04-30-2006, 08:01 PM #1
10 TIPS ON TIGHTENING HEAD BOLTS!!!
This applies to any/all internal combustion engine.
Please pay attention to Tip #5 & 7 especially
I post this bease there has a been a few instances in the past years where heads have been milled and the attention to the bolts are ignored.
They can bottom out if enough material is removed from the milling process.
In our GPR's, this can cause a water leak in the cylinder and/or loss of compression.
"Pay attention to every detail"
Be Very Meticulous when assembling any engine.
Also, If I may add, The head gasket is one of the most critical gaskets in an engine because it has to seal all of the combustion chambers as well as the coolant and oil passages between the head and block. The gasket has to provide a leak-free seal from the moment it is first installed, and maintain that seal for the life of the engine.
When a head gasket fails to go the distance, thereís usually a reason why.
The reasons can be lumped into basically three categories:
Design issues with the engine or gasket (hard-to-seal engine, milling or machine work, thermal stress created by bimetal engine or weak gasket design).
Installation errors (head or block not clean, smooth or flat; wrong surface finish; using the wrong sequence; procedure or torque specifications when tightening the head bolts; reusing stretched, damaged or dirty bolts; using a sealer on a gasket that does not require a sealer, etc.).
Operating conditions that overstress the gasket and cause it to fail (preignition, detonation and overheating).
04-30-2006, 08:38 PM #2
Good stuff Billy.
Just remember...if you mill your head/heads, that means removing material. Sometimes .015-.025 at a time. You have to make up the difference by adding a washer to your bolts, or cut the bottoms. If the bolt bottoms and wont tighten the head sealing area, you will leak water or compression
04-30-2006, 09:48 PM #3
Steller Info!! Awsome stuff.
with all this type stuff going on, there could be a big-azz book written and i bet everyone would get it.
05-01-2006, 08:38 AM #4
..............for those who did not see this yesterday
05-01-2006, 08:41 AM #5
maybe make this thread a sticky?
05-01-2006, 08:45 AM #6
Thats a good idea.
There have been alot of motors being built lately and this will make good information to keep in mind.
With all the motor-heads on this forum, it will be useful information for any engine assembly.
as I always say....... "Be very meticulous !"
05-09-2006, 01:53 PM #7
Lets say you had aftermarket heads with all aftermarket stainless bolts that had been torqued to after market manufacturer specification.
Now, lets say you want to change all these bolts out for oem bolts.
Would the best procedure be to 1)replace each bolt one at a time in the required pattern? In other words, remove a bolt, replace and 2 stage torque the new bolt. Remove a bolt, replace and 2 stage torque a new bolt etc
Or, would the best procedure be to 2)just remove all the old bolts, then start the staged torquing pattern fresh with the new bolts?
Seems like option 1 would keep a steady bind on the head gasket, whereas option 2 would potentially lose a working seal. Any thoughts?
04-05-2007, 10:46 AM #8
Go with option 1 if you already have a good seal
04-05-2007, 11:13 AM #9
Something I dont see here is retorque your head bolts after warming up the motor thats when there torqued right.
12-05-2008, 05:32 PM #10
reminder.....for those taking on winter projects
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