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Author Topic:   Bearing troubles
Hobby152003
Member
posted January 07, 2004 03:41 PM
The last five motors that I have ran all have had bearing trouble. Got a ballanced rotating (383 six inch rods), and spun 5, and 6 bearings. The others were all stock parts. Pink rods in two motors with forged pistons. broke five, and six and you know the rest, destroyed every thing. Put one together with the powder rods, same thing. I got my 383 crank turned and rods sized ran a 15 lap heat, and 40 lap feature seemed to have no problem. Pulled it out to fix a small oil leak in the pan and no. 1 rod had spun. All these motors were with different blocks, and cams. I run a 1/2 mile track, and turn 7000. Parts are breaking the bank. Any suggestions on what could be causing all these problems would be great. Thanks


outlawstock17
Member
posted January 07, 2004 05:37 PM
what are you running for bearing clearances?


Hobby152003
Member
posted January 07, 2004 05:52 PM
.002


orange2mod
Member
posted January 07, 2004 05:56 PM
Make sure the rods are side clearenced ..023 - .025. Gotta get the hot oil out.


rico 08
Member
posted January 07, 2004 06:17 PM
You must have something or are doing something wrong somewhere.I have seen a scat crank do that,it was a little tight everywhere and it would spin the rods.Also check the pan and make sure the gates are welded in the right way(not keeping oil away from the pickup)what 'bout oil?I always run valvoline straight 50 and i've only lost one engine and it wasn't oil related.


dirtrace
unregistered
posted January 07, 2004 08:35 PM           
.002 is the tightest I would ever run, actually I tried that and it didnt work out, lost mains in one race, I wouldnt run .002.

my machinest told me to run no more than straight 30 for oil ever in any motor we built unless it had a ton of wear, or oil pressure started dropping, which even on my cheapest motor with 62 races of 50-100 laps it never did.

we shot for just under .003 clearances.


have you taken a block, crank,and your rods to a diff machinist to have him measure also just to make sure???

I had one motor do the same thing twice, and it was the first motor I took to the most expensive machinest in town, turns out he was expensive to slow down business not because he was any good...


Blackgold
Member
posted January 07, 2004 08:52 PM
this may sound goofy, but make sure you have the rods installed correctly. the bearings will bind up on the bearing journal radius if installed backwards. when setting bearing clearances, i look for .0025-.003 on the mains and .0015-.002 on the rods. side to side clearance should be at least .018"


Raz_900
Member
posted January 08, 2004 08:05 AM
Probably a stupid question, but what bearings are you using? 7000 rpm is kinda high. You DEFINITELY need the H or Z series Clevite, Federal Mogul HP bearings or King HP series bearings. http://www.engineparts.com/motorhead/techstuff/brgselec.html

If you're running a stock type bearing, it's going to peel and spin in a hurry at 7000rpm. **** ... they'll peel at 6000rpm.

.002" on the rods and .0025" on the mains should be ok. .0025" R and .003" M would be good for a little added insurance with a slightly thicker oil (20w50 or 50wt racing). You are using a racing type oil right?


Hobby152003
Member
posted January 08, 2004 08:43 AM
I run .018 to.020 on side clearance. I always have ran castrol 20w50 oil. I know I haven't put any rods in backwards. I built two other motors this year for freinds and they haven't had any problems. One won 10 out of 12 features. They are both running lower classes though. streetstock, and powderpuff. witch they don't turn them as tight as I do.


Raz_900
Member
posted January 08, 2004 12:00 PM
quote:
Originally posted by Raz_900:
...what bearings are you using? 7000 rpm is kinda high. You DEFINITELY need the H or Z series Clevite, Federal Mogul HP bearings or King HP series bearings......

Are they stock replacement bearings? If the bearings are ~$20-$25 a set, they're stock replacement and won't take 7000rpm at all without almost immediate damage.

If they're ~$45-$50 a set, they're the HP bearings and should live.

