POWER ADDING crank balancing
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- čas přidán 25. 03. 2022
- In this , PowerTec 10, episode 51, part 2, DV tells how to balance a crank for smother running, more power and greater reliability.
Many racers are unaware of these moves and they can make the difference between winning and not winning. - Auta a dopravní prostředky
Excellent Mr. Vizard. When I was building Race " car " Engines, someone bought me parts machined another shop. They wanted me to assemble and dyno. Several RED FLAGS were set, but the biggest red flag was tungsten installed VERTICALLY into the counterweight. Basically drilled a hole, dropped in the tungsten, and welded up the hole on top. I was polite, but kindly asked him to take it somewhere else for assembly.
Of course he called me every name in the book and a few other made up curse words.
Long story short, the engine was assembled by a competitor, and scattered on the dyno. Nothing was salvageable except for 1 cylinder head and the induction system.
I enjoy all your videos, I detail a lot of my cranks and do things the other guys don't do and they still say all my little tricks are time wasting but they still can't see why my motors are reliable and win 😊 thanks for sharing your vast knowledge with us all
David you are the best, you know what you are talking about no BS, but it has certainly cost you a lot of time and money to acquire all this knowledge, and is so kind to share your knowledge to us.
This Guy is A legend..Good work David..Thank you...
Loved the video, I was lucky enough to design a crank for a nissan l20b and have it made on a CNC machine. It was something like 4 kg lighter than the stock forged crank. I had the big ends reduced in size to a standard used in nascar (48mm I think) and took 4mm out of the stroke. It had gun drilled big ends too. After the rotating assembly was complete it was 6kg at least lighter than the stock including the flywheel and clutch. We also reduced the moment of inertia hugely. Just running in the engine and I didn't think it would idle to well given the head and cam and reduced mass but it runs like a clock. It feels so strong through the mid range its ridiculous!
Dont forget lady's and gentlemen Mr.Vizard is attempting to do this sort of thing full time. So... if you can. Please donate to the cause. I sure wish I could so instead I'll just leave this comment for now. Sorry Dave brighter days ahead I hope. For the both of us.
Great vid, well done.
🔔😎
I've wondered about this over the years. I've done balancing in the race engine shop.
YOU Sir, are a genius. I am in awe of your expertise.
Thank you so much for sharing your knowledge.👍👍
Ray - - I'm not sure I can agree with the genius label but thanks a bunch anyway.
DV
Thank you ..I have been waiting for #2 crank clip ...very informational Thanks again David
I have A 598 big block chevrolet, The machine work was done by Bob Lane 5 or 6 years ago. I had a stroke 2 years ago but I haven't been able to put the thing back together. I have every part that goes together set up inboxes King Coded bearings, lunati cam.I had the head stolen from me when I have my stroke. Keep up the good work.
Hope you get to feeling better. My wife had a mild stroke 3 weeks ago and is doing ok so far an the hopes that her right side she gets her feeling back. But there is one thing I just hate an that is a thief and hope you can find your heads or head for your engine bud an you can enjoy the moment you start it up an can drive your car. Hope things get better soon for you stay safe an God bless. 🙏🙏
What heads where you using - if you are missing just one I may have a second single here at my shop.
Love that big pointer you use 😆. I’ve learned quite a bit from your books and videos, over the last few years. Thanks for sharing your knowledge...
Excellent information shared, as always. thank you so much sir.
Great video David. Thanks very much. Regards Greg
Thank you DV.
Very interesting material. Ive been contemplating possibly effective methods to remove weight type counterbalance assemblys from single cylinder engines that Im modifying for various recreational uses so the information that you provided concerning the best locations to add weight and where its most effective was just what I was looking to learn about. In my situation there are add on brass plates which may be attached to the crankshaft counterweights but I wondered if a better solution existed. Unfortunately in this case there are no strong ultra light con rods and pistons available. Of course with only one cylinder there isnt an adjoining cylinder to help counteract vibrations etc. Thank you for the great content
Great Video, Crank weight and the flywheel weight too are a big player in how hard the car comes off the corner, even on a street car it can have a big influence....
This vid makes me feel good as the shop I had do my work did as you instructed and my rotating weight has dropped 115g
Lovely job mate
THANKS DAVID
Brilliant!
Great inside into crankshafts.
"Ignore", Marvin 😉. Your engine building credentials are stellar. Spelling, ehhhh...
Would it be OK to totally agree with this???
Thanks for video!
Interesting, I wish I would have know this when I was racing.
