Engine builders might be familiar with the Honda K series, a high output high revving 4 cyl engine built between 2000 and in some form still built today.
The engine:
In europe we got the civic type r, it uses an k20 (means 2 liter) block with a special better flowing head which has V-tec and VVT on the inlet camshaft.
The engine we are building uses the k24 (2.4l) shortblock from an EDM accord type S and is fitted with the K20 Type R head.
The internals consist of race cams with heavy springs, carrillo rods and 12.5.1 comp wiseco 2618 alloy fully forged pistons which means it will have cold start slap/rattle due to the expansion.
For the oil clearances we maintained the stock Honda oil clearances, we did not choose to go al little loser because it will only be used on the streets and no heavy long temr race usage. Also the Honda clearances are known to be superb an capable of revving 10.000 rpm on stock engines.
The main bearing clearance is around 0.038mm/0.0014 inch
The rod bearing clearance is 0.050mm/0.0019 inch
The engine has an water/oil heat exchanger and will probably never see extremely high engine temps. This engine has a timing chain.
It will be used for daily drives every now and then, temperatures here are between 0 and 35 degrees but i dont think the car will be used much in the winter.
Performance:
The engine will redline at 8300 rpm because then the piston speed exceeds 25m/s. It should produce about 320hp out of 2.4l so that is 133 hp per liter which is more than a ferrari 458 which is the highest n/a hp per liter production car.
Stock oil recommendations:
The EDM civic type r where the head comes from was advised to use 5W40 or 10W30, however most use 5w40, which was also used in the old engine.
The EDM accord type S where the shortblock and clearance specs come from was advised to use 5w20. (the clearance specs for the k20 and k24 where almost the same)
The civic Type R was sold as an hot hatch, the accord type S as an sporty family car.
Thinner VS thicker:
The newest turbo Type r uses the k20c1 engine which produces 320hp out of a 2l turbo, it is advised to use 0w20.
The ferrari 458 which has a high revving n/a v8 is advised to use 5w40.
The older bmw M high revving v8 and v10 engines where advised to use 10w60 and had even thighter clearances, these engines where known for rod bearing failures.
I heard that modern motogp and formule 1 engines run on something like a single grade W8 oil, however those engines start already hot.
5w40 Thick oil:
- Beter extreme load bearing for better protecion under extreme conditions
- Is advised to use in the Type R and is used a lot with good results.
- Maybe a little better for the forged wisecos because the fit so lose during the cold start up.
5w30 Thin oil:
- Flows faster through the engine so is not exposed as long to the hot areas/bearings as the thicker oil, this cools beter and deteriotes the oil slower.
- Wont cavitate as quick as 5w40 does, the k20 has an extremely good flowing oil pump but cavitating of oil means that even for a short period the rod will probably seize and break. The engine will run 8300 rpm so that spins/flows pretty fast.
- Lighter engine running, maybe slightly more horespower but this is not our goal.
- Alot of k24s world wide run on 5w20 without any real problems as far as i know, also the specs from the factory where designed to use this oil.
So what do you guys think? I am not looking for brands or anything, only what viscousity you would advise and why/why not?
The engine:
In europe we got the civic type r, it uses an k20 (means 2 liter) block with a special better flowing head which has V-tec and VVT on the inlet camshaft.
The engine we are building uses the k24 (2.4l) shortblock from an EDM accord type S and is fitted with the K20 Type R head.
The internals consist of race cams with heavy springs, carrillo rods and 12.5.1 comp wiseco 2618 alloy fully forged pistons which means it will have cold start slap/rattle due to the expansion.
For the oil clearances we maintained the stock Honda oil clearances, we did not choose to go al little loser because it will only be used on the streets and no heavy long temr race usage. Also the Honda clearances are known to be superb an capable of revving 10.000 rpm on stock engines.
The main bearing clearance is around 0.038mm/0.0014 inch
The rod bearing clearance is 0.050mm/0.0019 inch
The engine has an water/oil heat exchanger and will probably never see extremely high engine temps. This engine has a timing chain.
It will be used for daily drives every now and then, temperatures here are between 0 and 35 degrees but i dont think the car will be used much in the winter.
Performance:
The engine will redline at 8300 rpm because then the piston speed exceeds 25m/s. It should produce about 320hp out of 2.4l so that is 133 hp per liter which is more than a ferrari 458 which is the highest n/a hp per liter production car.
Stock oil recommendations:
The EDM civic type r where the head comes from was advised to use 5W40 or 10W30, however most use 5w40, which was also used in the old engine.
The EDM accord type S where the shortblock and clearance specs come from was advised to use 5w20. (the clearance specs for the k20 and k24 where almost the same)
The civic Type R was sold as an hot hatch, the accord type S as an sporty family car.
Thinner VS thicker:
The newest turbo Type r uses the k20c1 engine which produces 320hp out of a 2l turbo, it is advised to use 0w20.
The ferrari 458 which has a high revving n/a v8 is advised to use 5w40.
The older bmw M high revving v8 and v10 engines where advised to use 10w60 and had even thighter clearances, these engines where known for rod bearing failures.
I heard that modern motogp and formule 1 engines run on something like a single grade W8 oil, however those engines start already hot.
5w40 Thick oil:
- Beter extreme load bearing for better protecion under extreme conditions
- Is advised to use in the Type R and is used a lot with good results.
- Maybe a little better for the forged wisecos because the fit so lose during the cold start up.
5w30 Thin oil:
- Flows faster through the engine so is not exposed as long to the hot areas/bearings as the thicker oil, this cools beter and deteriotes the oil slower.
- Wont cavitate as quick as 5w40 does, the k20 has an extremely good flowing oil pump but cavitating of oil means that even for a short period the rod will probably seize and break. The engine will run 8300 rpm so that spins/flows pretty fast.
- Lighter engine running, maybe slightly more horespower but this is not our goal.
- Alot of k24s world wide run on 5w20 without any real problems as far as i know, also the specs from the factory where designed to use this oil.
So what do you guys think? I am not looking for brands or anything, only what viscousity you would advise and why/why not?
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