[This message has been edited by Raz_900 (edited January 08, 2004).]

dirtrace
unregistered
posted January 08, 2004 12:25 PM           
If rods are on backwards he would know, he would have no side clearance at all because the brg is only chamvered on one side.

I quit running "H" brgs in my 6500 rpm motors
only 13-1 with 30 wt oil only, a couple years ago.

You guys running that thick old oil must have some extra hp to burn? or you dont change it?

4340
Member
posted January 08, 2004 01:17 PM
Somewhere i remember reading that bearing clearance should be .001 for every inch of shaft diameter. So on a typical saturday night dirt track 350 that would get you around 0.0025 mains and a hair over 0.002 rods. If anything i would err on the bigger side because if you get too tight there wont be enough oil flow to cool the bearings.



rico 08
Member
posted January 08, 2004 04:58 PM
The thick oil is madatory when using a stock type 4qt oil pan,the aeriation of the thinner oil always caused probems.The only time i didn't use it was when the rules allowed a good pan.BTW I tried castrol 20-50 and after a race it looked like water.Just my opinion...been there done that.


prostock15
Member
posted January 08, 2004 05:41 PM
quote:
Originally posted by prostock15:
i would also check that your carb is not running so fat that it dilutes the oil and your trying to oil your engine with fuel sounds crazy but can happen or if its not that the carb isnt bleeding fuel after you shut the engine off

That reminds me, when I worked at the engine shop, we once had a 454 blow apart 3 times. Couldn't figure out what it was. The guy finally gave up, we gave him his money back and he bought a crate 454. Blew 2 of them up too.

Turned out his fuel pump was bad and dumping fuel into the oil pan. His 3rd crate (6th total) motor stayed together with a new pump.


dirtrace
unregistered
posted January 08, 2004 11:08 PM           

Straight 30w oil looks like dirty water when you pour it in new!!!!!!!!!


It seams thinner than water hot, when its new.


Hobby152003
Member
posted January 09, 2004 10:42 AM
I've been running the stock bearings. I'll get the others. On the oil I (when it makes it through a night of racing) Change it every week. What would you'll recommend runnig besides 20w50.


dirtbuster
Member
posted January 09, 2004 11:05 AM
I think oil temperature comes into play also when talking about what viscosity to use. With a stock pan there is just not enought capacity to keep the oil down to optimum temp and lube the engine so you go to a heavier oil to carry the bearing loads required when it is hot. If you had an oil cooler and a 10 qt pan you could prob run 10w30 and never have problems. Most Winston Cup cars are likely running something like a 5w20 or 5w30 but because they can keep it at optimum temp it can sustain the loads placed on it.

Royal purple 41 is about the same viscoisty as 10w40 and their 21 is more like 5w30 and there are a lot of mods and late models running these oils around the country as well as the big boys. WE tried the 41 this year and yes it is thin and looks like grape kool aid but it does the job. you cant base everything on what it looks like pouring it. Plus a synthetic is always gonna appear thinner than a similar conventional oil. As for convetnional oil we have been using valvoline vr1 race oil to break them in.

dirtracer7
Member
posted January 09, 2004 12:01 PM
I run .0015--.00175 on the rods and .002--- .0025 on the mains.Federal mogual h mains and F.M. p rod bearings 15w40 royal purple going on its 4th season( bearings and rings) replaced yearly.Internals have been checked for cracks and size and reassembled.The motor looked better this year than last year i changed from mobil one to royal purple last year.7000rpms 20+ races a year.Don't care what the oil looks like when I put it in just what it looks like when I cut the filter open.


dirtrace
unregistered
posted January 09, 2004 12:31 PM           
A heavier oil builds more oil temperature.

You are working the pump harder also useing hp.As the thicker oil is squeezed in the pump and brg surfaces it builds more heat. A thinner oil that flows thru a properly clearanced motor will run a lot cooler. More heat breaks down your thick oil anyways.

