[RufusTheDufus]

Yet another turbo buildup thread.

I'm doing a log manifold for the H diesel in my 1980 HJ45 Troopy. There's really not much available out there for adding a turbo to an H so I figured I'd just do one myself. I know it's not the ideal engine for a turbo but I already have it so I might as well use it.

I had to replace the pistons so I did a valve job at the same time. (The replacement pre-cups are still on order.) It's the perfect time to add a turbo.

The only "special" thing about my buildup is a little fun with Solidworks designing an exhaust manifold mounting flange. I had them laser cut by Laser Cutting Services in Oregon.




The manifold will be made from 2" square 316L stainless. It's maybe not the ideal material but it's relatively cheap and easy to work with.

I'm guessing the total cost of materials for the project will be $450 to $500. That's a pretty cheap turbo setup if it actually works.

For more pictures and details see my blog at Parts is Parts | Rufus The Doofus

I'll also post more photos and updates here as I make progress.

[dingbatt]

Nice work going the DIY turbo install path, dude.

Should be a good thread, this!

Please, do go on....

[herbs]

I'll be watching this one with interest, I know a few years ago Denco here in Australia offered a turbo kit for the H - never tried it though. BTW, as an aside, anyone manage to bung a power steering pump onto one of the H motor successfully?

[Dougal]

Come on, post up the solidworks shots.

[RufusTheDufus]

The solidworks shots are pretty boring. They look exactly like the part in my hand above.

I didn't have the holes for the studs laser cut. The 2" square tubing is a tight fit between the studs. I'm going to drill the holes after welding the tube to the flange.

This photo will illustrate that more clearly.



The general plan at the moment is to cut 1 inch stubs of tubing and weld them to the flanges. A short piece of tubing will allow me to weld both the inside and the outside edges. When that's done I'll drill the holes and bolt the stubs to the head. I'll use their placement to mark up the long section of tube so I know where to cut ports.

Next I'll TIG the whole thing up and weld in block-off plates on the end of the long tube. Then I'll figure out where the 1/2" thick flange will go for the turbo. It should be fairly easy to pick a spot to place the turbo. There's lots of room on that side of the engine and it should be fairly easy to route the intercooler plumbing under the alternator too.

I'm thinking that I will need to gusset the stub-to-log welds. I haven't figured out how I will tackle that yet. I'm also wondering if I should double up the material on the side of the tubing with the manufacturing weld? You can see the weld on the inside of the tube in this photo. It's not visible from the outside.



I have no idea if a welded tube like this will eventually crack from thermal cycles.

[bigbrowndog]

With the tube that size and the studs being a bit short on space do you still have enough room for a ringspanner or socket to fit on the nut allowing for the weld chamfer or are you going to use set screws? It is difficult to see from the picture you posted. The stainless cuts are really cool, cheers.

[RufusTheDufus]

I should have enough room. I'll printed a 1:1 sized part on paper and placed a gasket and tube on it. I'll scan it later today just for illustrative purposes. It's tight but it should fit. I may need to drill into the weld chamfer a small amount. I plan to build up the weld in that area on the inside of the tube to compensate for the drilled area.

[BinaryDude]

i really can't wait to see how this turns out... my H diesel needs a turbo wakeup as well...

[RufusTheDufus]

I thought Oswald was going away?

[RufusTheDufus]

I traced the flange and the outside edge of the tubing. It's tight but I should be able to make it work.

Before I weld the stubs to the flange I may notch the tubing slightly and then build up the weld on the inner edge in those areas.

[Juha]

Originally Posted by herbs

BTW, as an aside, anyone manage to bung a power steering pump onto one of the H motor successfully?

[BC40]

Originally Posted by RufusTheDufus

I traced the flange and the outside edge of the tubing. It's tight but I should be able to make it work.

Before I weld the stubs to the flange I may notch the tubing slightly and then build up the weld on the inner edge in those areas.

Instead of notching you can dimple the tube in a bit.

[RufusTheDufus]

That crossed my mind too.

A friend of mine has a machine shop here locally. I was going to ask him what he recommended. I wouldn't be surprised if he has a tool to easily dimple the tube. He builds a lot of exo-roll cages for ski mountain groomers so he's got just about every tool you can think of related to tubing fab work.

[Dougal]

Originally Posted by bigbrowndog

With the tube that size and the studs being a bit short on space do you still have enough room for a ringspanner or socket to fit on the nut allowing for the weld chamfer or are you going to use set screws? It is difficult to see from the picture you posted. The stainless cuts are really cool, cheers.

Is it possible to use cap screws instead of studs and nuts?
It reduces the needed clearance by a huge amount, but sometimes they just don't fit.

[bigbrowndog]

Originally Posted by Dougal

Is it possible to use cap screws instead of studs and nuts?
It reduces the needed clearance by a huge amount, but sometimes they just don't fit.

Cheers Dougal, Pretty sure you used more correct terminology than me . I remember they were classed as screws because they had much finer tolerances than bolts. But you use an Allen wrench to tighten them, no need for external fitment of a ring or socket. These exhaust manifold bolts only need something like 15/20 ft/lbs, have to look it up. The last nuts on the 2H/HJ75 are a pain to do up from memory, early model may have more room. cheers

[herbs]

PM sent Juha.

The official name for those screws are socket head cap screws, I'm 99.9% sure, they're good as long as they're good quality and you use good allen keys/inhex sockets.

[bigbrowndog]

Originally Posted by herbs

PM sent Juha.

The official name for those screws are socket head cap screws, I'm 99.9% sure, they're good as long as they're good quality and you use good allen keys/inhex sockets.

