SS Manifold bolts

[Jaay757]

I just finished changing the manifolds on our 06, 8.1's. I thought I would be thorough and ordered new Oem manifold bolts. The new bolts came stainless steel with no collar. The old bolts were steel with a collar, original as they still had the black paint and never been changed. All removed very easily.
The parts #'s for the bolts are 10-40011151 and 10-40011158.
I found the difference odd and thought maybe I ordered the wrong bolts. I checked the mercruiser part lookup several times and no they were correct. I then contacted mercruiser with my serial #'s and part #'s and they told me these are the correct manifold bolts and they changed to ss with no collar. Have to say they were very helpful.
My question is have any others replaced there manifold bolts with these same ss bolts and has anyone had any problems removing these after years of use. My concern is not now it is down the road for my next manifold change, I don't want to be breaking bolts.

Thanks
Jason

 

[Xplicitlnck]

I'm an ironworker and the briliant minds that draw my blue prints always tell us to use ss bolts threading into steal. It never works. The stainless seizes itself to the steal. Half the time my even making it in all the way before doing so. I would not recommend doing it especially in a situation that envolves heat and expansion. If u do end up using them use lots or antiseize. But I would really recommend going with steal collored

 

[Bob & Sue]

I'm an ironworker and the briliant minds that draw my blue prints always tell us to use ss bolts threading into steal. It never works. The stainless seizes itself to the steal. Half the time my even making it in all the way before doing so. I would not recommend doing it especially in a situation that envolves heat and expansion. If u do end up using them use lots or antiseize. But I would really recommend going with steal collored

+1 on that.

I'm sure mercruiser has done their homework and used the correct stainless for the alloy steel they bolt into that being said I don't think I would use them. If I did first polish the SS threads making sure there are no burrs, run a tap down the threads and clean the holes out with air, then use plenty of anti seize and install them at a slow rpm making sure there's no galling at the first sign of seizing remove them and get Alloy Steel now or you'll never be able to remove them.. If it's the wrong SS for the Alloy steel you could have some REAL problems.

 

[Jaay757]

Thanks guys, that was my thought that mercruiser knows what they are doing. I know that a lot of auto manufacturers changed to ss manifold bolts also. When i installed them I did use plenty of anti seize, so at this point I would have to change them out before I launch. On another note they weren't cheap either $100 for 32 bolts.
Thanks again

 

[Jaay757]

I wanted to make sure this was the correct install, it's just how I am, So I did a little research today, called my local sea ray dealer and michigan Motorz, and spoke with the techs and mechanic. I was told that many of the late model 496's and 8.1's have ss manifold bolts. I was told that the bolts I removed should be ss. I will check this. The sea ray dealer said that they have had no problems with the ss bolts and highly recommend I use the mercruiser bolts. MM also stated the same. Therefore at this point I will leave well alone and leave the recommended/factory bolts.
Thanks again

 

[fwebster]

The metallurgy issue is easily handled with Merc Anti-Seize compound or Extreme Grease. The biggest issue is the condition of the bolts you removed. If they were anything but clean full threads, then chase the threads with a bottoming tap. The real advantage of using stainless bolts is the condition of the bolt heads after 5+ years in a salt water environment. When mild steel bolts in OEM manifolds are removed here, it is frequently necessary to grind away the bolt head then use a torch and vicegrips to remove the bolts because the heads round off and a socket won't turn them.

 

[Bt Doctur]

SS bolts don't hold torque, use plain old steel ones