does anyone know what the compression ratio is on an F22A4?
Does 9.5 : 1 sound right?

I'm building an f22 for a 120 wet shot! Ported n polished F23 vtec head. I didnt want 11 : 1 compression pistons, dont want to have to run high octane ( all the time). And 8.5 : 1 is to low, i'm not boosting it.

I was told 10: 1 compression or lower, 91 octane would be OK. And that there would be no clearance problems ( coming from a tech with a 300whp turbo F23 accord.) I 've had to search for 93 on EMPTY and that sucks!
Any way custom made 10:1 forged by CP. 620$

what do you guys think, will this be a good setup?

 

so i found the specs f22a4 8.8 : 1 f23 9.5:1

10:1 will be fine right?

 

I'd go 9.5:1

10:1 and you are restricted to super unleaded only.

Also, Nitrous increases the chances of going lean and detonating anyway, operating right on the verge of that on strictly motor is just a little too extreme for my money. I'd go with something that has a little less compression, and I'd jet the nitrous system fuel solenoid to be a little on the rich side just in case. You won't get FULL potential out of the system out of the box but once you take it to someone who knows how to tune it they will appreciate the fact that they have some "wiggle room".

The last thing you want is holes in those expensive pistons!

 

it should have plenty of wiggle room, ive got a walbro 255 lph pump n an adjustable regulator. putting a msd blaster ss coil on it too.

i guess my main question was :
there should be enough piston to valve clearance right?

they sell 11:1 so those should even theoretically work right, as far as clearance goes!

 

I give up.

It's not like I've been running 10.1:1 compression in my Nova for the better part of the last decade, having to run premium unleaded JUST to keep it running and 110 octane when it's time to play.

I hope you don't destroy the engine after a few nitrous runs, I really do. I wouldn't wish that on anyone.


Good luck finding 110 octane.


Modified by The_Caged_Bird at 5:52 PM 6/4/2008

 

why r u acting all high n mighty. so u have no idea on clearance huh!

5.60 a gallon about 15 min from my work ! and anyway u did nt even specify an octane u just said premium unleaded! u consider that 91? if so i'm ok.
would just have to knock out my cat my cat for the race fuel n its 115 where i can get it not 110

 

Yeah sorry about that.

No, when you build the motor you are supposed to turn it over by hand a few times with modeling clay on the top of the pistons and THEN you pull the engine back apart and measure clearance. I would naturally assume that if these pistons are made for the engine you are building and the head that will be used on it, they SHOULD fit if every thing is put together correctly.

I'm just saying that it sucks to be REQUIRED to run 91 or better octane, especially with gas prices the way they are, why do you think I bought a Honda? I wanted to be able to run regular.

If this is going to be a recreational car then I say go for it, build the engine, make sure you double-check everything before final assembly and I'd just use a straight pipe in place of the cat when you get ready to race at the track. Actually that's a lie, personally, I'd run the cat only when it's time to get inspected, but that's just me, I would never suggest that anyone sidestep the law.

I'd also take the time to upgrade the trans-axle and half-shafts to keep things from getting REALLY expensive!

 

cool man, i wasnt trying to get hostile. 91 is cool, 93 it even cooler but its just way to hard to find! plus not to mention i already get good MPG even if i lose some its not that bad. so if i can run 91 i'll be alright. and as far as the cat goes i would just knock it out n make a ghost converter so i dont have problems switching parts. i am an inspector! and the clay test only works if the the pistons are installed i dont have them yet and the motor is still in my car. i'm trying to make sure i have all the parts and odds n ends figured out before i pull it.

i'm really suprised no one else has voiced their opinion. there has to be some honda guys that have raised compression!

 

I figured they would've spoken up by now as well, I'm more adept to old skool engines and I'm still learning these little "1/2 motors" I'm anxious to hear how well it will work too.