Hello David, man you really put tech in the word technology, I really liked this video very much we've all seen everything about cylinder head porting and flow characteristics from many online videos but not too many if not anyone explained it to the fullest, I have done the knife edging on my crankshaft as you mentioned and some drilling with have to be done on the final balance of the total weight of the rods and pistons so that's my race engine. I have a backup crankshaft that came out of a motor and it has Mallory weights tig welded in the ends of the counter weights and it was a small journal SBC 302 with TRW pistons and stock small journal rods, I found it strange to see the Mallory in the crank and it nearly weighs as much as a big block crank now I'm not sure if this crank would be good for drag racing, most of my friends would just ad a big balancer on the 302s and 327s and call it a day would this crank be worth using?
Thank you sir for sharing stay safe guys
Thanks for sharing.
Interesting Info.
A lighter rotating assembly will improve throttle response. Throttle response doesn't show up on a dyno, but will show on the track.
Thank you for another informative video with a great explanation, it all makes good sense. On another YT channel a Cosworth 4 cylinder crank was knife edged obviously losing considerable mass from the counterbalances at the most influential diameter, they balanced the crank by itself. It struck me that the bending moments on the crank either side of each main bearing would be increased.
ANY CHANCE OF A LINK???
DV
@@marvingvx1 czcams.com/video/gXl6eezld9k/video.html
The crank was knife edged in another video on the same channel, I was just curious about the trade-offs, presumably windage and inertia are reduced but at the expense of crank fatigue?
I’d like to know more about balance strategies such as over balancing a crankshaft.
i love the music in the intro
i love this thank you soo much david vizard :oP
I saw a video of some guys balancing a crank, they had to add weight, they drilled nearly a 1" hole not all the way through, then welded a piece of tig rod across it. And filled it with lead, it was a motor cycle crank. They went with a piston about 1/2" larger, so they needed weight, when the lead cooled, they hammered it flat, then ground it flush, until it oxidized it looked stock, it was a poor Asian country I think, they didn't speak English, so I just watched the video, it's very interesting the things they make work!
It's amazing how you can put something in terms that are easier to understand than mechanics instruction/ technical manuals can. And beyond that to see things others didn't !! AGAIN! ( This is one of many topics that you have talked about that I've seen others discuss and I have read about, that "no one else saw!?"-- Until after you pointed it out) [ I was trained to; and have balanced Centrifical water pumps & steam turbine impellers ! ] Respectfully Kurt.
PS. Did you get a chance to read my 'LATE' response to your query about Cadillac B.B. Engines ? ( I posted it after my original post on the topic in "Comment's" on EP45 ? )
Thank's Sir
Very interesting. Thank you for sharing your knowledge. I always look forward to your videos.
I am very interested in the Dodge magnum series heads and would like to know how to deal with the roof of the intake port as it is very narrow and looks to be very restrictive. Thanks
I was thinking on the dyno deal it may not register as a hp gain but it might show as a faster sweep rate,
Hello Mr. David Vizard, could you explain how lightening the counterweights affects, do we lose torque? vibrates? And with the flywheel, if we remove weight, how does it affect the engine?
I am planning a video on rotting mass with drag strip results to make the point. Lok out for it down the road.
DV
@@marvingvx1 Hello Mr. David Vizard, I will be attentive to the channel to see that explanation, thank you very much.
Always great info. I have emailed you about attending the next seminar. Could you let me know when that is?
Thanks a lot...please a picture of the centerline hole....
Perhaps by drilling out the "big end" reduces the weight that the crank web from main bearing to "big end" bearing has to cope with... so with the reduction in weight makes the web effectively stronger as it has less weight to support the spinning "big end" and thus some the forces involved???? maybe perhaps?? my guess anyway!
Thanks DV, this short vid has come at an ideal time for me. I've got a new forged 4340 crank which is heavier than my stock crank so I'd like to loose 1.5~2kgs which is bit for a 4 cyl. Also, you mention there's HP to be gained with loosing weight. But what happpens to torque? Does it change?
Thank you so much for sharing :)
If you do a static balance you include the bob weight with the weight of the rings installed on the pistons.
That's why a 6 inch rod 383 will our run a 5.7 rod engine with everything else the same because you moved the wrist pin higher up on the piston. Its a balancing act.
The stock engine is designed for low rpm, start it up, putter to the store for a loaf of bread and a gallon of milk and come home.
In this application you want more weight to balance out the harmonic of the ignition cycles.
In a racecar its idle or full wide open and you don't care how much shake it has or how rough the ride.
