Installing Exhaust Manifold Rb20

[rayj]

I'm ready to install the stock rb20 exhaust manifold and just wanted a few pointers to make sure I do it properly.

The manifold has been machined so it's smooth and straight. I'm assuming the mating surface of the engine is straight as well...? Chances that it's not are probably very low, but I'll check with a straight edge anyway.

I know the torque specs and sequence, but how should it be done? In one pass, or 2 or 3 passes? Should I torque down in one go, or is it better practice to tighten down evenly, in the correct sequence, once or twice before torquing down to spec?

There are some nuts that are impossible to get a torque wrench on, do I just eyeball it, or is there a special method/tool?

After installation is it necessary to recheck nuts after a few days of driving?

What about things like gasket sealants? Are they overkill? If all surfaces are clean, smooth and straight with fresh gaskets, I'm guessing they're not needed?

Thanks heaps

[Missileman]

I use a 14mm combination open end and ring spanner with offset, the open end just happens to fit the 1/2 drive of my torque wrench, so I set the correct torque and feel how much pressure I need to apply to the spanner before the pin pops.

Then put the spanner on the nut and try and simulate that pressure, go full torque in the recommended pattern, no sealant on the gasket, and always new washers, yokes, studs, and nuts.

I do however use nickle based anti seize on the nuts, washers and yokes.

Edited September 2, 2015 by Missileman

[89CAL]

I'm fairly certain you can get to all the bolts with either a swivel or a wobble extension. I'm not 100% because it was quite a few years ago the last time I torqued up a stock manifold, but fairly certain I was able to get all of them with a torque wrench

[rayj]

Thanks Missleman and 89CAL, helpful as always!

I have all new studs, nuts, etc. Is there anything else to look out for, something I'm missing? The manual doesn't say much.

Edited September 2, 2015 by rayj

[rayj]

Just doing a final clean and noticed the stud holes don't look 100%.

The first and/or second thread of each hole looks slightly damaged, as if things have been over tightened in the past. Is it okay, or should it be fixed?

I'll also clean out the holes thoroughly with a small wire brush, some acetone or brake cleaner, and compressed air.

[Missileman]

they're fine, when a stud breaks it often takes out the first couple of threads

[89CAL]

Go and buy a starting tap and run that down them carefully if your concerned

[tridentt150v]

I.d use three steps to tighten....less chance of distortion or loading up one or two studs - plus even pressure. Also [and I'll prob get shot down for saying this] dont frett if you cant torque down completely. Get a feel for the torque on the ones you can access and just use that feel and the click in your elbow to do those that are hard to access. Torque settings are less critical on something like the exhaust manifold.

[rayj]

Thanks heaps