Synthetics arent able to carry the contaminents in your motor to the filter. So if you get dirt in there or slightly scuff a brg or lifter the contaminents will stay in the motor on the brg surface etc, never making it to the filter.



Raz_900
Member
posted January 09, 2004 01:47 PM
quote:
Originally posted by dirtrace:
....
Synthetics arent able to carry the contaminents in your motor to the filter. So if you get dirt in there or slightly scuff a brg or lifter the contaminents will stay in the motor on the brg surface etc, never making it to the filter.


Hunh? I've heard many old wives tales but that's a new one.

Sounds like something an oil rep would say when their company doesn't have a synth. oil that can compete with RP, Mobil, Redline, Amsoil and the other top synth. oil companies.

Not taking into consideration the fact that 'regular' oils are far FAR more prone to temperature/viscosity breakdown which leads to bearing scuffing.

I'd run 10w40 long before I'd run a straight 30w.



sixwillwin
Member
posted January 09, 2004 03:48 PM
I LOVE these oil discussions.....they are as entertaining as "pinion angle" and "avgas vs. race fuel"......Valvoline Racing 20-50...12 years, 40+ races a year, changed every 2 or 3 nites, never an oil related failure. MULTI viscocity...the best of both worlds. It works for me.....but the thing is...I dont give a rats behind what anybody else uses.


Hobby152003
Member
posted January 09, 2004 04:07 PM
Valvoline 20w50. I heard it was a good oil to run, just haven't tried it. When I get my motor back together I'll try it. Thanks for all the replys, and I will consider everything I see. Keep them coming.


dirtrace
unregistered
posted January 09, 2004 04:32 PM           
raz 900, I take it you dont subscribe to any magazines with tech articles, tests etc.

synth oil has been reviewed quite a few times and ever time the conclusion is not in a race motor because you change the oil often enough anyways. plus its too smooth for lifter rotation, and carrying away garbage etc.

very very old new...

but like everyone else says I dont care either what anyone else does, my motors cold with 30 wt allready have 90-100 psi, and 50-60 hot at 6500 so its worked out just fine for me.

LUBEGUY07
Member
posted January 09, 2004 04:32 PM
i run northland 20w50 oil and wouldnt change to any other after last years teardown 29 races on the motor and bearings look great and everything was clean. I change oil after 4 races or if it ever got hot


dirtracer7
Member
posted January 10, 2004 06:33 AM
If syn oil doesn't carry the contaminates to the filter how do they get there .I see fine particals in my filter.Somebody better tell nascar about seeing how most of them run syn oil.As mentioned before thicker oil creates more heat I think its called shear when the oil rubs against itself.I used val 20w50 race oil and had good results just didn't like or need 90-100 psi cold.And the slow to move when its cold.With the 15w40 I fire it and instant pressure.We all know most damage occurs at start up.If the lifters didn't rotate they would wear quickly I have run the same cam and lifters for 3 years with 394 lb springs and am replacing this year just to try a different cam.Hendron racing engines who visits here recommends mobil 1 or royal purple to there customers and said they run cams and lifters up to 5 years in some motors.I read on here people have worn cams in 1 season.I will change the oil every 3 races and filter every race just so I can cut it open and check motor health.

[This message has been edited by dirtracer7 (edited January 10, 2004).]

Mell00
Member
posted January 10, 2004 08:13 AM
this is true about opions, everybody has one.I called royal purple before i started using there oil.The first thing they told me was to get rid of the 50w oil (I was running 15w50 mobil 1) and that the extra bucks to buy there racing oil wouldn't benefit me to just run there street oil as they called it.I think there is about 3 bucks difference per qt.

[This message has been edited by True Blue (edited January 11, 2004).]

Raz_900
Member
posted January 10, 2004 07:54 PM
The last few posts reflect my feelings on syn oil. And do I get magazines? Yes, mostly so I can see what else is out there and learn from other peoples stupid mistakes. Most mags are written by JOURNALISTS not ENGINE BUILDERS so you have to take their findings with a grain of salt.