:b eer:
Thank Mate, well done. Thought someone would know what I was on about. It is called C.R.A.F.T.= can't remember a flaming thing.:

[RufusTheDufus]

I hadn't thought of using allen head cap screws. That's a great idea. I'll need to source some metric ones. Problem solved. I hope to get to welding and drilling this weekend.

[dingbatt]

Originally Posted by herbs

PM sent Juha.

The official name for those screws are socket head cap screws, I'm 99.9% sure, they're good as long as they're good quality and you use good allen keys/inhex sockets.

Spot on, SHCS the acronym.



They are used all the time on downhole oil tools, due mainly to spacial constraints. And, yes, make sure you use good allen keys, otherwise thay can be easy to strip. Otherwise they are very strong, and I think will be perfect for the job.

EDIT:

Oh, as long as you have a long enough allen key to get into the cap between the manifold.

[Dougal]

Originally Posted by dingbatt

Spot on, SHCS the acronym.

Most cap screws are grade 12.9-14.9. Much stronger than your average hex box.
Other flavours include:
Button head cap screw, with a rounded head and smaller hex.
Low head cap screw, like a normal socket head but shorter head.
Flat head cap screw (countersunk).

Just make sure to use a decent exhaust paint on them. The factory black finish has no corrosion protection.

[BinaryDude]

Originally Posted by RufusTheDufus

I thought Oswald was going away?

Still trying to, but until i do... gonna keep working and playing with him

[Ron R]

Even with cap screws it looks as if it is going to be very tight.
Why not "taper" the tube for an inch (or two)?. You can go as narrow as the passage in flange. This way the gasflow is also smoother.
Just saw off the corneredges over the distance you want them to taper, bend inward and weld the edges.
Off course you have to take out triangular shaped parts, narrow at the point where the tube will start to bend inward, wider at the edge where it connects to the flange.

[RufusTheDufus]

I was thinking about looking for some of these SHCS screws online and I got to thinking about corrosion between dissimilar metals. I forget if using stainless bolts into a cast iron head is a bad idea. I seem to remember that being a no-no since corrosion could occur in the head.

I guess the simplified question is: should I stick with regular steel or use stainless if I can find them?

[RufusTheDufus]

Originally Posted by Ron R

Even with cap screws it looks as if it is going to be very tight.
Why not "taper" the tube for an inch (or two)?. You can go as narrow as the passage in flange. This way the gasflow is also smoother.....

When I traced the tube I used a regular Bic ballpoint pen. It was impossible to get the ball point all the way in there. So the traced line is slightly larger than the tube.

I have the head off the engine still so I set the tube down on it just to eyeball the fit. I think the cap screws will work. I haven't had my eyeball calibrated lately so I might be wrong. I should know tomorrow. The weather should be nice enough that I can roll the Troopy out of the garage and get to work on it.

[Dougal]

Originally Posted by RufusTheDufus

I was thinking about looking for some of these SHCS screws online and I got to thinking about corrosion between dissimilar metals. I forget if using stainless bolts into a cast iron head is a bad idea. I seem to remember that being a no-no since corrosion could occur in the head.

I guess the simplified question is: should I stick with regular steel or use stainless if I can find them?

Don't use stainless for the exhaust bolts. Stick to normal alloy steel cap screws and paint them.

[RufusTheDufus]

I decided to measure the distance between the exhaust studs. (I know I did it at one point in time before I decided on 2 inch tubing.) They are 2.280" apart. This leaves .14" clearance per side if I nail the welding location perfectly. It might not work without modifying the tubing a bit.

Time to go find some specs on the screws to see how large the heads are.

[Dougal]

Originally Posted by RufusTheDufus

I decided to measure the distance between the exhaust studs. (I know I did it at one point in time before I decided on 2 inch tubing.) They are 2.280" apart. This leaves .14" clearance per side if I nail the welding location perfectly. It might not work without modifying the tubing a bit.

Time to go find some specs on the screws to see how large the heads are.

Is the metric system that hard? Decimal inches do my head in.
Afterall, the head will be metric, so the bolts will be too.

M8 Unbrako cap screws require a 14.25mm counterbore. Approx 13mm diameter.
M10 Unbrako cap screws require a 17.25mm counterbore. Approx 16mm diameter.

Different brands do vary a bit. You can also turn down the heads a little for clearance since this isn't a mission critical application.

Isn't the main reason for using solidworks to check things fit before you make them?

[RufusTheDufus]

Originally Posted by Dougal

Isn't the main reason for using solidworks to check things fit before you make them?

It's apparently really good for that but I'm lazy and didn't want to learn how to do an assembly. This little odd piece of steel is the first thing I have ever designed in SolidWorks. I was using SW primarily to generate the output files in a format that the laser cutter could use. I wish I had more time to learn the software.

[amaurer]

Originally Posted by RufusTheDufus

It's apparently really good for that but I'm lazy and didn't want to learn how to do an assembly. This little odd piece of steel is the first thing I have ever designed in SolidWorks. I was using SW primarily to generate the output files in a format that the laser cutter could use. I wish I had more time to learn the software.

I'm a CATIA guy, but its a solid modeller all the same, and I find it easier to model everything in part design, assemblies be damned. Professional designers would hate the models I make, but they're more useful for my purposes, and I just activate an deactivate features as need be and save many copies.

[Dougal]

Originally Posted by amaurer

I'm a CATIA guy, but its a solid modeller all the same, and I find it easier to model everything in part design, assemblies be damned. Professional designers would hate the models I make, but they're more useful for my purposes, and I just activate an deactivate features as need be and save many copies.

So instead of assemblies, everything is a multi-body part?
That method certainly has it's uses, but it makes some things really difficult.