Broken exhaust valve bolts....

classic-indy · Nov 29, 2014

I've got a problem. Both the bolts on my mag side exhaust valve broke. One sticks out from the mono block 2ish millimetres the other is broken flush with the mono block.

Has anyone had this problem?

Always war · Nov 29, 2014

I do believe these bolts only need 12 ft lbs. tops. Really you only need to snug em up with some blue loctite. Sounds like you'll need to drill them out. Make sure to cover up the valve port good, as not to get any shavings in the cylinder. Good luck!

cascadesnowjunky · Nov 29, 2014

Better check on the 12 ft lbs that seems like a bunch. As far as getting them out it will take a very small drill bit and easy out. Make sure to heat them just before trying to remove them to break the loctite loose, then work fast.

classic-indy · Nov 29, 2014

This is not going to be fun..... Aghhh.

LoudHandle · Nov 29, 2014

If you have decent welding skills or have a friend that is an accomplished welder. I would be inclined to weld nuts on what is left and let them cool a bit and spin them out.

The heat from the welding will soften the Loctite if it was used, and they should come right out. Regardless; mask off the internals to keep foreign matter from getting in.

89sandman · Nov 29, 2014

I would suggest investing in a set of reverse drill bits, if the bolts aren't seized in there most of the time they will end up spinning the broken bolts out. If they have Loctite on them a little heat first.

classic-indy · Nov 29, 2014

I can find a welder....

LoudHandle · Nov 29, 2014

All are viable options, all have the potential for damage if the proper care / precautions are not taken.

I just verified torque in the manual: for the 10.9 grade, 6mm bolts it calls out 11 Ft/#'s FWIW

garlic bear · Nov 29, 2014

the welder thing works the best and is the easiest

Indy_500 · Nov 30, 2014

Reverse countersink

LoudHandle · Nov 30, 2014

Indy_500 said:
Reverse countersink

Is that a question? A reverse countersink is typically the same as a blind countersink. You drill the hole thru the material, attach the counter sink head and it countersinks the far side of the material on the up stroke rather than the down stroke.

Regardless it will not work for your application.

If you are looking for the reverse drill bits mentioned previously? You will have more luck searching left hand drills. As the spiral flutes are ground in left handed and sharpened so that they cut while running the drill motor in reverse.

When used on Right handed bolts, they will often grab the bolt at some point and back it out, if it is not too buggered up or Loc-tite'd in.

Hope that helps

Always war · Nov 30, 2014

cascadesnowjunky said:
Better check on the 12 ft lbs that seems like a bunch. As far as getting them out it will take a very small drill bit and easy out. Make sure to heat them just before trying to remove them to break the loctite loose, then work fast.

Yup! It does seem like a bunch, hence the snug em up with loctite. What do you recommend as far as torque?

mountainhorse · Nov 30, 2014

Left handed bits... get them from NAPA...They sell individuals.

You will need to heat the area with a propane torch to release the locktite.

Center punch the bolt and drill with the left bit right after you heat it... it will probably back right out with just the drill...But if it does not... heat it again and use an easy-out.

When drilling... put tape over the port so that chips dont go into the exhaust/engine.

I've done a couple of these... the most important is to use heat, proper angle on the drill and steady feed rate.

You may want to remove the front overstructure to give you room to work.

.

Kraven · Nov 30, 2014

LoudHandle said:
If you have decent welding skills or have a friend that is an accomplished welder. I would be inclined to weld nuts on what is left and let them cool a bit and spin them out.

The heat from the welding will soften the Loctite if it was used, and they should come right out. Regardless; mask off the internals to keep foreign matter from getting in.

^^^^^^^^^^^^^^ AGREED^^^^^^^^^^^^^^^^^^^
I've had the BEST luck by welding a nut that's 1 or 2 sizes larger than the broken stud, (use a 5/16" or 3/8" in this case) and "baloney slicing" the weld nut in half, to make it easier to weld to the broken stud.

As previously mentioned, Apply a bit of heat to the cylinder outside of the broken stud to ease the Loc-Tite & to expand the aluminum

I've had marginal results with drilling & extractors (as driving in the extractor seems to expand the broken stud and worsen the situation)

GOOD LUCK!

Indy_500 · Nov 30, 2014

LoudHandle said:
Is that a question? A reverse countersink is typically the same as a blind countersink. You drill the hole thru the material, attach the counter sink head and it countersinks the far side of the material on the up stroke rather than the down stroke.

Regardless it will not work for your application.

If you are looking for the reverse drill bits mentioned previously? You will have more luck searching left hand drills. As the spiral flutes are ground in left handed and sharpened so that they cut while running the drill motor in reverse.

When used on Right handed bolts, they will often grab the bolt at some point and back it out, if it is not too buggered up or Loc-tite'd in.

Hope that helps

Sorry for the typo I meant reverse center drill the taper usually bites into the bolt and will pull it out. It worked great for me once. Reverse countersink spit out of my mouth because usually when checking threads with a go/no go gauge if the no go goes in we run a countersink in reverse over the hole, it mushrooms the top and keeps the no go from flying in

LoudHandle · Nov 30, 2014

Indy_500 said:
Sorry for the typo I meant reverse center drill the taper usually bites into the bolt and will pull it out. It worked great for me once. Reverse countersink spit out of my mouth because usually when checking threads with a go/no go gauge if the no go goes in we run a countersink in reverse over the hole, it mushrooms the top and keeps the no go from flying in

No problem, just trying to be of help. Yes, when available, a left handed center drill is a excellent choice for starting the drill out process and may indeed be all that is needed.

Good Luck with whichever option you use.

Sage Crusher · Nov 30, 2014

I know this may look a bit odd and " Yeah Right" but these have work in allot of tough applications here in my shop-I just removed a broken stud flush with the case....and saw this post.
Just might be the ticket to help ya-
Worth looking at.... and as MH stated- using heat will aid with easier removal.

https://www.buyspeedout.com/iispout/13.0000/index.dtm?mid=4487152

S/C

05900 · Dec 1, 2014

As long as you have it out replace it with a stud and nut,makes it easy to R&R next session.

Ult680 · Dec 1, 2014

I had the bolt that hold the fuel rail on break last year. After no luck with removal, went to drill and tap. Extremely slow but it's like new. Lots of patients! Oh and beer

NapaMatt · Dec 1, 2014

My Vote Goes to Welding a Washer... Then a Nut to the Washer!!

Works Very Well!!

Any one who drive's a Chevy 5.3 Knows this!! Dang Manifold Bolts!

Broken exhaust valve bolts....

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