Exhaust manifold bolts?

[DaveG55]

So, the new manifolds came today. They came with gaskets, new plugs, new bolts and, oddly, split style lock washers.
Now, the old bolts did not have lock washers nor does my manual (#17) show or mention lock washers. Further, I don't recall ever using lock washers on exhaust manifold bolts.

So, l don't think that I am going to use them.
Correct decision?

 

[achris]

What are you working on? Engine model, year and serial number please....
And are these new manifolds OEM or aftermarket?

 

[Fun Times]

What brand exhaust did you end up buying?

Your correct that you usually will not find washers on most OEM Mercruiser exhaust manifold. http://www.mercruiserparts.com/Show...IFOLD+AND+EXHAUST+ELBOW(CAST+IRON+EXH.+ELBOW)

One quick tip for you! If you bought Mercruiser OEM exhaust, it would be a good idea to run a thread chaser or tap to clean out any paint that may be inside the exhaust manifolds holes for the riser bolts. There have been a lot of online reports about cracking the manifolds while tightening down the riser bolts due to left over paint.

 

[DaveG55]

The boat is a 94 Monterey 206SCR, 5.0/Alpha 1, Gen 1. I ordered the parts using the engine SN which is OF157289. I had posted that info in a previous post asking advice on which manifolds to buy. I have the Mercruiser Service Manual (#17) that is correct for my engine.
I decided to buy the HGE manifolds as they came in a kit with everything needed for a reasonable price.

Now, back to my question. Lock washers or not? Or does it matter one way or the other? My biggest concern is how they would affect torque. The manual says 25 ft lbs but that is, apparently, without washers.
I have all the old parts off and just have to clean the old gasket material off and transfer a couple of fittings and will likely do the install tomorrow.

One final question, I don't have the Mercruiser "Perfect seal" or whatever it's called to seal threads. I plan to use Teflon tape on all the fittings and plugs. That's not a problem is it since we're just looking at IP fittings.

Thanks for the help guys!

 

[achris]

No, using the washers will not change the torque required on the bolts. Choose to use them or not, but the torque remains at 25lb-ft...
BTW, that engine number is for the Gen II range. Unless you are sure it's a Gen I drive, post either a picture of it or its serial number, but I think you'll find it's a Gen II.... If you don't have Perfect seal, use a pipe thread sealer, like Loctite 567....

Chris.........

 

[parttimr]

I used NAPA Aviation form a gasket per a post from Don S many posts ago since I could not get Perfect Seal locally and the shipping off the net was as much as the product and no leaks so far.

 

[DaveG55]

Drive SN is OF317617 and I just double checked and, you are correct, it is a Gen2. No clue why I thought it was a Gen1, probably oldtimers disease setting in...

 

[achris]

Drive SN is OF317617 and I just double checked and, you are correct, it is a Gen2. No clue why I thought it was a Gen1, probably oldtimers disease setting in...

Yep, Gen II....