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reusing head bolts #1343050 11/29/12 06:33 PM 11/29/12 06:33 PM
Joined: Mar 2005 Posts: 1,630 North Central Florida E eightlitermopar OP top fuel
eightlitermopar OP top fuel E Joined: Mar 2005 Posts: 1,630 North Central Florida	FOR THE RECORD: I have new head bolts for my 318 I am currently putting back together. I was wondering; we have been told to not reuse head bolts, they stretch, etc. Who has actually resued head bolts and seen a failure from doing this? This is just a question, not an argument starter, just curious. eightlitermopar Mopar or no car

Re: reusing head bolts [Re: eightlitermopar] #1343051 11/29/12 07:04 PM 11/29/12 07:04 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: Who has actually resued head bolts and seen a failure from doing this? no failures from reusing here & on a 318 I wouldn't give it a seconds' thought live every 24 hour block of time like it's your last day on earth

Re: reusing head bolts [Re: RapidRobert] #1343052 11/29/12 08:30 PM 11/29/12 08:30 PM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	Quote: Quote: Who has actually resued head bolts and seen a failure from doing this? no failures from reusing here & on a 318 I wouldn't give it a seconds' thought Have reused head bolts for years and never had a problem or given it thought.

Re: reusing head bolts [Re: eightlitermopar] #1343053 11/29/12 08:32 PM 11/29/12 08:32 PM
Joined: Nov 2003 Posts: 597 R robertop mopar
robertop mopar R Joined: Nov 2003 Posts: 597	The head bolts on any engine should be torqued to factory specs that are well below the yield point, i.e. the point at which they permanently stretch, so follow the engine specs and put your mind at ease. Bolts behave essentially like springs: you can stretch them up to a point and they will return to the same length as many times as you want, but if you pass a certain point (yield point) they will take a permanent set, as a spring would. All manufacturers specify a certain torque that should not be exceeded; if you do that you will be OK.

Re: reusing head bolts [Re: MoparforLife] #1343054 11/29/12 08:36 PM 11/29/12 08:36 PM
Joined: Jan 2007 Posts: 7,664 IN A ahy master
ahy master A Joined: Jan 2007 Posts: 7,664 IN	Re-using is generally OK as long as they are not the torque to yield type used on some newer engines. Re-using torque to yield is a no-no because stretching them the first time changes their properties and a second stretch may overload the bolt and joint. For standard head bolts, a thread guage is a good way to check for stretch. I was working with an experienced mechanic on a 60+ year old flathead. Those bolts had been re-used who knows how many times. He checked each one before re-installing and had to use some spares to replace those that had stretched in the threads.

Re: reusing head bolts [Re: ahy] #1343055 11/29/12 11:25 PM 11/29/12 11:25 PM
Joined: Mar 2005 Posts: 1,630 North Central Florida E eightlitermopar OP top fuel
eightlitermopar OP top fuel E Joined: Mar 2005 Posts: 1,630 North Central Florida	These were the stock bolts that were installed from Ma mopar. Hmmm...maybe I'll return my head bolt set then and get my 33 bucks back. Where this is a budget build, I could use the money. Acutally, I already opened the new box of bolts so they are non-returnable now. I am putting '96 magnum heads on this old 318 so I wanted to be sure they were the right head bolts. However, this is good information to know for the future! Thanks! Mopar or no car

Re: reusing head bolts [Re: ahy] #1343056 11/29/12 11:27 PM 11/29/12 11:27 PM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	Quote: Re-using is generally OK as long as they are not the torque to yield type used on some newer engines. Re-using torque to yield is a no-no because stretching them the first time changes their properties and a second stretch may overload the bolt and joint. For standard head bolts, a thread guage is a good way to check for stretch. I was working with an experienced mechanic on a 60+ year old flathead. Those bolts had been re-used who knows how many times. He checked each one before re-installing and had to use some spares to replace those that had stretched in the threads. "The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."

