okay, correct me if im wrong.
Raising the boost is a good thing as long as you have a turbocharger that can take such load.....?

 

I've seen dyno whp numbers vary by 20 percent on their correction numbers. At 500 crank hp, they could read 100 hp difference.

As far as reliability, if you have OEM assembly for OEM assembly on a 2.0 vs say a 2.3, then yes the lower speed/higher displacement engine would last longer.

In reality, the stroker kits are comparatively new, and once you peel open a perfectly good motor, you open yourself up to Murphy's Law - even with a good motor built by a good shop. Everyone's got their own recipe, who do you trust?

A built stroker motor, done right with supporting head mods will cost you in the $5K area. That's before you touch the turbo, exhaust, cams, clutch, etc... but if you do all of that stuff at the same time, you can save on labor.

I'd suggest you drive one before embarking on that route. I understand the car really feels different, though I haven't driven one.

I like the higher reving 2.0 with a carbon clutch to slip for getting out of the hole quickly. The high revs give a longer gear in a race and the clutch puts you in the power band. You'll need the long gear when racing a high reving car like an M3/ f430 etc.

on a 2.0, if you keep revs under 7800, you shouldn't see any internal part failure as long as you stay away from detonation and heat.

 

That is correct.

If the turbocharger/tracts/cooling system/engine components can be made more efficient, stronger, etc. to take the increased compressive and/or heat load of increased boost or massflow, then it is ideal that the extreme inertial stress and the fast consumption of finite number of cycles of high RPM be avoided.

For a recent real life example of this, read how Cosworth evolved their old Champ Car XF engine (to XFE) - resulting in sevice life in race miles rising to a staggering 300% of original. This was accomplished mainly by..
1) dropping RPM 25%
2) raising boost pressure some 20%.

Power was purposely reduced by some 17%, only because of CART's safety concerns. It is estimated that if the rules had allowed retention of original power output via higher boost, service life would still have easily been 280% of original.

 

IDK, if the motor is small enough and designed to rev to higher numbers, can't it be ok?

B16? That motor can hit 9000 for WELL over 100,000 miles. Hell the B18 too. If it is designed to how can revs be a big problem? Having a LARGE motor with a LARGE stroke puts a lot of stress too, especially when the piston changes direction so dramatically under pressure. Idk....just a thinkin....

 

^^^^^im not sure whether those motor are designed to hit 9000 rpm. They hit 9k bcuz tuners make them that way. Hell if they were designed that way, then why not make it 9k rpm stock coming out from the factory. just my opinion. Plus i want my car to last more than 100k miles. Yeah its true that smaller the stroke the higher the rpm. not necessarly the best way, since your practically squeezing and pushing its rev limits to the max.


but i think ill go 2.2 liter stroker by jun. i still need some advice on this tho. prolly try to get my hands on those omega forge pistons that the fq 400 have.


sorry but this is out of the blue.

can you purchase just a crankshaft w/out the pistons, rods etc.?????

 

The mileage that a street motor that only now and then pulls to 9 or 10K RPM for a 1/4 mile cannot be considered race miles. There are too many unstressed street miles mixed in to confuse the result. I could build a race engine that is capable of 12K RPM, but if I spin it to redline only twice in 100K miles of street driving, with the rest of the driving being mainly highway cruising at 2500rpm with an extremely tall (numerically small) 6th gear, do I then consider that I built a everyday driver 12K RPM machine? No!

Look at 12, 24, 25 hour endurance racing events. How many engines do you see running 10K RPM or higher redlines that last the entire duration of the race, are competitive, do not have excessive wear, and do not cost a bomb to build? None. In case anyone brings up the EDL GV5 as an example.... it does not qualify because it costs a bomb (F1 based engine) and they run a very small stroke compared to street based engines we modify.

Having a large motor with a large stroke does in fact increase the stress level for a similar RPM. However, to make the same power, we do not need to turn similar RPM because we now have more displacement and are flowing a lot more air per RPM. So, we build it bigger, rev it lower, have better power delivery, suffer less friction, less wear, and still make the same power target. Of course there are limits as well before you run into stroke clearance and crank strength problems, or abnormally inefficient and lage chamber or dish to maintain low CR, or pistons that sit too low in the block to provide quench or squish - all basically bad geometry. But at 2.3 or 2.4 stroker levels, you are still quite far from running into any of these problems.

 

100K miles is still extremely optimistic any way you look at it, given the power target. The only exception is if you almost exclusively drive non-spirited street miles and hardly ever hit the tracks. If you hit the tracks, limiting race miles run will help.

