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Author Topic:   Harmonic Balancer
tazracer
Dirt Roller

Total posts: 6
posted April 08, 2003 03:02 PM
I'm running a sbc ,what size balancer would be best? I'll be turning about 5800rpms on a 5/8mi. track.

mod4
Dirt Full Roller

Total posts: 64
posted April 08, 2003 07:28 PM
5800rpm on a 5/8's ?
Don't run a balancer at all. Run an aluminum spacer.
Change the bearings every 10 nights, if you have a decent balance job.

sdhnc29
Dirt Freak

Total posts: 467
posted April 08, 2003 10:33 PM
WHAT ???? This advise makes no sence at all !!

tazracer ,

Sounds like your running a stock type engine . If it's in you budget , buy a good aftermarket balancer , at least a 6.250" . If not , then any of the internal balanced SBC balancer's will work ok for you .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

mod4
Dirt Full Roller

Total posts: 64
posted April 09, 2003 10:35 AM
Sorry, wasn't trying to be an idiot ... years and years ago running Hobby Stock we felt we gained something by losing the balancer. I guess either I was wrong or it's not worth the hassle.

I certainly would listen to Steve before me.

66jj
Dirt Freak

Total posts: 352
posted April 09, 2003 05:11 PM
STEVE what do you think of running a hub only, i tried it. knocking the ring of a stock one.

i had one balanced with my last motor to try, but IT gave a un nerving vibration feeling .. only did a couple laps.

supposedly WOO run no balancer right??

as for what balancer to buy id buy a sfi that competition products sells for 130.00 5.5 lbs degreed, and 5.75 i think. made by pioneer i think.

tazracer
Dirt Roller

Total posts: 6
posted April 09, 2003 05:23 PM
quote:
Originally posted by tazracer:
I'm running a sbc ,what size balancer would be best? I'll be turning about 5800rpms on a 5/8mi. track.

Thanks guys, you make life alot smoother when it comes to running on a budget.

JMillerJr76
Dirt Full Roller

Total posts: 62
posted April 09, 2003 09:38 PM
Yea, but you got to realize that the WoO guys run like 3 or 4 nites on a motor, not 3 or 4 months. I have seen guys running prostocks here in OKC, that didnt have balancers, just hubs, and some nites they run up front, and some at the back. I have aslo seen quite a few of them blow the bottom end smooth out of the motor due to...a bearing failing. I would personally run some type of balancer, even if it was a stock unit

sdhnc29
Dirt Freak

Total posts: 467
posted April 09, 2003 11:02 PM
JMillerJr76 took the word's right out of my mouth .

Without a balancer , the bearing wear is a problem , but what you will see mostly is broken cranks , main cap's , and broken main web's . Pretty much any engine that must have any type of endurance need's a balancer . I've had two engines in my shop this season from new customer's , that had been run with only a front hub like your speaking about 66jj . One engine had a cracked crank and a cracked front main cap , and the other engine had the front two main web's cracked . I think it's a case of what is most important to the average guy . Personally I would rather have a damper on my engine , even if it weighed 25lb's (extreme example), than to have to replace my crank and block . The minimal amount of instant RPM gain from just running a hub or no balancer , is just that .... minimal . And it will not make the difference between winning and losing 99.99999% of the time .

BTW , no offence intended mod4 . I've seen some of your post's , and they have had good info .

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

racer17j
Dirt Forum Champ
Total posts: 1565
posted April 10, 2003 07:47 AM UIN: 54865418
we had a post about this a while back and if i rember right the sprinters that don't run them use the water pump as type for fluid damper not exactly sure of the setup just rember reading it on here

mod4
Dirt Full Roller

Total posts: 64
posted April 10, 2003 09:55 AM
Yup they do. I'm running a 360 Sprint this season and the water pump mounted on the crank is "supposed to dampen the harmonics".
I have zero clue if it really works, these Sprints are weird. Thank goodess I just push the pedals and turn the wheel.
It was a hoot at the first race pulling up next to the $300,000 tow rigs with my open trailer and pickup truck tho

66jj
Dirt Freak

Total posts: 352
posted April 10, 2003 05:10 PM
STEVE thanks, i agree with you thats why i only tried it once.

i didnt mention that i was no faster whatsoever with it that way. the track let me time in twice that night for a test.

ive done this same test with stock 37 lb clutch *** . versus a 3 disk of 13 lbs. again no faster.

STEVE HERES ANOTHER ONE to open a new can or worms. i dont like fluidampeners, i believe they are ok for drag cars but not stop and go circle track cars. i had bought 3 for all my motors, but lost some bearings and attributed it to them.

seems to me that when you let of the gas, the fluid doesnt slow the same as the motor so somewhere along there upon excelleration, it probably catches up but must mess with your balance job.

seems like i remember 10 yrs ago when they first came out everyone said they were junk, seems like good advertising to me.

i have seen some on some seriously expensive motors as per the builders instructions.

THANKS JEFF

outlawstock17
Dirt Forum Champ
Total posts: 620
posted April 10, 2003 09:45 PM
66jj, i agree. my experiences seem to indicate that the light clutch doesn't help lap times much. re-starts is where the light stuff has a big advantage. if you can jump a guy by 4 car lengths on a restart, it's worth it to have the mini-clutch.

sdhnc29
Dirt Freak

Total posts: 467
posted April 10, 2003 11:14 PM
Several year's ago , we used the Fluidamper's quite a bit , as did a lot of other engine builder's . I can not actually say if they extended the crank life on the 4340 crank's or not . According to testing that I received from different Cup team's a few year's back , the Fluidamper ranked pretty low in their test's . Pretty much everyone , including us , have now switched to the ATI damper . Once again , I have to trust the Cup guy's multi-million dollar R&D program's to be correct in finding the best part . I think the Fluidamper has it's place , but probably not in endurance type engines .

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

towmandan
Dirt Maniac

Total posts: 110
posted April 11, 2003 10:10 AM
Mod4 is the only one I remember using the term that comes to mind and that is harmonic balancer and harmonic vibration I dont care how good your balance job , metal will fatigue with extreme harmonics....Buy a good balancer.....towman

Fast132
Dirt Full Roller

Total posts: 27
posted April 12, 2003 12:00 AM
Okay, so would you consider running a KSE sprintcar type water pump "balancer" on a mod? Advanage?? Major disadvantages?
Besides the fact that sprints can't stop and go while running, there radiators are half the size of my mod and run no fan at all. They're basically the same engine as my mod, so why do we hang all the traditional stuff on the front of a mod? I started running a sprint this year along with the modified and I keep wondering.
Fast132

mod4
Dirt Full Roller

Total posts: 64
posted April 12, 2003 11:51 AM
Fast132 you're off subject Heh. Just kidding y'all, he and I race with / against each other in both the Sprints and the Mods.

Sprints are gonna run cooler because of the fuel injection,(I think) and if you put one of those SprintCar waterpumps on your Mod, I am gonna complain, complain, complain.
Or maybe do the same thing.

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