My feelings on syn oil are based on a college research paper I did in 1997 in which I researched the differences and advantages of syn versus dino oil. I read books till I was almost blind and contacted Mobil, Amsoil, QuakerState and Pennzoil for information. I don't have a copy of it to quote right now (not worth looking for it) but I do recall that syn oils can take something like 7 times the pressure and 4 times the heat of dino oils. (might be 4 times pressure and 7 times the heat...) Additionally, syn oils need less additives to work properly, so they're more stable over time. The wider the viscosity range (like 10w40, 20w50 etc) the more additives a dino oil needs to work and shorter it's life. "Straight weights" don't have very many additives at all and were rather poor in things like sludge and acid control ('member, circa 1997 and was dino 30w and 40w).

... and I also tested my findings in the Engineering fluids lab for viscosity stablity with heat. Not all 5w30s, 10w30s, 20w50s etc are alike.

Soooooooo... believe the mags if you'd like, I'll go with what I saw with my own eyes and what the 'professional' class engine builders/manufacturers seem to agree with. That's the great thing about this country. We're all free to make our own decisions.

outlawstock17
Member
posted January 10, 2004 08:28 PM
no arguement here raz. i use mobil 1 15w-40, by GOD!


sdhnc29
Member
posted January 10, 2004 10:57 PM
Killer post Raz_900 !! It always amazes me that people will spend thousands on a race engine, yet try and save a few dollars on oil (engine blood).

You absolutely hit the nail on the head regarding these magazine "journalist's". We had an article back in the 80's in Hot Rod and the Car Craft engine annual about a 460 Ford combo. The journalist that wrote it stated that if Edelbrocks new intake manifold had been available, we would have used it on this engine rather than the Offy that was used. It was a total fabrication to the story!!! We dyno tested the Edelbrock (which Edelbrock sent us to test for this article before it was released) vs. the Offy, and the Edelbrock was a piece of junk. So our article was falsified by the journalist. When confronted about this, we were given the answer......" Edelbrock spends 10 times as much advertising in Hot Rod and Car Craft than does Offenhouser. So we need to cater to their business." Kind of completely sums up magazine product testing, and your statement.

Steve

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


4340
Member
posted January 10, 2004 11:14 PM
A TEST!!!!!!!!

Place a flat sheet of steel on a hot plate burner outside. (If you do it inside you wife/girlfriend etc.. will get upset) place some natural motor oil on the plate, beside it place some syn. motor oil (both of the same weight). Turn the burner on and see what happens, more important see how fast it happens.
Regular motor oil RUNS (read that as moves very very very quickly) away form the heat.
The faster it moves the less heat that is absorbed and carried away.

Just a Redneck oil test.

P.S. I have seen some of the syn. gear oils for industrial use that will actualy move to the heat. We ran some of this in a quickchange in the gaer cover. (At$250 a gallon it was a little steep to run on the main gear until we tested it). In a 75 lap race in a fast 3/8 mile asphault track the car showed some liquid and had a smell at about 10 laps then it went away. After the race we found that in a wreck on the track I ran over something that cracked the cover and dumped the oil, There was very little visable damage to the gears, we sent them in and had them pollished and finished the yaer with them. We started running it in the main case. The company we got it from could clean it and treat it and send it back for a small fee.
Try that on regular lube.


rico 08
Member
posted January 16, 2004 08:03 AM
$250 a gallon?


Ego Racing
Member
posted January 16, 2004 10:01 AM
YEA!! $250 it was for some kind of highspeed veri drive on an electric motor, it turned 5500 rpm input and like 17000 rpm output. The place I worked got rid of the machine and he gave me what was left of the lube.
It said it was for Extreme High Pressure and Temprature. If you put a pencil in it and twisted it back and forth it would climb up to your fingers. It also smelled like all **** and was a light green color.


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