All,

I came across some videos that remove the Head and Intake Manifold bolts a half turn at a time and do a reverse bolt torque sequence as not to warp them.

I don't think this is a bad thing, but really want to see what others think of this really being necessary.

For Cast Iron heads?

For Aluminum Heads?

For Cast Iron Intake?

For Aluminum Intake?

Thoughts???

 

I’ve never worried about any sequence in removal. Only on installation.

 

Sounds like AI generated bull$hit to me. I've disassembled 100s of engines too. Zip them loose and don't look back.

 

Lets think about warpage this way. Warping is just a natural aging process (Stress relief) of engine parts. Any parts that are cast, perhaps also forged have internal stresses when new.

A guy by the name of Bill "Grumpy" Jenkins got a dozen new blocks each year and and stacked them outside, behind his shop in Pennsylvania. They sat all summer, fall, winter and into the spring. When he needed a new engine block for racing, he picked one out of the pile. The heating and cooling cycle from being outside for several months relieved internal stresses and became stable for machining a race engine.

A used engine from a junk yard has gone through the "aging process" that relieved all the internal stresses created during the casting process. Jenkins got his blocks from GM, at a very reduced cost or free. He could have also got a junkyard engine full of grease and grime, but why do it when he could start with a new, clean block ?
I think he could have done the same thing with cylinder heads.

 

Great pics of Da Grump!

 

^^^This! I usually use an impact wrench to remove them.

 

I remember the story where Jack Roush would bury brand new Ford blocks for a year to age them before machining for the ProStock cars. Of course, those WERE Ford blocks...

 

John Force told a story about sending a crew member out with an infrared thermometer and having the kid randomly point it at the car. The next race all the other teams were feverishly taking temp readings and writing them down...sometimes these guys just make their tracks fuzzy to mess with the competition

 

Smokey Yunick used to pull some of the same sort of stuff.

 

Originally Posted by OLDSter Ralph A guy by the name of Bill "Grumpy" Jenkins got a dozen new blocks each year and and stacked them outside, behind his shop in Pennsylvania.
Some of those "Old school" people recognized things that people today do without knowing how it evolved.

The internal stresses accumulate due to the different parts of a casting cool. The thinner sections cool faster than thicker sections. The larger the casting the more it will change when stress relieved.

I think we can agree that people use Remflex and other materials to seal the exhaust side of Oldsmobile heads because the exhaust manifold and head surfaces are no longer flat. Most good engine builders "True up" the block and heads before actual precision machining is done.

 

Just a quick question... is it wise to reuse head bolts once removed or should they be replaced? Just wondering about the number of times they can safely be re-torque'd.

 

These are not torque-to-yield bolts. So long as they are not damaged or rust pitted, there is no issue in reusing them. Be sure the threads are clean and in good shape, and follow the CSM instructions for lubing them with motor oil when installing.

 

^^Solid advice^^

Lubricating (clean) head bolts prior to installation & torque removes chances of dry friction, galling & poor clamping force in order to enable a more uniform clamp & provide accurate torque value(s).