ProjectBoosted

iTrader: (1)

I have a ls crank and a gsr crank and i'm trying ot build a 500+ hp turbo motor. which crank should I use on my gsr block? Do i have to do anything to make the ls crank work?

clayne

b18c1 crank, cmon.

G2K

I'd use the gsr crank, the LS is nice if you want some extra torque in the low-mid range, but the make power up high you want to rev it out. But its up to you, you can easily make 500whp on either crank.

dome

iTrader: (1)

go to the ls crank , just get some ls rods. bore it to 84mm and have about a 2.0l motor. i rev mine to 10k


Modified by dome at 6:48 PM 10/22/2006

clayne

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dome &raquo;</TD></TR><TR><TD CLASS="quote">go to the ls crank 100 bucks from ge</TD></TR></TABLE>

go to the gsr crank 0 bucks from nowhere

b18bEKcoupe

Are you talking out of your *** or do you actually have an opinion on why the use of a GSR crank is a better choice?

clayne

He has a b18c1 block already. Do you want things to be hard or easy? Use the crank that's already implicitly compatible especially if you already HAVE the crank and no need to split hairs.

Oh, and this is on top of the other 800 already archived threads on b18c vs b18a/b cranks in various b-series blocks.

nowtype

LS crank will make more torque everywhere. It's not a huge gain, but it's a gain.

rocket256

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by G2K &raquo;</TD></TR><TR><TD CLASS="quote">I'd use the gsr crank, the LS is nice if you want some extra torque in the low-mid range, but the make power up high you want to rev it out. But its up to you, you can easily make 500whp on either crank.</TD></TR></TABLE>
I was going to say the same thing.

clayne

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nowtype &raquo;</TD></TR><TR><TD CLASS="quote">LS crank will make more torque everywhere. It's not a huge gain, but it's a gain.</TD></TR></TABLE>

...and a loss in places as well. R/S ratio. been debated countless times already.

vaporboy12

ive reved a 500hp motor with a ls crank and eagle rods to 11,200rpms so r/s ratio is out the window hehe

clayne

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vaporboy12 &raquo;</TD></TR><TR><TD CLASS="quote">ive reved a 500hp motor with a ls crank and eagle rods to 11,200rpms so r/s ratio is out the window hehe </TD></TR></TABLE>

Continous load and high rpm operation or just revved it that high once?

Try doing that on a circuit multiple times per lap - it won't last.

BoostedEG6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by clayne &raquo;</TD></TR><TR><TD CLASS="quote">

Continous load and high rpm operation or just revved it that high once?

Try doing that on a circuit multiple times per lap - it won't last.</TD></TR></TABLE>

If built right and tuned right it will last just as long as the GSR.... there are lots of people who do this and have never had a problem and make BIG power and rev 9500+ rpm's

HiProfile

The one fact that isn't debatable is the oiling surface size. The LS crank gives you almost 10% more surace area. Assuming you'd get aftermarket rods from the same company, this would mean the large bore is going to be stronger, and I don't have to get into the possitive aspects of that.

FYI I know a local with a b20/vtec block (obviosly aftermarket rods/slugs) that goes up to 9500 with his drag car all the time w/o issues, and his b20/vtec street car had just arias slugs in it and he beats the **** out of it.

clayne

I keep hearing a lot of "can rev up to." I'm interested in examples of long-term SUSTAINED endurance/circuit usage - not drag passes.

I'm also not debating that the LS crank can be made to be reliable - but the basic fact is that the GS-R crank has a better R/S ratio and that will have a play in continuous high rpm loaded conditions and *especially* situations involving multiple downshifts and associated engine braking during where the rod fasteners and wristpins are seeing the most brutal loads.

