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Discussion Starter · #1 ·
Here's a few thoughts. Assuming that there was a way to get the s2000 pistons to work in a k24a stock block....

What would the final compression be? On a CRV longblock? Accord ? Element? TSX? K24a/k20a2 stock frank?

Again, I am not asking how to get it to work. I am just interested in knowing/estimating the final compression.

As far as compression height and pin bore, the K20A &
K24 pistons have 30mm compression height, while the F20C piston is 27.75mm.
Thus you would need a longer than stock K24 rod, or reduce the block deck
height 2.25mm (shudder). The pin bore size for the K20 & K24 is 22mm,
whereas the F20C piston uses a 23mm pin. So you would either need to get a custom rod made or bore the rod 1mm.

Any idea? Guess?

Nikos
 

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nikos said:
Here's a few thoughts. Assuming that there was a way to get the s2000 pistons to work in a k24a stock block....

What would the final compression be? On a CRV longblock? Accord ? Element? TSX? K24a/k20a2 stock frank?

Again, I am not asking how to get it to work. I am just interested in knowing/estimating the final compression.

As far as compression height and pin bore, the K20A &
K24 pistons have 30mm compression height, while the F20C piston is 27.75mm.
Thus you would need a longer than stock K24 rod, or reduce the block deck
height 2.25mm (shudder). The pin bore size for the K20 & K24 is 22mm,
whereas the F20C piston uses a 23mm pin. So you would either need to get a custom rod made or bore the rod 1mm.

Any idea? Guess?

Nikos
1-Reduce the block
2-Bore the Rod
 

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you could bore the pin height on a stock K24A rod and use a thicker head gasket than stock that the turbo guys use and you'd probably be almost at the right height.
Thats about the only way around the question that I can see, unless the S2000 runs the same block height and crank journals in which case swapping in the S2000 crank rods and pistons would be the answer..
Looking at the specs on te rods the K20-K24, H22, F22, F20C all have the same size BE but they are all different widths.
If in fact you did need a longer rod, then the S2000 is the only one longer than the K24 and it has the right size pin hole. so you could use it provided you could get it to fit into the K24 crank, so you would have to machine 2mm out of each side of the rod or the crank.. But the rod is only 1mm longer than the K24 so you will need to run a thin gasket but you'll still be about 1mm short. so you will still need to machine the block..
 

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I also would like to know. Im thinking of buying a k20a2 and a k24 block separetly, then use all the k20a components, add custom rods and s2000 pistons, since they will probably cost less than foged ones. What do you guys think? How much compression will that combination yield and will the valves hit hte pistons??


Thanks
 

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Forget the S2000 pistons. You can buy after market forged pistons which are much, much stronger and also have any compression you want for $400 - $500. My turbo pistons were $380, including ceramic coating. S2000 pistons will cost as much or more than this unless they are used, plus you need to add the machining costs as well.

Boring out the factory rod even 1 mm scares me. The OEM rods are not that good. 4 out of 5 K20A race cars on the west coast have lost engines using stock rods/pistons. Even revving to factory redline the pistons break and/or the rods bend. If you're going to the trouble to replace the pistons, do youself a favor. Crower makes an excellent rod which is not too expensive.

Also you shouldn't replace the piston rings without a rebore or hone. Otherwise new rings will never lap in, and your leak down will forever be bad. You would need to check what piston/wall you would get from 87mm S2000 pistons and a 87mm K20A bore - Honda will match the piston to the bore ('A' and 'B' piston sizes). Who knows how well this will work with parts from different engines. Thus it would be better to use a 87.25 mm piston and over bore the block to suit the piston. Most seasoned K20 and K24 engines have bores which are no round nor straight and the re-bore will sort this out.
 

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Discussion Starter · #6 ·
Thanks for the advice. On honda catalogue, it says $160 for a set of s2000 pistons... I thought that meant for 4 of them...I guess I am wrong.
 

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nikos said:
$160 for a set of s2000 pistons
You might be correct - new JDM K20A pistons are around the same price. Still, best to stay away from the machine work to make them fit.

There was a race car with a K24 using TSX rods and S2000 pistons, but it died today so I guess that's another point in favor of aftermarket rods/pistons.
 

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Rubber Chicken said:
There was a race car with a K24 using TSX rods and S2000 pistons, but it died today so I guess that's another point in favor of aftermarket rods/pistons.
i take it the bottom end failed?
 

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Discussion Starter · #10 ·
Rubber Chicken said:
You might be correct - new JDM K20A pistons are around the same price. Still, best to stay away from the machine work to make them fit.

There was a race car with a K24 using TSX rods and S2000 pistons, but it died today so I guess that's another point in favor of aftermarket rods/pistons.
:( Not good.. I was very excited about that car. Hopefully they are going to have time to fix it.
 

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nikos said:
:( Not good.. I was very excited about that car. Hopefully they are going to have time to fix it.
More info? Who's car, what was done, what failed?
 

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Anyone try it out yet?
 
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