Topic: Re: 650 overbore/550 engine hybrid underway...final stages

[MRieck]

 Absolutely RIGHT. The bigger the wheel the better the reading. I'll never use less than a 12".....usually a 24" Moroso. You're a smart guy Paul. I said it before. Before electronic gauges people used ENORMOUS wheels for NASCAR stuff etc. I'm talking 5' diameter stuff.

[paulages]

Absolutely RIGHT. The bigger the wheel the better the reading. I'll never use less than a 12".....usually a 24" Moroso. You're a smart guy Paul. I said it before. Before electronic gauges people used ENORMOUS wheels for NASCAR stuff etc. I'm talking 5' diameter stuff.

...and you're just the guy i'd want to hear that from, mike.    i'd also like a 2' wrench to turn the crank with if i could. the one i used was about 12". next time i'll use a big cheater bar so i can turn it in smaller amounts along with having the larger degree wheel.

is it normal to see that much variation in lobe centers on megacycle cams? all the ones i measured were within .5 degrees of each other, but there was lots of up and down within the fully closed portion of the lobes. the open and close numbers were pretty off too, but i chalked that up to the difficulty of finding exactly zero valve lash. i measured at running lash a few times, measuring at .036" instead of .040", but always came up with the same lobe center, telling me that consistency in measurement was the only really important thing.

[scondon]

    Paul, are the cam numbers you posted "zero" lift numbers, or ".040" lift numbers. If they are zero lift numbers(open/close measured at .00 lift) then my hat is definitely off to you in gaining any info of use to you with that 8" wheel and shaky stand. Dead serious, my hat is off. Those lobe ramps are so minor at the beginning of lift that I haven't been able to get anything consistent within 5 degrees when trying to measure to them.

    In my experience Megacycle is pretty damn accurate with their cams/cards matching up and consistent grind.

[paulages]

    Paul, are the cam numbers you posted "zero" lift numbers, or ".040" lift numbers. If they are zero lift numbers(open/close measured at .00 lift) then my hat is definitely off to you in gaining any info of use to you with that 8" wheel and shaky stand. Dead serious, my hat is off. Those lobe ramps are so minor at the beginning of lift that I haven't been able to get anything consistent within 5 degrees when trying to measure to them.

    In my experience Megacycle is pretty damn accurate with their cams/cards matching up and consistent grind.

those measurements were at zero lash, but .040" lift as directed by the timing card (or at .004" lash and .036" lift). i assumed that the open and close numbers were at .040", but maybe they are actual beginning and end of ramp numbers not to be compared to those measured at .040" lift? maybe the 650 rocker geometry affects the measurement somehow? not sure how it would, as my measurements were taken the the valve, but they were taken at the adjuster rather than the retainer. i did end up bolting a piece of steel flat bar to the cam cover just to make sure my dial indicator wasn't moving at all. in any case, the math worked so i'm happy. you can keep your hat off if you'd like, though. 

[scondon]

   Ok then, back to staring at cam spec #'s and imagining a degree wheel. It's late and I forget direction of travel on the wheel, but you can figure this stuff tomorrow Paul...........


       If you use the #'s you've posted you can actually plug in different lift or cam position to see if you can reach the desired card spec.   i.e    If you take the 27/57 open and plug in a different lift then you end up with 25/55. Lift will expand or contract(duration) the open/close #'s. A degree wheel is needed in order to grasp which direction the #'s will move and how it will then affect the exhaust #'s.

     You can also "move" the cam on paper with the #'s you've posted. It's a bit of math and scrunching of the forehead but you've grown use to this right?


        Quick look shows that you are 2.5 degrees advanced or retarded(too sleepy to figure which ). With a "square" profile cam you just want the #'s to match as close as possible between intake/exhaust. Yours appear about 5 degree difference between intake/exhaust which equates to about 2.5 degree "tweak" from spec. I retarded my cam 2 degrees and the power is higher up the rpm band as a result. Me likey, especially in bumpy tight mountain roads

[paulages]

   Ok then, back to staring at cam spec #'s and imagining a degree wheel. It's late and I forget direction of travel on the wheel, but you can figure this stuff tomorrow Paul...........


       If you use the #'s you've posted you can actually plug in different lift or cam position to see if you can reach the desired card spec.   i.e    If you take the 27/57 open and plug in a different lift then you end up with 25/55. Lift will expand or contract(duration) the open/close #'s. A degree wheel is needed in order to grasp which direction the #'s will move and how it will then affect the exhaust #'s.

     You can also "move" the cam on paper with the #'s you've posted. It's a bit of math and scrunching of the forehead but you've grown use to this right?


