its *possible* to get 1.7:1 rod ratio with a pretty extreme piston, but I think around 1.65:1 is as good as you can get it with off the shelf bits.
NA Tech Race to 100whp per 1000cc's
- Thread starter LordWorm
- Start date
its *possible* to get 1.7:1 rod ratio with a pretty extreme piston, but I think around 1.65:1 is as good as you can get it with off the shelf bits.
WHo makes off the shelf sets for this engine with that kind of rod ratio. Mine's about 1.49:1 with K1 longrods?
by off the shelf, i mean, available rods - not specifically for the FSDE
you find a rod which will fit from another motor with no/minimal modification and go with that.
3SGE rods, for example
some rods from some honda motors
SR20 long rod kits
etc.
those are the usual suspects.
whats it matter anyway? its unlikely you're going to tear your motor down *again*.
you find a rod which will fit from another motor with no/minimal modification and go with that.
3SGE rods, for example
some rods from some honda motors
SR20 long rod kits
etc.
those are the usual suspects.
whats it matter anyway? its unlikely you're going to tear your motor down *again*.
IIRC the Honda F engine has a similar bottom end to us, would require using the FP Crank though I think.
To run a longer rod than the K1 would require new pistons to be made with the top end raised towards the crown to accommodate the extra length at least AFAIK
Its not just the length of the rod that enables you to rev high its the weight of the reciprocating assembly (other factors pertaining oil source etc etc). Installshields rods and pistons where so light that the engine almost had problems starting in the cold winter months. I think his rod ratio was about ~1.58 if that helps.
To run a longer rod than the K1 would require new pistons to be made with the top end raised towards the crown to accommodate the extra length at least AFAIK
Its not just the length of the rod that enables you to rev high its the weight of the reciprocating assembly (other factors pertaining oil source etc etc). Installshields rods and pistons where so light that the engine almost had problems starting in the cold winter months. I think his rod ratio was about ~1.58 if that helps.
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his rods were aluminium..and my numbers are out... 1.65 is about as far as it can be pushed, going through old emails ... and it was compromising alot of things to get it to work (wildly short piston skirts, extremely high wrist pins, relatively narrow wrist pins to get the centerline as high up as possible).
weight is an issue (F=MA and all that)... but the is an angle of influence which causes problems (lower the rod ratio, the greater the rod angle, the more loading on the sidewall and so forth).
for the purposes of achieving 100hp/L specific output though, an reasonable chromoly rod at a reasonable rod ratio will get you the required RPM...
weight is an issue (F=MA and all that)... but the is an angle of influence which causes problems (lower the rod ratio, the greater the rod angle, the more loading on the sidewall and so forth).
for the purposes of achieving 100hp/L specific output though, an reasonable chromoly rod at a reasonable rod ratio will get you the required RPM...
twilightprotege
Member
- :
- 2001 323 Astina SP20 (P5)
there's always my 1.5:1 rod/piston combo that's or sale and available... 
jimmysuite
Member
- :
- 2003 Mazda Protege5
Seems pretty darn similar to whats on my car...
jimmysuite
Member
- :
- 2003 Mazda Protege5
You have definitely gone a couple steps further. Nice work.
Twiggy cams
SRI
MT LT10 EMS
PnP head with three angle valve job
Coated 10:1 pistons
Titanium retainers
stiffer valve springs
626 manifold
Thunder headers
MAM midpipewith highflow cat
Racing beat Catback
9lb flywheel
welded MSP differential
spec stage two clutch
innovate LC-1
aluminum underdrive crank
AWR oil pan and mounts
my dyno sheets are in the NA dyno ladder thread which (LW hasn't updated in years.....)
Twiggy cams
SRI
MT LT10 EMS
PnP head with three angle valve job
Coated 10:1 pistons
Titanium retainers
stiffer valve springs
626 manifold
Thunder headers
MAM midpipewith highflow cat
Racing beat Catback
9lb flywheel
welded MSP differential
spec stage two clutch
innovate LC-1
aluminum underdrive crank
AWR oil pan and mounts
my dyno sheets are in the NA dyno ladder thread which (LW hasn't updated in years.....)
TXMazdaSpeeder
T is for Turbo
- :
- 2003 Black Mica MSP #566
I was actually comparing it in the FS's favor as all I said was I'd have a hard time doing the same with a much bigger displacement motor. I whole heartedly agree with you, however that still does not make the LS platform a "terrible" engine. That was my only counter. But like I said, im not going to clutter this thread arguing about a 2.0L dohc 4v 4 cylinder vs a ohv 5.7L 8 cylinder. Its a moot point.
And mine, minus the computer (piggyback for me), manifold (stock MP3 for me) and header (completely custom)
You didn't list Engine Management, which is probably the most important of all? There's quite a few other things that you didnt mention;No Cats,MAF,EGR or PCV. Throttle body coolant detour. That's why I said horseshoes and hand grenades is what almost only counts in. I know it's a saying, but,it's the little things that will add up. It's too bad both of you live so far away,or we could do a little playing at the strip.
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What RPM did you make that HP at?
Hmm. Did 190whp on my 2044cc B series block without touching the head- might have to try and build the wife's 5.
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