Just need a little help fabbing a new front mount manifold, (havent made many manifolds). The postion of the turbo flange wants to change when I start to do all the finish welding. It moved like almost a 1/2 back towards the block. Is there a better way to weld the pipe(sch10 ss) to keep it from moving, or do i just have to build a jig. THANKS

 

I yell , it seems to help.... just jig it.

 

You definitely need to build a jig. No two ways about it. Unless you have tons of room and don't really care where the turbo ends up when you're done.

 

It also depends on your fitups.

After everything is tacked, I break each runner off one at a time and weld it up, so each runner is entirely free to distort any old way it wants- but they generally don't.

If your fitup is good and you have applied even heat all the way around the weld, it shouldn't move much.

The odd time I will leave an uneven gap on a joint, and 9 times out of ten they bit eme in the *** becuase I go to put the runner back on the manifold, only to find it doesn't fit any more. It's worth the time to fit everything up IMO.

 

if i dont have a jig made, after the runners are welded and im ready to put the flange on i run a small 1/2" or so bead on the top of #1, bottom of #2 top of 3 etc. then go back and do the other sides. ive also found that welding the insides of the ports before finishing the outsides helps to reduce warpage. but typically if its moving around then your tacks arent strong enough, just run more/longer tacks before finishing the welds.

 

Thanks for the tips

 

does anybody have any tips for welding the last runner to the collector? it is a really tight area and i cant seem to fit the tourch between the 4 runners to weld all the way around.. iv heard about a very small tourch kinda looks like a pencel but with a curve on the end.. any one seen anything like it