Just some fab work I did over the last week, I spent 4 days (8-10 hours each day) on this single manifold in coming up with the design and building it










This customer is shooting for 1000hp but is worried the gt42r will restrict him so when he maxxes this turbo out the is going over to gt47r
-James

 

looks good james.

 

Very nice. A few questions though... any plans to plane the head flange? I'm working on a 42r manifold myself and ran into the same problem with the warping. Haven't decided how I want to go at it then. 2nd, where did you (or the customer) get the oil inlet piece for the turbo from?

 

The truth behind warped flanges that nobody but manifold fabricaters know

Yes the head flange is warped a lil but check this
tubular manifolds can have flanges warped and it not be much of a deal why?

Well because the runners are so long they have alot of flex in them
I put this on the head and yes it was warped by about 1/8 " on each end but when ever u put a nut on the studd and start tightneing it pulls flat very easily (aprox 10 lbs trq and it pulls flat against the head)
I have been building manifolds for 3 years and on every singal tubular manifold I have sent them to the customer with the head flange like that and zero customers have had any problem
I might accosinally get one that is paranoid call me and say it was warped but what I tell them
" bolt it on the head and tighten it down just as it is supposed to be, if you have a leaking issue (about 1 in every 100 manifolds actually leak) then get a $20 mr gasket 1/8" thick copper gasket and I gaurantee it will be perfect"

Now check this

I have milled several manifolds flat in the past but there is still the internal stress of the manifold, by the time the manifold has been deliverd (shipping is usually 3-5 days) the flange will be warped again because of the manifold's internal stress so what is the point of flattening?

On manifolds such as logs and short manifolds this will not work because they are so small and compact that they have no flex to them at all, but on every tubular I build (top mounts, ramhorns, min ram, etc) they all pull flat when put on the head as a final resort if they dont pull perfectly flat is I cut slots on the back of the heade flange (not all the way through because then the internal stress of the manifold makes the pieces move by like 1/8" and you have to ghetto oversize allt he bolt holes and then you have poor primary alignment on the head) but cut so that there is aprox 1/16" thickness left this allows it too tighten up on the head extremely easily (even log manifolds will flatten out on the head if you do this trick) it takes about 5 mins to cut these slots as opposed to 30 mins to an hour to mill it flat and it will still warp by the time the customer recieves it.

-James

 

Good points made. The manifold I'm working on is a top mount as well so there should definitely be a lot of flex allowed out of it. I originally tried welding the head side of the runners to the flange in hopes of combating against the front welding to be done, but once I went over the runners it warped anyway. Copper gaskets and orange rtv ftw.

 

you can get the turbo oil inlet at http://www.atpturbo.com

 

I actually already have a flange with 1/8th npt threads in it that'll bolt on, but I'm looking for a nicer 1 piece aluminum flange that has a male -04an on it, like the one pictured above. ATP doesn't appear to sell one exactly like that.

 

makes me want to pick up welding

 

what car has that been shoe horned into

 

That is a rb26 swap in a s14
-James

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by carbonall &raquo;</TD></TR><TR><TD CLASS="quote">makes me want to pick up welding</TD></TR></TABLE>

Do what your best at lol I tried picking up carbon fiber and doing my welding at the same time, I will say that it is hard enough doing one skill recuired job well much less adding another, it just wares you out to much

-James
btw. hook me up with some s2000 carbon fiber stuff

 

doesn't look like tubing to me, looks like pipe.

nice work otherwise james.

 

Tubular design = anything other than a log manifold
Yah it is sch 10 pipe but it still has more than enough flex in it
Tubing has a huge amount of flex
-James

 

So james,

Whats the trick to welding between pipes and joints where you really can't get the cup/torch in there? Did you weld each runner individually off the mani or what? Looks great!

Ian

 

how come he is going for a single turbo
most of the fastest skylines stick with the twin setup, or isnt there room in the s14 bay for big twins?

