3.8L Head Bolt Torque

Cosworth · April 23rd, 2007, 02:01 AM

My manual shows a final torque sequence for my '01 V6 Mustang to be "rotate an additional 180 degrees". When I try to perform the final step it really seems like the bolts are going to snap off. Should these bolts be replaced prior to torqueing them down? I am reusing the bolts from the original engine.

Onemanzu · April 23rd, 2007, 02:22 AM

i heard that it was only 90 degrees past the final torque setting... if you fear the bolts breaking then go ahead and get new bolts... cuz a broken bolt in the block will suck so hard

uhh yea i was told only 90 degrees past

singe · April 23rd, 2007, 03:44 AM

Yeah man...get new bolts...there not supposed to be re-used.

stephen · April 23rd, 2007, 01:04 PM

For a 99 Mustang it is 180 degrees and I believe that applies to later engines as well. I believe it was 90 degrees for earlier mustangs.

Yes the head bolts should be replaced. They are torque to yield type bolts. Since you loosen each bolt one at a time, I believe you could replace each one at the same time. Of course if you loosen them all at once you have to replace the head gasket.

The idea of torque to yield bolts is that you stretch them into a non elastic region where the torque remains constant as the bolt is tightened further. The engineers think this is more accurate than measuring torque.

Hope this helps.

Juggalo_X · April 23rd, 2007, 02:21 PM

it is 180 degrees there is a torque routine you should really purchase a Haynes Manuel because it tells you all of this.... and there is a special posses in torquing the head bolts on your engine which requires u to loosen the bolts one at a time again and then re torque and stretch it with a 180 turn.

Cosworth · April 23rd, 2007, 04:02 PM

Jug...I already have the manual, that's why I was asking the question.

Stephen...Thanks for the info. This is my first experience with "torque to yield bolts". I'll get new bolts and replace them one at a time. I'll be working on the car again Thursday. I'll let you know what happens.

Juggalo_X · April 23rd, 2007, 04:05 PM

Originally Posted by Cosworth

Jug...I already have the manual, that's why I was asking the question.

Stephen...Thanks for the info. This is my first experience with "torque to yield bolts". I'll get new bolts and replace them one at a time. I'll be working on the car again Thursday. I'll let you know what happens.

k dude 180 is correct tho man... they are stretch bolts you torque to speck then stretch

April 23rd, 2007, 02:01 AM	#1
Cosworth Newbie Join Date: Apr 2007 Posts: 2 iTrader: 0 reviews	3.8L Head Bolt Torque My manual shows a final torque sequence for my '01 V6 Mustang to be "rotate an additional 180 degrees". When I try to perform the final step it really seems like the bolts are going to snap off. Should these bolts be replaced prior to torqueing them down? I am reusing the bolts from the original engine.

April 23rd, 2007, 02:22 AM	#2
Onemanzu ¡ʇsnq ɹo uʍop ǝpısdn Join Date: Oct 2006 Location: Looking for free hand jobs in poland springs nebraska... silly gooses Posts: 12,514 Blog Entries: 1 iTrader: 0 reviews	i heard that it was only 90 degrees past the final torque setting... if you fear the bolts breaking then go ahead and get new bolts... cuz a broken bolt in the block will suck so hard uhh yea i was told only 90 degrees past __________________ My Foz

Threads Similar to: 3.8L Head Bolt Torque
Thread	Thread Starter	Forum	Replies	Last Post
Head bolt seeping antifreeze	demononwheels	5.0 Mustangs	23	September 30th, 2007 09:51 PM
Head Bolt Headache	Buttaz	V6 Mustangs	14	August 2nd, 2007 09:06 AM
i6 Head Bolt Torque	tnknepp	Classic Mustangs	5	July 30th, 2007 09:21 PM
Re-Torque of Head Bolts?	lwhitetrash88l	V6 Mustangs	11	April 16th, 2007 02:15 PM
Stubborn Head Bolt	lwhitetrash88l	V6 Mustangs	4	April 11th, 2007 12:49 PM

April 23rd, 2007, 03:44 AM	#3
singe Regular Join Date: Feb 2007 Posts: 117 iTrader: 0 reviews	Yeah man...get new bolts...there not supposed to be re-used.

April 23rd, 2007, 01:04 PM	#4
stephen Hardcore Enthusiast Join Date: Feb 2007 Posts: 1,181 iTrader: 0 reviews	For a 99 Mustang it is 180 degrees and I believe that applies to later engines as well. I believe it was 90 degrees for earlier mustangs. Yes the head bolts should be replaced. They are torque to yield type bolts. Since you loosen each bolt one at a time, I believe you could replace each one at the same time. Of course if you loosen them all at once you have to replace the head gasket. The idea of torque to yield bolts is that you stretch them into a non elastic region where the torque remains constant as the bolt is tightened further. The engineers think this is more accurate than measuring torque. Hope this helps.

April 23rd, 2007, 02:21 PM	#5
Juggalo_X I Post Entirely Way Too Much 2001 Mustang 232/CBR600 14+@Slow Join Date: Jan 2007 Location: South Western Ontario Posts: 6,688 iTrader: 0 reviews	it is 180 degrees there is a torque routine you should really purchase a Haynes Manuel because it tells you all of this.... and there is a special posses in torquing the head bolts on your engine which requires u to loosen the bolts one at a time again and then re torque and stretch it with a 180 turn.

April 23rd, 2007, 04:02 PM	#6
Cosworth Newbie Join Date: Apr 2007 Posts: 2 iTrader: 0 reviews	Jug...I already have the manual, that's why I was asking the question. Stephen...Thanks for the info. This is my first experience with "torque to yield bolts". I'll get new bolts and replace them one at a time. I'll be working on the car again Thursday. I'll let you know what happens.

Remove Advertisements Sponsored Links
Forums at Modded Mustangs Advertisement Advertisement

All times are GMT -4. The time now is 05:17 AM.
Contact Us - Modded Mustangs - Privacy Statement - Top
Modded Mustangs is ©2005-2008, All Rights Reserved, And is Not Affiliated with Ford Motor Company. Forum is powered by vBulletin ©2000 - 2012, Jelsoft Ent. Ltd. & SEO by vBSEO 3.3.2 ©2009, Crawlability, Inc.