It's just a tiny hole, can you weld it up?

Stainless turbo manifold off a Nissan 200sx, less than a years use and only the stock turbo fitted



This is why it is was brought to me


Pretty obvious from this pic that the another (pulsed autogenous) pass was made after welding the manifold- presumably to get 'the look' . Looks to have been 'well cooked' too. You can just make out the crack running away from the hole. I found several more

There was some discussion about the merits (or not) of gusseting this sort of thing on WW so i DPIed it to see how bad it really was and make it easier to photograph

The gussets were a pain with regards to DPI but this is what we have after 10mins contact time

Close up time...









Don't know how useful/interesting this'll be but what the hell

That looks more like too much dye to me. There's no way tig should show cracks like that. I'd do it again, but clean as much dye off as poss before the developer (i'm assuming you havn't done it properly, but will stand corrected...).

The sides of the gussets wern't welded anyway, were they?

The welding does look a little, "for the look". Where your pinhole is, it also looks like the parent has been ground a bit thin. I'd just run a bead over it and get another year or two out of it!

EDIT!! Just seen the other photos. Scratch what I wrote above. Ouch!

The gussets have induced cracking. Design flaw methinks. If they'd been welded along the sides and not at the ends, that might not have happened.

Ha Ha! Didn't go overboard with the dye but the silly gussets did trap a fair bit- too lazy to carefully mask up the openings. Was cleaned reasonably properly but getting the excess out from behind the gussets was too much of a ball ache- only did it to make the cracks easier to see in photos. Found a LOT more flaws but the area around the gasket flange/gussets is obviously a bit compromised DPI wise

looks scrap to me!

A new member who makes bike frames has a good bit on gussets on his website. Name escapes me at the mo.

Blackjack

http://www.thefont.pwp.blueyonder.co.uk/bikes/gussets.htm

thats the one

Maybe the wrong grade of stainless too? thats one of the usual culprints...

Those gussets look like a half baked idea. They'll be running a lot cooler than the pipe so as the pipe expands it will pull on the gusset (different amount of expansion). Add to that the pre-existing stress from the welds cooling down when they were put in, and the fact all of the stress is concentrated at the edge of the weld in he heat affected zone..... And it lasted a whole year?

Might be worth a shot removing the gussets and welding up the cracks. And explain to the customer that it might not work.

Looks like yet another cheap ebay manifold, seen a few of them now. Tell him to just stick the original cast manifold back on, there`s no point in running a standard turbo high mount.

With gusset design, it's important not to abruptly end them, (as confirmed in the link), as the sudden change in stiffness will cause stress concentrations and can lead to fatigue cracking, as with the manifold. In that particular case, allowing the pipes to flex as the engine moves and the temperatures cycle is rather important. Making engine mounted stuff stiff isn't always a good idea.

When I worked for CAT (as a backhoe loader (thats a JCB to those not familiar) structures designer) we often had issues with gusset and doubler plate designes causing high stresses where they ended. They really do have to taper out to nothing.

Phil

Whole thing was an abomination- it's kicking around somewhere, might be useful as a pattern if i'm asked to make a manifold for an 200sx. Owner replaced more than the manifold, cars now home to a skyline (RB25? IIRC) lump.

FWIW i think it came (direct) from an American tuning Co although it was probably made in a sweatshop in China (or similar). As i said in the initial post, it got DPIed simply to show what a bad idea those 'gussets' were on another forum. Just thought i'd post it here as an example of how NOT to do it

Personally i think gusseting something like a manifold is a bad idea full stop- as said, differential expansion/restraint/stress risers etc. Something along the lines of a Cosworth turbo damper though...

Storm Monkey, bicycle industry had the same issues when they stated gusseting frames- simply moved the failure point to the end of the gusset till they figured out how to make 'em

ha i used to build backhoe loaders (small world)
looks like a japspeed/xs power manifold your man did well to get it to last a whole year.
rb25 swap is a good 'bang for your buck upgrade' imo