the first test fit/install.