Re: reusing head bolts [Re: eightlitermopar] #1343057 11/30/12 11:25 AM 11/30/12 11:25 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: I am putting '96 magnum heads on this old 318 so I wanted to be sure they were the right head bolts. I believe the mags take a unique bolt (P4876759). I have a set for a Magnum swap also & I'm not sure if they are torque to yield or not. You have used ones that you were considering reusing? If not TTY then the thread gauge check sounds excellent & I'd just lightly wire brush em clean & good visual for nicks that would screw up your torque readings. live every 24 hour block of time like it's your last day on earth

Re: reusing head bolts [Re: eightlitermopar] #1343058 11/30/12 12:07 PM 11/30/12 12:07 PM
Joined: Nov 2008 Posts: 178 New Berlin,Wi F Firepowerflyer member
Firepowerflyer member F Joined: Nov 2008 Posts: 178 New Berlin,Wi	I have built several engines over the years 440s along with many pontiacs,never have I bought new bolts,I just used the factory ones.Most of the motors were pretty healthy,the only new bolts that I invest in are the rod bolts.Save the money and return them.

Re: reusing head bolts [Re: RapidRobert] #1343059 11/30/12 12:14 PM 11/30/12 12:14 PM
Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O 70Cuda383 Too Many Posts
70Cuda383 Too Many Posts Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O	Magnum headbolts are NOT torque to yield, and I've re-used them several times without any problems. however, on a high compression performance build, I would suggest going with new ARP hardware anyway. but for a mild build, stock bolts are fine. mine has re-used stockbolts, and it's about a 350-ish hp engine. (285 RWHP) However, Magnum head bolts ARE different than LA head bolts. I found this out when I ordered a set of ARP hardware for edelbrock heads off Mancini. They arrived with 3 different length bolts. The Magnums use 2 length bolts, 5 long ones down the middle of the head, and 5 short ones for the base of the head below the exhaust ports. When I called Mancini they confirmed that the LA heads use a different bolt set than a Magnum bolt set, and took the opened set of LA bolts back without any problem, and sent me the correct head bolts instead. Photobucket sucks

Re: reusing head bolts [Re: 70Cuda383] #1343060 11/30/12 02:00 PM 11/30/12 02:00 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: Magnum headbolts are NOT torque to yield, Thank you live every 24 hour block of time like it's your last day on earth

Re: reusing head bolts [Re: RapidRobert] #1343061 11/30/12 04:13 PM 11/30/12 04:13 PM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: Quote: I am putting '96 magnum heads on this old 318 so I wanted to be sure they were the right head bolts. I believe the mags take a unique bolt (P4876759). I have a set for a Magnum swap also & I'm not sure if they are torque to yield or not. You have used ones that you were considering reusing? If not TTY then the thread gauge check sounds excellent & I'd just lightly wire brush em clean & good visual for nicks that would screw up your torque readings. magnum INTAKE bolts are supposed to be TTY, IIRC, not the head bolts. and there's 1 or 2 that are different length for an LA, so LA head bolts won't work. I reused mag head bolts when I put mag heads on an LA 318 roller, didn't have any problems. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: reusing head bolts [Re: patrick] #1343062 12/01/12 01:01 AM 12/01/12 01:01 AM
Joined: Mar 2005 Posts: 1,630 North Central Florida E eightlitermopar OP top fuel
eightlitermopar OP top fuel E Joined: Mar 2005 Posts: 1,630 North Central Florida	thanks for the info. My brand new head bolts ARE for magnum heads. I was curious if they were different, and now I know. I'll let you know as I progress. eightlitermopar Mopar or no car

Re: reusing head bolts [Re: patrick] #1343063 12/01/12 09:11 AM 12/01/12 09:11 AM
Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O 70Cuda383 Too Many Posts
70Cuda383 Too Many Posts Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O	Quote: Quote: Quote: I am putting '96 magnum heads on this old 318 so I wanted to be sure they were the right head bolts. I believe the mags take a unique bolt (P4876759). I have a set for a Magnum swap also & I'm not sure if they are torque to yield or not. You have used ones that you were considering reusing? If not TTY then the thread gauge check sounds excellent & I'd just lightly wire brush em clean & good visual for nicks that would screw up your torque readings. magnum INTAKE bolts are supposed to be TTY, IIRC, not the head bolts. and there's 1 or 2 that are different length for an LA, so LA head bolts won't work. I reused mag head bolts when I put mag heads on an LA 318 roller, didn't have any problems. Are you sure about that? D0 they really TTY at just 12 ft lbs?! I've always replaced the stock bolts regardless though, because they are always corroded and look like 75 year old junk that sat at the bottom of the ocean when I pull them out. Photobucket sucks

