Author Topic: Time to upgrade my CB550 Rods?  (Read 921 times)

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Offline Rocketman

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Time to upgrade my CB550 Rods?
« on: November 18, 2015, 03:10:44 pm »
In the never ending quest for more horsepower I am planning to install higher compression pistons (11.5 to 1) and a DP335 cam in my CB550 racer.  My best guess is I'll be making 55 to 60 HP at the rear wheel.  Anyone have experience with stock rods and similar HP?  Am I asking for trouble?

Offline FunJimmy

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Re: Time to upgrade my CB550 Rods?
« Reply #1 on: November 18, 2015, 04:42:43 pm »
Bwaller is running that kind of HP in his race bike.
Don't know if he is also using stock rods but believe the rules require he does.
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CB550 Cafe Interceptor a Gentlemans Roadster
http://forums.sohc4.net/index.php?topic=27159.0

Offline bwaller

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Re: Time to upgrade my CB550 Rods?
« Reply #2 on: November 18, 2015, 05:32:25 pm »
500/550 rods are not considered a weak link. Definitely replace the rod bolts with CB750F2 bolts (bolts 13213-KVO-000, nuts 13214-410-003) Rods could be peened. Mine was low 60's on stock rods, however I did buy Carrillo's later as the power ramped up. (not against the rules  ;D)

EDIT: Martin, I have experienced "rod stretch" at high rpm. With stock rods build in some extra clearances.
« Last Edit: November 18, 2015, 06:17:19 pm by bwaller »

Offline Rocketman

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Re: Time to upgrade my CB550 Rods?
« Reply #3 on: November 18, 2015, 08:00:39 pm »
Thanks for the advice.  With less than 500 miles on the engine I was hoping to avoid opening the engine cases! Generally I look for .050" on the intake and .080" on the exhaust.

Offline FunJimmy

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Re: Time to upgrade my CB550 Rods?
« Reply #4 on: November 19, 2015, 12:08:34 am »
500/550 rods are not considered a weak link. Definitely replace the rod bolts with CB750F2 bolts (bolts 13213-KVO-000, nuts 13214-410-003) Rods could be peened.

Thanks for the tip Brent. I didn't know about the CB750F2 bolt upgrade.
You never see a motorcycle parked outside of a psychiatrist's office!

CB550 Cafe Interceptor a Gentlemans Roadster
http://forums.sohc4.net/index.php?topic=27159.0