evoeone

well, i buddy of mine might be gettng rid of a b series engine stand with an engine, manifold and a turbine housing, so i was thining of making some local friends some downpipes. i can MIG/TIG no problem (just check teh welding thread ) and they are very very very very easy to make in my opinion, ive made a bunch of one off turbobacks for like 4 local jetta 1.8T's and wrx's,
ANYWAYS
i just wanna see how to line up the DP with oil pan so it can meet teh cat or cat back as straight as possible

Bailhatch

one way to do it is to measure from 2 points on the engine to get the center of the stock Y pipe. then use those to position the DP.
I made one for my D16 in the same fashion and it was within 10mm of the stock pipe position. I can't imagine you could get it very close from a picture.
$.02

evoeone

i think imma just have it snug and paralel to teh oil pan
gonan be nice, full 3" AC compatible

Bailhatch

ya you want it squared up but you need to have it be somewhat in the middle of the exhaust tunnel, especially if you want to run a cat.
3" should be more common for DPs. Do you have it mocked up yet?

evoeone

nah, i havent even started them, liek i said, a local friend is "trying" to make them, but he mentioned getting rid of the engine/stand/manifold/turbine housing etc, so isnce its no big thing to me a make downpipes (ive made a bunch of them) i was gonna take that stuff off of his hands and make some nice, TIG'ed out full 3" AC compatible DP's
unless someone else in the CT/NY/NJ area has a blown b series head/block im not gonna be making them soon
if not ill just have to buy my own
but im doing research as to not run into any problems

Bailhatch

sounds good. If you plan on making lots of them you should just make a jig. Throw the bends and flange into it, tack it then weld it up. You could even hire little kids to do the jig layup and monkeys to pack them in boxes.

what are you going to use to make the 3" AC compatable? those fabrication donuts and some kind of 2.5-3" transition?

evoeone

ehh, i made a real tight radius, nt cheated at all full 3" for my car clearance is just as tight as the hondas, i prefer to make them off of a engine, just so its gauranteed to fit, probably donuts tho , immamock em up here ta my house, tack weld them with my mig in like 2 spots just 2 small dots , then take em to my machien shop and TIG em out!!!