        Quick look shows that you are 2.5 degrees advanced or retarded(too sleepy to figure which ). With a "square" profile cam you just want the #'s to match as close as possible between intake/exhaust. Yours appear about 5 degree difference between intake/exhaust which equates to about 2.5 degree "tweak" from spec. I retarded my cam 2 degrees and the power is higher up the rpm band as a result. Me likey, especially in bumpy tight mountain roads

by "expanding" or "contracting" the numbers, they don't move linearly. if the intake open retards- say from 27 to 25- then the number goes up in degrees, as it is degrees before TDC. since the piston is traveling down towards close, the opposite is true- 57 BBC becomes 59 BBC. i did this on paper until i knew how much to advance to get my lobe center. i may not have megacycle's open and closing numbers, but i am pretty damn close on the centers. i'm pretty sure there is some part of my measuring method that accounts for the discrepancy.

mike, what do you think? should i be happy with 105 intake and 104.5 exhaust?



for anyone curious, here's the math:

intake--- 27 (open) + 57 (close) + 180= 264
              266/2= 132
              132-27= 105   

exhaust--25+54+180=  259
             260/2= 129.5
             129.5-25=  104.5                                 

[MRieck]

   Ok then, back to staring at cam spec #'s and imagining a degree wheel. It's late and I forget direction of travel on the wheel, but you can figure this stuff tomorrow Paul...........


       If you use the #'s you've posted you can actually plug in different lift or cam position to see if you can reach the desired card spec.   i.e    If you take the 27/57 open and plug in a different lift then you end up with 25/55. Lift will expand or contract(duration) the open/close #'s. A degree wheel is needed in order to grasp which direction the #'s will move and how it will then affect the exhaust #'s.

     You can also "move" the cam on paper with the #'s you've posted. It's a bit of math and scrunching of the forehead but you've grown use to this right?


        Quick look shows that you are 2.5 degrees advanced or retarded(too sleepy to figure which ). With a "square" profile cam you just want the #'s to match as close as possible between intake/exhaust. Yours appear about 5 degree difference between intake/exhaust which equates to about 2.5 degree "tweak" from spec. I retarded my cam 2 degrees and the power is higher up the rpm band as a result. Me likey, especially in bumpy tight mountain roads

by "expanding" or "contracting" the numbers, they don't move linearly. if the intake open retards- say from 27 to 25- then the number goes up in degrees, as it is degrees before TDC. since the piston is traveling down towards close, the opposite is true- 57 BBC becomes 59 BBC. i did this on paper until i knew how much to advance to get my lobe center. i may not have megacycle's open and closing numbers, but i am pretty damn close on the centers. i'm pretty sure there is some part of my measuring method that accounts for the discrepancy.

mike, what do you think? should i be happy with 105 intake and 104.5 exhaust?



for anyone curious, here's the math:

intake--- 27 (open) + 57 (close) + 180= 264
              266/2= 132
              132-27= 105   

exhaust--25+54+180=  259
             260/2= 129.5
             129.5-25=  104.5                                 

  mike, what do you think? should i be happy with 105 intake and 104.5 exhaust? Yes......I think every Yosh street cam ever made used 105/105LC.

[paulages]

fan-#$%*ing-tastic.   

[bwaller]

Ladies & Gentlemen.....we have a winner!   

On to the next hurdle Paul.

[paulages]

knock on wood-- i do believe my last hurdle is fitting the 550 stator to the 650 crank. it was already opened up and installed, but when i went to fit the cover it was out about .148" to far. just have to turn the tiniest amount off of the inside chamfer i think.

i remeasured with an extension on the dial indicator riding on the retainer instead of the adjuster and came up with 25/55 for the intake. that's one degree off on close from the megacycle specs, but still puts my lobe center at 105. i'm calling that good. went ahead and set all my valve lash adjustments and buttoned up the top.



just have to install the clutch assembly and she's finally done... 

[MRieck]

 Looks good Paul. A little simpler way to get LC i.....just subtract the opening # from the closing #, add 18-0 and divide by 2. IE   57-27= 30  30 +180 =210  210/2=105    I always measure cams at there actual running clearance. Just subtract the clearance from the checking lift. IE .006 clearance checking at .040 of lift.....get your opening (or closing) number at .034 of lift.

[paulages]

Looks good Paul. A little simpler way to get LC i.....just subtract the opening # from the closing #, add 18-0 and divide by 2. IE   57-27= 30  30 +180 =210  210/2=105    I always measure cams at there actual running clearance. Just subtract the clearance from the checking lift. IE .006 clearance checking at .040 of lift.....get your opening (or closing) number at .034 of lift.

that's exactly what i did, mike. my running clearances are .004" (I) and .005" (E), so i just compensated accordingly. i found that the math works the same for the lobe centers no matter how you do it.

and on to more exciting news: ladies and gentlemen, she's buttoned up. 

