| onan heads [message #286095] |
Sat, 29 August 2015 09:26  |
jodist
Messages: 30
Registered: April 2011
Location: pottstown,pa
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Is it ok to cleane heads with soap and water?
What should heads be torqued to? The nuts were not tight at all.
John Stehle
78 Royale
John Stehle
78 royal by coachman
Pottstown,Pa
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| Re: onan heads [message #286096 is a reply to message #286095] |
Sat, 29 August 2015 09:34  |
Tilerpep
Messages: 404
Registered: June 2013
Location: Raleigh, NC
Karma: 7
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http://www.bdub.net/manuals/index.html
scroll down to find onan manuals, pick yours. torques and everything in there. piece of info I gleaned off the forum archives not in manual was to reuse the head gasket with a thin coat of anti-seize. and to use a "distributor wrench" to tighten the oil pressure sender plates, some models those two are hard to reach
1975 Glenbrook, 1978 Royale rear bath
Raleigh, NC
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| Re: onan heads [message #286104 is a reply to message #286095] |
Sat, 29 August 2015 16:31 |
cbryan
Messages: 451
Registered: May 2012
Location: Ennis, Texas
Karma: 3
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jodist wrote on Sat, 29 August 2015 09:26Is it ok to cleane heads with soap and water?
What should heads be torqued to? The nuts were not tight at all.
John Stehle
78 Royale
John,
You got some good advice with respect to using the anti-seize on the old gasket. According to Matt Colie, who in a former career was a gasket specialist, using a good older gasket is preferable to using a new one, because the older one is pre-compressed.
He recommends, and I will follow his recommendation, to torque the heads today, and retorque them tomorrow. Lube sparingly the threads, chase the head threads (run a thread tap down it) if you are super careful and blow them out with compressed air using a thin tube almost bottoming out on the blind threads, might use that computer duster air and tube for this, lube under the bolt head, too, and torque them in the proper sequence, to 50% of final, 75% of final, and 100% of final. Now, using Matt's advice, go back tomorrow and loosen them and retorque one at a time to 100% and see if you get another quarter turn. You will be at the best humans can do at this point, so far as I can tell.
The shop manual put out by Onan calls out 17 - 19 lb-ft (cold engine) with a torque wrench, but a supplement they later put out quotes 22 - 25 lb-ft (still cold engine), and may be part of the reason you found loose head bolts. A good number of those removing Onan heads in recent months reported them loose as you did. See http://www.bdub.net for the manuals. Like Jim Hupy says, never rely on memory for torque values, penalty for being wrong is too great.
HTH.
Carey
Carey from Ennis, Texas
78 Royale, 500 Cadillac, Rance Baxter EFI.
[Updated on: Sat, 29 August 2015 22:00] Report message to a moderator |
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| Re: onan heads [message #286111 is a reply to message #286095] |
Sat, 29 August 2015 18:35 |
jodist
Messages: 30
Registered: April 2011
Location: pottstown,pa
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Thanks for the information. I put antiseize on the gasket and torqued to 18. Tomorrow I will back the nuts off and retorque to 24.
John Stehle
John Stehle
78 royal by coachman
Pottstown,Pa
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