Crankshaft Oil Hole Chamfering

[rahs98991]

I did this to my Ford engine it turns over 8 grand on the tach all day long at the track Ive got over 50 runs on the engine it still carries 80 psi oil pressure at idle havent had one failure . So you that have doubts dont knock it till you try it . I wouldnt build another engine without doing this

[OGsteezy]

CHAMFERT

[U3erpru7ser]

Does this affect the oil pressure in any way?

[4g63justin]

How does this not cause a stress riser and cause a failure on the crank.

[TheWorldGatekeeper]

my Crankshaft spin faster,

[ibraaaheeem86]

Sorry but this is stupit . If u wanna make oil runs good at 9000 rbm u should change the oil bomper as well . The holes u gives lower pressure for the.oil in crankshift .

[rwdford]

I use a small carbide burr to do this, using a smooth tear dropped shape with grinding on one side only, btw you have the main bearing "oil chamfer" facing in the right direction but the big end chamfers need to face the other direction, think about it, the crank turns clockwise but the big ends turn anti clockwise, you want to scoop oil into the mains which you got right, and then the big ends should draw oil out from the mains

[JoeSwagon]

@rwdford thats completely wrong. the crank spins in the block CW. his work is right. the rod spins CCW on the crank. his work is still right. the chamfering trails the direction of rotation

[rwdford]

@JoeSwagon

Lol take a few minutes to figure this out, what I said is 100% true, you are wrong about the big ends, the chamfer on the big ends should be facing the opposite direction to draw oil out of the big end oil supply holes.........................­.............

[ted850760]

@rwdford draw oil out? the oils preasurized

[rwdford]

@ted850760

Yes the oil is pressure fed, but machining tear drop shape oil grooves into the big ends on the trailing side of the oil supply hole will help draw oil out of the channel from the big ends, (this is the whole point of tear dropping the crank) I also do this with competition gearboxes that are not pressure fed and it easily draws oil into the gears due to a small suction effect when spinning fast, we have noticed a massive reduction in main shaft to gear wear with this modification

[augustoescobar50]

Chamfering is a standard procedure for high rpm and hi performance applications. Just because he decided to do it with a grinder as opposed to a mill or machine of some type does not affect it in a negative way at all. If it did affect the longevity or cause damage, i'm sure he would'nt be in buisness for that long! Chamfering the oil holes is cheap insurance and mandatory at that high of RPM period. These negative comments make the people posting look like idiots!

[jayguy173]

@augustoescobar50 once the bearings are on the rods it wont matter just let more oil stay behind

[AntDX316]

@augustoescobar50 why isn't all crankshafts chamfered?

[ericsbruteforce08]

can i cut the some weight off a crank for racing ???

its a 400ex atv ...

[ginnnga]

wow that looks professional :|

[KXrhyder547]

How dose this method compare to a machined chamfer ? any preferences or benefits of one vs. the other?

[ccexped]

someone paid for this?? id pay not to have it done!!

[fiatnutz]

@ccexped - Please send my your money.

[flipmodeOptimus]

@ccexped really??? if your pushing 9k revs you dont want the oil to ease into the mains!??

[5150jafo]

@ccexped...

Stay away from motors then.

[syncerrornot2per]

Nothing to cringe about. It's a standard issue procedure. 

[bddc201]

Cringed when I saw this.

[testbooster]

Could someone explain to me the interface between the Oil pump and how the oil gets into the crank shaft. I can't find a straight answer on the Web.

[haleford48]

@testbooster oil travels under pressure to the main bearings via passages within the engine block,called galleries,then 'floats' the crankshaft on a microfilm of oil that the passages within the crankshaft main journal pickup and by the combination of pressure and centrifugal force,send it to the rod journals.chamfering these 'holes' or passages help increase the volume of oil picked up,or scavenged at high r.p.m.

[rabidu2b]

Would it be better to leave a leading notch in the mains and a trailing notch in the rods?

[rwdford]

@rabidu2b

You hit the nail on the head there, that is how I always do it and it is by far the best way

[rabidu2b]

@rwdford Yep, I did my civic crank about 9 months ago and so far the results are positive. I also did many other things such as porting/shim the pump and main bearings and a little larger rod bearing clearance so I can't say the crank mod was it.

