The Ultimate IH Fourbanger

I think I am going to try and utilize the OEM 3 bolt exhaust manifold. Did a very rough mock up, and I think it will work. Plenty of space for the turbo charger and plumbing.
The compressor housing will index about 80-85 degrees to face the outlet more of less up if I need to. I plan on having a charge air cooler so down facing is better as it would go below the engine mount bracket and through the existing oblong 3X4.5 hole in the core support, through the cooler and back through the same hole.

I went ahead and bought the exhaust and intake flanges so I could see how they would.

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Been a long time since I had a model 80. So there will be room above the frame rail? Just trying to visualize it.
 
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You might be on to something. I have two of these manifolds and one for sure came from a 152T. This mock up engine has a special port in the lifter cover that was likely the oil return for the oem turbo?.
I had just assumed that these were standard three bolt exhaust manifolds. I had better use one that I can source new.
 
Got my 2 bold manifold and swapped it on to the mock up engine. It is exactly the same flange height as the 3 bolt 152T manifold. It will have the rear bolt in a difficult location so I'll use a stud threaded into the flange and a nut up above if it is a problem. Pix of course.

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Robert Kenney said:
Does anybody know if a oem turbocharged 152 was stamped with a “T” in its ID pad, EG 152T instead of 152E or 152A?
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For some reason I have one left-over, fubar 152T compressor housing and it still has that little ID plate on it. Is what you are looking for on that plate or perhaps cast onto the housing's surface?

How does the overall diameter of that T25 compressor (or exhaust) housing(s) compare to the original TRW turbo? Smaller, I imagine?
 
I was referring to the engine block pad where they also stamp the SN of the engine. I think the mock-up was once a 152T from the parts on it. The block is stamped 152E.

This GT turbo is smaller but will flow enough for 270 hp but has smaller in and out diameters than the OEM unit.
 
Robert Kenney said:
I was referring to the engine block pad where they also stamp the SN of the engine. I think the mock-up was once a 152T from the parts on it. The block is stamped 152E.

This GT turbo is smaller but will flow enough for 270 hp but has smaller in and out diameters than the OEM unit.
Click to expand...

Sorry I misinterpreted your question. It's a good one - like to know the answer to that myself. I'd post this on the BB. There are a couple of people that still having running 152Ts.
 
Still mulling over the location for the turbo. I have sourced another GT turbo with journal bearings and no water required. It has better turbine flow capacity and still will support 250 hp. It is the gt2252.
Still however mounting it low like I have photographed has some drawbacks:
1) Being low exposes the turbo to water and other objects.
2) Tucking it in close to the block for space, will create some plumbing issues. The OEM manifold to turbo inlet is a tough angle. While doable, I will end up with having to preassemble the turbo and manifold prior to installing on to the engine. As well as requiring that the oil drain be plumbed into the pan with little drop.

I'll break out my 152 T exhaust manifold spacer (sorry Mark) and mount the manifold pointing up for mocking purposes. I wonder how bad repoping the spacer would be? probably SS or steel billet :yikes:. Or find an extra one. If there are any members willing to part with one PM me.

I'll tinker with the options and see what makes the most sense.
 
Bolted the 152T exhaust manifold wedge/spacer and the new 2 bolt manifold. The spacer is in super nice condition. All threads and surfaces are perfect. It makes a nice combination with the smaller modern turbocharger. Will need to make the rectangle to round adapter riser but that shouldn't be bad. The little turbo sitting up on the manifold looks odd.

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Lookin' nice! So...do you think it is possible to get the dimensions from that spacer so one could be duplicated? Costly, maybe, but hmmm...

Edit: Robert, this engine is going back into a model 80, with that 15 degree rotation, right? Are you going to upgrade the T90?
 
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I think a custom "Log Styled" manifold would be better and cheaper. I would want it to be SS rather than any steel.

Yes to the stock Scout 80. The T90 should survive non abusive driving.