Re: reusing head bolts [Re: 70Cuda383] #1343064 12/03/12 01:52 PM 12/03/12 01:52 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	KUDOS to robertop for the correct answer. Straight out of Strengths of Materials. I have never bought a new head bolt and as they are inside the engine I haven't seen any that were corroded badly. Oily, yes. If you have a few thousands invested in an engine it is nice to spend a few dollar$ and have new bolts. But on a 318? only if you are running forced induction or something like that. R.

Re: reusing head bolts [Re: dogdays] #1343065 12/03/12 06:02 PM 12/03/12 06:02 PM
Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O 70Cuda383 Too Many Posts
70Cuda383 Too Many Posts Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O	Does anyone know if there are engines out there that DO TTY the bolts that hold on the heads? Seems like there HAS to be a few of them, otherwise there'd be no myth about having to replace them every time and just for the record, I was talking about the intake manifold bolts when I said that I replace them. the originals always look like junk because of the galvanic reaction taking place between the 3 different metals (whatever alloy the bolts are, the cast aluminum of the intake, and the cast iron of the head.) head bolts NEVER look bad when taking apart an engine. Photobucket sucks

Re: reusing head bolts [Re: 70Cuda383] #1343066 12/03/12 08:03 PM 12/03/12 08:03 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	Thank you. I would assume that some of the newer engines using the torque-plus-angle tightening method actually do torque to yield. However, I have been hearing the same old story since before TTY bolts were thought of in automotive applications. It seems that it is easier to spend someone else's money telling them to goldplate a project, than telling them where the $$$ can be saved. And of course, rod bolts are a different story. BUT, as I said earlier, if you have a few thousands stuck in a motor, then a couple of hundreds for new bolts doesn't seem out of line. R.

Re: reusing head bolts [Re: 70Cuda383] #1343067 12/03/12 09:49 PM 12/03/12 09:49 PM
Joined: Jan 2007 Posts: 7,664 IN A ahy master
ahy master A Joined: Jan 2007 Posts: 7,664 IN	I had to pull heads on a couple of water cooled VW's while living overseas. A 1600 cc and a 1043 cc. Both were torque to yield. They would have been late 80's, early 90's builds. The FSM, dealer and parts store all said the same thing... change them!

Re: reusing head bolts [Re: ahy] #1343068 12/04/12 01:22 AM 12/04/12 01:22 AM
Joined: Mar 2005 Posts: 1,630 North Central Florida E eightlitermopar OP top fuel
eightlitermopar OP top fuel E Joined: Mar 2005 Posts: 1,630 North Central Florida	So what would the downside be: to getting the right size intake bolts from a local hardware store in a grade 5 or 8 so that they can be reused in the future? Do they HAVE to be replaced with a TTY bolt? Also, what is the torque spec on these magnum intake bolts? TTY or otherwise? Mopar or no car

Re: reusing head bolts [Re: 70Cuda383] #1343069 12/04/12 01:33 AM 12/04/12 01:33 AM
Joined: Mar 2005 Posts: 7,052 Madera, CA. MowP4rsn master
MowP4rsn master Joined: Mar 2005 Posts: 7,052 Madera, CA.	Quote: Does anyone know if there are engines out there that DO TTY the bolts that hold on the heads? Seems like there HAS to be a few of them, otherwise there'd be no myth about having to replace them every time and just for the record, I was talking about the intake manifold bolts when I said that I replace them. the originals always look like junk because of the galvanic reaction taking place between the 3 different metals (whatever alloy the bolts are, the cast aluminum of the intake, and the cast iron of the head.) head bolts NEVER look bad when taking apart an engine. I'm stretching my brain a little trying to remember this (see what I did there? ) but I seem to recall the Neon 2 liter had TTY head bolts.

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