head bolts too long?

[Anonymous]

I have a head gasket leak on my 170 with a 75 200 head. The head was milled .055. The block was decked just enough to get it flat. I'm using a composite gasket. Everything looks good, but i have a compression loss between #5 and #6.......Is it possible that I bottomed out the head bolts just enough to reduce the clamping force? I think I should add head bolt washers, does anyone have a good source and maybe a part number? I'd rather find them local if I can. Thanks!

 

[t-west]

Wouldn't any hardened washer of the right size work?

--tom

 

[Anonymous]

ARP has some nice bolts and washers

i would think that bottoming out would break the bolt though?

 

[addo]

You can get generic hardened washers from an engineering supplies. They're extremely cheap and yellow zinc plated. I can't see how the ARP ones can be that much better - but maybe I'm missing something...

Regards, Adam.

 

[Anonymous]

http://www.geocities.com/mustang_man_19 ... _tips.html



Doug

 

[mustang6]

My local auto parts store had the hardened head bolt washers in bulk.

 

[Anonymous]

After further investigation, I found a head bolt hole that I didn't clean out when I built the engine. Shame on me.....The one bolt must not have been tight enough, which caused the head gasket leak, as it is right next to #5 cylinder.....Lesson learned!

 

[addo]

The other culprit with leaky gaskets is not allowing relax time between torquing. You should wait five to twenty minutes minimum between the first and second stages, and preferably overnight before the final crank.

I see some mechanics "crack" each bolt in turn before final torque, but never seen this in modern gasket literature. Think it's an old-time routine.

Use moly grease or motor oil on the threads, and under the bolt's head. You can swap out bolts one at a time on a head like the Ford one, but I don't want to be seen endorsing this. It's worked for me but that's no guarantee for you, if you get my drift.

Cheers, Adam.

 

[CobraSix]

Yeah, I chased all the threads prior to reinstall.

I just used standard hardened washers for $.10 each vice ARP ones of $1 each.

For torquing, I did 30 minutes between 1st and 2nd stage. Then I did final stage the next morning.

Slade

 

[Anonymous]

I couldn't find the head bolt washers for my car anywhere locally. I ended up having to buy them at the machine shop.

I dont know what brand they were, but either they were really good and expensive, or just overpriced. Or maybe my machinist took advantage of me not knowing what the going price was for washers...

When I asked my machinist about them, he said he had some, and they weren't cheap. I thought in my mind, "well I've spent enough money on the engine, no reason to go with the cheap ones here..." I was thinking a set for $10 or so.

I later left the shop with 14 washers and $25 less in my wallet. I think I overpaid.

I know Jegs has a set of the Mr. Gasket ones, but their handling charges are outrageous. I believe when I looked at them, the handling prices ended up being more than the washers, but I dont remember.

 

[Anonymous]

I see some mechanics "crack" each bolt in turn before final torque, but never seen this in modern gasket literature. Think it's an old-time routine.

Not old time at all.

Torque values are supposed to be "running".

It takes too much torque to get a bolt moving again once it has stopped, so the torque needs to be reached while the bolt or nut is still moviing.


HAVING SAID THAT...It really isn't going to make that much of a difference in 99% of the engines here. Just torque em down.

If you really want a good fuzzy feeling inside, then torque them like the big racers do - - Torque, let the gasket settle a while, then go back, ONE AT A TIME, and crack it loose and bring it up on torque again.

 

[addo]

Yep, I meant one at a time. Some of the Euro cars require a couple of hours running, and then you go through and re-torque. If I was unsure about a bolt, I might crack it first.

But as to cracking them otherwise, I can only see that as necessary if the final torque is close or likely to be exceeded by the breaking torque. Cranking from say 65 to 75 foot-pounds, it's always going to start moving if lubed properly.

I might be fussy, but I use the wrench to find the breaking torque when pulling off a head. Sometimes, it will reveal an issue.

 

[Anonymous]

I have used a thin white paint line (like "white out") to mark where the bolt started at, then loosen it and retorque, then see where the line ends up.

If the gasket settled a lot, the bolt will have turned a bit further. If it has stabilsed, the bolt mark will be near where it was when you began.

 

[addo]

That'd be good indicator for TTY fasteners. Standard lore here is "Tighten 'til it breaks, then back off a quarter turn". Can't believe how many guys re-use them here!