Manifold Design

[Henk]

Hello all,
Got a MK1 caddy which hes been chopped up, and am hoping to start on re-building the engine soon.
It's a 1.9TDi with a land rover fuel pump (still needs the bracket modifying, and figure out how the hell to put a new sprocket on etc), .240 or .260 nozzles, FMIC, 2.5" straight through, and a GT2052V turbo.
Problem is, I've been advised to use a direct actuated brake servo, which for us RHD cars puts it right behind the engine
Would rather not use a linkage and move it over to the other side due to being a pretty beefy system (11" discs, 4 pot calipers, 9" servo and 22mm M/C)

SO, in order to make some space back there, and in the name of a more efficient engine, i'll be looking at something like a 1X manifold, or a modified D24 intake, but the exhaust is looking like a custom job
I chopped the flanges off an old manifold, these will be port matched to the head.
I can get hold of weld elbows, although not very thick walled
1. does it matter if the header pipes are of equal lengths, like on N/A's, or should the aim be to just get the gas to the turbo as quickly as possible?
2. does the order in which it enters the turbo really matter? i read it somewhere
3. would i be better off just using a log style exhaust manifold to get the gasses straight to the turbo (simple, pretty efficient i imagine), or individual pipes and a collector at the turbo flange?

Some photos for reference

thats with a slightly better than stock intake, and a 4 bolt manifold (would still need an adaptor)


a possibly kind of design for the exhaust? (it's the inlet on an old Massey Ferguson MF35, but it's the shape that matters :p)


sketch of the exhaust header. this will put the turbo on the right of the engine, out of the way, but also easier for routing the stainless tubing for the IC

Thoughts, opinions, criticism, all welcomed

Regards
-Henk

PS, is there any reason why I couldn't have a bare engine block shotblasted?

[R.O.R-2.0]

this is my manifold..

the way you have it, you will need to re-clock the vane assembly..

my manifold requires no re-clock of the turbo..

[Henk]

is that home made or off the shelf?
I'd be a bit worried about the steering rack with the turbo down there
Re-clocking just requires re-making holes for the 3 dowels right?
Interesting inlet there too

[R.O.R-2.0]

is that home made or off the shelf?
I'd be a bit worried about the steering rack with the turbo down there
Re-clocking just requires re-making holes for the 3 dowels right?
Interesting inlet there too

its a bit of both..

i took a street toys2000 manifold, and modified it to work with my mk2..

whats the difference if ive got a turbo above the steering rack or a downpipe/header?

the intake manifold is custom.. the bottom half is oem VW.. the top half is my design.

the turbo re-clock is simple, but not, at the same time.. its a bit more than just drilling 3 new holes..

i believe you have to deal with the actuator lever as well..

[Henk]

just a bit concerned about the heat down there, heard of a few MK1's that's been set on fire by running the exhaust too close to the steering rack/gaiter, although may not be so bad for you LHD guys.

Have never taken a turbo apart, let alone a VNT, so would it be just the dowels and the lever's pin too?
I have access to milling machines at work where i can do it so I don't see it being too complicated. just a bit of a bugger if i have to change the turbo, but not something i'm too concerned about.

[R.O.R-2.0]

just a bit concerned about the heat down there, heard of a few MK1's that's been set on fire by running the exhaust too close to the steering rack/gaiter, although may not be so bad for you LHD guys.

Have never taken a turbo apart, let alone a VNT, so would it be just the dowels and the lever's pin too?
I have access to milling machines at work where i can do it so I don't see it being too complicated. just a bit of a bugger if i have to change the turbo, but not something i'm too concerned about.

re-clocking a VNT is 100x harder than a normal turbo..

[Henk]

not done one of those either  why's that then?

[libbydiesel]

I've clocked several Garrett VNTs.  They have all had the vane assembly bolted to the turbine housing and then the center cartridge pinned to the vane assembly/turbine housing.  IMO, the best way is to drill and tap new holes for attaching the vane assembly to the turbine in the new position.  Then one more hole for the pin between the center cartridge and turbine housing.  All of this has to be very precise.  Doing it on anything less than a drill press is a very bad idea.  The accuracy of a drill press for this process is questionable.  Measuring and marking accurately is essential and even then, the vane lever to vane assembly position can be off slightly resulting in new vane geometry.  

While it is certainly possible to clock a VNT, it seems to me that since you are already making a manifold adapter, it would be less work to design the manifold adapter to put the turbo at the correct angle.  Bear in mind with a little grinding you can flip the ex manifold. 

[Henk]

okay, i think i understand that (this is my first time working on cars/engines, so still consider myself new to the game!)
As i said i can put it in a milling machine at work, as long as the setting up is right you're talking accuracy to easily within .1mm
While you may be right about simply modifying the manifold, i shall have a look i a bit as to how the turbo sits in relation to the oil in/out ports.
Can't put the turbo below i don't think, due to it being much bigger than the stock K03(?) and I'm not risking having the steering boot set on fire either!


Due to the lack of room behind the engine (want to use a decent intake, off perhaps a D24, PAS, plus a direct actuated servo behind it, which is a P.I.T.A on a UK car) I'm thinking about putting the turbo next to the head, on a home made manifold like this




While not perfect, i think it would give a good balance between performance and space, plus much easier to work on there...

[GTiTDi]

What would work even more efficiently but at a cost of being slightly more complex would be to pair up 1+4 and 2+3 on separate runners that would tie into your turbo inlet flange...The manifold you designed is too restrictive, and the exhaust flow would be very turbulent. In a fixed speed industrial application it would work fine. Just like the stock 1Z/AHU camshaft

my graphic art skills are no where near yours but if we were on adjacent bar stools I could have a nice drawing for you in a couple minutes with a pen and a napkin!

Think about this manifold design

but in the orientation you desire...