 

seeing this car in person.. you can tell that there wasnt much room. im still questioning how these guys are gonna get a 4'' dp around the steering shaft. once this car is up and running tho, well see how it does against a 2jz swapped 240.

 

I have a question then about manifold building. Do you bolt the flange to anything on a tubular design when you weld it? And the runners are being pulled on and welded one at a time correct? and how do you keep them from shifting so they still line up with the collector and the head flange? I just built my first log and learned alot about doing all of this, but would love to get some more info/experience on tubular design and tips. thanks

 

cool looking manifold

in regards to the warpage, it looks like you have more like 1/4" at least on both sides.

if it were me, and i had welded up that manifold and had warpage that bad i would be junking it and starting over. (as a matter of fact i just did this!)

if you build a fixture to weld the manifold in you will not have any warpage problems


here is a 5th gen prelude manifold i did a week ago in its fixture

 

2jz whats that, supra lump?
do you have many of these nocking around out there then

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by legendboy &raquo;</TD></TR><TR><TD CLASS="quote">cool looking manifold

in regards to the warpage, it looks like you have more like 1/4" at least on both sides.

if it were me, and i had welded up that manifold and had warpage that bad i would be junking it and starting over. (as a matter of fact i just did this!)

if you build a fixture to weld the manifold in you will not have any warpage problems


here is a 5th gen prelude manifold i did a week ago in its fixture


</TD></TR></TABLE>

I have been building manifolds for quite some time on long primary manifolds the warping isnt as much an issue as it is with shor tmanifolds like that
As to welding on a plate I did (1/2" thick mild steel back plate that was ont he fixture).... but note this flange is nearly 2 feet long with as long as it is it doesnt take much pressure to make it have a "bow" to it

Also with it being so long you have a lot of leverage against it when it comes to putting it on the head that is why it is so easy to bolt up

The camera makes it look a little worse than it is because of the lense, note that is on the tailgate of our truck and note how it makes the lines in the tailgate look warped also....

I see no reason in scrapping it as it is perfectly good it bolts on the head and seals just fine, if you want to scrap yours when they are still 100% functional go right ahead.

-James

 

yep i know exactly what your saying

when you bolt the warped flange to a cylinder head and tighten it down, your are putting your welds under alot more stress then they already are under. just makes cracking that much more likely over time

but you say you have not had any problems so i guess they are ok, just not the way i personally do it

 

You both have good points. The milling and the welding all add and remove internal stresses from the material. It is very difficult to get things flat and all squared away unless you are dealing with just a double ground jig plate. if anyone really wanted to, they could weld it up, stress relieve the whole thing manifold, and then lap the flange that mounts to the head. that would be the "ideal" way, but both of your ways will work well.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by legendboy &raquo;</TD></TR><TR><TD CLASS="quote">yep i know exactly what your saying

when you bolt the warped flange to a cylinder head and tighten it down, your are putting your welds under alot more stress then they already are under. just makes cracking that much more likely over time

but you say you have not had any problems so i guess they are ok, just not the way i personally do it </TD></TR></TABLE>

As soon as the manifold goes through 1 heat cycle in normalizes in a nuetral position

As to the added stress you know as well as I do each time you make a weld the metal pools no matter how good a support you have to keep it from pulling, you have 4 primary's each pulling in their own direction there is huge internal stress in it wether it has been done on a fixture or not
-James

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JG-Fabrications &raquo;</TD></TR><TR><TD CLASS="quote">

As soon as the manifold goes through 1 heat cycle in normalizes in a nuetral position

</TD></TR></TABLE>

true enough, i send my manifolds out in the fixture and have them stress relieved by a local guy. same diff i guess!

 

Here is pics of another rb26 manifold I finished up today and shipped out
The color is a little duller because I didnt have flash on ,it looks just as good as the other one though
As you might notice I modified primary number 5 it made the manifold alot easier to build and a whole lot easier to weld, it still has more than enough room for a 4 or 5 inch downpipe

-James