A notable local machine shop in my country offered me a service of removing the counterwheights of the crank shaft and then balancing everything including the oil pump, flywheel, PP, timing belt gear, pulley and counterweighting the rods and pistons.

Is this good for all motor?? he says hes done it to many cars that are even daily driven with no problems what so ever. I know that one guy with a 1.6l 8V sohc FIAT has it and the engine flys and does road racing.

I mean, are the reliability risks and making the car more of a pain in the as to drive, worth it??

I guess that with a lightened flywheel and an N1 pulley the throttle response must be brutal and so must be aceleration which means a faster car (not more HP)

LMK what you guys think

 

THe counterweights mainly help keep the crank stable at high rpms. It is also used in the factory balancing procedure.

IF you have it rebalanced with the rest of the rotating assembly then your only jeopardizing structural integrity for slightly improved throttle response. :-)

 

how much will structural integrity be jeopardized?? has anybody one it and had problems with it?? If hes done it on non forged cranks and they have lasted road racing im guessing a forged honda crank will do the same if not more right??
I plan to spin to 8.5K rpm

 

It will be fine once it is balanced. I had it done to my ITR crank and I see occasional revs in the 9500 rpm range. It is all preference really.

 

do you like how the engine feels and drives without them?? is there any difference in daily drivability without them??

My car is my daily and Id like to build an LS/vtec with as much usable power as possible. I dont know if removing the counterwheights is too much for a daily driver

 

No it is totally fine. Just helps get me into the sweet spot of the powerband that much quicker. This mod won't net you more power but it will help you get to where your making power more quickly.

 

does anyone have a pic of this done to a crank? I am just curious.

 

your rpms will also decrease faster...plus at high rpm's.those pistons and rods are gonna wanna come thru the top of your motor.because there is no weight to bring them back down.

i was going to do the same thing on my deck plated h motor....but after talking to some dirt track guys and some crank manfs.for a daily driver they flat out said no.they also said that it will wear your mains out also.which does make since.


harv

 

I would tell you to run from this machinst as far as you can. I think the guy is just goofing on you. You cannot balance an oil pump, pressure plates are already balanced, timing belt gear...be serious, counterweighting pistons and rods...impossible. Cutting the counter weights off the crank completely would probably ruin the crank and I doubt the engine could even idle.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jetpilot &raquo;</TD></TR><TR><TD CLASS="quote">removing the counterwheights of the crank shaft </TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jetpilot &raquo;</TD></TR><TR><TD CLASS="quote">counterweighting the rods and pistons</TD></TR></TABLE>

So he's going to put the counterweights back on the crank?? That's what they're there for, to counterweight the mass of the rods and pistons. I agree with earl, tell him thanks but no thanks, and run. It sounds like spun bearing city.

 

could it work for a drag car? I am building a drag car not a daily driver. Has anyone actually done this and could they please post pics?

 

Are you guys talking about cutting or removing the counterweights completely or knife-edging and lightening the crank. I have never heard of removing counterweights for more performance--if that was the case why do higher performance motors have 8 counterweights as oppsosed to some of the economy motors which have 4?(talking about 4 cyl here)

 

This is what I am wondering too.

 

As has already been said a heavier crank is more stable at high rpm.Use a light flywheel instead if you want the quicker reving engine.Type R's don't have a heavier crank for emissions of better fuel mileage.
Glenn

 

Think about a engine trying to operate without almost any internal rotational inertia....I don't think so. The few pics I have seen of F1 internals still have freaking couterweights. This has to be a miscommunication regarding knife edging....

 

bump for answers

 

i do not think it would have any problems idleing like earl suggested.but for a daily the answer is hell no.i am telling you that it will wear your mains out so fast.i know alot of people that are into racing.but i will tell you where your real answers are.the guys who race dirt track.almost all of them do it.but they only go in circles....not drive everywhere.


the good......your motor will rev. like a dam motor cycle.

the bad..... by by mains and your revs. will fall quicker also."just have to learn how to shift faster".

harv

 

F1 cars don't have counterweights on their cranks, but they spin to 20,000 rpm's!!!

 

do you drive a f1 car everyday....

 

Ok, I was a bit missinformed on some stuff, heres how it is

The counterwheights are CHOPPED off completely and then the PP, flywheel, crank, timing belt gear, damper pulley and all bolts are balanced as one piece (everything bolted up together).

I didnt do this on my build, just had them balance the whole thing but no cutting on the counterwheights.

They have done this to many cars and the only one I really know personally is a road race FIAT selecta with a 1.6L 8V SOHC that I have to tell you guys SCREAMS and holds up race after race with no rebuilds THAT I KNOW OF (maybe they do but Im not really sure). Mind you its not drag racing its road racing

EDIT: I forgot the pistons and rods are not counterwheighted they are just balanced (making all rods and all pistons separately wheigh the same).

And the oil pump gear is not balanced, sorry about that

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1700anddroping &raquo;</TD></TR><TR><TD CLASS="quote">do you drive a f1 car everyday.... </TD></TR></TABLE>

I'll tell you what, I would if i could
I sure could get to work a whole lot faster.
I just threw that out there.

 

yeah it would be nice to drive something like that.you would be def. in a matter of minutes..he he?

harv