Cam cap threads threads upgrade

  • gordone
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Cam cap threads threads upgrade

17 Apr 2021 01:04 - 17 Apr 2021 01:04
#846912
cam cap threads/bolts

When the engine is old and bolts is old, I guess Its a possibility to damage the threads or twist off the bolts...?

what is the best upgrade to avoid these problem?
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Last edit: 17 Apr 2021 01:04 by gordone.

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  • hardrockminer
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Re: Cam cap threads threads upgrade

17 Apr 2021 04:52
#846915
A good torque wrench!
I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
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  • hugo
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Re: Cam cap threads threads upgrade

17 Apr 2021 04:59 - 17 Apr 2021 05:00
#846916
Is steel on aluminum.   It is not because is old, but how many times has been retorqued. ..how many cycles..  Inevitably, aluminum wears against steel.   But in this case, the cam caps bolt take little torque.   Barely more than on oil sealing gasket.    I good sensitive torque wrench should be enough.    

...here torque is so low, I use the dial and bending-arm type, rather than the 'clicking' one.   I prefer to see the dial
Last edit: 17 Apr 2021 05:00 by hugo.
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Re: Cam cap threads threads upgrade

17 Apr 2021 05:21
#846917
There is a lot of stress on the threads when installing the cams because you are fighting against the valve springs.  I like to clamp the cams down into the bearing journals using a pair of vice grips before installing the caps like shown in the Suzuki GS manual.



 
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0

www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know

1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
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Re: Cam cap threads threads upgrade

17 Apr 2021 09:03
#846925
Along with Nessism's suggestion, I clean the threads of the bolts, and I only torque to 96 in/lbs, as opposed to what the manual suggests (in my case, I believe it's 144 in/lbs). 

If you want peace of mind, you could have steel threaded inserts installed, but I think of that as a "when it's necessary" modification.

I remember seeing someone use studs and nuts instead of the bolts, and while some pointed out that the nuts would cause damage if they ever came off, it may be okay if you match the stud heights to the valve cover. I'm not sure what torque value this arrangement would need, though. 
1982 KZ750 Spectre - 6 speed swap, BS34s, 18" rear wheel

2001 ZX-6R
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Re: Cam cap threads threads upgrade

17 Apr 2021 09:15
#846927
I've used barrel inserts to repair some pulled threads. Hard to do on the bike but if the head is off it's pretty easy. The best thing to do is be very careful and don't use the bolts to pull the cam down. 
Jim
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1982 GPz750 R1
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Re: Cam cap threads threads upgrade

17 Apr 2021 10:47
#846931
Whole thread on the subject here .  kzrider.com/forum/2-engine/607517-stripp...nder-buckets?start=0
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  • gordone
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Re: Cam cap threads threads upgrade

17 Apr 2021 14:44
#846945
wrote:
Along with Nessism's suggestion, I clean the threads of the bolts, and I only torque to 96 in/lbs, as opposed to what the manual suggests (in my case, I believe it's 144 in/lbs). 

If you want peace of mind, you could have steel threaded inserts installed, but I think of that as a "when it's necessary" modification.

I remember seeing someone use studs and nuts instead of the bolts, and while some pointed out that the nuts would cause damage if they ever came off, it may be okay if you match the stud heights to the valve cover. I'm not sure what torque value this arrangement would need, though. 


 
You only clean the bolts, not the wholes?
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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Re: Cam cap threads threads upgrade

17 Apr 2021 14:48
#846946
thank you all!

correct summary?:
1. clean the bolts (and whole?)
2. Push the cam down as  Nessism  advise
3. don’t torque to service manual spec, do 50 in/lbs lower then spec.

These shall avoid any issues then?
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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