Author Topic: Blown Head Gasket  (Read 1938 times)

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Offline DA71FX

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Blown Head Gasket
« on: Sunday, July 29, 2012. 02:55:22 PM. »
Well it seems the garage gods are working against me and the 93" shovel.....after replacing the worn ignition switch and fried unilite ignition module i start the bike up....set the timing....and take her out around the block to just make sure everything is good...and as I am starting to come around the corner  heading to the house I hear the distinct sound of a blown head gasket....when I got her in the garage....I could see the gap between the head and cylinder surface at the rear of the front head.....I have always used the blue James head gaskets without issues but at this point it seems time to pull the heads....send them out and replace the gaskets....any suggestions on gaskets....cometic or james or what......static compression is around 8.5:1 and I am running an andrews #2 cam I will post pictures once i get the heads off.....thanks
93" 1971FX
86" Mongrel Stripped FL

Online 76shuvlinoff

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Re: Blown Head Gasket
« Reply #1 on: Sunday, July 29, 2012. 03:01:22 PM. »
My S&S 93"er has Cometic MLS on the heads and cylinder bases. I had leaks with the solid copper and again with the blue teflon head gaskets. It was likely all my fault but I had leaks nonetheless. No such struggle for me with the Cometic MLS.

.02

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Offline DA71FX

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Re: Blown Head Gasket
« Reply #2 on: Sunday, July 29, 2012. 03:05:23 PM. »
Great...now one more related question....Headbolts....is there a purpose made 12 point head bolt wrench that fits the big bore jugs...or are the better choices in head bolts.....
93" 1971FX
86" Mongrel Stripped FL

Online 76shuvlinoff

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Re: Blown Head Gasket
« Reply #3 on: Sunday, July 29, 2012. 03:08:33 PM. »
Here are the various tools I stack up to get at and torque those head bolts. The welded up crows foot was an attempt to find something for the base bolts, it had limited results.

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Offline 79FLH

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Re: Blown Head Gasket
« Reply #4 on: Monday, July 30, 2012. 10:05:15 AM. »
  Nice collection 76 !!  I have an offset Snap on wrench that I took to the grinder to get it slim enough to fit in there, broke a couple of craftsman wrenches before I tried the snap on, so far so good.  I've also used a socket with one of those universal extensions with limited success..  Good luck !!
Ride it like ya stole it !!

Offline JC 92FXRS

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Re: Blown Head Gasket
« Reply #5 on: Monday, July 30, 2012. 10:25:33 AM. »
Mark...how do the extensions affect the torque readings? Do you just read the wrench and convert for the extra length?
Cheers, Jeff

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Re: Blown Head Gasket
« Reply #6 on: Monday, July 30, 2012. 10:56:43 AM. »
Somewhere around here I have saved that formula for extensions and torque wrenches like 277 times but I am sure not going to find it now.

 What I remember is if the extension is 90 degrees to the head it's supposedly a 1:1 thing... or at least close enough for the girls I date.
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Offline rkrcpa

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Re: Blown Head Gasket
« Reply #7 on: Monday, July 30, 2012. 11:46:14 AM. »
What I have found works well on 12pt head bolts is to run them up snug with a 1/4" socket on a flexible extension using a variable speed drill. Beats the hell out of a box wrench and 1/4 turns. Works well taking them out also. I use the extension shown in the picture for torque purposes, I had to grind mine a little to get enough clearance.

I attached the conversion info for the torque adapter.

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Offline FSG

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Re: Blown Head Gasket
« Reply #8 on: Monday, July 30, 2012. 12:23:52 PM. »
Quote
Somewhere around here I have saved that formula for extensions and torque wrenches like 277 times but I am sure not going to find it now.  .... 
 
It's in the HarleyTechTalk Tech Tips & Links Tech Tips  SECTION

http://harleytechtalk.org/htt/index.php/topic,1215.0.html

Offline JC 92FXRS

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Re: Blown Head Gasket
« Reply #9 on: Monday, July 30, 2012. 02:33:16 PM. »
Thank you gents...makes sense. The 90 deg thing I thought would not change anything.
Yea, the girl I date isn't particularily torque-sensitive either... :teeth:
Cheers, Jeff


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Re: Blown Head Gasket
« Reply #10 on: Monday, July 30, 2012. 04:22:30 PM. »
Quote
Somewhere around here I have saved that formula for extensions and torque wrenches like 277 times but I am sure not going to find it now.  .... 
 
It's in the HarleyTechTalk Tech Tips & Links Tech Tips  SECTION

http://harleytechtalk.org/htt/index.php/topic,1215.0.html


 Mom is that you?  :hyst:   I need to write myself some reminders....

  Thanks FSG!

 79 and rkrcpa
 that obstacle wrench I have in the pic is a Proto (whoever makes those)  I did have to thin up the head of it to get it in there on all the bolts. I have used it several times and I always wonder if the click I feel is the torque setting or the wrench snapping.
« Last Edit: Monday, July 30, 2012. 04:32:17 PM. by 76shuvlinoff »
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Online 76shuvlinoff

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Re: Blown Head Gasket
« Reply #11 on: Monday, July 30, 2012. 04:36:03 PM. »
and....
  somewhere I read you do not need to retorque with the Cometic MLS, or maybe I hallucinated it. I was too chicken and after a couple heat cycles I retorqued them and I was glad I did because they needed it.
The attendance at your funeral will be largely dependent on the weather.

Offline 96flhpi

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Re: Blown Head Gasket
« Reply #12 on: Monday, July 30, 2012. 06:08:38 PM. »
and....
  somewhere I read you do not need to retorque with the Cometic MLS, or maybe I hallucinated it. I was too chicken and after a couple heat cycles I retorqued them and I was glad I did because they needed it.

I read that too.  I use usually James fire-ring but the one time I used MLS the bolts were definatley closer to right torque but also definately needed to be redone.  Only took 1 retorques before the settled, as opposed to the 3-5 retorques with the James (maybe I'm a little anal).

Offline bob_e95482

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Re: Blown Head Gasket
« Reply #13 on: Monday, July 30, 2012. 06:42:55 PM. »
I do my retorqueing with just the 2" torque extension, at 90 degrees. in some spots, I turn the torque wrench over and hit the reverse selector. I have a 1/4" drive 9/16" socket from MAC, that JUST fits for running in the head bolts.

Offline easyricer

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Re: Blown Head Gasket
« Reply #14 on: Tuesday, July 31, 2012. 06:09:36 AM. »
On all engines that I use the MLS gaskets on, I have to re-torque after the first test ride. It's a real SOB doing it on Twinkies!
EASY
Just ride the damned thing!

Offline gary11623

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Re: Blown Head Gasket
« Reply #15 on: Friday, August 03, 2012. 01:58:29 PM. »
I am partial to cometics mls.

Offline DA71FX

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Re: Blown Head Gasket
« Reply #16 on: Sunday, August 05, 2012. 08:37:36 AM. »
ended up using the Blue Teflon James gaskets....re-torqued after heat cycle.....3 times before they finally settled in.....next shovel I will try the cometic  MLS....
93" 1971FX
86" Mongrel Stripped FL