Author Topic: APS-PG-750 bike reworked  (Read 17185 times)

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Offline 55chevr

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Re: APS-PG-750 bike reworked
« Reply #15 on: July 25, 2011, 09:48:44 AM »
I would love to retire but the damn job keeps the cash rolling in. The available time to work on the machines would be welcome but the projects need to be funded.

Offline oz

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Re: APS-PG-750 bike reworked
« Reply #16 on: July 25, 2011, 01:04:39 PM »
Nice to see you back jim looking good!
Newcastle born and bred a City built on Coal and Steel and a people built of stronger stuff

Offline JimL

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Re: APS-PG-750 bike reworked
« Reply #17 on: August 21, 2011, 12:14:32 AM »
Just a quick note to thank all the folks who stopped to chat in impound.  We had some good luck, despite wind and weather, and got to spend every day (from Saturday) in impound.  It's a lucky event when you don't need to set up a pit.

Results were a 154+ APS-PG-750 record for me, a 158+ APS-PF-750 record for my son, Marc, and a 133+ MPS-PG-650 record for my friend Dan Wagner.  Marc did a great ride, despite leaning the bike into the wind....all the way down to a bent exhaust pipe and ground heat wrap.  Dan pulled the record up with one of my de-stroked "680-to-650" engines (my 750 engines are a little small).  His engine is 647cc and made the record with 4 bent intake valves and a cracked head (on the first pass....yes...my fault).

Perhaps next year some much stronger 650 class engines, for both bikes, and then a full 748cc from my current 680.  As we used to say in Colorado, "God willing and the creek don't rise."

Also a big thanks for all the great SCTA folks, especially the MC tech/impound staff.  Everyday, non-stop, always patient and fair.

Thank you, gentlemen!

Have a great build year, everyone, and hope to meet you again.    JimL


Online salt27

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Re: APS-PG-750 bike reworked
« Reply #18 on: August 21, 2011, 12:48:16 AM »
Congratulations future neighbor, it was good to chat with you in impound.

Don

Offline JimL

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Re: APS-PG-750 bike reworked
« Reply #19 on: August 21, 2011, 12:56:36 AM »
Thanks, Don....also good to finally meet you and see your project.  We'll be in touch shortly.

JimL

Offline coloradodave

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Re: APS-PG-750 bike reworked
« Reply #20 on: August 21, 2011, 09:41:05 PM »
We were down the row from you a few spots on Sunday in impound and I meant to come and say hello but we got busy tearing down the motor, congratulations on a very succesful week at Bonneville, 1 record is great, I can't imagine what 3 would be like. :cheers:
No regrets

Offline JimL

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Re: APS-PG-750 bike reworked
« Reply #21 on: August 21, 2011, 11:35:48 PM »
Thanks!  You did well, also.  It is pretty amazing how the time completely fills up in impound. :?

We'll cross paths again, I'm sure.

Regards, JimL

Offline DKA

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Re: APS-PG-750 bike reworked
« Reply #22 on: August 24, 2011, 09:00:39 PM »
Jim,  I talked with you for quite a while in impound.  I was very impressed with your build.  Made me think about yanking the motor out of my drug from the bushes CX 500 and turning it sideways.  Thanks for all the tips you gave and the wonderful impression you left on me.  Congratulations on such a great speed on a pushrod bike.  Hope to see you next year.

David
If it can be built, it can be raced.

Offline JimL

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Re: APS-PG-750 bike reworked
« Reply #23 on: August 24, 2011, 11:29:05 PM »
Good to visit with you, too!  

A follow-on to the orange bike and Dan Wagner's 650 class bike.... I opened the engines to see where the horsepower had slipped away and found intake valve contact on all the engines (valve reliefs are out of position about .040").  The leaking valves explain where the high RPM power was failing us, this year.  I was kinda' puzzled why this thing couldn't get past 160.....like they say, "there's always a reason for everything". :oops:  

My goof (not double checking the valve fit) ruined one head, so that is already out (with another casting) to get sorted.  One intake valve hit hard and square enough to crack both sides of the valve guide boss, into the water jacket.  That cylinder was swallowing water on both runs.

Off to get new pistons started, tomorrow.  We also learned we're too low on compression ratio, so that will be going up (on both the 680cc engine and the 647cc engine).  Maybe next year we can go a little faster....the closer I get, the more I find out I don't know!

Now all I have to figure out is why the bike goes fastest (by 8-9 mph) in a headwind, compared to sidewind or almost no wind.  I must have something goofy with the aero, but right now it makes no sense.

regards, JimL

« Last Edit: August 24, 2011, 11:31:17 PM by JimL »

Offline 55chevr

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Re: APS-PG-750 bike reworked
« Reply #24 on: August 24, 2011, 11:31:10 PM »
Jim -- can you post some pictures of the fairing?  It has a nice look to it.

Offline JimL

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Re: APS-PG-750 bike reworked
« Reply #25 on: August 24, 2011, 11:37:41 PM »
It is the AirTech Charlies Toy package (fairing, tail piece, and front fender).  The tailpiece is modified with a piece of Kent's Electric bike tail, turned upside down and bolted in.  If you look in old postings for 1350cc Pushrod Bike, you'll find the build diary when this bike started out as a twin engine (that failed during initial run).  There are many pics throughout that diary.  Maybe this will get you there:

http://www.landracing.com/forum/index.php/topic,7416.0.html

This sure has been a lot of fun.

Regards, JimL


Offline 55chevr

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Re: APS-PG-750 bike reworked
« Reply #26 on: August 25, 2011, 12:11:54 AM »
that is one of Kents ... nice stuff ... thanks for the link.

Offline oz

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Re: APS-PG-750 bike reworked
« Reply #27 on: August 25, 2011, 01:09:50 PM »
Way to go Jim good on ya!!
Newcastle born and bred a City built on Coal and Steel and a people built of stronger stuff

Offline JimL

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Re: APS-PG-750 bike reworked
« Reply #28 on: August 27, 2011, 12:34:04 AM »
Thanks, OZ,.....pulled down the orange bike today....got some wear showing in a few places.  I guess it's turning into a high mileage vehicle! :wink:

I did find another broken head.....these castings are a little thin and were certainly never meant to make this much pressure.  I'm hoping to find some more junkers, over the winter.  First find a place to live, second find bikes to tear apart!

Simple plan, don't you think?  As daddy always said, "Time flies when you're confused!"

JimL

Offline oz

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Re: APS-PG-750 bike reworked
« Reply #29 on: August 28, 2011, 04:15:28 AM »
If you have trouble finding parts drop me a line thet were very popular over here as dispatch bikes hence there are loads in the breakers for peanuts.
Newcastle born and bred a City built on Coal and Steel and a people built of stronger stuff