setzep

This is the type of welding I was worried about. I just fusion welded the main runners going into the engine flange. Is this going to be strong enough?

twokrx7

iTrader: (1)

I'm anxious to hear from the experienced welders here on your dry wash technique. I would expect you to use filler with a full pen weld config (v- or j- groove weld with a bevel in the header flange and wld technique with filler metal). Not sure how feasible this would be since warping of the flange is an issue. Surprised to hear that your machinist cannot machine the flange flat ... Marcus, what is your take on his machinist's opinion?

Kyle

setzep

Well it's not the physical machining part of it that he isn't sure of (he made the flanges) it's figuring a way to clamp it in a vice/bolt it to the mills table.

How would you clamp this in a mill?

twokrx7

iTrader: (1)

I've machined parts like this on a mill before. Worked in a machine shop back in college and we made some weird stuff for grad student projects. None of us were really trained or say professionals in the shop, just mechanical engineering students let loose in a shop full of tools pushing the limits of our imaginations. Looking back we tried some pretty risky techniques to make one-off stuff.

Kyle

setzep

Ok, how did you clamp the parts like this then?

To tell you the truth the flange isn't warped that much. If you set the turbine housing on it and press down on one end there is about a 1/16-1/8 gap on the other side. When you bolt it down with all 4 bolts the flange straightens out and goes back flat. But I figured I might as well try to do something about it now while I'm in the prosess of making it.

-Cam

Manolis_D

iTrader: (2)

Hey Cam, lookin' good! If you put some SS bracing in between the two flanges I'd imagine that it would help the welds out a lot. That's what I plan to do at least!

About the machining problem.. How about a horizontal mill? The machineshop I've been messing around in has a mill with the shaft sticking out horizontally. That might make it easier to machine the thing (?)

-Manolis

setzep

Hey Manolis
I brought up the bracing issue before and it was shot down. Because stainless likes to move around a lot with different temperature changes (high expansion rate) it tends to break off either braces or crack the welds due to it pulling on each other.

I guess it's just a matter of me finding a vice with a deep enough jaw to allow me to clamp the turbo flange in it.

Hows your manifold comming?

-Cam

twokrx7

iTrader: (1)

Gotta get creative when using the clamps you have or find a larger mill.

If the gap is 1/16 or less and you can pull it up without excessive torque on the bolting then you should be good to go. I hate to recommend this for any flanged joint but after seeing many bolted flanges go together and operate leak free in Chemical Plants over the years I sometimes have to defer to what "works". After a few heat cycles the flange warpage may lessen, curious to see it after its in service for awhile.

I second your conclusions on the brace. When designing pipe systems for elevated temperature the braces overconstrain the part and they will crack at the welds. Think of it this way, the brace is usually several hundred degrees cooler than the pipe so the pipe thermally expands more than the brace ... overconstrained. Better to use proper thickness on pipe/flanges and full pen welds.

Maxthe7man

Hey Cam, any real cylinder head shop should be able to give that flange a skim cut, there are cylinder heads out here the size of your entire car that get skim cut on the face..
The fusion welds should be ok on the flange, I use filler rod on my mine, but your pipe is nearly 3 times thicker than what I used, and even one my tube to tube fusion welds, they have been fine, except for when I ran a 4x6 plank on the highway and cracked the wastegate tube.....Max

setzep

Thanks for the kind words and the suggestions guys. I think I'm going to just run it and see if after a few heat cycles it will flaten out like twokrx7 suggested. If it leaks maybe I'll bring it down to a cylinder head shop and see if they can do a little machining on it.

Regarding the welds. Max Good to hear that some of your manifold is just fusion welded and it has been trouble free...well except the pesky road debris

I did end up welding the inside and outside of the flanges even though some of you recommended not to. The pipe was just begging to be welded Hope this is ok.

Marcel Burkett

So after you decide where and how you are welding in the runners for the wastegate , how are you going to make the holes in the primary runners (leading to the turbo).

crispeed

Just about every machine shop got a surfacing machine.
It's used primarly for finishing cyl. heads after machining.
It's also used for surfacing intake and exhaust manifolds. We've got one in the shop that we use for that very purpose. Most machine shops charge about $10 to $15 per side.
It's very important to have a flat, leak free surface. You might have a leak and it's not audible but it will affect performance greatly.

crispeed
87 RX-7 TII
9.204@150.47mph
2600lbs
un-tubbed

setzep

No problem, Just clamp the engine flange in the vice on the bridgeport at work. I'll use a hole saw and probably a end mill to cut the holes. I think I'm going to make the wastegate runners come out of the main runners ~3 inches after then main flange on the top side of the main runners. What angle should I have the WG runners come out of the main runners? I was thinking a little less than 45 deg?

setzep

Ahh hell.. didn't want to hear that but I suppose it only makes sence. Guess I'll have to take it to a machine shop with a surfacing machine.

80-CU.IN.T

Just about all of the questions that you asked have already been answered by many different people. This is just one example. Just reread your post.

80-CU.IN.T

Sorry - That was a bit Harsh. So much for the Christmas Spirit.

peejay

I'm seriously worried at how close that manifold is to the frame rail. For your sake I hope you're running solid metal motor mounts, because regular motor mounts WILL allow the engine to move quite a bit in every direction, no problem. Barring solid motor mounts, you always could just relocate the engine an inch or so to the left, or attack the body with a hammer.

Directfreak

iTrader: (2)

Or just get an engine torque brace if you get paranoid.

setzep

80-CU.IN.T- you're right that was a little harsh. Looks like someone is getting coal in his stocking . But really, I guess I'm just paranoid about this whole manifold thing. Just want to make sure I get it right is all.

peejay- just went out to the garage and measured it again, 7/8" from the frame rail. Plenty of room Id take a pic of it but looks like my dad decided to come over and steal his camera back.

Directfreak- no worries here

peejay

Trust me 7/8" is NOT plenty of room

Even with only 130hp and a torque brace I was seeing that much movement!

80-CU.IN.T

Yah sorry about that - That is what happens when I am too tired to sleep. I turn into an even bigger dick.

At 7/8" clearance, You should definitely think about solid mounts. Yes, the vibration will get irritating in a street car.

Bad2ndgen

Burns stainless does not have schedule pipe. All they have is thin walled tubing and 321 is alot more expensive, it is also much harder to work with ( ask your machinest friend ) 321 is an alloy that contains titanium and I have never seen it in sch pipe. The good thing about 321 are its heat retaining properties but I think you are doing just fine with 304. And you can always get it coated.

setzep

There is no way it can hit the frame rail the way it's in there. The only way I can see it hitting the rail is if I broke both engine mounts and the engine was to hop over there. I'll take a pic later on tonight to show.
But till then, I gotta go back to work
-Cam

Maxthe7man

Yeah it really depends where the space is in relation to the axis the motor tends to twist on. I have at one point only a 1/2" gap between my downpipe at the floor board heat shield, it never touches...Max

setzep

Here they are.