[fangoul]

Ok so I was working on the Burb a couple weekends ago with my Dad and I'm trying to decide what to do about the exhaust manifold/turbo placement. The problem is with the low mount chevy manifold that came on the engine it only gives me about 3" to the firewall. So I bought a manifold kit from Mooktank and was planning on using that to put the turbo wherever I need to. So I make up a jig of sorts to test placing the turbo to get clearance from everything and I keep wanting to move it lower.

So my crazy idea is this... Instead of building my own manifold I use the stock manifold but I make an adapter using a couple of these. And use some 1/8" plate to twist and move the outlet on the manifold forward to around cyl 2/3 and drop it by about 4". This would put my turbo a few inches above the framerail and give me lots of room for running my intake elbow from the air cleaner and get lines on the back of my AC comp. I'm going to try to draw something up in UG or solidworks since this description probably sucks

Anyone see a problem with doing this? I have a H1C turbo with the divided turbine housing. Should I try to keep the split in my adapter or will it not matter much?

 

[66gaza]

you can get a cummins manifold that turns down between the 2 middle cylinders. you could get one off a 6bt and chop & plate ends or look for a 4bt one here is a pic that belongs to Crewcab59 (top manifold) I couldn't fid one of a 4bt so you will have to use your imagination. Incidentally this is exactly the same as my commercial 6bt manifold. If I am way off with what I think you are trying to do the just ignore me.

gaza

 

[fangoul]

You aren't way off I'm trying to move the turbo forward and down. If I can go roughly 4" forward and 4" down then there would be plenty of room for any turbo I could possibly want to run. My initial problem was if I was keeping the turbo at the same height but just moving forward I'd end up putting the intake elbow right into the back of my AC comp. Also if the turbo is mounted up high like on a 6bt manifold I think it would put the turbine too close to the AC evaporator.

 

[66gaza]

Fangoul the manifold in the pic does place the turbo low, they are all able to spin the turbo either up or down.

Gaza

 

[fangoul]

I know it sets the turbo low but I was looking at setting it even lower by building an extension/adapter. It just seems to me it would be easier to build something that can bolt in between the turbo and manifold that would move the turbo forward, down and out from the block rather than build a complete custom manifold. I guess I'm just looking for someone to give me a reason not to try it.

 

[66gaza]

How much lower are you wanting to go? a spacer in there would lower it some more. Keep it simple.

Gaza

 

[mooktank]

Just build the damn header!



It's not that hard...

 

[66gaza]

Just build the damn header!



It's not that hard...

You tell him mook.

Gaza

 

[fangoul]

Here's what I came up with wasting a morning in Unigraphics.

The tubing is 1x2x0.12 rectangular. This might be a bit easier to put together than a header. I know I already have the header kit I might as well use it but I'm feeling kinda lazy and I can whip this thing up in an afternoon.

 

[CrewCab59]

1. The problem your gooing to run into with zig zag thing is high egt ,the flow won't be good.
2. you'll also need extra support ,that will also put the turbo at the frame.
3. Build the header that you have or chop down a 6b manifold.

CrewCab59

 

[Dougal]

Here's what I came up with wasting a morning in Unigraphics.

The tubing is 1x2x0.12 rectangular. This might be a bit easier to put together than a header. I know I already have the header kit I might as well use it but I'm feeling kinda lazy and I can whip this thing up in an afternoon.

Not good geometry.

Put the turbo where you want it, rotate the housing to fit and connect the flanges in the smoothest way possible.
You can probably do a smooth single arc and keep the turbo centreline in the same place you have it already.

 

[mooktank]

Just hold the turbo where you want it in the engine compartment and slowly work your way there with one tube just tacking the pieces and rechecking. That's the hardest part. The rest you can do on the bench. It took me like 4 hours my first one.

 

[fangoul]

I realize it's not the best geometry. I was basically looking at what would be the easiest to fabricate. Not to mention easiest to draw in UG Its a PITA to figure out how to do 3D curves.

I'll probably just end up making the header. Especially since I've already paid for that! Been spending too damn much money on this swap.

I'm probably going to take a few extra days off from the lab next week and try to make some more progress on the Burb.

Thanks for the reality check guys

 

[IHWillys]

The turbo oil return is gravity feed to a sump(engine sump normally), so there is a limit on how low before other mods are necessary. Just a consideration to keep in mind with the myriad other bits.

Ken

 

[turbos10]

Flow on turbo manifolds/headers is not a real big concern...heat and pressure make things work out. The real deal is in keeping it close enough and heavy enough not to loose EGT. Coating can fix alot of this problem as well.

Both of my turbo gas engines (home built) have long headers with a pipe similiar to what you are doing for ideal location of the turbo. Both spool fine...

 

[mooktank]

From my experience and knowledge, having a piping systeam that flows well will take less energy from the working fluid and this energy will be extracted by the turbine.

It made a difference to my setup.

 

[turbos10]

From my experience and knowledge, having a piping systeam that flows well will take less energy from the working fluid and this energy will be extracted by the turbine.

It made a difference to my setup.

Not trying to be difficult, but unless you are really pushing the envelope or have a real mess of a manifold(which I am thinking you had from the pics?), the extension we are talking about here should work with no measurable difference. If you look at most factory turbo manifolds, from a fluid dynamics standpoint....they suck. There are diesel tractor pullers running 12-1300HP through one turbo on a factory manifold with the turbo mounted in the factory position , 90 degrees to the natural exhaust flow....just an observation.

 

[Carl Donica]

Can I get an AMEN! Turbos10, you and I are thinking alike. Historically, the poor flow characteristics of a diesel engine have always aggravated me. Lots of power missed by pulses slamming into each other and abrupt 90* turns. I fully intend to address some of these issues when I get more time/money.
Carl

 

[turbos10]

Can I get an AMEN! Turbos10, you and I are thinking alike. Historically, the poor flow characteristics of a diesel engine have always aggravated me. Lots of power missed by pulses slamming into each other and abrupt 90* turns. I fully intend to address some of these issues when I get more time/money.
Carl

Yeah, but the issue is that the turbine is driven by the heat and pressure change across it. While sequencing the pulses with manifold tuning might help initial spool up, unless there is a restriction in the manifold greater than that of the turbine it should not make alot of difference in total power output. The turbine basically works because it is the restricition in the system....

 

[WC53]

it is more complicated than you think

Actually the piston moving up pushes the air into the manifold system . The air speed and hot air expanding spin the turbo and the air is sent on to the exhaust system . Smoothing out the manifold flow should increase HP and torque but this is where we get all bent out of shape and unless we are using a Dyno , I think alot of stuff said regarding performance gains can be taken with a grain of salt .
Bigger exhaust can give better HP and torque numbers but at lower RPM in many cases the HP and torque numbers drop . So very often you lose power at the sweet spot and gain it at a RPM level that the engine seldom runs at. Then there is the scavanging effect of the exhaust to consider.
Would a tuned header work and improve HP and torque at a lower RPM ? TRI Y systems work on gassers at lower RPM to about 3200 , it is reasonable to assume that similiar gains could be found by removing the bends in both the intake and exhaust manifold but I want to see the dyno numbers as proof .
Ditto with the intake . What is with that abrubt right angle bend there ? I wonder what effect a triangular plenum would have . A drop in milage and torque or would it go up ?

I sure wish Banks would toss one of these 4bts on a dyno and have at it for a few days . I bet a few of the 6bt parts would fit right up. The results would be interesting .