Doesn't crower have a billet 2.3 or 2.4L stroker crank? I would go that route if so.

I think you can

 

S2000. And MANY street bikes too. AS far as the larger motor...



This is dependent on head design and cam profile. AGain I have seen big a$$ pontiac 502's comming in boats making LESS then 200 HP, that is scary iron heads or not.

 

Try putting the S2000 through a 24 hour race. Try properly tracking the S2000 every weekend and then see how it lasts 100K miles.

The bike engines run tiny displacements and strokes and are trying to optimize power given limited space for the engine. The high RPM bike engines will not even go 20K STREET miles.

Yah and I have seen big a$$ race 427s making more than 600hp after racing 24 hours.

You can pick the extreme example of poorly designed, poorly put together, inefficient low compression american iron and attempt to make a point, but it will not hold up due to poor logic.

Name one engine that has raised engine speed and lived longer
Why don't you de-stroke your evo engine and run it?
Why are endurance engines always as big as possible (within the rules)?
Why are air restricted endurance engines STILL always as big as possible (within the rules)?
What is the most noticeable thing about 250K mile engines?

 

The high RPM bike engines will not even go 20K STREET miles. 15K miles is considered high mileage with the valvetrain and lower assembly needing a freshen.

 

Also I think people are not putting enough focus on power width and response. Drag racing, highway racing, is one thing. Power width and response to get off the corners quickly on a road course is another. A power band barely wide enough that you can stay in completely in a drag race, will not be sufficient for a road course because gearing never properly suits the whole range of corners. Road course racing requires a wider power band .

Regarding not seeing any damage on a 2.0 revving 7800 RPM and under... not seeing damage does not equate to not stressing it. Wear is inevitably accelerated.

 

It would do fine, it is designed to it's a Honda Motor it'll last, they aren't know for blowing unless you boost them or really play with them. Also again look at the sport bikes, they are fine too, although teh driver is normally teh one who doesn't last



They used to use 1.5 Liter motors making over 1000HP, they made them larger and now have less HP. SO I really don't know. Response I guess


IDK about that, again it's the drivers who blow their brains out.

Honda B18 and B16 seems to outlast MANY MANY American V8's, by far too. And when they finally DO go, it is either thehead gasket or the rings.


In teh interest of spoolup, but there are MANY drag racers who actually destroke their motors for this reason of more WHP and topend. Short stroke motors pull like crazy up top.


That they are Honda Motors or Turbo Diesels ....

 

Bad logic!

I will return in a couple hours to reply to your last post. For now I'm off to watch IRL qualifying

When I ask for an example, I want an engine that has RAISED its engine speed from original and lived longer. Quit comparing totally different engines.

 

??? Quit changing you're arguement? There are TOO many variables in making a motor that effect longevity. Manufacturers normally increase displacement for an easy boost in power as it is the simplest way to do so, but not the best. Longevity? You'd be hard pressed to find a more reliable motor then the HIGH reving B16A.

 

Don't be vague. Name the race class, driver, result.

The FIA outlawed turbocharging. Don't let your poor knowledge of documented history distort physical reality.

If I wanted to be vague as you, my reply would be "Chevrolet LS1s and LS6s seem to outlast MANY MANY Japanese I4s, by far too. Such vagueness would be quite useless though.

You are making a big mistake equating power potential of large bore/stroke ratios to engine longevity.

In the interest of maximum power from a rule limited displacement, large bore/stroke ratios are ideal (modern F1 around 2.3, modern high performance street car, little over 1). Bore is increased, stroke is decreased to stay within the displacement limit. Large bores allow large valve areas, and large valve areas mean power potential provided the lower and upper assembly can rev. Result is a powerful high revving engine that makes great specific ouput, but does not have good longevity versus one of larger displacement that revs lower and makes the same power. The teams cannot choose the larger displacement because of the rules. No one ever sacrifices displacement and goes faster or lasts longer. If you think there are, please provide names of the engine developers, the race class and team.

Honda motors don't go 250K miles. Low revving diesels do. They run at extremely low RPM and high MEP. You would think high MEP just like the Cosworth XFE, would lead to more wear, but that factor is eclipsed by the lack of the tremendous inertia loads of high RPM. High RPM stuff sounds good, allows small high output engines to fit in small vehicles, and impresses friends with high specific output figures. Often it means a fast car too. BUT engine longevity and BSFC are poor.

I hope you get at least somewhat specific with examples. If you don't, then I'm done talking to you.

(I am betting a certain article from a constantly error-filled but popular boy racer mag, gets mentioned soon.)