60 years ago it was a common occurrence for the harmonic balancer to fall apart from the shake of the big block Chevrolet and the balancer weighed a ton and the flywheel was probably 50+ lbs. Now you can drive the transmission with a small drive hub and a balancer that weighs a couple of lbs.
Thank you David for all the that you do for all hot Riders on a budget my question is do you need to have a crankshaft balanced after you take all the metal off of it and all the metal off the rod like you showed in the first part of the crankshaft Android video you showed especially on a externally balanced engine I'm building a externally balanced 86 model 305 and it's virtually the same crying same type of rods that is in all small block Chevrolet but I'm not sure if you take all that metal off the crank and the rods will it need to be rebalanced I'm guessing that it will but if I do all of that and take it to a reputable machine shop they're going to laugh at me
100% correct. Caĺlies 46 lbs forged Crankshaft will increase hp by about 50 ft lbs in a 500 hp engine and will spin faster so a dirt track car wit😂the right tire compound will out run a better car with a bigger engine and a crappy tire.
Big late model race 2400 lbs late model and my 3200 lbs street stock was running 7th in a 26 car field with used tires, steel wheel and tubes in the tires. With a wore out stock 400 sbc and cast iron double hump 194 heads and a cut down crank.
I think I had the stock cast crank cut down to 36 lbs... The bottom end has to be stout but all of the horsepower comes from the heads, intake and carburetor. And you must maintain proper valve and ignition timing.
Jesel belt drive makes a big difference.
👍👍👍
Looking for information on the BSA A65 crankshaft. Specifically the purpose of the massive Bolton flywheel. And why it is so heavy
Does Rod length make a difference in balancing (Bob weight) if the rod weight and rod small end and big end weigh the same as the 'original' different length rod????
Is it possible to drill the big end journals safely on a split journal crank? (Like the GM V6 L67)
Mr. Vizard, could you please explain the advantage if any,of painting the crankshaft. Thank you in advance
why dose drilling out the crank creates more strength? because it produces more "Surface Area". like a thin-walled tube is stronger than a small OD rod of the same weight.
I learned that in 7th grade metal shop in the mid 70s
Holley has some April fools stuff you need to test on CZcams! Skyram and moonshot.
Knife edge or rounded on the bob weights
Engines operating over 7000 rpm can benefit from a 3% over balance (adding 3% to the reciprocating number in the bobweight)
My! We used that division of weight principle on bubble wheel balancers when the computer balancers couldn't get it right on one point.
Could you then change an externally balanced engine to internal balance with a neutral flywheel and damper using these principles?
Yes I hate external balance deals so I try to rid them from my life one way or other.
DV
So hate to ask BUT how much does it cost to do something like this? Also! Dose anyone know how to do this stuff? I really can’t see the shop up here doing this. Good stuff like all ways.
my Biland sa250 is a 13000rpm 180 twin 4stk
forged. any thoughts Dave on littening this.
Hello David what are your thoughts on putting a hole in the con rod opposite the cap but close to bearing surface ? Thanks so Much for your help !
This channel is dead for now, find his other channel here: www.youtube.com/@DavidVizard
Less weight equals faster revs which in turn equals faster acceleration. Just my two cents.
Thank you -
What about an engine with 3 bearings, such as a Volkswagen flat 4?
Easiest crank to balance in the world for a 4 pot motor.
DV
Hi everybody! Do I understand correctly. Each counterweight balances the weight of its connecting rod bearing (crankshaft journal + connecting rod with connecting rod cap + bearings). Thus, if we reduce the counterweight, then we must reduce the weight of the connecting rod bearing by the same amount. Is this correct or am I wrong?
👍💪
Good info but cost effective and more practical thing to do is just buy a quality aftermarket crankshaft like callies,scat,lunati,ect.
Scat Crankshaft are junk, put it on a Crankshaft grinder and you will discover that the throw doesn't match because the clock position is off from one to the next by more than several degrees. If you have to grind a new Crankshaft and reward the throw to correct it, you end up with the oil passage being in the wrong place
Mr. Vizard. Is it possible to accurately determine cranks throw weights by using a homemade pin jig, or in a laith, to center it, and then use bubble balancers almost like an old tire balancer? Also, on a" V " style engine. with journals sharing rod and piston weight, next to a single journal. do you need to take more metal from the throw weight that is outside the shared journal? such as the front then second throw weights on a GM V8. If that makes sense..... I guess what I am basically asking is. Are there any older methods of balancing a crank that does not need expensive tooling, that one could do at home in a small Forge or workshop. I am very intrigued by the vintage race cars of the 20's and 30's. such as the Bugatti's, Almicar's, Harry miller, and other fairly high revving cars of the day. and wonder how they were doing this. Thank you. Love your books, and videos. Thanks you. Tom B. from ND.
