Another factor to add in, most if not all honda/acura blocks that are built and rev to 9-10k, have the cylinders Sleeved.

 

1) A stock OEM EVO head is about 210cfm and a stock 2g DSM about 230cfm. I have a 2g head I ported with stock valves that is about 250cfm and another 2g with 36mm valves that is a little bigger ports and flows about 290cfm. I think the 250cfm head makes more power and definitely has better low rpm performance. I think the high tumble port design has problems at really high revs, almost regardless of flow.
2&3 answers are below
4) The Honda and Mitsu bearings are VERY similar.

#2 - I haven't seen many mitsu 100mm stroke engines successfully run to 9k and #3 does not need to be guessed at in any way shape or form. They wipe out center main bearings due to high bearing loads from a combination of light counterweights on the crank and heavy rotating parts. It may be possible to increase the counterweights to fix the bearing loads, but then all the bearing loads are very high. I'm attacking it from the lighter rotating parts point of view. I'm also trying some looser main bearing clearances this season to see if it helps. The bearing failure mode looks like overheating of the shells. At OEM clearances the center main bearing will be wiped out in somewhere around 20 passes.

Kevin

 

thanks for the input!

 

Any thoughts on the cylinder sleeves helping the k24 and other hondas out rev a 4g64?

 

I'm no engine builder but I don't see how a sleeve would help with reving. I believe its because they are alum blocks and so they sleeve them so they can run bigger amounts of boost.

 

Sleeves have nothing to do with the rpm capabilities of a honda motor...Ive pushed stock sleeve b series motors to 9500 plenty of times...

 

^^^^ At least with the B series, they sleeve them because they're an open deck design and past a certain point cylinder flex becomes an issue, and then of course to enable the use of larger sized pistons. An NA Honda B-series can rev to 9K reliably, but I wouldn't trust the bottom end to handle that with a lot of boost thrown into the mix.

 

Always been my dream to put a K series in a Evo lol The motor is just a work of art.

 

noooo!!!!

 

You can't discredit the EVO like that! I would, however put at Long Rod K24/K20 into a EG hatch LSD of course with a nice HTA3582! 600+hp in a 500lb car SICK!!!!

The 4G64/4G63s are great engineered motors and preform amazingly. there are not many other motors out there that you can run 500-600hp through a stock motor. Well the F20C can hold a great deal in stock form too...

Kevin, you have oversized bearings right? How did those help you? I think if we lighten our rotational mass we coud rev higher as long as the power is still there.

Mikey

 

lol they just flow and make power so good. We build a lot of them and see 300whp plus on pump gas all motor with 12:5:1 comp and good cams.

 

interesting convo for sure

 

I'm currently running intake cams and exhaust and making 330awhp on 91 oct...so why put a lesser motor in the car. Seems retarded to me.

 

i found it interesting about the comment of the 2.0 would walk the 2.4 on a highway on the street at the strip to the grocery store and to the house haaaaaaaa but on a track its king so i guess all us 2.3 2.4 DD guys made the wrong choice

 

That "lesser" motor is making almost the same hp as you, without a turbo! Slap a turbo on the K24/K20 and it will eat the evos ***!

Mikey