14 page r/s ratio thread in All Motor

mike1114

iTrader: (1)

**** on the R/S ratio.....Even Earl Laskey says that the R/S ratio difference is very negligable in Honda Motors.

Why wouldn't the LS crank be able to rev as high as the GSR? Its not like the GSR crank is made out of some better material or anything.

nowtype

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by clayne &raquo;</TD></TR><TR><TD CLASS="quote">...and a loss in places as well. R/S ratio. been debated countless times already.</TD></TR></TABLE>

Why would R/S ratio cause losses? The only "problem" with RS ratio is the fact the piston will put more force against the cylinder walls which is why people don't suggest revving them. The reason why the LS crank makes more power is due to the RS ratio but primarily the increased displacement. We are talking about minor differences which is why minor gains occur. Also, the surface area does not change to whomever said that. The only thing that changes is volume ie the change in displacement. Surface area changing would mean larger pistons and since when does a LS have a larger piston than a GSR?

clayne

14 page r/s ratio thread in All Motor

BoostedEG6

Key word in that statement is "All Motor"

clayne

Still applies more than ever.

HiProfile

All-motor power comes mainly from revving when its a honda. Any extra low-end in a boosted honda, esp in roadracing, means easier to control boost, or at least a bigger turbo w/same spoolup.

The best example of r/s has to be the chevy 350, which has near identical rod/stroke lengths as b18's. You can either go with .3" longer rods for more torque, or .3" more stroke. One is more displacement, one is a slower rod that lingers near the top longer. (read about Smokey Yankovic's thoughts on this, hes a famous Nascar/V8 guy). You may even consult the Endyn guy, as he went from ford v8's to hondas.

Now with that in mind, we go to boost. Cylinders with a pressurized charge will be putting a greater load on the piston, and for a much longer amount of the stroke (the Corkey Belle book has a nice graph). I would surmise thats already doing the job of the longer rod, except you don't have an extremely hot charge thats very high pressure lingering, focusing the heat & pressure on the sleeve lip/head gasket. D-series have headlifting when you run too much timing - running too much timing means the charge is buning with the piston around TDC longer. And that happens to be on a motor with 'bad' r/s, meaning its not even up there for that much. If it was moving past TDC slower, that means terrorizing the sleeve lip and head/gasket all that much more.

My opinion is that relating a boosted motor to NA discussion is like compairing an inline motor to a horazontally-opposed motor. People have problems with egging cylinders and cracking sleeves when they have other problems, such as low oil pressure, and lean conditions/detonation respectively. As with a d-series, people do ls/vtec because its cheaper. When you try to save a buck, you take risks. More risks = higher chance of a blown motor.

Last bit of info I'll add here: very few competitive racers will expect a motor to last a season. I can't recall what NASCAR guy said it, but goes like "Ideally, the car will fall apart right after it crosses the finishline, otherwise it was overengineered." Thats saying if you want to go *****-out power, go with the LS crank. Otherwise pussyfoot behind the real competition with a GSR.

clayne

Lot of good compliments. However, I'm not going to agree that FI vs NA is like inline vs transverse one bit. People would LIKE to make it out to be night and day and that somehow concepts are allowed to be entirely ignored, but that isn't the case in reality.

Also, pussyfoot behind the real competition with a GSR crank? Just a bit over the top there.

BoostedEG6

kind of off topic but Clayne I don’t understand why you keep bringing up <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by clayne &raquo;</TD></TR><TR><TD CLASS="quote">I keep hearing a lot of "can rev up to." I'm interested in examples of long-term SUSTAINED endurance/circuit usage - not drag passes.</TD></TR></TABLE> and bringing NA into this when someone is asking about information on a FI motor not NA

Most people who Turbo Hondas don’t do much circuit racing, granted there are a few people who do.... but most do Drag racing

I thought this whole subject was information for ProjectBoosted who is trying to "build a 500+whp turbo motor" that right there tells me that this motor is not being built for endurance/circuit usage....

clayne

But how is R/S ratio intrinsically ONLY an NA topic?

It's engine design in general. The only reason NA got brought into the fray was because you had said "keyword: all motor" and basically I was just saying that it is not an induction issue when it comes to the reliablity concerns.

FI also is not an open reason to just forget about high RPM performance.