M10 Stroker W/S14 EVO Crank

[winstontj]

I've posted recently regarding this subject and as I start to look at a few things like Rod Ratios, Intake and Exhaust Porting, and Piston Bore I'm starting to wonder if going that big is a smart idea? There are several 02'ers out there that are running M10 2.2L S14 stroker motors right now with huge success so I wonder if going any bigger will really yield anything more? If I were go get up to 2.3 or 2.35L by using a 92mm bore and an 87mm stroke would that be best saved for a forced induction motor? I've been doing some reading about the max RPM that a cylinder will completely fill upon intake stroke. My worry is that I'd spend a ton of money on a NA ITB EFI setup with an EVO stroker M10 and then be totally limited by the 8V head. I know that a 2.2L 84mm stroke M10 will yield ~185 @ the flywheel in proper tune... with that said and knowing that the 2002 really doesn't need any more power.. would it be best to run the larger displacement motor (EVO crank) with forced induction? My only fear with this is that the exhaust valves would now become the single most limiting factor.

There's really not that much difference (in displacement) between the 84 and the 87mm strokes when you stay at a 92mm bore it's a little... and there's more of a rod ratio difference unless you start spending S14-type big $$ on rods and pistons. (you'd need EVO rods and a custom EVO type 92mm piston) It just seems like it's almost not worth it because the 84mm stroke is about the limit of the M10 unless you're going FULL FULL race with things....

Your thoughts and guidance is always appreciated....

[BAhyow02]

Winston,

IMO the Evo III s14 crank in a m10 block is overkill. You have not stated what rod length you are planning on using.

Stock m10 rod is approx 135mm center to center

Stock s14 rod is approx 144mm center to center

EVO s14 rod is approx 144mm

2.0L s14 rod is approx 148mm

m10 rod to stroke ratio is 1.6875

2.3L s14 rod to stroke ratio is 1.714

2.5L s14 rod to stroke ratio is 1.655

2.0L s14 rod to stroke ratio is 1.85

m10 rod with s14 crank (84mm) is 1.607

m10 rod with s14 evo crank (87mm) is 1.551

The opinion of many professional engine builders is that a rod ratio of 1.7 to 1.8 is close to optimal for most engines. Some small bore engines (hondas) can get away with less than desirable rod ratios since the piston rock/snap is less with smaller bores/clearences. A lot of racing honda engines use longer rods than stock to get better rod ratios (even to the extreme of taller blocks or deckplates). The rod ratio determines many attributes that affect other engine perforamance parameters. The piston dwell at the top of the cylinder and maximum acceleration are two large contributers to engine performance that are changed with rod ratios.

I know people have done the 84mm crank with stock rods (I think CD has one) and you could ask him how it works for him. Most that i know of use the 84mm crank and s14 length rods in a m10 block.

I do know you will have to clearence the m10 block for the 87mm crank. Also if you are using m10 length rods, you might run out of cylinder head breathing at higher RPM due to the higher piston acceleration. Since you know you are giving up cylinder head breathing potential by using the m10 head (compared to the 16v s14 head), might as well choose the best rod ratio you can get. An added factor to consider would be engine life due to higher piston sideloads (ovalizing wear on bores and piston/ring life) due to the worse rod to stoke ratios.

Personally I do not think the little extra displacement you gain from the EVO crank is worth the extra expense. I'm going to be building a s14 stroker m10 motor but will be using aftermarket h-beam rods from a different make of car to have similiar rod ratios as the stock s14. My thinking is since either way you are going to have to get custom pistons made, as long as you can spend the extra money might as well get the proper length rod to go with the stroke you want.

Goodluck with your engine build. Perhaps you should talk to Eric Kerman who has done quite a few 2.2L stroker motors.

-Bernard

[Guest Anonymous]

you can get almost 2200 ccs by boring

[winstontj]

Winston,

IMO the Evo III s14 crank in a m10 block is overkill. You have not stated what rod length you are planning on using.

