Wife had eye surgery last Wednesday.
She has had some complications and as I am her caretaker my shop time has been limited.
She is on the road to recovery but she will be seeing the doctor on a daily basis for the near future.
She is becoming a bit more self sufficient so I should be able to get back to some very much needed shop time.
First of all I would like to thank gggGary for sending me a junk head to explore limits with.
I will be sharing all the information gathered with the community once I am at that point.
I still have to assemble my incline manometer. I have it all and since my wife's doctor appt is early tomorrow I am certain I can complete it.
Then the bench calibration/tuning can begin. Then at last the testing of the head.
In the meantime I have managed to sneak parts of my shop into the kitchen to accomplish a few things after the wife was put to bed.
This is ALL about information gathering at this point.
I cc'd the combustion chambers on Garrett's head. His cumbustion chambers appear untouched.
I measured them both at 58.8cc
Looking into the manuals I could find nothing that matched that measurement.
I did find 3 different cc values:
78 650E - 44.18cc
80 650G - 42.5cc
83 650SE - 43.6cc
Obviously these values are vastly different than what I measured.
The junk head that gggGary sent me was loaded and had one cylinder that sealed so I tested it as well.
Also 58.8cc. I reached out to a couple of members (gggGary was one) to try and better understand the discrepancy.
The picture gggGary posted are those I sent him
He reached out to Dennis (@kopcicle
) to join the thread. Dennis was kind enough to message me and we had very good very long conversation about many many different things. VERY Knowledgeable, very informative, and gracious enough to share some of that knowledge.
Reminded me greatly of my conversations with Michael "Mercury" Morse. Truthfully 2 of the most interesting conversations I have had the pleasure of having regarding the xs650. Many many illuminating points to contemplate. Dennis explained that Yamaha included the piston dome in the calculation instead of specifying the actual chamber (flat plate) measurement. Our conversation went waaaay beyond that I want to thank Dennis for taking the time to share some of his knowledge while helping to expand mine on a variety of subjects.
I think perhaps that anyone doing a build where they are changing out the pistons and have a desire or need to calculate their CR should be using the 58.8cc volume in place of the printed specification.
Of course it was the intake ports that I was really interested in.
I measured the one STOCK intake port that I had available with valves that sealed.
(This will be confirmed with my other stock head once the valves have been reinstalled)
The STOCK head intake port measured 79.6cc
Garrett's D Port measured:
Left - 77.2cc
Right - 82.8cc
That's about a 7% difference.
The ports should be balanced to 1%
Soooo.... Issues beyond the delamination.
Interestingly the stock head's value is nearly centered between the two.
I am curious to see what differences the flowbench will reveal as well.
Stay tuned. It is coming VERY soon. Regardless of what life throws at me.