I am doing some engine work to my F23A1 ( i know, buy a different engine ), and needed your help / advice on the project.

I am wanting to change my rod / stroke ratio of the engine, and I was wondering what would be the best combination to get my engine to a 1.7:1 or 1.8:1.

Right now my R/S ratio is around 1.45:1 if the information that I found is correct. (Rod equals 141mm, Stroke equals 97 mm). I noticed that the K24A Rod Length is 152 mm, and my stroke is 97 mm giving me a R/S ratio of 1.57:1.

I also noticed that if I really did some calculations the K20A Rod Length of 152 mm combined with the B18A1,B18B1, or the B20B4 Stroke is 89 mm offering my a R/S of 1.7:1.

Does anyone know if this will work, and if not, what will. Thanks for the help!

 

What you a basically wanting to do to the motor is called de-strock it. Its pretty comon with road racer's. I'm assuming your wanting to do this to rev the engien higher, am I correct? If so then you best bet would be to get some custom rods that are about 5mm shorter then yours and have custom pistons made with the wrist pin set higher in the piston. If this is done correctly you shouldbe able to get the 2.3l down to around a 2.0 or 2.1l. There is no need to go any lower in displacement because you'll loose to much torque and won't be able to move the car. I hope this helps.

 

Yes, that's exactly what I am going for. A higher rev with more power at top end. Being that I will lose torque, which is expected when going for more power at top end, what should I expect to lose.

I am currently at 152 ft/lb tq but that is bone stock. I have some mods that bring it to approximately 160 ft/lb tq.

Thanks again!

 

you can rev the F to all hell, its not gonna make any more power

 

But isn't it true that since a longer rod will make more torque with the same piston force, that the power will increase?

Also, since the sidewall pressure and internal friction will be less, won't that be beneficial for the engine to make more power?

With a longer rod the piston would be at Top Dead Center (TDC) longer and allows for more flow of intake and exhaust gases, allowing for a stronger energy release on the piston itself. Isn't that going to provide yet more power.

 

by saying its "not gonan make any more power", of course i mean signicant power....the kind you'd get from boosting or an H22 swap.....without running very aggresive cams and high compression, the F isnt gonna make alot of NA power

 

Okay, in your opinion then, as far as a turbo setup would go, what would you recommend? I am interested in doing a turbo setup later, but just tinkering with the engine right now ... kind of just learning the in's and out's as much as possible.

I used to help my father work on his old Mercury Cougar with a 351 Windsor, so I have experience, but I really want a good strong engine with good power.

Would a turbo setup with a high rod / stroke ratio and a mild / aggressive cam work well, or would it work better with a low rod / stroke ratio with a mild / aggressive cam?

Thanks for your input so far.

 

honestly, im not the one to ask when it comes to technical engine building. Ive yet to hear of a street/daily drive turbo F accord with modified rod/stroke ratios....because thats not a big issue for people, because they're fine with putting down 225+ whp on complelty stock internals.....keep in mind that the sleeves are iron, so those will hold up well, however with most engines, you have to worry about the rings, as they are gneraly the first to go on a newly boosted motor....also, theres currently no real place to get a totally new cam for a SOHC accord....everything you'll see online is a regrind. if you plan on staying NA, try to get ahold of bisimoto...he pretty much knows everything there is about making power out of F22/23's