Seal up hole in cast iron manifold

[jimrat]

Hi

I need to modify a cast iron exhaust manifold. The hole circled in yellow needs to move 15mm, to where the yellow dot is.

How do I go about blocking off the hole? A multilayer metal sealing gasket runs directly over the hole, so whatever I use will need to be ground or milled flat. I've got access to mig, stick, or AC/DC tig welder. It bolts right up to the turbo, so is going to get hot.

Thanks
Jim

 

[bricol]

I assume it's a mounting hole that is no longer needed? Does it need to be blocked off - if it doesn't interfere with anything, I'd leave it alone.

 

[Wildefalcon]

Tap it and insert a brass stud?

 

[jimrat]

Hi

Yes it needs to be blocked off as the (narrow) sealing gasket runs right over the top.

 

[tom2207]

looking at the rest of it ,,, its not a racing car ,
I would drill it and tap it , screw a bolt though and then add a drop of braze and cut / file / grind both sides until they were flat ,,, bit of overkill but Id be happy at that.

 

[BrokenBiker]

Drill it to next size up for threading, tap it and locate a grub screw in...doesn't need to be flush with the mating surface as long as it doesn't protrude and you can tidy the top up with a flap disc, die grinder or just a file. If you are worried about it winding back out, pein it over on the back side with a punch to expand the stud at the top. Personally I always try and avoid welding cast iron if it's not necessary

At a guess id say it was an 8mm (or imperial equivalent) clearance hole, so an 8.5 should clean it up then tap for m10

 

[tom2207]

Drill it to next size up for threading, tap it and locate a grub screw in...doesn't need to be flush with the mating surface as long as it doesn't protrude and you can tidy the top up with a flap disc, die grinder or just a file. Ifnyou are worried about it winding back out, pein it over on the back side with a punch to expand the stud at the top. Personally I always try and avoid welding cast iron if it's not necessary

At a gues id say it was an 8mm (or imperial equivalent) clearance hole, so an 8.5 should clean it up then tap for m10

if you use a countersunk screw and put it in from the gasket side it will be flush after tightening , grind to suit ,,, never can screw out as its into the gasket ,,, lots of options, depends on whats to hand

 

[Brad93]

Braze all day long, least likely to crack

 

[Pete.]

Tap a thread in and stop short. Screw a bolt on, cut off and file flush. 10 minutes work and it'll never come out.

 

[8ob]

BSP tapered pipe plugs are good for this sort of thing.

Bob1,535 × 1,535

 

[jimrat]

Thanks folks - lots of good suggestions

 

[Puglet1]

In an emergency I once used JB Weld high temperature epoxy for a repair on a VW Camper manifold .
It was supposed to have been a “get me home” bodge but is still effective 18 months after.
……..I’m now waiting for the flack to hit me from the professional engineers on here.

 

[Brad93]

If you plug it then peen the plug and the cast iron you'll never know it's been done