I got a B18C1 block w/knife edged crank that I'm selling. The person buying it wants to boost on it. I'm assuming he won't be running past 10-12 psi. He's planning on 9:1 JE's, Eagle rods and PR3/B16 head. I figure for this application it won't hurt performance, only downside I can think of is it may falling out of VTEC on short shift, but I don't know never run the knife-edge on a boosted car before. Anyone got an opinion on this? Later Allen

 

Come on. Earl, Art, Tony, Jason anyone. Just want to clear this up, I'm not asking you to sign a waiver that it'll never hurt performance I just want some opinions. Later Allen

 

why would it fall out of vtec>? is it cus it will drop the rpm too fast inbetween shifts?.. thats a slow shifter if thats the case

 

The revs drop just as quick as they climb. But I can't think of anyother ill effects. Later Allen

 

My 2.0L LSVTEC that i built I knife edged the crank... Mine is boosted as well, and I have no porblems, no falling out of VTEC or anything like that...

 

Knife-edged crank will throw the balance off in a boosted car is what I've heard.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatchback19 &raquo;</TD></TR><TR><TD CLASS="quote">Knife-edged crank will throw the balance off in a boosted car is what I've heard.</TD></TR></TABLE>

Umm, not true. The knife edged crank will work fine unless he's making enough power to where you have to worry about the strength of the crank (over 700hp). I think he'll be fine

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatchback19 &raquo;</TD></TR><TR><TD CLASS="quote">Knife-edged crank will throw the balance off in a boosted car is what I've heard.</TD></TR></TABLE>

rumor..

why would it throw it off balance if its balance after being cut? but anyways... ive had a knife edge crank on my b16.. with a 9 pound flywheel... ive never once fell out of vtec with a vtec engagement at 6500... ofcourse this was my old crx.. built.. all motor..the onyl way for a person to fall out of vtec is long gears such as an LS.. or a slow shifter...my revs never fell when i draged.. the most it fell after shifts was 2200 rpm that was from 4th to 5th.. but inbetween shifts.. 500 rpm if not less

 

The drop between gears has nothing to do with rotating weight. The gearspread has to do with gearing and only gearing. You're confusing the loss of inertia of the flywheel with rpms falling.

 

From my understanding you don't really need to knife-edge a crank on a honda. It is an old V8 trick they do because their cranks are submerged in oil.

 

Right, I'm not recommending anyone do it, just saying that it will work. There is possibly still a small benefit from it though as it should be more aerodynamic. It does spin kinda fast down there! I wouldn't risk losing the strength of a honda crank though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DIRep972 &raquo;</TD></TR><TR><TD CLASS="quote">From my understanding you don't really need to knife-edge a crank on a honda. It is an old V8 trick they do because their cranks are submerged in oil. </TD></TR></TABLE>
Yes exactly. This is what I have been told.

 

Cool, I've seen and experienced the benefit of a knife-edged crank, UR crank pulley and a 7lbs Fadanza. It was all motor and rev'd up like a motorcycle. I just didn't want to sell this motor and have the kid be disappointed with the setup. Thanks for the feedback. Later Allen

 

knife edged crank will not affect an motor to fall out of VTEC. Knife edged crank ar just designed so that the crank turns easier since they are less parastitic drag when turning. It's usually common in the V8's guys since they're crank is submerged in the oil pan, while honda's aren't.

stan

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">

Umm, not true. The knife edged crank will work fine unless he's making enough power to where you have to worry about the strength of the crank (over 700hp). I think he'll be fine </TD></TR></TABLE>

Like I said it's just what I heard. A lot of peopel talk about this, im not even exactly sure what it involves I just know I've seen talk about this throwing the balance out. If it was out of balance I think it wouldn't work for boost or N/A but what do I know. Anyways thanks for clearing it up,
Matt

 

well, honda crank are very well balanced as it is if not it'll be within a few grams and it will not make any significance difference.

If the knife edging is done properly and all weight factors is considered ( meaning, everything that is bolt on to the crank are being balanced as well when you're taking materials off) then there should be no difference in the balance of the crank itself.

stan

 

You are correct, not like I need to tell you that. I already recommend that it's a must to have everything balanced for the new build.