[bwaller]

Great news man...... now get some sleep. 

[paulages]

ok, got a little sleep.  woke up thinking about that damn motor though... 

just had the oil lines made and are now fitted to the engine. all i have left to do is install the damn thing. sounds easy i know, but i still have to finish rebuilding the 750 carbs that are going on it, and while the 550 engine is out, i plan a thorough cleaning as well as reworking some things that have been needing it badly (cartridge emulators in the forks while in there fixing leaky seals). i want to put this engine in a tip-top clean bike, so there's more work to do. i'll get a bunch of pics today.

[electronbee]

Impressive and dangerous thread. It's giving me all kinds of ideas to do for my current CB550 engine.

OOC: would you mind providing a break down of what it all cost?

I'm really thinking of doing this for my CB550 engine.

eb

[paulages]

Impressive and dangerous thread. It's giving me all kinds of ideas to do for my current CB550 engine.

OOC: would you mind providing a break down of what it all cost?

I'm really thinking of doing this for my CB550 engine.

eb

i think if i give you the breakdown, you might choose another route.  i'll break it down when it's all said and done, but it's well over $3000 right now. machine work, mike reick's fine work, parts... throw in a dyna 2000, new pipes, 520 conversion, cam, oil lines, etc. and the price climbs. a major variable for giving you a breakdown is my machine shop invoice... they can't remember what all they did for me it's been going for so long. i got the final invoice, and they had billed me again for things i paid for and took forever ago, and forgot about a few things like crank and piston assembly balancing. i have to revise the invoice myself and see what they end up charging me.

roughly though: headwork and parts will be about $500 if you port. honda parts will be about $500. megacycle cam is $330 or so. pistons? pipes? donor engine? ignition? machining?

take out your wallet, friend...  luckily i paid for all of this in bikes bought and sold, and builds and repair for other people. "bike money" as i refer to it. 

                           

[electronbee]

Wow, a lot higher than I thought but for some reason I am not surprised.

My CB550 engine has a frozen No.2 piston. So, I was thinking of a 550/650 hybrid. Just not as intense: 650 jugs/head/pistons/cam. I know machine work will be required for the valves if I buy a used cylinder head. Likewise for the jugs and pistons. But I would stay within the realm of the next size up in stock ring size. Or, I may buy a recently parted engine from a 550. Dunno yet.

Or, maybe something totally coo-koo like this:

http://www.dieselbike.net/AndrewsRoyalEnfield/AndrewsRoyalEnfield.htm

Ok, enough distractions from me!

eb

[bryanj]

No point in 650 jugs as the 650 is stroked to get the capacity

[paulages]

No point in 650 jugs as the 650 is stroked to get the capacity

it's true about the stroke-- the 650 didn't have much of an increase in piston diameter from the 550. i'd have to verify the compatibility of the 550 tensioner assembly with the 650 chain, but i feel like there was some good reason i decided to go with the 650 jugs. it's been a while since i did mock up. 

[paulages]

IT LIVES. 

[scunny]

you don't get off that lightly. come on tell all 

[bwaller]

He's off riding. We'll maybe hear from him again in the wee hours! 

[MRieck]

He's off riding. We'll maybe hear from him again in the wee hours! 

Yeah........it was only 4:00 PM there (based on EST). This should add some lively banter. I remember porting that head.....it seems like years ago.

[paulages]

ok, i guess i'll give a little more detail. 

i had a few speedbumps, which is why i haven't reported on it lately. one of the holes in the head that accepts the oil line in the head stripped and i had to make an insert for it. i barely tightened the thing, which makes me think it was tapped poorly to begin with. in any case, the rotor is now fit to the crankshaft (had to take another .015" off of the inside to make it fit all the way onto the 650 crank). i've spent the last week frustratingly wrapping up loose ends. i basically rebuilt the whole bike while i had it apart, so there were lots of them... new wire harness and electrical arrangement, custom made; rebuilt the entire front end with cartridge emulators and a m.c. off of a ducati sport classic.; lots of new stuff.

anyway... i rode it around the block. WOW.  there is lots of power in the low end. i really can't wait to wind it up. i have lots of little oil leaks to fix (outer o-ring on the oil pump, clutch cover gasket...jesus, is that thing always hard to seal up at the bottom.., some of the oil line fittings, etc.) and i have to sync the carbs and it's ready to ride.

 

[MRieck]

 Nice. Keep it coming Paul.