I have a b16a on the way, and have been reading that the exhaust manifold for the b16 is shorter than the b18.
If I were to just get an aftermarket header that will delete the cat will that fix the problem?
or should I just weild a piece of pipe onto the exhaust manifold to connect to the CAT?
Did that swap a few years back and don’t recall that being a problem. Don’t remember if we used the B18 or the B16a header - but did not have a problem bolting up to the cat. The big issues are engine mounts, clutch cable/hydrolic conversion, power steering, and Vtec wiring.
[QUOTE=Josh721;2234920]I have a b16a on the way, and have been reading that the exhaust manifold for the b16 is shorter than the b18.
If I were to just get an aftermarket header that will delete the cat will that fix the problem?
or should I just weild a piece of pipe onto the exhaust manifold to connect to the CAT?[/QUOTE]
Hmmm, well I have the whole swap on the way, I thought I read that the motor mounts should line right up. I’ll have both the stock motor mounts, then the ones the engine is coming with, along with the wiring harness. It’ll still be kept Obd0.
What year was your teg?
mine is the 91 gs
Depending on which chasis your b16 comes from, you will most likely swap the drivers side mount and use the one from your 91gs. The others are the same.
Exhaust can be a pain in the rear. You may have to buy an exhaust adapter (ebay has plenty) to extend the exhaust. Also the alignment of the flanges (cat) may be off. Worst case scenario would be a trip to the local muffer shop.
Ng
That’s what I was reading, people were going to the muffler shop, If i were to buy the megan racing header, do you think it would be long enough to get get to the cat? or even delete the cat?
I’m not familiar with the megan header, but if that’s what you want (and it’s in your budget)…get it. You won’t know for sure until it’s on. Then you will see if you need an adapter or test pipe. Ebay has plenty of adapters and test pipes with adjustable flanges to make almost anything work. Then a nice loud trip to the muffler shop to weld up any exhaust leaks 
Ng
That sounds great to me, I heard that the Megan racing header was decent. Do you know the diameter of that header? I can’t find it anywhere that they sell it.
Mine was a '93 and needed left and right conversion motor mounts, clutch cable conversion, Vtec wiring extended to the computer, and Power Steering hose conversion.
Like I said - the exhaust manifold was stock with no modification. Thought I could reuse motor mounts too - until installing the motor.
… why are you wanting to run cat-less? Regardless of if you don’t have to pass emissions testing or not, do it correctly and run a cat.
Don’t use the B16 harness… use the stock harness, and buy/make a ‘obd0 vtec subharness’. BoomSlang/Rywire/ebay all have them easily available.
You shouldn’t need ‘conversion’ mounts unless going from AT to MT… otherwise a combination of OEM brackets and mounts should get everything ligned up. You just have to use the (driver side) 3-bolt motor bracket from your B18a, and then the actual mount itself… Come to think of it, I spoke too soon. I could see you needing a conversion mount to use a hydraulic trans in a cable-trans-equipped car. But if your swap comes with a cable trans, stock brackets/mount from your B18a setup should work fine.
[QUOTE=demons;2235114]Mine was a '93 and needed left and right conversion motor mounts, clutch cable conversion, Vtec wiring extended to the computer, and Power Steering hose conversion.
Like I said - the exhaust manifold was stock with no modification. Thought I could reuse motor mounts too - until installing the motor.[/QUOTE]
You had to go through all that trouble cause from the sounds of it you got a swap out of a 92+ civic Sir. If he got a swap out of a crx or DA all his stock items will work.
The engine isn’y in yet, but the swap is from an 89 crx sir, I’m just trying to have everything when It comes down to the time of me putting it in. The guides I read didn’t say which car they got their swaps from,
It should be cake… no special transmission mounts needed… just vtec wiring and the powersteering issue.
If you’re talking about the 1 piece megan 4-1 type-r header with the 2.5" collector, it is 6.5" shorter than the stock exhaust manifold.
^^ That is exactly what I needed to know, still trying to decide if I should order one now, or wait and see what happens.
I guess i should specify, that the stock manifold I’m referring to is the b16a 2nd generation. Don’t know how similar it is to others…
Hmmm, Alright, I guess I’ll just have to wait and see