427 block thread pulled
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
427 block thread pulled
Well, have finally got my new brodix RR heads, after all the shipping dramas
Have been in the process of installing them tonight.....but last long head bolt ( front of cylinder head on the final torque started to go "soft" Dam it all!!
I noticed the block has 2 helicoils all ready.( other bolts)
This bolt had 60lbs on it before it started to pull....
Best fix for this, advice please engine guys.
The engine had studs, I removed them and replace with bolts to reduce interference with header flanges, perhaps I should have left then alone!
Gutted
Have been in the process of installing them tonight.....but last long head bolt ( front of cylinder head on the final torque started to go "soft" Dam it all!!
I noticed the block has 2 helicoils all ready.( other bolts)
This bolt had 60lbs on it before it started to pull....
Best fix for this, advice please engine guys.
The engine had studs, I removed them and replace with bolts to reduce interference with header flanges, perhaps I should have left then alone!
Gutted
Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
Helicoil
Front one went in mine too guess its common.
Plenty of guys have tried to remove their old head bolt (up front like yours) only to remove half of one the other part was corroded. Right there by the water pump.
All is not lost.
Front one went in mine too guess its common.
Plenty of guys have tried to remove their old head bolt (up front like yours) only to remove half of one the other part was corroded. Right there by the water pump.
All is not lost.
Burning Brakes
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From: CA
Race Director
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Did you get the correct length bolts for the Brodix heads?
Timeserts or Helicoils should hold OK.
JIM
Timeserts or Helicoils should hold OK.
JIM
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If those threads have been overstressed in the past, it's just a matter of time before they strip. A bolt thread in a steel block should be able to withstand a 25-30% overtorque without any permanent damage. If any threads can't handle that, it's Heli-coil time.
Drifting
Joined: Oct 2005
Posts: 1,528
Likes: 148
From: East London/SW Essex UK
When I had a 'seasoned' block built-up using oval port Race Rites' I had a similar issue, but this was with the 'tappings' for the water pump - fortunately I was able to 'Helicoil' the block without removing the engine!
This was certainly a 'bolt length' problem (as Jim has guessed) - not too short, but in reality slightly too long, consequently bottoming-out in tapping and stripping
This was certainly a 'bolt length' problem (as Jim has guessed) - not too short, but in reality slightly too long, consequently bottoming-out in tapping and stripping
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Team Owner
Joined: Jan 2006
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From: Crossville TN
Even if the bolt 'bottoms-out', it would still require significant overtorquing of the bolt to cause it to strip threads. This is exactly why a torque wrench (or well-calibrated hand/arm) is required...to detect problems like this before the threads become stripped. There are lots of "failure" points when dealing with fasteners; proper torquing minimizes them.
Drifting
Joined: Oct 2005
Posts: 1,528
Likes: 148
From: East London/SW Essex UK
Even if the bolt 'bottoms-out', it would still require significant overtorquing of the bolt to cause it to strip threads. This is exactly why a torque wrench (or well-calibrated hand/arm) is required...to detect problems like this before the threads become stripped. There are lots of "failure" points when dealing with fasteners; proper torquing minimizes them.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Interesting. I've always felt if the part wasn't locked down when fasteners were fully torqued, the problem was an interference of parts or a fastener issue. I've NEVER found a good reason to overtorque anything.
Drifting
Joined: Oct 2005
Posts: 1,528
Likes: 148
From: East London/SW Essex UK
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Sheer age and coolant corrosion can weaken them. Get the block real hot on top of that and they can pull out fairly easily. REal pizzer.
Too bad they dont make repo blocks.
Too bad they dont make repo blocks.
