:rant: Threaded Cam/Rocker Cover Bolts.

Hello All,

I changed my Inlet Manifold Gasket and Rocker/Cam Cover Gasket this afternoon. All went surprisingly well until I found out how much of a cheapskate the previous owner was.
(Why do people bodge things up that only cost a couple of quid to replace :bang: )

Firstly, the Inlet Gasket had a load of instant gasket around it. Not an issue, I just cleaned it all off and fitted the new gasket.

Now, rather than buying a new Rocker/Cam Cover Gasket the previous owner just tightened a couple of the bolts so tight that they have stripped the thread so now don't go on as tight as they should.
(according to the tightening sequence, it is bolts 1, 2, 3, 4 &

It is holding for now, but obviously it isn't going to stay like this. I was wondering what would you guys recommend to do with it?

I'm not buying a new head. I know that much!

Would it be best to cut a new thread for the bolts in the head? (I would get all 15 redone anyway)
Or would it be best to drill, and heli coil?

Any other suggestions welcome!

Thanks in advance!

if its just a couple of bolts you may be ok,recutting to a larger size is the only other way,you can heli col it but upsure if you can get them that small.

Thank you for the reply!

Just a quick thought, does anyone know the bolt size that are for the Rocker/Cam Cover and maybe a suggested size to go up to?

Has anyone had to do this before themselves?

Thanks again

how about fill the holes with metal filler and drill and retap.....they dont need a lot of torque and it should be ok , the only problem going oversize is the 8 mm head will go to 10 mm and may not fit into the recess on the cover

Thank you for the reply.
That thought did cross my mind with the filler.

I would try to keep the 8mm head, but just a thicker thread.

Thanks again

you have to drill the cover to fit the bolt.We simply get the head holes alloy filled ,redrilled and then retapped,but its a head of job.another way that we used to use when I first started in this game.was tinfol ,wrap the bolt and bolt it in.but you really have too choices,one is alloy fill the hole .or redrill the hole.
we have a very good engineering firm down the road so jobs like this we simply hand to them.We cant bodge customers cars so for us its alloy fill and retap.but for you over sizing the hole and retapping will do a good job.If you use a allen headed bolt the larger size will fit into the cover recess

Thank you very much again for the reply!

Chemical metal, then drill and tap :broon: works every time. Even used it on a towing eye bolt once. Pulled fine

If it was my cylinder head, even though the bolt isn't particularly loaded, I'd be helicoiling it.

helicoling is a clever bit of kit,

Thanks again to everyone who has replied and offered suggestions.
Of course, I am still deciding on the best course of action for me.

I am appreciative of all the help

Helicoil for me too. :broon: