FunK73

iTrader: (6)

So the intermediate pipe on my 84 12a rusted clean off so i had to order up a replacement. I ended up buying my buddy a racing beat header in exchange for his full exhaust off of his 81. I know the catalytic converter est up and piping are different but I plan on replacing the whole system from thermal reactor to muffler tip. My question is, will it just straight bolt in? Im kind of hoping all the bolts are in the same locations for mounting but I havent actually gone to look just yet

mazdaverx713b

iTrader: (91)

well, not exactly. first, you most likely do not have a thermal reactor. those were only on the 79-80 models. if you do, then someone had either swapped in an SA engine or just the TR.

at any rate, if you are using the 81 exhaust on an 84 you will need the exhaust manifold from the 81. the 81-82 exhaust uses a longer extention off of the manifold to the first converter and if you tried to bolt the 81 system up to your 84 manifold, the piping for the rest of the system would be too short. i can post a pic tomorrow of the two manifolds if you'd like.

FunK73

iTrader: (6)

I have his manifold too. Mines also a manifold, i always call it a thermal reactor cause it makes it sound cool lol. Its a bad habit I know.

So basically i should swap his manifold for mine and all the piping back should line up?

mazdaverx713b

iTrader: (91)

thats correct. make sure you are using the 81 manifold with the 81 exhaust. love those "pancake" converters, lol. i have a set at the shop. figured that i might as well hang onto them. you never know.

FunK73

iTrader: (6)

Yeah im really looking forward to have a full factory exhaust (from some year of FB anyway) since mine was a "midas job" from the last cat back.

How much of a pain is it going to be to pull off the manifold, mainly those bottom 2 bolts.

mazdaverx713b

iTrader: (91)

the bottom bolts are the easy ones, lol. just make sure you don't snap the studs. be careful and use seafoam if need be. the top bolts require a 6" extention and a deep well socket.

FunK73

iTrader: (6)

Ive taken mine off many times doing my 3 engine rebuilds this summer lol. Just never when its in the car. Hopefully all goes well! Ill post some pictures of the new exhaust after its on lol

mazdaverx713b

iTrader: (91)

that sounds good. best of luck when taking the manifold off. remember not to rush it and be patient.

FunK73

iTrader: (6)

I have a feeling that will be the easiest bit. Trying to get the back half of my exhaust off with its brackets and piping made of rust will be a hell of a time.

trochoid

iTrader: (6)

Seafoam? I'll assume that was a brain fart and you really meant PB Blaster.

FunK73

iTrader: (6)

Ive got lots of penetrating oil, no worries =D

mazdaverx713b

iTrader: (91)

not a fan of seafoam? i like it and use it to lube the threads once the nut ot bolt is free..helps a lot if its tight coming off. i prefer PB Blaster for penetrating oil.

trochoid

iTrader: (6)

I've found PB makes a good lube too for fitting rubber hoses over tight metal tubing, etc., and preventing rust. Never tried using Seafoam that way, it ends up in the fuel tank too quickly.

DivinDriver

iTrader: (15)

Be glad you don't have one of those cool-sounding thermal reactors, bud... because getting one safely off without first removing the intake manifold is well-nigh onto impossible without special tooling.

I ended up changing mine to smaller-profile nuts, which lets me do the job with a flex-socket. Barely.