Rep Power: 303

anyone know the formula to claculate mean piston speed. i am trying to see how efficient our motor really is for boostd application. i was looking at dsport and they show the mean piston speed of a b16 to be like 5049 feet per minute @10,000rpms' and a b18c to be 5109 feet per minute@ 9,000rpms. this means that the b16 is a better choice for a boosted application because it can create more efficient power at a higher rpm than the b18. but since we are in between the motor size i am wondering if a d17 has a lower mean piston speed than the b18 as well.

also what is the fastest tim e anyone has run with a boosted d17. and what internal mods were done. has anyone done a full motor build with a d17 and turbo???
sorry so many questions just trying to figure out if it is worth it to go big on this motor.........

 
Rep Power: 400

Piston speed would be the last thing I'd look at when comparing engines suitable for turbocharging.

Displacement, Cylinder head flow, Parts availability, and overall design strength are more important when it comes to that.

The bottom end of a B16-B18 is signifigantly beefier than a D17, not to mention superior head flow, cams, and displacement.

My advice is to K motor swap it.

 
Rep Power: 285

stroke x RPM

so if your stroke is 4" and your at 10,000 RPM, then your piston speed at 10,000 RPM is 40,000 in/min
(40,000"/min) / 12"/ft = 3333.33 ft/min

(3333.33ft/min) * 60min/hr = 200,000 ft/hr

(200,000 ft/hr) / 5280 ft/mi = 37.87 mi/hr

 
Rep Power: 285

the stroke on a D17 is 94.4mm
1 inch is 25.4mm

94.4mm / 25.4mm/in = 3.717"

redline is ~6700 so.....
3.717in x 6700 rev/min = 24903.9 in/min
(24903.9 in/min) * (60 min/hr) = 1494234in/hr
(1494234in/hr) / 12in/ft = 124519.5 ft/hr
(124519.5 ft/hr) / 5280 ft/mi = 23.583 mi/hr

 
Rep Power: 303

piston speed is actually one of the main things you want to know when building a motor. the parts such as crank pistons and rods can all be replaced and are manufacturered today. headwork can also be done to achieve specific flow rates. i know that the d series engines are not ideal for a turbo but i cant swap here. im in cali and swaps can only be made if the motor came stock in the vehicle. if i do not build this motor i might be able to come up on a 99si for like $1k. it got stolen and stripped. they left the motor though they didnt have time pull it before they got caught. so if i do end up buying this car i am doing a b16 build up if not i might be building the ol d17 after all. it all depends on if my buddy buys his car back from the insurance company or if he is over it. either way something is getting boosted. i was going to boost my s10 4cyl. but ill get better times out of a honda than a 3200lb truck with a weak transmission. i have everything but the pipes to do the install on the truck but if i do the si or my sedan i am going with a piggyback and injectors rather than use the cartech fmu i have for the truck. to build a motor right piston speed is going to be a big portion of making power at higher rpm's before meltdown. whatever i do its definately going to be a 10000rpm motor shooting for 450-475whp on pump gas with average boost levels (15-20psi) on high boost maybe like 650hp wiht race fuel. i dont think i am going to get those #'s out of a d17 though. i am just ging to have to talk to the right people

 
Rep Power: 400

that answer that you are attempting to disagree on, was given to me by an American Honda Engineer who had a hand in development of the D17, F20C, and K Series engines, who also happens to own several race teams. So my advice would be to rethink your approach regarding piston speeds. As he stated there are many other things far more important.

 
Rep Power: 329

also, why are you so concerned about the legality of an engine swap, and suddenly not concerned about the legality of said turbo???

 
Rep Power: 303

well a swap isnt as easily overlooked as a turbo around here. i can get it smogged as long as all the vins match. i have a guy that will do it but not with a different motor. as far as the gov goes if i get pulled with a swap he could get rolled if i have a turbo then he could say i put it on after the smog.

 
Rep Power: 303

i agree to a certain extent. it is a good part of a motor build when looking for peak hp in high rpms but there are a lot of other thing to worry about. but most of those i ahve ironed out already. i have a guy that will do the head, there are plenty of parts out there such as crank rods and pistons a cam can be ground to my specs and cryoed. i really dont think the d17 is going be my build up motor only because there are far more efficient motors and cars that can be had for cheap but it never hurts to inquire to see if what i have is actually worth the build

 
Rep Power: 400

i think if you're overall building a motor, then obviously it would be an aspect you'd like to consider, particularly if you're going to be raising your redline. your initial question, howver, made it sound like you were talking about piston speed in relation to turbo'ing a car, which is different. i think this is where the confusion is coming from.

 
Rep Power: 318

you could buy a drag car for 20 grand on ebay right now. Drag 94 hatch with 700hp.. dont know what shape engine is in though

 
Rep Power: 303

i want to build my own. i would never purchase a project car that was already built. it would be cheaper but not for me!

 
Rep Power: 318

can allways put a k24 in and make 250hp. however your going to pay an arm and a leg

 
Rep Power: 303

i think i am going to go for a eg. 94-96 hb wiht a b16. either that or a crx. but if i can get my buddies stolen and stripped 99si for $1k that his insurance wants i am jumping on that quickly ill keep you guys posted