Manolis_D

iTrader: (2)

Hey!,
I just finished installing a used RB header in my friend's 1991 NA today (wow that took awhile). I made a section of tubing up and welded it to connect the header to the current exhaust (right before the main cat). The car is really loud right now, and there's a bit of a 'ticking' (or really sharp puffs of air) at idle and under power, and the noise is rather 'honda-ish' (high frequency, almost like insane amounts vibration, except you can't feel it). It sounds like there's a hornet's nest under the car, just a lot louder!

Is the engine -> header gasket reuseable? How many ft-lbs of torque should I put on that thing? I know there are two small leaks at the two flanges (before + after the cat), but I don't believe that they could create that much noise!

How do I fix it?

Thanks!,
Manolis

Manolis_D

iTrader: (2)

Forgot one thing... How much louder should the car be with the header (as opposed to the stock manifold / melted precat). On the up side, i think it's got a bit more power, especially around ~6k rpm (It got sideways for the first time around a corner... friend almost killed me for that )

darkwaveboi

I dont know if its a necessity, but im under the impression that every time you take off a header/manifold to the engine, you use a new gasket because of heat damage/broken sealing (cracks).

The ticking may be your cat converter, mine clicked for the LONGEST TIME, and it turned out to be my main cat was collapsing on itself internally, see if its coming from the middle of the car or at the engine.

Jeff

Manolis_D

iTrader: (2)

The ticking pretty obviously comes from the motor -> header joint. How much of a leak does it take to make the car that noisy? I would imagine that it's pretty significant, but I can't feel that much air moving around down there!

Thanks,
manolis

darkwaveboi

well..think about when your at idle, how the engine shakes back and forth, and if there is a broken off peice on the gasket, then the engine will hit the header and could probably make a tapping annoying enough for you to hear.

My brother has a small exhaust leak near the manifold + turbo and it is pretty noticable and embarrasing
the only exhaust leaks ive heard dont seem to be clicks, but low to high whissling(sp?) sounds

Silkworm

No, the ticking is an exhaust leak, almost 100% certain. You did torque the nuts down right? I wouldn't reuse a header gasket, but that's just me.

However, a straight pipe and header is going to be a magnatude louder than you were used to, it's not this big hunk of cast iron soaking up soundwaves, and a cat to help muffle the exhaust further.

PaulC

darkwaveboi

ive been prooved wrong. I didnt know that ticking was exhaust leak. Silkworm: about how much quieter is a turbo setup then an NA setup?

Node

iTrader: (1)

a lot if they're both completely free flowing. The turbo quiets down the exhaust a lot, where N/A just spits out fire and brimstone

darkwaveboi

Gefunk

Right, does the ticking sound more like a small helicopter under the hood? Goto remember that rotarys have blasts of exaust, which would make a ticking sound as it freely hit the header walls. However, you should have changed the header gasket. So do that and tell us what's up

SpeedRacer

THe header will make it quite a bit louder, but if you have an even small exhaust leak, especially at the block, then it will be WAY louder than it should be. Way back in the day, when I was stupuid, I did my first mod to my car which was a bonez racepipe. I retardedly put a washer between the gasket and the racepipe. Well needless to say this caused an exhaust leak that made my car SOOO loud, even at idle. After about a week I realized what I had done, fixed it, and after that my car was quite again at idle, still louder wat WOT, but not NEARLY as loud as with the leak.