Stock m10 rod is approx 135mm center to center

Stock s14 rod is approx 144mm center to center

EVO s14 rod is approx 144mm

2.0L s14 rod is approx 148mm

m10 rod to stroke ratio is 1.6875

2.3L s14 rod to stroke ratio is 1.714

2.5L s14 rod to stroke ratio is 1.655

2.0L s14 rod to stroke ratio is 1.85

m10 rod with s14 crank (84mm) is 1.607

m10 rod with s14 evo crank (87mm) is 1.551

The opinion of many professional engine builders is that a rod ratio of 1.7 to 1.8 is close to optimal for most engines. Some small bore engines (hondas) can get away with less than desirable rod ratios since the piston rock/snap is less with smaller bores/clearences. A lot of racing honda engines use longer rods than stock to get better rod ratios (even to the extreme of taller blocks or deckplates). The rod ratio determines many attributes that affect other engine perforamance parameters. The piston dwell at the top of the cylinder and maximum acceleration are two large contributers to engine performance that are changed with rod ratios.

I know people have done the 84mm crank with stock rods (I think CD has one) and you could ask him how it works for him. Most that i know of use the 84mm crank and s14 length rods in a m10 block.

I do know you will have to clearence the m10 block for the 87mm crank. Also if you are using m10 length rods, you might run out of cylinder head breathing at higher RPM due to the higher piston acceleration. Since you know you are giving up cylinder head breathing potential by using the m10 head (compared to the 16v s14 head), might as well choose the best rod ratio you can get. An added factor to consider would be engine life due to higher piston sideloads (ovalizing wear on bores and piston/ring life) due to the worse rod to stoke ratios.

Personally I do not think the little extra displacement you gain from the EVO crank is worth the extra expense. I'm going to be building a s14 stroker m10 motor but will be using aftermarket h-beam rods from a different make of car to have similiar rod ratios as the stock s14. My thinking is since either way you are going to have to get custom pistons made, as long as you can spend the extra money might as well get the proper length rod to go with the stroke you want.

Goodluck with your engine build. Perhaps you should talk to Eric Kerman who has done quite a few 2.2L stroker motors.

-Bernard

I own a set of Pauter 144mm S14 rods that I was planning on using with the 84mm M10 Stroker. I have just purchased a stock (used) set of S14 144mm rods because Pauter is willing to take my set back in exchange for a set of 148mm rods. This way I'll have the option of both... OR maybe even running the 84mm stroke with the 148mm rods. Either way for a motor that's probably never going to see over 7,500rpm it won't matter that much. I agree on the breathing issue and that's why I'm looking at other rods - NOT the stock M10 rod. Also having pistons designed for the application will help but all in all I tend to agree and think that the M10 motor is probably maxed out at about 2.2L with an 84mm stroke.

[winstontj]

you can get almost 2200 ccs by boring

delk,

the most you can safely bore is 92mm. Some go up to 93 or more but the sidewalls get too thin and the cylinder walls bend and flex too much. Bore is maxed out at about 92mm which leaves most of your displacement dirty work up to the crank. Problem with the crank is as others stated: You start to get too much piston accelleration which maxes out the breathing of the head before your max out your RPMs.

I think the process I'm going through is a good one but it's making me realize that the M10 is maxed out at about 2.2L (or whatever 92mm bore X 84mm stroke ends up being. No way can we run up into the 92mm that the stroker EVO S14 guys run. Might as well just get yourself an S14 at that rate...

[Guest Anonymous]

with what bore? My math says ~2.127 which is a long way from 2200.

92mm bore and 80 mm stroke.

[BAhyow02]

Anthony,

I think Winston is refering to a stroker engine so 84mm stoke with the 2.3L s14 crank.

bore x stroke (eqn => bore*bore*pi*stroke/1000) (measurements in mm)

stock crank

92mm x 80mm = 2.127L

93mm x 80mm = 2.173L

2,3L crank s14

92mm x 84mm = 2.233L

2,5L crank s14

92mm x 87mm = 2.313L

[winstontj]

I think Anthony thought (as did I) that delk meant you can get 2200cc from an 80mm crank by boring the block. This is not possible... simply not possible with a standard M10 block.

[schwartzerritter]

2127?

with one overbore maybe

I had 93mm overbore no problems

[schwartzerritter]

92 mm bore/80mm stroke