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Busted Intake Bolts!


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I'm in the middle of swaping motors and on one of them I busted two of the intake bolts. There are 3 on each side and 1 busted on each side in the same location. How do yall feel about installing Helicoils? Have a recommended size?

Thanks,

 

Oh and its a EA71

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On my last one, I welded nuts onto the remains of the broken bolts, and that freed them up enough to twist out with a socket. I then drilled and tapped for a helicoil in the stock size (8x1.25 I think), and made sure to anti-seize the crap out of it putting it back together. Just make sure you properly seal the intake passages, or else you will have to pull the heads to get the little welding spatter balls out of the engine.

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I'd try and easy out them first..

 

 

If they broke off because they were stuck, easy outs will most likely not work.

 

 

It's too late for this time, but I have found that if I run the engine up to normal operating temperature just before removing the bolts, they come out with a lot less trouble.

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If they broke off because they were stuck, easy outs will most likely not work.

 

 

It's too late for this time, but I have found that if I run the engine up to normal operating temperature just before removing the bolts, they come out with a lot less trouble.

 

True, I tried using heat and Pb blaster, but didn't work. Try and use the style of easy out that has the little tabs you can hammer down to lock it in place. That way it won't come out with the bolt next time you remove it.

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For future reference, If you use a breaker bar and put pressure against the bolt, hit the top of the breaker bar on top of the bar, socket and bolt. my dad showed me that trick 200 years ago, you'll never break another bolt again.

 

It's a little to late for that now but you can always replace a head.

 

 

Jeff

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Thanks for all of the info,

 

Last night I got brave and drilled out the 2 bolts that were broken off. I couldnt get it to normal temp bc its sittin on a bucket in my garage, but thanks for the tip.

 

I tapped them and installed helicoils!

 

But I drilled about .150 too deep and ended up being able to see I guess one of the water jackets.

At the very bottom of the hole theres a little space thats either where water goes or its part of the intake channel. Who ever does this in the future be very very careful.

 

As far as fixing mine I guess i will just put some high temp silicone or something. Any ideas? Anyone done this before???

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Thanks for all of the info,

 

Last night I got brave and drilled out the 2 bolts that were broken off. I couldnt get it to normal temp bc its sittin on a bucket in my garage, but thanks for the tip.

 

I tapped them and installed helicoils!

 

But I drilled about .150 too deep and ended up being able to see I guess one of the water jackets.

At the very bottom of the hole theres a little space thats either where water goes or its part of the intake channel. Who ever does this in the future be very very careful.

 

As far as fixing mine I guess i will just put some high temp silicone or something. Any ideas? Anyone done this before???

 

 

It's OK, a bunch of the bolts already extend into the cooling jacket. the bolt seals the hole. If you like, a trick we used to use on BB chevy(which also had bolts extend into the Waterjacket) is to put a dab of RTV on the very tip of the bolt threads. That keeps the water from making it's way up the threads and corroding the bolt into the aluminum.

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But I drilled about .150 too deep and ended up being able to see I guess one of the water jackets.

 

I just looked at one of my spare heads:

 

The 2 holes on the sides of the intake intersect 2 of the head bolts. They are drilled through as OEM. Not supposed to be water in there. No harm done.

 

The end bolt, if you drill deep enough, would intersect the air space above the head = crank case.

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Loyale I was thinking that i only drilled about .150 too deep but DaveT says that they are like that from the OEM.

 

Thanks for the info Dave.

 

I stabbed the disty last night and will probably put the intake on tonight and just might get it running this weekend.

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I just looked at one of my spare heads:

 

The 2 holes on the sides of the intake intersect 2 of the head bolts. They are drilled through as OEM. Not supposed to be water in there. No harm done.

 

The end bolt, if you drill deep enough, would intersect the air space above the head = crank case.

 

There is no Dead air open to the crank case in the heads. Except of coures the 2 passages in the bottom for oil return. But otherwise there is nothing in the head that is open to the crank case. I can tell you for a fact that that is a water jacket under the long bolt.

 

I think they are drilled through like that now that i think about it. That is why that long bolt often has corrosion all the way up it's shaft, from the water seeping up between bolt and intake.

 

Edit: I had it reversed, there are 2 long bolts and one short one. The 2 long ones (holes closer to block) are already drilled thorugh into to head bolt passages. The shorter bolt (hole closer to valve cover) would actually punch through to the area under the valve cover, which is part of the crankcase. So although there is no space IN the head that is open to crank case, once you put a valve cover on there it will be. Either way no problems drilling it out. Won't hurt a thing.

 

FYI, on the MPFI(dual port) heads, one of the 2 longer bolt holes does already punch through into water chamber. Other 2 bolts are like the Single port heads

Edited by Gloyale
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The ones that busted are the two short ones closest to you if your looking at the front of the motor. There are 3 bolts that hold the intake down on each side and the ones that busted are in the same spot. I drilled and tapped them and installed helicoils, I think with a little high temp RTV they will be ok. I will sure let you know how it turns out.

 

When i get this thing going im going to install a tach. it doenst have one factory. What do yall suggest is the redline for a stock EA71?

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