Main seal carrier bolt torque specs?

[jon8christine]

First time building an engine. I've been searching on here and my manual and can't find any torque specs for the bolts that attach the seal carriers to the front and rear of the block... Auxiliary, front and rear main seals. It looks like the generic torque for a metric 8.8 (us grade 5) m5 bolt is 4.2 ft-lb. Is that what you guys use?

As for the thick paper gaskets, for those it seems like there is varying opinions on how to install them so you don't get any leaks. The permatex website says don't put gasketmaker on gaskets to act as a sealant. My manual says to put grease on them, so that's what I did.

[davidbruce]

Jon, that is the number I found on the online bolt charts for a dry, zinc plated bolt. I don't own a torque wrench that goes that low so I would be relying on feel anyway. As for gasket sealant. I am a fan of Gasgacinch. I use it on virtually all paper and cork gaskets I install. A thin coat on all surfaces, let it dry and assemble. You have to be careful it isn't too old as it will start to jell in the can. I will open the can in the store because I have gotten bad ones straight off the shelf. Also the surfaces have to be clean or oil on the surfaces contaminates the brush and remaining sealant in the can. I don't put on a lot of miles on my Spider but after about 2000 kms and my second season after rebuilding my 2 litre I have virtually no drips on my garage floor (touch wood).

[18Fiatsandcounting]

Torque specs are hard to find for these M6 bolts and nuts, but my general rule is around 6 or 7 ft lbs but no more than 8. This would apply to the seal carriers, water pump bolts, heater pipe nuts, etc. In practice, I usually do it by feel using a 1/4" drive ratchet with my hand wrapped around the ratchet head (and not on the end of the handle).

I actually don't know what works best for gasket "dressings". I used to slather Permatex RTV over everything, but my machinists are telling me these days that gaskets should be installed dry. I think the quality of the gaskets has a lot to do with it, as some are better than others.

-Bryan

[Nut124]

These front and rear cover bolts are not under a structural nor dynamic load of any kind and should not be torqued to the max spec for the bolt size, grade. I do what Bryan explained above.

I think too tight could deform the cover.

[jon8christine]

Cool thanks. My Haynes manual says 17ft-lb for the same small bolts on the water pump. I got half way there and stopped, thinking that is crazy... No way.

[18Fiatsandcounting]

My Haynes manual says 17ft-lb for the same small bolts on the water pump. I got half way there and stopped, thinking that is crazy... No way.

The Haynes manuals are pretty good, but they do have mistakes. This is one of them. Those M6 bolts for the water pump should be no more than 6-7 ft lbs, 8 ft lbs max. No way 17 ft lbs.

-Bryan

[Nut124]

Cool thanks. My Haynes manual says 17ft-lb for the same small bolts on the water pump. I got half way there and stopped, thinking that is crazy... No way.

17 ft-lb surely would snap the little bolt.

[OllieKrause]

Wow I wish I saw this thread an hour ago. My manual said 12ft*lb which I thought was a lot but ignored my intuition and went ahead with it. Anyways, I ended up shearing one of the four mounting bolts and am at a loss at what to do. I tried various bolt extractors and they seemed to grip pretty well but all failed to get the bolt stub to move. Do you think it's possible to install the water pump with the three remaining bolt holes? The only alternative I can think of is retapping the hole as an M8?



https://ibb.co/0mdD9Tm

[18Fiatsandcounting]

Do you think it's possible to install the water pump with the three remaining bolt holes?

Hmmm, maybe, but I kinda doubt it. I can't quite tell from your picture, but which bolt hole is the one that's messed up? the one on the left, or the one at the top?

As long as the block is OK, I think it's a question of removing what remains of the bolt, which usually involves very carefully drilling it out. I think you should be able to do this without removing the engine.

-Bryan

[davidbruce]

Ollie, a machinist friend of mine removed an exhaust stud that was broken off in my manifold. I had tried a screw extractor to no avail. He drilled the hole I had made progressively bigger. He stopped when he hit the housing. My original hole was off centre so what was left of the stud was crescent shaped. He took a small punch and drove the ends of the crescent inwards. He was then able to unthread the remains and pick out the small bits with an o-ring pick. Hope this makes sense as I have no pics.

[Nut124]

If you cannot get it out then I would drill and tap to M8.

You need that bolt in there.

[OllieKrause]

Thank you all for the great suggestions! I ended up following a rough version of what davidbruce suggested. I drilled a hole dead center in the sheared bolt and progressively enlarged the hole until it was just at the edge of the sheared bolt threads (having an extra set of hands hold a drill guide in place was a must to make sure the hole was normal to the engine block surface). I then followed it up with a M6 tap which seemed to clear out any of the remaining stuck threads. I was lucky that the bolt only sheared about halfway into the hole. When drilling, I could feel when I broke through the end of the sheared bolt and it felt like I had about 5mm of fresh threads left on the other side. The threads I ended up re-tapping are a bit loose but with the fresh threads beneath, the I was able to torque the water pump down to 6ft*lb.

That sure was a scare but I think it should hold now.

[18Fiatsandcounting]

....but with the fresh threads beneath, the I was able to torque the water pump down to 6ft*lb.

That should work. Awesome, Ollie! Another disaster averted.

-Bryan

[Nut124]

Good work.

[davidbruce]

Well done.