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View Full Version : Valve cover bolt problems.



Mysterio
06-13-2013, 06:09 PM
So I broke off one of the bolts into the head the other day tightening it down and just being stupid and doing things I know I shouldn't. So I drilled it and since I'm a double dumbass I center punched it a bit off center and the easy out wouldn't work so I just drilled it and tapped what was there a smaller size to thread a smaller bolt in. I'm then bolting all the other bolts in and one is going in a bit rough so I run the tap through it to clean the threads and clean the threads on the bolt and am tightening it down and bam the damn threads come right out. Aluminum heads blow. At this point should I just helicoil every damn hole?! One of the ones in the rear was going in a bit harder than it should so I stopped but I suspect that one will be culprit #3. I was thinking about just throwing a few washers underneath it since it went in about 7/8th of the way fine but was a few turns away from tightening and I didn't wanna break it or rip those threads out. Mind you this is a brand new unused head that was built by TU so it's not like its been used for years and had a dozen bolts ran in and out of it. This is ridiculous. What do you guys do with these things?

cordes
06-13-2013, 06:22 PM
Helicoil. Also, make sure that you're using the proper length bolts. A lot of guys will use bolts which are too short for the VC and then the threads can't offer the resistance to the torque. You are using a torque wrench for the VC bolts right? They don't take much.

Mysterio
06-13-2013, 06:50 PM
I'm reusing the actual valve cover bolts from when I took it apart as well as a few off the car in the JY I took apart since I lost one or two on accident. I didn't even use a torque wrench because the one that broke never got tightened all the way to need it and the one that stripped out was only like 1/2 way threaded in lol. I know not to tighten them too much but all the problems I've had were before it was even at the point of needing to torque to spec. $32 for an m6x1 helicoil kit!? Jesus!

I suppose I'll just wait till pay day and pull the valve cover back off and helicoil the stripped one and helicoil the one in the back that was offering too much resistance since I'm sure it'll just cause problems later.

GLHNSLHT2
06-13-2013, 07:33 PM
yep, just heli-coil the ones that strip out. M6x1mm thread heli-coil is what you want.

contraption22
06-13-2013, 09:45 PM
Just a note, if you are using a valve over with a one-piece gasket, I have gotten away with only using the 4 corner bolts without any leakage. I finally put the rest in when enough people teased me about it.

Shadowjake
06-13-2013, 11:49 PM
Install studs! I can send you a complete parts list with lengths of studs. Only costs a few bucks. But it takes to stress off the aluminum threads. And only tighten to 105 inch pounds alternating a little at a time as you go. I have a Menegon ported work of art for a head and got super paranoid when I stripped a couple. Haven't had an issue since doing this.

iangoround
06-14-2013, 12:34 AM
Install studs! I can send you a complete parts list with lengths of studs. Only costs a few bucks. But it takes to stress off the aluminum threads. And only tighten to 105 inch pounds alternating a little at a time as you go. I have a Menegon ported work of art for a head and got super paranoid when I stripped a couple. Haven't had an issue since doing this.

I'd be interested in that parts list. Post it up!

trannybuster
06-14-2013, 02:31 PM
Silicone will glue it in place, can pratically remove the bolts......then later fix them properly.

Shadowjake
06-14-2013, 03:31 PM
I got:

4 x Metric set screws, Allen, Cup point, Class 14.9 steel black oil finish, 6mm x 1.0mm x 50mm (http://www.boltdepot.com/Product-Details.aspx?product=8867) for the 4 corners.

5 x Metric set screws, Allen, Cup point, Class 14.9 steel black oil finish, 6mm x 1.0mm x 35mm (http://www.boltdepot.com/Product-Details.aspx?product=8864) for the middles.

I tried 25mm ones but they were too short. If I were to do it over again, I would get 7 @ 40mm and 2@ 50mm and only use the longer ones on the timing belt side. the 35mm ones are just too short for the ends where the valve cover is thicker and the 50mm ones look kinda dumb on the tranny side being so long

- - - Updated - - -

Oh, and of course some 6x1.0mm nuts. You'll need 9 but I just ordered a box of 25 or 50 for cheap.

Mysterio
06-14-2013, 04:10 PM
Unfortunately the corner front bolt by the timing belt is the one that stripped out. I already have a tap & die set so I may just drill it out to an M7 and thread it and buy a stud for that size. I really want to just get this damn thing running after the 12 different problems I've had holding things up while putting it back together so maybe I'll just do that and only use the 4 corner bolts with some RTV for now, since it is a 1 piece gasket valve cover.

Tempted
06-15-2013, 02:26 PM
I've never had luck getting broken valve cover bolts out with an EZ Out. I usually break the EZ Out off in the hole I just drilled. Helicoil will hold well enough for a valve cover without much worry. I've also had luck using JB Weld to fill the hole, then drill and tap it to the correct size. Then I use a super thin nylon nut on the top of the bolt's threads to prevent the JB Weld from being pushed out of the hole when its tightened. For obvious reasons don't install the bolt until the JB Weld completely dries.

Mysterio
06-15-2013, 03:59 PM
I've never had luck getting broken valve cover bolts out with an EZ Out. I usually break the EZ Out off in the hole I just drilled. Helicoil will hold well enough for a valve cover without much worry. I've also had luck using JB Weld to fill the hole, then drill and tap it to the correct size. Then I use a super thin nylon nut on the top of the bolt's threads to prevent the JB Weld from being pushed out of the hole when its tightened. For obvious reasons don't install the bolt until the JB Weld completely dries.

If I don't helicoil the stripped hole and rather just drill it and tap it one size larger (I already have a tap set so this will cost me nothing) will that work? Is the aluminum head strong enough or should I go 2 sizes up to make sure I've got enough meat on the threads? I'm not really concerned about the hole being a different sized bolt tbh. I'll probably never sell the car so it won't make a difference lol. I'm just not sure if going up to an m7 will have enough meat on the threads if I tap it?

cordes
06-15-2013, 07:04 PM
How common is 7mm? I always see 6 and 8. You may want to look into that if you're not sure yet. After Helicoiling many of the threads on my head for the VC holes I'm more than happy with it.

Mysterio
06-15-2013, 08:07 PM
How common is 7mm? I always see 6 and 8. You may want to look into that if you're not sure yet. After Helicoiling many of the threads on my head for the VC holes I'm more than happy with it. I hadn't really checked yet but I have a tap & die set with any size from 5-10mm so I could do whatever. Probably easier to go with 8mm since then I'll garuntee I clean the hole up enough for a good set of threads. The only reason I'm trying to do it this way is I'm trying to save money and spending $32 on a helicoil kit to literally helicoil one valve cover bolt is not really in the budget for me since I need new shocks up front, new brakes all the way around and a new starter, on top of whatever small odds and ends I run into while putting the rest of the car back together lol.

cordes
06-15-2013, 08:35 PM
I hear you there. The little stuff adds up quickly.

shackwrrr
06-15-2013, 11:08 PM
If you can find a 7mm bolt go with that because if you wish to helicoil it back to 6mm in the future, no other tapping is required. 6mm helicoils are 7mm od

GLHNSLHT2
06-16-2013, 01:04 AM
Spring for the Heli-coil kit. If you already have 1 stripped bolt down the road you're bound to have another. When dealing with aluminum you should either run studs or if you must run bolts that will be taken in and out you should always run a heli-coil or if you have enough meat a timecert. I've had my 6mm heli-coil kit for probably 12 years now. Used it on my cars, and my friends cars. Tap is still going strong and if I run out of Heli-coils a run to the local fasteners store gets me a whole bunch for a couple bucks.