Broken stud- repair or replace heads?!?!

topcatcustom · Post by **topcatcustom** » Tue Aug 19, 2008 2:41 pm

Hi, I had 2 broken exhaust studs on my RR lump, one came out a treat and the other has bitten off the end of my stud extractor (whilst being careful!) Is it worth taking it to get someone to try and remove it or should I just get a cheap pair of heads off ebay?(as there are loads about)
It's a 3.9 and there are some 4.0 heads currently for sale on there from a 2001 model, mine is a 1991- would there be any difference or benefit?
(I have tried to search for previous answers!)

chodjinn · Post by **chodjinn** » Tue Aug 19, 2008 2:59 pm

Depends what type of heads you have at the moment. If they are SD1 you're looking at a chamber size of 36cc, and the later spec heads are only 28cc, therefore you'd be looking at a slight increase in comp ratio.

Can't you carefully drill and retap the stud out?

How about tack weld a bolt onto it and unscrew, seen that done on a water pump before now with a stubborn bolt.

topcatcustom · Post by **topcatcustom** » Tue Aug 19, 2008 3:09 pm

Well one was sticking out far enough to put an external extractor on and I unwound it by hand (good penetrating spray!) but the other was too short so I drilled and used an internal extractor which broke inside so too hard to drill now.
The lump is from a 3.9 RR, the heads I have seen on ebay are from a 4.0 RR and if anything I want to lower the comp ratio a little as I am supercharging the engine... after I have rebuilt it so I know everything is good!

HairbearTE · Post by **HairbearTE** » Tue Aug 19, 2008 5:50 pm

Theres a Normfest product called "Super Crack" that is very good for freeing up stubborn studs, bolts, calipers etc.

Mark · Post by **Mark** » Tue Aug 19, 2008 6:31 pm

Try to find a toolmakers near to where you are, they can spark erode the broken extractor and stud out in one go for around £25 cash if the head is off the engine

I've lost count of the number of broken taps that I've sparked out over the years

Mark

topcatcustom · Post by **topcatcustom** » Tue Aug 19, 2008 9:25 pm

Brilliant thanks for that- will have a look tomorrow!

topcatcustom · Post by **topcatcustom** » Thu Aug 21, 2008 8:39 pm

Well after some fidling around this evening I sorted it- I drilled out a bit with an 8mm drill then very slowly and carefully burned away at the broken extractor with a plasma cutter, drilled out and still would not come out so I just re tapped the hole and blew the swarf out! Good ol plasma cutters and a bit of noodle!!!

Sorted

ppyvabw · Post by **ppyvabw** » Fri Sep 05, 2008 10:34 am

If they are not too far in, broken taps and drill bits I have managed to get out with a thin punch, and wellied it until the bit or tap broke up in the hole.