...to make an S2200 ourselves? Just punch the F20C out to 2.2 liters and...wow! Could you imagine? I bet the torque would rise signifigantly, as well as the hp. It'd still be 'all motor' as well...hmmm... Honda did this with the S500, 600, and 800 no? Just thinkin' out loud, what do you guys think?

Andrew

 

Well would you incrase displacement with a bigger crank or a bigber bore.

I think you'd have problems with an increased bore because I don't think the cylinder liners are removable/replacable.

A custom crank would cost BIG$$

 

[QUOTE]Originally posted by S2Kguy
[B]...to make an S2200 ourselves?

 

You guys will have to forgive me on this subject, I can talk all day about the physics of thermodynamics, but increasing displacement...uh...whatever. Anyway, the FRM+ceramic in the cylinder liners can be bored, I have a honda bulletin on such, but I wonder if I'd feel comfortable going to 9,200 rpm (which I do several times a day) with it removed, ...probably not. Anyway, just thinkin' outloud again... C'mon UL, tell us what we can do...

Andrew

 

From what I know of Hondas, 1mm overbore is all that's "recommended." Going further than that would take some serious research, possibly even testing, on a bare block. I'm not sure but am betting we are an open-deck design and probably don't have much room to work with.

A new crank, rods, or pistons would likely be prohibitively expensive. 1mm could be had easily with stock parts, but would only result in about 30cc or .03L more displacement (not much).

To get .2L of displacement, you're talking about .165" overbore, more than 1/8" or over 4mm!!! You're going to be getting AWFULLY close to water jackets, plus need new pistons.

Break out the checkbook...

 

 

Actually, older factory Hondas only recommended a 0.5mm overbore max, although you could usually go 1 mm over and be safe (but you couldn't always get factory pistons).

Because of the FRM liners, the S2K manual only recommends a maximum 0.25mm overbore, so anything over 0.5mm on the stock liners might be an issue (FRM allows the liners to be thinner to begin with). Even with a 1mm overbore and 1mm stroke increase you'd only be looking at about 2070cc total (roughly).

The best solution would probably be to resleeve the block with ductile iron liners. This costs about $750-$1000 for a I4 engine. This would allow you to increase the bore by 3-5mm easily. A 4mm bore increase would net you a total displacement of 2187 cc without increasing pistons speeds at all (and being able to retain stock rods, bearings, etc.).

However, when you increase displacement, especially bore, there are other changes you have to make. In particular, the head gasket will probably have to be modified (or a new copper one made up). Additionally you'll probably want to open up the combustion chamber a bit. The extra quench around the edges might be o.k., but if you increase displacement by almost 10% without changing combustion chamber volume, your compression ratio will go up accordingly, in this case to about 12.1:1, which is a bit high for the street. Increasing the chamber size by about 3-4 cc would do the trick (this isn't hard to do) or you could put a smaller dome on the pistons. Finally, the cams will behave like less aggressive grinds with a big engine. Thus, the peak power rpm may drop. This isn't necessarily bad, but to fully take advantage of the increase in displacement, you'd want somewhat more aggressive cams.

All in all, assuming you could do the liners, you'd be looking at about $1000 for block prep, $500-800 for new pistons, $600-$1200 for head work/prep depending on what you had done and another $200-$300 or so for misc bearings, gaskets, etc. Call it $3k plus labor for pulling and reinstalling the engine ($500 min).

In return, assuming you had just enough headwork done to make sure everything clearanced right (no heavy duty porting) and assuming the ECU could compensate for 9.5% more displacement, you could expect peak torque to rise approximately 10% (increased compression helps a bit) to 170 lbs-ft with the peak occuring somewhat lower than stock. Peak power might not actually increase by 10% if you retain the stock head flow and cams. However, the power peak would come at a lower rpm and be flatter and would still have a somewhat higher peak than stock.

Personally, the only way I'd do such a mod is if I had some big gnarly cams, some good head porting and an ECU I could program. With those tweaks, it wouldn't be hard to get peak torque up over 180-190 lbs-ft and peak power into the 280-290 range.

UL

 

How does Mugen gets almost 2.2 on their cars?
Anyone from the trip to Japan knows?

 

I think I read they used a stroker crank (and seem to remember a reduced bore so maybe they added liners).

 

Thanks UL, I was hoping you'd read this thread, and you gave me exactly what I was looking for. My next question is...is this a viable thing for Honda to do cost effectively in-house on upcoming model years? Or, perhaps, is this really just the wrong avenue to explore altogether? I'm just trying to get a feel for what Honda would do, being the conservative company they are, for additional power gains (most probably a foregone conclusion). This is the type of thing they did with the NSX, right? It's probable that we will see airbox modifications, as well as more agressive cams, or iVTEC before any additional displacement, but it is possible...right?


Andrew