I have the same question .
David, would you possibly do a video on turbochargers, turbine sizing,overlap and exhaust valve opening to suit the application.
Yes please
He probably cant
@@sexyfacenation if he can't it's not because he lacks the knowledge to.
@@davidreed6070 what makes him a turbo guru?
@@sexyfacenation back in England years ago it is said he did a lot of research and development for manufacturers. He has written a lot. What he writes is research he has done. I have read and followed through with his knowledge for about 40 years. I have never disagreed with what he says.
Do you know when you next live stream is going to be?
yes!
So is it good or bad to take weight off the crankshaft? After 19:01 minutes of video I did not find out
It's all explained at 19:02 😁
From what I understood you can gain a bit of power, and you can actually make the crank stronger.
Yes it is good. It won't make any more power measured at a steady state, but it frees up power as it accelerates to that steady state.
do you think indexing the crank is worth the money? great work as allways
yes, if you are racing
If you have writers block, I'd like to see your work on 4 valve cylinder heads.
I agree, also, I wouldn't mind 3V or 5V engines.
When you balance a straight six, do you use bobweights? I'we heard both yes and no..
I used to do all the balancing in a race engine shop.
Only V engines are bob weighted. Opposed and inlines NO.
But I'm not sure about an inline 3 or 5. Never balanced one.🤔
David, are you advising us to attempt to balance our own cranks by drilling the big ends and grinding the counterweights? Or is this really meant for the machinist in the balancing shop?
Mr Jeffry sir, I am just informing you what needs to b e done. I have balanced several cranks the ways shown here but I had access to a balancer. The first balancer I used was home made but we only did 4 cylinder engines as in Mini's.
DV
How does drilling a hole in the crankpin "increase" the strength of the crankshaft?
I just was going to post why above! it's because drilling it out creates more "Surface Area". like a thin-walled tube is stronger than a small OD rod.
It's because you lose the fulcrum point of a solid mass when the crank flexes.
What do you know about balancing a crank at 52%? Thanks...
This channel is dead for now, find his other channel here: www.youtube.com/@DavidVizard
Thank thy Crank. Ignor(E) no more...
Daves way of spelling is the light weight hot rod version,
Hey DV, this is a little off topic but are you going to do some video´s on import/4-6cyl/DOHC type of stuff? Not that all the v8 stuff is interesting but not all of us are gonna stuff a v8 in our race car.
All though this video would also work for that type of stuff.
DV did a 2.2 dodge head a few vids ago.
Yes he did develop few 4s and six heads, but his proven theory applies to all port to bore volume
Yes but there is only me and Andy and Marvin and Dave McLain and Sean and Mervin and uh ---- you know we should be able to get to that with that kind of man power - shouldn't we???
I Want to play with a 53 ford flattie v8 crank...all shops are booked for a year and i want to do as much as i can on my own ....how much can i do not to ruin it for ballancing ?
That's tough. You're also likely stuck with 3 main bearings which complicates things. You need to not do anything that lessens that crankshaft's stiffness, as it's quite literally very unsupported.
@@life_of_riley88 Thanks ..u r correct about the 3 main issue...i want to know if drilling the inside of the rod journals would help or hurt strength
I think you can weigh your rotating parts, rod big end, rod small end, and note them down. You could send that data and crank to a specialist, then have it sent back.
Hey David, do you talk to Tom Monroe or Larry Scheib?
Last spoke to Tom about 1980 and Larry about early 2000's when we met up at some show like SEMA.
DV
I recognize that all of this appears to be about maximum power but wonder if it benefits low or mid range torque. Would that require a whole different approach?
This channel is dead for now, find his other channel here: www.youtube.com/@DavidVizard
You are removing weight from the reciprocating mass. This is why Nascar racecar uses a carbon fiber drive shafts and lightweight wheels and gun drill the shafts in the transmission and the drive axle.. 5.3 Chevrolet 4L65E will out run a 6 liter engine because the 6.0 has the 4L85E transmission with a torque converter that weighed 40 lbs more. Having to waste energy trying to spin all the extra weight robs hp..
You said in your book that balancing is a waste for street cars. Make up your mind.
