Stupid head bolt question (LX9)

[asylummotorsports]

So I am sick and tired of my rusty head bolts on display for all to see when I'm trying to make it all pretty.

Now I KNOW the answer to this question as it pertains to old school iron V8's BUT with aluminum heads I'm not sure.

On a STONE COLD engine how "unadvisable" is it to replace one head bolt at a time (Just the visable 5 on the front)? I'd like to install ARP pretty ones. Starting in the center and working outward to the outside/ends.

Go ahead flame away, but I'd like some opinions.

There ya go folks! 2010 stupid question nominee just 3 days in!

[IsaacHayes]

I'd clean them and paint them. Yes it will take some delicate hand work, but that's what I would do. Get a small paint brush, paint of your choice and go to work. I've even used a small thin artist brush with metallic spray paint. Just sprayed some card board then dipped and painted away...

But yeah interesting question... I'd not risk it though...

[Superdave]

I'd clean them and paint them. Yes it will take some delicate hand work, but that's what I would do. Get a small paint brush, paint of your choice and go to work. I've even used a small thin artist brush with metallic spray paint. Just sprayed some card board then dipped and painted away...

But yeah interesting question... I'd not risk it though...

x2

I'd just clean them with a 3M pad and give them a coat of paint.

[ForcedFirebird]

Forget the paint! Go to Home Depot and get yourself some "Etch and Prep" concrete etcher (it is phosphorus) - it is the EXACT same chemical that comes in the Por-15 kits. Use a small brush and keep putting coats of the etch on the bolts until the rust washes off. Put on a couple more coats and the bolts will just look gray for a long time since you are essentially creating a "black oxide" type of coating on them.

[60dgrzbelow0]

So I am sick and tired of my rusty head bolts on display for all to see when I'm trying to make it all pretty.

Now I KNOW the answer to this question as it pertains to old school iron V8's BUT with aluminum heads I'm not sure.

On a STONE COLD engine how "unadvisable" is it to replace one head bolt at a time (Just the visable 5 on the front)? I'd like to install ARP pretty ones. Starting in the center and working outward to the outside/ends.

Go ahead flame away, but I'd like some opinions.

There ya go folks! 2010 stupid question nominee just 3 days in!

This is a very thoughtful and intelligent question. On a problematic scale of 1 to 10... removing individual head bolts that mate Aluminum Heads to a Cast Iron engine block...is a 10. The reason being that when you bolted the heads on in the first place... you followed a bolt up torque pattern that should be adhered to IN REVERSE when unbolting the heads. The reasons for this are two fold: (1) If you remove the head bolts on a block of aluminum that is already pre-stressed via the original bolt pattern... you run the risk of either warping or cracking the head. (2) Because the mating materials in this odd "sandwich" are of dissimilar metals that follow their own rules of flexing, expansion and contraction... as soon as you unbolt even one bolt...the stress points that are already involved become shifted as the unequal pressure spreads outward from the relief of the torque holding the pressure in stasis. In plain English... you can get all three components to move of their own accord... The Head... The Gasket...and The Block...in such a manner as to cause them to move and break the "seal" you originally achieved when they were torqued down and stretched to hold properly.

What most people do not realize ...is that when two or more pieces of metal are properly torqued down...there is absolutely no stress on the components of the system being held together. It is only when things become either too loose...or when too much torque is applied to a fastener that things begin to break down. And as a rule... fasteners should always be replaced as a complete set... and not piecemeal in any mechanical device that requires a torque pattern to remain firmly together.

So it is a good thing that you can question your automotive vanity...and not have your heads leaking like a sieve for the sake of something cosmetic and non-contributory. One last issue with using the "etching" method using Phosphoric Acid is... make certain you dab some wet Baking Soda on the area around each fastener after you are done with the rust removal because otherwise... any residual acid will set up conditions for electrolytic corrosion between the bolt head and the Aluminum... and behave just like a battery. And just like battery terminals that loosen and get all white and puffy from the oxidized metal in between, there is the certainty that electrolysis can degrade the Aluminum under the bolt. Of course, once that happens... the bolts will be subject to loosening... with or without being properly torqued down and in place.

[asylummotorsports]

OK thanx guys.

I think I'll have a look at the etching thing.

Thanx again!!