Author Topic: CB500 race engine parts  (Read 2410 times)

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Offline Aussie500

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CB500 race engine parts
« on: June 02, 2018, 04:27:43 AM »
Hi All,

I have just started work on building a 72 CB500 to race period 4 here in Australia. Can anyone recommend the go to place for pistons, cams and other engine parts? My first port of call was Davies but they don't have pistons and cams listed.


Offline calj737

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Re: CB500 race engine parts
« Reply #1 on: June 02, 2018, 03:39:31 PM »
http://www.dynoman.net/engine/pistons/dp-CB550.html
Or Wiseco makes a 59mm piston that is very nice too. Its not a slipper like the Davies though.

Mike Rieck, a member here, is an absolute genius with the valve train work and can recommend a Megacycle cam as well. (I realize you're in Oz and Mike is in the US, but throwing it out there in case you're short on resources).
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

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Offline andyman

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Re: CB500 race engine parts
« Reply #2 on: June 03, 2018, 01:07:15 AM »

Offline Aussie500

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Re: CB500 race engine parts
« Reply #3 on: June 03, 2018, 03:00:24 AM »
Cheers for the info fellas. I have taken note and will pass on to the fella who is building my engine. I had John from Davies get back to me so it looks like i have a couple of options.

Offline Rod

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Re: CB500 race engine parts
« Reply #4 on: June 03, 2018, 03:03:12 AM »

Offline turboguzzi

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Re: CB500 race engine parts
« Reply #5 on: June 03, 2018, 08:37:07 AM »
cal, 59mm pistons will surely put him well over 500c.c..... if it's 500 class then it's a no go. in italian classic racing most you can go is 57mm and that's already with 3.5% overbore allowance
aussie, if you dont want to spend too much, then xl125 pistons can be made to work well. then there's a range of monkey bike pistons too...
usually these need decking the block as most are have a bit lower crown than stock 500/4

Offline Aussie500

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Re: CB500 race engine parts
« Reply #6 on: June 04, 2018, 03:34:11 AM »
CMS seems to have standard replacement sets for around $460 AUD which sounds pretty reasonable. Davies have hi-comp pistons that fit std rods for around $1050. Im sure they are worth the money and heavily R&D their products but not sure my riding ability warrents them. On the other hand will I be wishing i spent the money in a few months time. Will be touching base with the fella building the engine this week.

Offline Rod

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Re: CB500 race engine parts
« Reply #7 on: June 04, 2018, 06:22:55 AM »
+1 with TG the xl pistons work well, & will give you higher comp which standard replacement units wont of course - the Davies parts are impressive but I wouldn't put ultra trick pistons at the top of the wish list on these engines, there are better areas to spend your money, especially if this is an initial build. My advice, take a look at some of the excellent build threads on here by guys who are racing these engines, better still, spend time talking with folks in the paddock, you can get more gems of reliable info in a 10 minute track-side chat than hours of trawling the net & the after-market websites.
« Last Edit: June 04, 2018, 12:20:17 PM by Rod »

Offline Aussie500

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Re: CB500 race engine parts
« Reply #8 on: June 05, 2018, 03:46:26 AM »
Thanks Rod, good to hear multiple people recommending the same thing (xl pistons). been chatting to the blokes on track but the the 500 class currently has a total of 1 other 500 but luckily my mech runs a very fast p4 CB350 so is super helpful. Ive have started looking at the build threads and agree one of the better uses of time. i think a fairly standard build with a racier cam to let it breathe better might be the go especially for the first season on it. It will be a lot different to the p6 CBR 250 I'm currently running.

Offline turboguzzi

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Re: CB500 race engine parts
« Reply #9 on: June 05, 2018, 08:56:53 AM »
aussie, remember also that two ring pistons (1 comp, 1 oil) like Davies's look racy, but it means replacing rings once every 1-2 season. 3 rings pistons might eat more power but less of a PITA....

Offline Aussie500

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Re: CB500 race engine parts
« Reply #10 on: June 05, 2018, 02:51:24 PM »
Good point. The less time working on it and the more time racing sounds good to me. I don't see myself being a front runner so may aswell have a reliable bike... Or 2... Or 3

Offline classic bike tuner

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Re: CB500 race engine parts
« Reply #11 on: June 05, 2018, 11:46:37 PM »
look at this from howell   building a 500 racer   its from 2009

http://forums.sohc4.net/index.php/topic,63228.msg688538.html#msg688538