😀
Hello Mr. Vialzard, I am new to the channel, and I have learned so much from the channel aready. I run in a factory dirt class of ford 4 cylinders Lima motors. Ford 2.3 sohc rules are suppose to be either hydraulic or solid lifters, and stock intakes. The big money guys run illegal esslinger raceing heads. which us poor guys cannot afford, and they have no competition. Have you done a video that would relate to the 2.3 sohc? Is the mini or pinto motor, talked about in seminar video, similar enough to it, if know. Or can you do a video about them if have time. Thank you sir.
Sorry miss spelled you name typing error. Thank you
Have you talked to Esslinger about air flowing and porting your head? I built a nice 2.3 L street engine decades ago
Has there ever been a machine that would measure the balance of the rotating assembly while it is mounted and spinning in the engine it is going in?
you can measure the vibration of a machine, lots of technology on vibration analysis
@@blueyhis.zarsoff1147 I was thinking more on the lines of using the engine it's self as the balancing jig outside of the car. and spinning it with an electric motor. This way you are checking the actual balance of the real parts at any giving rpm for different harmonics. but how would you measure " per journal " the imbalance?
I have also seen the way some folks balance single and dual piston motorcycle cranks. by using the actual rods and pistons. then laying them on a parallel bar frame. this is close to the way i have balanced old grinding wheels at my blacksmith shop.
@@tombrown879 were they 2 stroke bike engines, thats a whole different thing.
@@blueyhis.zarsoff1147 no. Four strokes.
Does this work with diesel engines?
No
hmmm. I believe ( many years ago) "somebody" from the Brooklyn Dodgers had a similar comment.- He said- "Less is more". Kind of like "addition through subtraction" To be clear. I am not suggesting you are from Brooklyn. Nor am I suggesting that you are trying to confuse anyone. I am, however, suggesting this video may be a little confusing to many people. Please do not confuse these statements with anything Casey Stengel may have said. Warren Spahn said "I played for Casey before and after he was a great manger". Sadly, this simply adds to the confusion surrounding the word "balancing". However, In summary I must say- on balance this is a great video. The REAL problem? Getting someone to do work like this. Did you know the Brooklyn Dodgers played on a field of metaphors?
Lol. Omg. Gm has been doing this for years.... Look at a 305 vs. 350 crank. A 305 has less, is flat horizontally in relationship to the rod journal. However, a 350 actually has a bell shape, vertically in relationship to the rod journal.
More easily explained, if you set the crank on a bench like it was installed, you could place a straight edge on the counterweight a 350 would lay parallel on the counterweight edge. A 305 would fall off, as there is no flat or parallel edge.
Hello Mr. David Vizard, I have another interesting question, how does the disposition of the crankshaft counterweight affect, having the same mass, but closer or farther from the crankshaft axis?
Thanks
Best regards
High School physics was a long time ago, but I remember that it took up more energy to spin up a gyroscope which has the majority of it's mass at the outside edge than having it's mass evenly spread. Think of a bicycle tire vs a disk. The reason that gyroscopes have so much of their mass at the outside edge is to they retain their momentum and take longer to spin down. I am probably not describing this very well. You probably want to look up gyroscope videos. You really want to look up *rotational inertia* or *moment of inertia* here on youtube.
I cannot hear this
You really need to sort out the audio, it can't be all in one ear when talking
Great. but most racing crankshafts are balanced by adding weight
Whether weight is added or subtracted is dependent upon the bob weight...a blanket statement saying most are balanced by adding weight is not correct.
fk im too drunk right now but ill save and be back tomorrow
Are the spelling mistakes intentional?
No - just don't spel 2 goood
That makes me think that maybe they are.
Sorry about that they're going to laugh at me about all the metal that I've taken off of the rods and the crankshaft and probably not want to balance it
Hello,
Our company would like to invite you to try our products, how can I get in touch with you?
Ignore is spelled with an E on the end.
Not if u use ur imagineation
Yes but I choose to ignor that!!!
Dayvid Vizard!!
You'd have more credibility if you could spell.
DV has had brain surgery. He has admitted to a spelling deficiency many times before. You'd probably have better luck with some of this if you read his books. I find only excellent editing and no spelling errors in his many literary offerings. You'd also have more credibility if you had say a winning racing career, a long history of motorsports journalism, a CZcams channel, a porting school, and an open mind.
DV surely does not need to feel more credible to you, and those of us who follow him do not share your stupid way of thinking. Just seek knowledge somewhere else.
Because spelling matters in racing 🙄
It's an old bloke talking about stuff. Take it or leave it.
Credibility with who that matters?
Thank you Sir