What is the difference between the aluminum kits and the cast iron ones? im guessing its about weight?
What is the difference between the aluminum kits and the cast iron ones? im guessing its about weight?
cast iron ones can be rebored of they are seized. plus the cast iron bore is a lot tougher to begin with. ive seized my cast iron metrakit twice and it still has great compression.
im not sure what the advantages of the nikasil lined aluminum ones are.
Light and run cooler is my guess... For racing purposes, every ounce counts and that is why most racing kits are alluminum...
makes sense.
Nikasil reduces friction so less drag = more power , same reason to have a kit with only one piston ring . Also Im pretty sure that the lining is tougher than the bare metal by itself .
nikasil linings and cast iron sleeves reduce wear, by virtue of being very hard. hot steal/iron rings on bare aluminum is a recipe for trashed. they allow you to run aluminum jugs which bleed heat efficiently.
cast iron kits are harder to break, but run a lot hotter, they're also harder to work with when porting, and are generally going to produce less power due to thermal inefficiency. Aluminum kits are basically the opposite.
so yeah, to overly simplify this, cast iron for reliable, aluminum for fast.
Looks like cast iron is for me, im not looking to make a rocket, just a safe reliable way to boot around town.
Malossi 70cc cast iron kit with the malossi high comp head should be enough power anyways..
Intrestingly, non pro weed wacker engines just have uncoated alu bores. They typically suggest a 32:1 oil ratio. Alu conducts heat 3X as well as cast iron. While I lean towards alu I think it's cool that a lot of that shit flying around in the cosmos are cast iron objects.
Zack, why do you say that cast iron bores are harder to work on when porting?
also the shit flying around in the cosmos is mostly iron, very little cast iron unless some put a kit on a rocket. hahahha
because it's cast iron! it's hard stuff. aluminium on the other hand is a "soft" metal
That cosmic iron was probably molten at one time and cast in space
Casting, a process by which a material is introduced into a mould while liquid, and allowed to solidify into a specific shape
I've notched the cast iron block to clear oversized valves on many Datsun engines . Wasn't bad at all , wasn't easy as aluminum but not hard. Using a plain ole high speed die grinder and a carbide bit , then finishing with a heatless red stone. It only took about 1/2 an hour to notch 4 bores (8 recesed based on the headgasket.
You have a mind like a steel trap Ben
hahahahha
An iron trap is more like it. Ive been reading a brief history of nearly everything by Bill Bryson so im all into the cosmos right now. But if we were to be real technical a lot or the molten iron in the cosmos is indeed cast it the tiny holes of celestial rock so to that I bow to you. hahahha
Now more on topic. I use an air powered angle grinder with carbide bits to grind my cast iron cylinders. It does take longer but its not bad at all.
Yeah well how long does it take you to open/file the transfers ? Exhaust/intake ports are one thing but when it comes to transfers you enter a whole new world of finger cramping pain ! Damn tiny files ! Damn iron !
Tiny files? Whaaat?
DREMEL
Yeah, I ported a metra 80 cylinder last week. No problem with a dremel and good dremel bits. Eats through shitty home depot ones, but they still do the job.
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