incorrect #77 the stock compression is 9.1:1
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incorrect #77 the stock compression is 9.1:1
Im in the middle of putting my 416 kit back together, im now hesitant on putting it all together because im kinda not sure about what to do with my stock cam. Replace with XR or not?
Heres my worry:
1. Losing too much low end!
2. Reliability
3. LOW END!! (Im really worried about that)
I dont race on any tracks, but i tend to just stick to riding poker runs, and steep soft sand hill shoots. And alot of sand hill dragging.
Now, lets just say I put the XR cam in, i hear Ill lose low end, but if I am already putting in the higher comp piston, wont that make up for it, or not? Will it be more or less than stock when it comes to bottom end.
Sure I want mid to top to increase, but I like the bottom end power to tourque my way out of the hills that i virtually have to start at directly on the base, with no chance of getting a run.
Does this make any sense?
Looking for suggestions.
Rhan
SOrry this is so long.
Here's what I learned after recently upgrading my engine to a 416.
If you upgrade your engine to a 416cc with a JE 10.8:1 piston it will boost power everywhere--no specific gain in any particular area...just everywhere! What changes, shifts, or moves the powerband is your camshaft selection. The more of an agressive cam you go with the more high end power you'll gain, but at the same time also lose some in the bottom end. If you add an XR400 cam you will lose a little bit of your newly added power in the bottom end, but it will be very little. Mine feels just as powerful in the bottom end as when it was stock, if not a tad bit more!
My advice would be to install the XR400 cam. You won't notice any difference in low end power, and will really like how the engine pulls once the revs start to build (thanks to the cam). You might also think about adding a larger carb such as an Edelbrock or FCR. I have the FCR and really like it...the carb also makes a noticable difference with these mods.
NVR2L8, Are you running race gas or just 93octane. Also are you guys talking about the stock honda xr400 cam? This sounds like somthing i would be interested in I've talked myself out of the Sparks 416 kit . I dont want to spend that much to just trail ride and enter a hare scramble or two each summer.
I run a 50/50 mix of 111 octane leaded race fuel with 92 octane unleaded premium--about an effective octane rating of 101. From what I've been told you can run premium pump gas with compression ratios up to 11:1...I did run mine for a while on 92 octane though and it seemed fine. I decided to run the 50/50 mix since I do a lot of hard riding at the dunes, and wanted a higher octane fuel for the times when I really work the motor hard. For my mods the fuel ratio is probably overkill, but it does help it to run cooler and eliminates the possibility of detonation.
go 11:1 run ur 93 octane and some octane boost in the mix. I know a guy who did tht on his 426EX and he has had no problems yet!
or even better,
protect your investments,run race fuel when at 11:1.theres too much money in built motors of any kind.i heard that 10:1 on any type of motor is questionable...(maybe not a 2 stroke)
11:1 is the highest that you should run with 93 octane.
426 i'm not sure?since my 11:1 i have ran race fuel since i built my motor.i've heard that it will use 93 and i've heard that it takes a mixture of 93 and 110.i'm just protecting my investment.....
your motor runs cooler with 110 fuel? I know it burns slower and hotter and needs compression so it will ignite quick and not sit there and burn.... so did someone say it makes your bike run cooler? how does it do that? I could have misread this.