i was told today by a machine shop (import machine shop) that GM used an odd size tap for the LS1 motor and they would have to have one custom made. has anyone ever found one? i need to tap out a broken bolt in the block. only option so far is to use another thread size and use a bolt that match's in that 1 hole. any help here would be great.

 

A tap doesnt remove a broken bolt. I'm not sure what you are asking. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

 

they are gonna drill out the bolt, just inside the threads, and tap out the rest.

has anyone repaired the threads in any way?

 

Can they not just back the bolt out using an EZ-Out? There are taps available I'm sure, but I bet its gonna be a $30-$50 tap from some machine shop supply warehouse. You can get a tap for anything if you find the right place.

Any idea why the bolt broke?

 

why the bolt broke? would you belive me if i told you i was destracted talking w/ a friend, and turned the bolt the wrong way? 3 pulls w/ a 25" breaker bar, and snapo.

as for removing it, its 3" down the hole. i drilled a nice 1/8" hole in the end of it, punded a torx into the end and it came out about half way, then snapped. had to have it EDM'ed out. got home and put a "CRAPSMAN" easy out in it, and snapped it. took it to an import shop and asked them to EDM it out, they did, and took 1/8" of threads w/ it. they are gonna try and back it out tomorrow, but if it doesnt come out, they wanna drill it out and tap it, or re-thread it. they called all over dallas/ft. worth today loking for a tap, w/ no luck. seems they are a very odd size metric. a local place can custom make one, but it will be next week before it will be finished. i need to have the machane shop (a different shop than this one) do the work on the block, and crank and get it assymbled. plus get it back in the car, tuned @ LGM, and cleaned up for SLP day on the 15th of feb.
i got a line on a used block, and i think i'll just take it and get it to the machine shop now, and fix this one later. this all has been a 3 week ordeal that seems to get worse every couple of days.

 

WOW <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

 

Call a local GM dealer. Kent Moore makes a special helicoil kit for the LS1, the price for the kit is $460 <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> I was quoted by a local dealer $172 to helicoil the the bolt holes for both heads. It's the thread pitch that GM uses that is irregular. The helicoil is actually stronger than the aluminum threads. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Hope this helps.

 

could you list the name of the local dealer. the shop i'm @ now has been called by some local dealers looking to have this done. i need info, please.

 

I don't know about the helicoil but there is a tap out there. I've seen it in use. Call your local Snap On guy. He can probably fix you up.

 

"the kit is $460"

You might as well just get a new block & switch everything over. (LS6 from Valvegod for $500) For piece of mind, if nothing else.

This is assuming you cant get the broken bolt out. Good luck.

 

valvegod is $600, and a week wait. i want the car ready for feb 15th DFW SLP day. i dont mind the cost, its the wait.

the bolt size is a 11mm x 2. only the GM kit has this tap and repair parts. i searched all over the net for a tap this size w/ ZERO luck. so, no you cant get this from snap-on.

i waisted 3 weeks w/ this bullshit. GM sucks *** for always doing crap different. why not just use a regulare thread even if it is metric. it works for all the other car manufactures. sorry to vent, just i'm sick of dealing w/ this. <img border="0" alt="[bang head]" title="" src="graemlins/gr_banghead.gif" />

 

I think the tap is M12*2.0. I'd hate to see you get a custom tap made and it be the wrong thing. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />

John

 

Seems like there are alot of sponsors in your area, I'd be calling around to see who can do what. Someone must be able to help you out. Maybe even a dealer..

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by XLR8NSS:
<strong> I think the tap is M12*2.0. I'd hate to see you get a custom tap made and it be the wrong thing. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />

John </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Everything I've read say's it's a m11 with a 2.0 thread pitch?

 

Tool made specificially for this:

GM Part #
J-42385-107

LS1 Thread Tap.

11mm
2.0 Pitch

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by smokin' joe 00 ss:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by XLR8NSS:
<strong> I think the tap is M12*2.0. I'd hate to see you get a custom tap made and it be the wrong thing. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />

John </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Everything I've read say's it's a m11 with a 2.0 thread pitch? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Good deal, it looks like your right. I just did some searches on here and read M12*2.0 but, I see the GM part # and description above. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Sometimes the search feature is dangerous. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

John

<small>[ January 30, 2003, 05:41 PM: Message edited by: XLR8NSS ]</small>