used the wrong tap

[fatty]

So I went to bottom tap my block today and somehow used a 12 x 1.5 tap instead of 1.75. Found out when I pulled threads out of the block going to 90 ft-lbs. Will I beok drilling and tapping theblockfor 13 by 1.75 bolts? Or does anyone have a better idea?

P.s. I know I'm an idiot, no need to tell me now.

[Tacoclaw]

Ouch

What do you plan on running for bolts/studs if you drill them out to a 13x? There's a bigger set of studs made, but they're hella overkill for the level our engines are at, both strength and price-wise.

Is there any chance of a heli-coil? I've heard of people using them for pulled threads in blocks, and it would allow you to reuse the studs you already have. It will still be torture redrilling and tapping all those holes.

[fatty]

I was just planning on buying some really strong bolts of the bigger size. Helicoils would be just as much work and I think more expensive is why I want to do bigger bolts.

[Tacoclaw]

Yeah, I don't think there's gonna be a win situation here. It would let you reuse your studs you've already paid for though...

It's up to you though and not to kick you while you're down, but you'll have a PM in a second.

[fatty]

I'm using the stock head bolts still. Don't have studs now but I figured while the head is off I should tap the holes in case I ever get studs.

[Tacoclaw]

Oh, that's not nearly as bad then.

It still totally sucks, but it doesn't totally suck +$400 in the hole. I guess it's up to you then, sounds like you know what you want to do.

[bgilbert]

Time for 14mm studs! Rough mistake .

[KTA]

FWIW I ran into this issue before and helicoils would not hold. If it was me i would go 9/16 to fix it as that will totaly clean out the messed up 12mm threads and a 14 won't do that. Problem is you will have to drill out your head to to clear the bigger bolts. I put another block in the truck i worked on to fix it.

[Douglas]

FWIW I ran into this issue before and helicoils would not hold. If it was me i would go 9/16 to fix it as that will totaly clean out the messed up 12mm threads and a 14 won't do that. Problem is you will have to drill out your head to to clear the bigger bolts. I put another block in the truck i worked on to fix it.

Ummmm...tap drill size for M14x2 is 12mm. Pulling out 12mm threads will leave a hole right about 12mm. If one could find M14 fine threads, the tap drill is even bigger. There are 14mm bolts available too. 14 times .03937 is .5512 and 9/16 is .5625
cheers,
Douglas

[KTA]

The the max diameter of the threads cut in the block is a little over 12.000mm. A M14x2 bolt has a minor diameter of about 11.700mm therefore you will not achieve full thread engagment. Some threads will because they overlap and line up, but others wont because of the diffrence in thread pitch.

[fatty]

http://timesert.com/ For the win! These things work great, and are pretty cheap. About 250 bucks for 23 of the inserts and the kit (tools), with 50 dollars of that being for overnight shipping.

[redneckroot]

A local guy to me had a similar problem. The head came off that truck four times until he finally changed out his block. He tried to use an insert style thread repair and had three that wouldn't torque down. He put three new ones in, month later head started leaking. Four of them were loose when he brought it up here to check it, so head came off again. Went through this four times and ended up getting a different block. I hate to say it, but if it was me I'd pull it and start over.

[fatty]

Ha I just finally remembered to update. I got 23 of them things holding my head on. I put them in about 3 months ago and torqued my head bolts to 125 ft lbs. Still holding good.