someone with great knowledge give me a link or explain why and how? just curious.

 

Smaller crank & longer rods . . . . Honda did it in the F20b (Accord SiR & SiR-T).

Basically sacrificing displacement for improved engine geometry & high rpm potential.

 

so does that mean better toque? Mechanically how does this work?

 

higher revving

 

also mugen used the 2.0l destroked h22a in some formula engines ..

i know that they atttained 220HP with all the limitations ..
but at somewhat lower than i would think RPM ( ~8500 rpm )

the accord SIR-T got a F20B2 engine, F20b is kinda not the same thing


i do not think that it is worth destroking the H22a unless u are going with a custom high revving applicaiton where u absolutly wanna proove that u can rev up to 9000rpm eheh

 

so you just put in a smaller crank and longer rods and its destroked? What other kind of work would needs to be done? And the other question would an SI-R fit in the 4th gen like an h22 drop?


[Modified by cecknight, 11:57 PM 9/16/2002]

 

yes b ut it's not SI-R but rather SIR-T

it's basicly an H22a with different block dimensions and all
by the way, i'm pretty sure that the bore isn't the same on the F20B2 than on the H22a so it wouldn't work 100%

 

85 mm stroke, 88 mm bore

1997 cc

it'd be fun to mess with, but expensive...the auto version had 180 ps and the manual had 200 ps...i've never seen the manual version for sale

 

I've seen them on a few sites - $4,000 or so for a swap package. Better option than a B18c5, in my opinion. It's basically a factory reliable CR-VTEC with the engine geomeotry of a B16a.

If you want to destroke an H22, it's never as simple as just the parts - although it'll "work" with just a new crank & rods. But you won't get the best performance without the cams, intake manifold, throttle body, valves, ECU, bore, etc. that are all designed to work together on the engine.

 

the f20b isnt a destroked h22. it has more in common with a f22 than a h22.

85mm bore with 88mm stroke.

i did all the math for putting a perfect rod/stroke ratio in a h22 and came up with an 83.6mm stroke and a 144.5mm rod. the stock stroke on a h22 is 90.7mm, the stock rod is 143mm.

if you use a 90mm piston then that gives you 2130cc as opposed to the 2157cc of a stock h22. if you had the money it could be worth it. you could remove the balance shafts and rev as high as you wanted.... you would basicly have a big *** b16 as far as reving goes. custom cams, itb's and some headwork and you could prolly put over 250 to the wheels all motor.

 

well said furry

 

but as far a keeping the motor big and reving it also now with deckplates that is all possible!!! 2.4 and 11,000 rpm ohhhhhhhhhhhhhhh yeahhhhhhhhh. pistons speeds after around 11,000 on a rod that long are starting to get crazy.

 

i dont know about that deck plate stuff...... you wont find me building a motor with a deck plate...

cause with my calculations you only loose 30cc so you wont notice the loss in displacement so its all gains...

after i get a track car built im gona start working on 12000 rpm h22 for my dialy driver...... prolly a year and 1/2 away

 

How do you determine what the RPM limit will be depending on your calculations? The method I currently use is using the piston speed and comparing it with other high revving engines such as the s2000, itr, etc...

 

Main reason I've asked for this info if b/c I do have an extra f22 engine sitting around and I think if I can pull it off on that thing. I'll do it to the h22a. What are some of the disadvantages to destroking?

 

less displacement and its expencive as ****. 2500 for a custom crank and around 1000 for custom rods..

im gona rev that bitch till it done make no more power. piston speed really isnt an issue imo. i mean those little *** F1 engines rev to damn 17000 and motor cycle engines rev to like 12 and ****. why cant any other engine do it.

 

would a destroked engine still work for a daily driver? or is this thing going to be like a freking drag engine?


[Modified by cecknight, 7:44 PM 9/17/2002]

 

deffinatly not a drag engine..... it would be most suited to road racing

 

now when you say a custom crank and custom rods at what specs do I need to get theses made and where can I find someone that can do that. Isn't there somebody who sels destroking packages or something? when I change the whole valve trane and TB/IM do I just needs these other items to be fitted for a 2.0 liter instead of 2.2?

 

noone that i know of sells kits.... there are a few companys that make custom cranks. crower, etc.

i dont understand what ur talking about valve train, tm, im???


its still a h22....

 

all this talk about revving to 12000 rpm has got me really wanting to go this way...i'm in a real mess trying to decide to go all motor or turbo...i love both, and until now, i haven't really heard anything about destroking, and what is does, thanks furry!!

I've had a GSX-R before so revving high sounds delicious to me! But then again the sound of a turbo really gets me going, what the **** am i going to do???

 

ahhaha funny ****..

there is now way u are gonna reliabily rev an H22a or a modified ( F20 ) one to more than 10 000rpm that's for sure

more than that the pistons would go faster than it would support neway

please keep in mind that at 8500rpm a B18c type R pistons goes like 24.5 metre/sec or something like that wich is the same speed ( approx ) than the Honda F1 engine bears. .

and the reason why they rev that high ( + 12-14K rpm ) is beacuse they have half or less our stroke

unfortunatly there is not perfect R/S ratio and the only thing t consider if you wanna go into high rev is perfect balancing and piston speed ..

i would say that if you bring up an H22a to 9500rpm with stability and u make it work for occasional rev to that speed u will be good

 

diong this destroking thing...would it cause one to loose torque at the lower rpm range?

 

u will loose torque on all the rage if you go down in CC
u will also loose potential torque on all the ranges going with a smaller stroke keeping in mind that this is theorically and that everything else remain unchanged in size/function

but i've heard more than 1 time that with long stroke engines run high torque numbers on low rpm but can't rev up as high and keep the power because factors that we already know


as a complement..

Raceworks's prelude for SWC was making 220WHP + ( he told me 230WHP )
with a 2.3 base + h22a head and competition cams ( special cams that were made for pace cars ) and a custom fuel management system..

all that at lower than 8K RPM
so one does not need to go high reving to make good power with H22a engines..

 

ok....I've been wondering the better way to go. B/c I read somewhere that they had destroked h22a's running 300 whp N/A. That's kind'a the route I'm wanting. I don't know if I'm up for running frankenstien h23/h22 engines. I'm just looking for a fun project on my old f22 and if I'm succesful at that then I'll do it to the h22.