45 RS EVO head bolts

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Brandon Atwell

Brandon Atwell

Well-Known Member
Joined
Mar 11, 2012
Messages
1,203
Any idea what thread sizing and length for the 45 head bolts? Mine decided it didn’t need two of them :)

Thanks!
 
Brandon Atwell said:
Any idea what thread sizing and length for the 45 head bolts? Mine decided it didn’t need two of them :)

Thanks!
Click to expand...
strange ..my year old evo45 did the same 2 bolts over the exhaust areas just sheared off midway . they did seem corroded even tho I always give the head a flush out, stainless in there now.think mixed views on high tensile and stainless re the torque strength between the two?
 
Funny, same two bolts on mine also...
I haven’t looked to see if they sheared or not, I was working in the shop and noticed the water jacket was missing them. I’ll have to see, hopefully they just backed out
 
they are 3 mm. i stock iron in 16 and18 mm long,and ss in 16 and 18 mm long. i have never broke a ss bolt,and use ss in all engines that have water on the bolts.i replace them when the socket starts getting bad
 
steve wood said:
they are 3 mm. i stock iron in 16 and18 mm long,and ss in 16 and 18 mm long. i have never broke a ss bolt,and use ss in all engines that have water on the bolts.i replace them when the socket starts getting bad
Click to expand...
Hey Steve!
Can I order two sets of SS from you then? Not sure which length is best as well? Looks like 16 according to Mike!
Good to know on switching them out also guys, I will change them over on our other EVO as well.
Thanks!
 
Have not had any head bolt issues with the .45 EVO. I stopped using SS as they stretch and get soft. Always use a torque wrench and tighten in a crisscross pattern, in 5 in-lb increments with max torque being 15-17 in-lbs.
 
Last edited:
Brandon,
The bolts are 3mm x 16mm. Black oxide bolts are the best. Flush your water jacket at the end of each day with WD-40 and then alcohol. No failures, rust or stuck bolts.
Stu
 
Pulled the head off completely, bottom bolts were toast! Thanks to Danny King in addition to all of you in here for pointing out the angle of my water outlets was also making it retain water in the bottom of the jacket. Bottom bolts held the most water. Always did corrosion X after running but probably wasn’t blowing out the puddle at the bottom.
Cleaned it up, Corrosion X’d it up and when the new bolts come in she’ll be ready to rock and roll.

that copper anti-sieze Is cool, never heard of it! I’d think you’d have to err on the side of caution using it with these jackets because the screws are exposed? Get it too thick and I’d think you might risk blocking the flow.
 
My bad, I said 2.5. Thats the allen size which is the next size up for bolt.......DUH. What was I thinking. Was NOT.
 
Brandon Atwell said:
that copper anti-sieze Is cool, never heard of it! I’d think you’d have to err on the side of caution using it with these jackets because the screws are exposed? Get it too thick and I’d think you might risk blocking the flow.
Click to expand...

Yeah it is cool stuff, I mainly use it on my headers and head bolts on my drag truck..
SBC head bolts live in the water jacket of the block, and when I pull the heads, the bolts spin right out and there is usually lube still on the threads. I use ARP bolts and washers on the aluminum heads and have never had issues with the header bolts or head bolts holding torque. I use it on my RC motors just because I have it sitting on the bench... good stuff.
just don't over apply it and you will be fine..
 
Brandon Atwell said:
Hey Steve!
Can I order two sets of SS from you then? Not sure which length is best as well? Looks like 16 according to Mike!
Good to know on switching them out also guys, I will change them over on our other EVO as well.
Thanks!
Click to expand...
yeah. ss will be $.25 each,iron $.30 each. priority is $8.45 now. i can ship regular mail cheaper but don't know how much shipping will be till after i ship
 

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