Head bolt tightening

#1

Yet another example of why I need to stay the f— away from my car when it’s past 10pm and I’m tired. Particularly when doing something as critical as tightening the head bolts.

Instead of tightening 22/90/90, I tightened 22/180. Since some time back in elementary school up until about 10 minutes before tightening, I knew that 90 degrees was a quarter turn. Then, for some dumb reason that I will never be able to full explain or live down, I thought 90 meant going halfway around. Fortunately (???), before doing the 2nd “90”, I realized my mistake and stopped. So I’ve effectively turned each bolt the prescribed 180 degrees, but in a single stage rather than split into 2 stages.

On a scale from 1 (you’re an idiot) to 10 (you’re a huge effing idiot), how badly did I screw myself here?

I’ll likely end up trying to put it all together and giving it a shot anyway, but I figured I’d ask so I could put myself up for ridicule (to make myself feel better) and to determine how much I should be preparing myself, mentally, for a disaster.

Or, if I’m extremely lucky, someone will say, “Meh, I’ve done it before. No big deal.” :slight_smile:

Som

#2

2

#3

You’re probably fine. Some places where one reads about the tightening specs on our headbolts specify that one should wait 15min between each stage, and do the last stage after the engine has warmed up. You see this a lot when referencing our early style bolts, less often with late style. If there is anything to that idea, all you did was fail to give the HG that time to settle. So maybe after you get the engine running, pull the rocker cover and give each bolt another 10deg of rotation.

#4

Thanks guys. Should be wrapping up assembly tomorrow. Hopefully no big deal!

Som

#5

Som,

I’d loosen them all and re-torque. If you want, I can send you some re-usable head bolts.

#6

Ah man. I have it all buttoned up again, too. :frowning:

With the reusable bolts do you have to follow the old style tightening procedure where you have to warm the car up for 25 minutes before retightening?

I’m kinda curious what the purpose of the staged process is. I originally thought it had something to do with applying even pressure to the head to prevent it from being damaged. I’d reeeeally prefer not to retighten the bolts from scratch. I figured I’d recheck my valve clearances after the Saturday race and just tighten up Scott’s 10 degrees suggestion at that point. Is there a known/common issue I should be concerned with if I don’t retighten?

Som

#7

If you aren’t inclined to start the tightening process over, I’d just leave them be. I don’t think 10 degrees will do anything useful. The reason for the staged process is to avoid deforming the head and head gasket. I doubt skipping a stage hurt either. You’ll know after you run it though…