Drawbacks of aliexpress CNC heads?

Sharif

Member
Joined
May 28, 2019
Messages
114
I still haven't tried mine yet. Im going to have to modify it to fit on my bike because of the clearance issues. It's on my winter rebuild list. I am curious what you think of yours once you get it installed. It looks like the combustion chamber is bigger than stock so the compression is going to be a little bit lower. However the cooling benefits of the head outweigh the compression loss. The compression can be made up by milling the head down.
Looking forward to see what you think about it when you get it installed
Don't have the tools to mill the head down, it's kinda funny knowing my new head high compression head is actually the other way around haha.
Hoping the new jets and open air filter make up for that, it's just that dialing in things like that will take so much time I barely have these days.

I have 2 goals out of the little upgrades, cooler engine and reaching 50 km/hr on a flat road, as I always have to be on the side of the road (Bike lanes sort of don't exist here) Currently top out at 42 kmph on a flat road which means I'd be slowly traffic down staying on the lane. Changing rear sprocket is not an option either with all the hills here.

Will let you know! WIll try to spend sometime this weekend
 


Sharif

Member
Joined
May 28, 2019
Messages
114
I still haven't tried mine yet. Im going to have to modify it to fit on my bike because of the clearance issues. It's on my winter rebuild list. I am curious what you think of yours once you get it installed. It looks like the combustion chamber is bigger than stock so the compression is going to be a little bit lower. However the cooling benefits of the head outweigh the compression loss. The compression can be made up by milling the head down.
Looking forward to see what you think about it when you get it installed
Been riding for a little over a week now, don't see rain droplets vapourising from the head anymore lol
It's definitely radiates heat better and it's bigger mass probably hold more heat as well.

As for performance, feel like the engine runs smoother, but to be frank I barely noticed it and I am still asking myself if it's just placebo.
 

FurryOnTheInside

Well-Known Member
Joined
Sep 23, 2013
Messages
3,940
Have you optimised your squish gap? Have you got as much compression as you can with the head by bringing your squish gap all the way down to 0.75mm?

And yes it is only one bolt-on mod.
You can also increase the amount of unburnt fuel/air filling the combustion chamber by adding a more flowy air filter and doing a few hands-on (free) mods that don't even require any large or expensive tools.

When you add an expansion chamber to that you'll need all that extra cooling area. 😄
 

Sharif

Member
Joined
May 28, 2019
Messages
114
Have you optimised your squish gap? Have you got as much compression as you can with the head by bringing your squish gap all the way down to 0.75mm?

And yes it is only one bolt-on mod.
You can also increase the amount of unburnt fuel/air filling the combustion chamber by adding a more flowy air filter and doing a few hands-on (free) mods that don't even require any large or expensive tools.

When you add an expansion chamber to that you'll need all that extra cooling area. 😄
Squish gap? The sparkplug gap?

I got my hands on an open air filter, but had to take it off as I noticed there was huge drop in power, will it back on after I rejet sometime this week, or after. (Barely any time, after I got back into school again) Since then, did move the clip up one notch to run it a bit more rich, didn't add the air filter back as I fear the issue is at wide open throttle as I noticed it was worse at WOT.

My final upgrade will be expansion chamber 😁, accidentally purchased a banana pipe thinking it's an expansion chamber.
 
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