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Hi there, does anyone know where could be found the valve timing diagram for 1000s?
 

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No, what I need is a diagram which shows when the inlet/exhaust valves open and when they close according to the piston position (it is usually shown in degrees of crankshaft revolution). Nothing to adjust on the bike about that, I am just curious about how it is solved on these engines and I couldn't find that in any manual I've checked. Thanks for response!
 

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I have looked in my manuals and cannot find specs on the 1000 cams either, I know I have found it somewhere before. I have the specs on 1100s which are as follows. *= degrees.
At 1mm lift
intake opens 5*BTDC, closes 43* ATDC. Exhaust opens 45* BBDC, closes 5* ATDC.
 

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DaveO430 wrote:
I have looked in my manuals and cannot find specs on the 1000 cams either, I know I have found it somewhere before. I have the specs on 1100s which are as follows.          *= degrees.
At 1mm lift
intake opens 5*BTDC, closes 43* ATDC. Exhaust opens 45* BBDC, closes 5* ATDC.
The red letter should be "B", right? One more thing, OK for opening these degrees are for 1mm lift, but for closing are they also when the valve comes back to 1mm lift or when it closes tightly?

Thanks:applause:! I guess that it's similar for GL1000. I'm finishing the heads repair job and putting everything back to the bike so when I was installing the RH side camshaft it made me curious when I saw how much the pulley moves out of the position which fits #[email protected] and #[email protected] DC (belt installation marks aligned) until the cams get off the rockers (I was particularly following #3 intake valve as I could directly see it) so it looked to me that it takes too much movement of #3 piston up from BDC (compression stroke) before its intake valve closes. Actually, the camshaft (NOT crankshaft) pulley moves 3 teeth (about 27*) forward out of the position which fits #3BDC until #3 intake valve rocker arm gets to the "rounded" part of the cam (I guess here the valve is lifted about 1mm) and it takes the camshaft pulley further 3 teeth (about 54* all together) until the #3 intake closes tight. Knowing that the crankshaft rotates 2X faster then the camshaft, it means that the #3 intake valve will go back to 1mm lift 54* of crankshaft revolution after #3 piston @BTD and it will seat tight not before 108* after BDC. As the whole piston's travel from B to T DC accounts 180* it means that the piston makes almost 2/3 of its way up in the compression stroke before the inlet valve closes! At the first view it looks a way too much for me, but I guess Honda engineers knew what they were doing....
Thanks for the info and sorry for bothering you with something that is factory given and cannot be changed but I was really curious about that :smiler:
 

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Found it for 1000s! At Randakk's site. There he told it's in the service manual, chapter 5-2. Interesting that I was searching in all the manuals including the factory one and never found it, probably because I expected a graphic diagram and it's given as a table in the manual so I just didn't pay attention to that. Anyway here it is: http://www.randakks.com/TechTip32.htm or in the factory service manual chapter 5-2.
 

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Yes you are correct about my "T", should be a "B". The reason the intake does not close until after BDC is called ram effect. The air/fuel mix is moving into the cylinder at high velocity and will continue to fill the cylinder even after the piston begins to move up.
 

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Newton's 3rd Law.

A body in motion wants to stay in motion.

Air and fuel have weight and mass, and travel at 150+ miles an hour in the upper rpm range.

BDC givesmoretime than TDC for reverse motion to happen.Something to take advantage of. Once it starts to happen the 3rd Law is in high effect with no plans on slowing down.

The longer the valve remains open, the more atomized fuel will enter the combustion chamber. Leave it open too long and our lower rpm range will suffer even more lack of power.

Highly effective induction takes advantage of this "supercharging" effect through resonance tuning and other optimization.

It's Volumetric Efficiency, and it's a balancing act of trade-offs.

We 1000 people know our bikes like to be ridden rev'd. This is why. You've found where our power has been optimized; ...in the upper rpm ranges.

Highly optimized induction exceeds Volumetric Efficiencies beyond factory induction.

Optimizingthe exhaust is done in the same way and tuned for resonance as well, but viewed from the exhaust valve. Not to fill the combustion chamber, but empty it beyond TDC. Induction and exhaust work together for total optimization of the rotating masses.

This equals more power, which equates to higher performance.

;)
 

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And how about putting a '78. or later camshafts on a '77. or earlier engine to obtain more power at lower RPM range (because later engines have different valve timing with less "overtiming")? I've read somewhere that not only the cams but the intake/exhaust port diameters are different as well between 75-77 and 78-on models, but still would it make sense to have later camshafts on an earlier engine? Used camshafts can be found at reasonable prices at Ebay and I prefer having more torque at lower revs, that's why I ask.
 
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