[jayguy173]

so would this cause less oil pressure but have more valume

[FJoeForty]

Would it be of any benefit to chamfer the approach side of the lubricant hole, leaving the trailing edge alone? Considering the direction of crank rotation and how the eliptical shape might quench the localized oil as the chamfer moves past the orifice in the crankcase. Is the pocket of localized oil in a chamfered area not just a momentary drop in oil velocity since the crank journal lubrication holes are still the same diameter as the ones in the block?

[TheSaho]

OMG OMG OMG OMG OMG OMG OMG YOU ARE FUCKING RETARD !!!!!!!!!!!!!!!!!!! you fucked up the crankshaft :X:X::X

[ipissed]

ouch looks nasty dude use a milling machine and gouge it out, ive seen the strongest conn rods dead head from hydraulic lock. That means it cant spin anymore your rod turns over on you 90 degrees

[QuattroStig]

@ipissed

I agree. That craftsmanship is terrible. It's much better to pay more for a milled job.

[thek20coupe99]

does this mod have to be done to your crank if your engine is goin to rev over 9,500 revs?or would it definatley cause damage?

[alexspencerx1]

nice work! very very nice idea ,maybe it can be perfectioned.

[quad4midget]

John,

I just did this to mu Quad 4 crank. Question about the crank in the video. Did you mill off the counterweights? was that just to reduce rotating mass? How hard was it to balance afterward?

[fiatnutz]

No additional prep was done to this crank except the polish & chamfer. The c-weights were machined on one side to balance the crank. Apparently the centerline was off to one side. Find my video on crank counterweight knife-edging. That helps with low-speed acceleration.

[MrGuvEuroman]

Never seen that done before John. I've taper drilled them before but I'll try yr method next time. : D must remember that DOR rule you said! : )

[robertopaulinho]

magnific !!!

[citydriver]

freakin genius

[1SICKYJ]

Was that a cast crank if so who would spin it to 9k.

[fiatnutz]

Yeah, it's cast steel - not cast iron, and 9000 is just about right for this vehicle on certain straight aways used in autocross. JE...

[1SICKYJ]

Oh thanks for clearing that up.

[ChevetteMan]

I'm glad you posted this. I'm getting ready to assemble a Chevette racing engine, and didnt want to wait on a machine shop to chamfer the oil holes in the crankshaft. Any recommendations on what type of grinding stone to use? Any certain angle? Thanks - ChevetteMan

[fiatnutz]

I used a 60K rpm Bosch grinder w/pink stones 1/2" (13mm) in diameter. Good luck and let me know how your crank turns out. JE...

[zyou8er]

How much does this modification cost? i was quoted at $300, i think this is the same thing as the guy told me. He said for $300 my bearings would get more oil at higher RPM.

[fiatnutz]

I think for $300 you are paying too much, I charge around $60-$70 for this mod.

[zyou8er]

Thanks, another question. One guy from our car forum stated that his bearings went south by 12k miles, and he thinks its because of chamfering.

Could it be, that the machine shop didnt micro polish the crank after they did this mod? causing the bearing to eat up.

[fiatnutz]

Not if its done correctly, my guess would be dirty assembly.

[materialclassified]

But you're probably replying to someone with the crank installed.

I'm sure your speaking of the crank removed.

Cost of removal and install are more though, right?

[fiatnutz]

Yes, the crank must be removed from the block - cleaning is an essential part of the assembly process,

[materialclassified]

And you do that for $60.00?

You got all my work...lol.

greaty vid..luv 'em.

[dnl5649]

@fiatnutz i built a 400 ford engine that put out around 400 hp at 450 lbs torque and my con rod and main crank bearings were worn to the copper after less than 50 miles. it had plently of oil and the oil pump seems good, do you know what might have gone wrong?

[fiatnutz]

@dnl5649 - Most likely, dirty assembly, or possibly wrong size bearings.

[ericg83z]

@dnl5649 iff you were getting enough oil, 1 could be oversized bearings were used ,2 no lube was applied to the surface of the bearings?

[ted850760]

@ChevetteMan I can't help myself.....Chevette racing engine?????sorry I just never saw those words together