Replace 1.8 exhaust with 1.7?
 

This is my first tech post and I have to say this site is great. You guys have saved me so much time. I hope I can contribute.
I need to replace my ’75 1.8 HE’s due to rot on the shrouds. The PO removed the majority of the emissions stuff and I plan to get rid of the cat (the car is exempt from smog test in MA). With that in mind, should I replace the HE with a pair from a 1.7, as well as the muffler? I know this will involve some heat ducting fabrication and probably the exhaust hanger plate, but other than that, does the header end of the 1.7 HE bolt right to the engine without modification? I’m tempted to go without heat for a season by cutting off the original HE shrouds and modifying the engine side of the headers to direct the exhaust straight back (getting rid of the hairpin bend in the pipes) into the stock exhaust, minus the cat. Any advantage to this or should I just go with the earlier 1.7 design.
Any input would be appreciated.

Your best bet would be the system from a '73-'74 2.0L as the pipes are bigger and better flowing.

That said the earlier 1.7/1.8 systems are better than what you have.

To convert(1.7/1.8 style):
Early support bracket
Heat exchangers
Muffler of some type
New exhaust gaskets
New exhaust nuts
And I believe you would need the remainder of the heat system tin (elbows, connector pipes, etc) if you wanted heat.

To convert to the 2.0 Style:
Late support bracket
Heat exchangers
Muffler
New exhaust gaskets
New exhaust nuts
And what was mentioned

All of this will bolt right up to your Teener.

Most of what was mentioned is available used from us Teener freaks. Ya just need to ask. Some of us may even have the SS shrouded heat exchanges too (shameless plug huh)!

Go with the 1.7 or early 2.0 setup. The cat is not that huge a constriction in the flow; the tight 180-degree bends and massively unequal lengths of the piping are more to blame IMHO.

--DD

Thanks guys. I'll scrap the stock HEs and mufflers and seek some early model stuff. Scrappy,

Oops, must have hit enter by mistake,
anyway, Scrappy, I'll look you up and post when I am ready to buy, maybe you will still have what I need. Meanwhile, I'm in the throws of a longitudinal rebuild from Rest Design which has put me on a limited budget for the next few weeks.
Thanks again

i'm right in the middle of doing this. i'm going with the ss 2.0. you will also need the lower tin that attaches to the h.e.'s and the bottom of the engine. the 2.0 style gives you more options with regards to the muffler.

kevin

914club member