Thread: Confirm tq specs for head
12-16-2007, 07:35 PM #1
Confirm tq specs for head
Putting a buddy's ski back together and came across a discrepancy in the manual:
For main stretch bolts spec calls for (off the top of my head)...40nm / 30 ft/lbs (which doesn't add up)
Then for the smaller bolts in the vicinity of the cam chain it calls for 10 nm / 89 ft/lbs (which does add up)....
What is it really....Initially we bolted it down per the 30 ft/lbs then went the additional 120 degrees then the 90 degrees but it felt far to easy...
12-16-2007, 07:53 PM #2
I see what you are talking about. It says 40nm/30 ft/lbs like you have but the other ones are 10nm / 89 in/ lbs.
Last edited by seadoo951; 12-16-2007 at 07:57 PM.
12-17-2007, 11:40 AM #3
12-17-2007, 12:00 PM #4
Those numbers are correct, but different from what I have always been told. 40 nm = 29.5 lbs-ft (they round up to 30 lbs-ft.). But I always thought (been told) it was 40 lbs-ft. then 120 degrees, then 90 degrees. So I am interested in this answer as well.
And why don't they just give one torque spec rather than a torque spec with degrees of rotation?
12-17-2007, 12:43 PM #5
12-17-2007, 02:48 PM #6
they pretty much bottom out everytime i put my head on... i usually can't even get the full last 90 degrees of rotation. that sucker is TIGHT!
12-17-2007, 02:53 PM #7
When I initially did them to 30 ft/lbs then 120 then 90 there was still plenty of room for me to keep turning...I wasn't even remotely straining (I realize this is relative)...
As it is now it does not seem to me to be tight enough....There feels like there still may easily be another couple turns in them....I just would hate to loosen and then re-tighten a brand new set of stretch bolts...
12-17-2007, 03:30 PM #8
what kinda torque wrench u using... how u measuring the 90 and 120?
12-17-2007, 04:09 PM #9
Well....the angles were a wee bit eyeballed.............. however
I'm a surveyor so I'm usually pretty well dead on when it comes to turning angles...(seeing as I do it approx 45 hours a week) If I would have had to wind it (360+) that would have been one thing but 90 and 120 are pretty basic...If anything...they're currently a few degrees in excess of 210 (90+120) as I figured they could use a little extra for good measure...
Don't know the brand of the tq wrench but it's a high end commercial one he uses for his line of work...
I mean don;t get me wrong...it's snug but I can specifically remember you and a few others comment on how damn hard that last 90 degrees was and when it went as smoothly as it did and wanted more it set off warning bells...
12-17-2007, 04:28 PM #10
i'd like to hear what some others felt when putting their heads on... i mean i've only put two of my heads on myself so far and had the same experience twice... the rest of the time i make my friend put my motors together.
anyone else consistently find that doing 30ft/lbs then 120 and 90 is damn tight and pretty hard to complete the last 90? or you feel there's still room to go even after the last 90?
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