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Hello, I need some help with my build with engine clearances. This is my first engine build and I’d like to hear others opinions.
Build breakdown:
K24 Stock stroke 90x99
4P pro stock piston
Grp aluminum rod
Ported Pump
K20a2 ported Head
Skunk2 bmf2 cams
DC roller rockers
30mm ex
37mm int
M1 fuel

What are your recommendations on piston ring end gap and bearing clearances. specifically for all motor k-series onM1 methanol fuel!!!

My parts did come with instructional guide lines.
 

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Arouse the DAMPFHAMMER!
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Welcome to K20a.org N/ACAL
What are your recommendations on piston ring end gap...specifically for all motor k-series onM1 methanol fuel...
At which cylinder height are you going to measure it? What crosshatch are you hone into it? You know methanol wears out the liners more fast so ring seating on break in is of high importance, otherwise that engine won't reach 1 % at leakdown testing.

As methanol burns faster, which means the average temperature of the chamber touching parts is lower, you may lower the ring end cap clearance for a lower blowby mass and more power. But it depends on what material and fabrication process rings you use (e.g. casted vs. forged). There can be a huge difference in ring end gap.

Regarding main bearing clearance you can procced as it would be a gasoline fuel as the impact on methanol accumulation in the oil is neglectable, especially because you have a drag application and have very frequent oil intervals as duty!
 

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for the ring end gaps on Methanol I'd call Wiseco or 4P. They should know.
Methanol runs very cool. Could be you can get away with rather small gaps and lower that usual piston to wall clearances.

Is you block already bored?
 

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Discussion Starter · #4 ·
for the ring end gaps on Methanol I'd call Wiseco or 4P. They should know.
Methanol runs very cool. Could be you can get away with rather small gaps and lower that usual piston to wall clearances.

Is you block already bored?
There LA sleeves installed by RameyRacing. They are bored and honed by him also. I’ve emailed 4P and they won’t disclose the ring gap spec. They’ve told me to reference the pink sheet that came with the pistons.
 

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do some reading at worst. Seems like cylinders run cooler on methanol, but rings less so.
For drag things stay recently cool anyhow.
Then comes the general rule, rather too lose than to tight. There is little to lose with slightly wider ring gaps.
With your alloy rods, you have to swap them out anyhow fairly often, so you might experiment with tighter ring gaps shall blowby be too high. Might be useful to install a crankcase pressure sensor and log the data.
 
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