My single biggest concern of this whole project is the 4 bolt/cylinder head configuration on these SV's. My concern may be unfounded as other manufactures successfully utilize this configuration, but from a forced induction perspective, I have the most experience with GM's and they use 5/cyl.
It won't take long to find out where the weak link is. :eek:
 
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How much boost you wanting to run? I'm going to keep my next iteration at 7#, which is probably well within the safety margin. About your T-90. Maybe you can score one of those special 152T T-90s listed in the Sales brochure, you know, the ones with "the shot peened gears for added strength" :icon_rolleyes:.

I can tell from your pics that the plane of your exhaust outlet is horizontal; that's due to the 15 degree rotation of the engine itself. When I had those parts on my 196, the plane was rotated 15 degrees outward due to the normal placement of the block. I recall early on you advising me to use a modern turbo, and so now I come around to your way of thinking. I knew that to do that an adaptor of some sort would have to be made to replace the iron elbow, and it would couple the turbo closer to the engine. Looks like you are blazing the trail on fabbing that adaptor. What makes this so appealing to me now is that I think the T25 is a smaller package than the old TRW, and would eliminate the hood clearance problem I had, something like 1/2" or so.
 
The log style manifold would need to be built such that the bolts that attach it to the head were either below or above the log. Either that or the log is set out wide so you could install and tighten the bolts between the log and the head. I thought space would cause issues.

That factored into my decision to test fit the wedge/spacer.

One caveat on having the turbo and other masses hi high and above the engines center of mass is that it is subject to a lot more transverse displacement vibration than down low and close to the crank center line. That being said, I could be wrong (not surprising to me) by the way, and most of the vibration displacement is vertical.

You brought up physical turbo size so here is a photo or two of both of my modern turbochargers. The one with the silver wastegate diaphragm is the gt2252 the other is the gt2554R.

The gt22 actually flows better through the turbine ,but nets a lower air flow than the gt25. The gt22 is oil only and journal bearing center section while the GT25 is oil lubricated and water cooled, and is a ball bearing.

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Looking at the end-view pic of the wedge/manifold. Imagine just the wedge bolted up, with a heavy wall log, say, 2" or 2 1/4" OD, lying against it. That log would be in about the same place as the main body volume of the up-turned iron manifold. So the log would be spaced out the distance of the wedge. From what I'm seeing, that would still allow clearance to remove the plugs (a super pain nonetheless); four very short, heavy-wall schedule 40 sections would replace the wedge, bridging the gap between your exhaust header flange and the log. Then the turbo flange is welded to a short section welded onto the log. This flange mounting surface would be located in space at about the height of your manifold + your anticipated spacer mounting surface. As far as flow through the log is concerned, would it be worse than as through the stock manifold? Would it even matter? In the end the question is making a weldment as strong as those iron pieces to support the turbo without shaking and cracking.

Edit: Oops - haven't forgotten the most important thing. The center axis of this log will be just high enough above the centerline of the exhaust manifold mounting bolt holes so the bolts will clear! I think that can be done.
 
Some progress on this project.
1) Rotated the center bearing unit so the drain is down.
2) With the stock designed 2 bolt manifold I played with optimized turbocharger mounting and orientation.
3) Created a solid model for a one piece Turbo inlet transition. I'll use this to create the tool paths and wire EDM geometry/program. The one piece transition will sit the turbo about 3/4" higher than the pictures here.
4) Bought the turbine outlet plate, and the azzhats missed on a hole location. So I fixed that. You can see it in the photos

Oh yeah, to Marks question regarding boost, the waste gate is set for 10psi. But I don't see that as a limit.

A few snips of the model. and how I will orient the turbo. About 15 deg. clocked CCW leaves the ports in better locations for plumbing.

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Kind of a wait and see. I envision an air cleaner housing on the passenger side front inner fender. Still looking for a suitable one.
Turbo outlet, down and in between the middle two intake runners, forward into the intercooler, and back, and up into the intake plenum.
 
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