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| rillo |
 Posted: Sat Dec 02, 2006 11:54 pm |
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Junior member
Joined: 02 Dec 2006
Posts: 10
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I have a set of 811cc pistons, 64mm and a webcam grind 41 bolt on cam. With the new pistons, and the new cam, if I install high performance springs can I expect to increase my redline to 9000 rpm or above? If not, will 29.1 mm carbs help?
Thanks.  ) |
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| Satanic Mechanic |
| Posted: Sun Dec 03, 2006 7:58 am |
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Moderator
Joined: 04 Sep 2005
Posts: 309
Location: Munich, Germany
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With high perf springs, you should be able to push your redline to 9000 or above, but I am not sure how much power you will have there. The new springs will give you more safety when overreving the engine (but as every coin has two sides, it will also cost you power). IMHO there is no need to push the redline upwards if the power band doesn't require you to do so.
It's the cam which sets the characteristics of an engine, and the torque and power band. The Web Cam 41 isn't very radical (it is supposed to be a bolt on for stock engines). I wouldn't expect it to move the power band upwards much.. If you want to have good power output at higher revs, you should go for a 'hotter' cam, like Web Cams 63a or 63b.
Larger carbs won't help much there. If you want to use them, remember to open up the intake ports.
Hope that helps.  |
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| rillo |
| Posted: Mon Dec 04, 2006 8:17 pm |
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Junior member
Joined: 02 Dec 2006
Posts: 10
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Thanks for the reply Axl.
I just spoke with Webcams and they stated the 63a would be a good choice for my application. However, everything that I have read, which is not much, states that in order to rev higher you must have sufficient airflow through the head to not starve the cylinders.
I have had my head modified slightly to allow for better airflow, I only had the machinist clean up the head to take care of the rough edges. Is there anything else I should do outside of porting and polishing to get the most out of the bored out carbs or should I continue to go stock regardless?
Thanks.  |
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| rillo |
| Posted: Mon Dec 04, 2006 8:26 pm |
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Junior member
Joined: 02 Dec 2006
Posts: 10
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Axl,
Should I need to worry about heavy duty cylinder studs or connecting rods with the 811cc kit? Everything I have read or heard, again not much, states that only with an 836cc kit or higher should I look into these items. Thanks.  |
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| Satanic Mechanic |
| Posted: Fri Dec 08, 2006 2:13 pm |
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Moderator
Joined: 04 Sep 2005
Posts: 309
Location: Munich, Germany
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I don't think you need to worry about the H/D studs or stronger rods. These will become an issue with 900cc or bigger, and really radical cams (and high revs) but with the mods you have in mind the stock stuff will still be ok.
Bear in mind though to use new bolts on the con rods if you had to open them - these bolts are single use only, they will stretch beyond elasticity when tightened properly and they may come loose if they are reused.
All the best! |
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