jerryd87

iTrader: (2)

so last night i was starting to put togeather my 305(new pistons, rings, rods and all new bearings stock crank) the crank was polished a little bit nothing to even really change but anyway i put the crank in and spins freely np. now when i put the pistons and rods in it kept getting hard to spin the crank(i expected a little so i dint pay any attention to it) after one of them i couldnt turn the crank, so i pulled the cap off and the bearing surface was actually shredded off from where i tryed to turn it. i pull the rest of the caps off and everyone of them is groved(except for the flaked one) i checked the clearence and they where all right around .009(i read that .003-.033 was good) im not sure if the specs i got where wrong or if some dirt or something got into the lube(since i filed the rings right before i put them in mayby some metal shavings got caught in my hand and come out in the lube) i already used some emry cloth to increase clearences a little bit since i had enough room and sprayed and wiped everything off and ill clean it real good again before i assemble it again but i wanted to know if anyone else has had this problem

ljnowell

Ok, If you are talking about .009 clearance on a rod, thats way to much. You need a third of that or less. See if the rods are all in the right way. If you are putting them in backwards they will bind and tear up the bearings on the outside edge usually.

jerryd87

iTrader: (2)

thats really wierd i know there in right everythings marked(machine shop marked the rods so i cant mess up the caps and pistons are notched at the front along with a little "f" guess ill mess with it more when i get home

BASSETT IROC 85

iTrader: (2)

Glad you stopped. Sounds like you know how to assemble a engine. The key to engine building is clean, clean, and clean. If it was me, I would pull it back down, wash everything in warm soap and water. Blow it dry making sure the oil holes in the block and crank are clear. As you put in each rod and piston in torque it down and spin the engine over. If you do that every time when the crank will not turn over you know witch one it is. The notch in the piston goes to the front. remember the rod bearings go lock to lock. locks to the outside.

lukn4trbl

This is not good at all. At a minimum, you need new rod bearings. Don't try
to reuse bearings that are grooved, scratched, flaked, etc.

That is way too loose. You want no more than 0.002 to 0.0025 for the
rod bearings, and between 0.002 to 0.003" for the mains.

If you run that motor, you will have oil pressure issues and spun bearings
in no time...along with a bunch of knocking.

Check the crank dimensions again. You may need oversize bearings if
the crank has been turned. Something is definitely not right.

jerryd87

iTrader: (2)

oh sorry i just realized that lol i guess i should have reread my own post first the specs i had where between .0003 and .0033 and mine where .0009 my bad looks like mine where too tight ill check em again when i get home(i already used some emry cloth to open them a little more on my lunch break but i have to check them when i get home) and i already got new bearings when i saw the groved ones i pulled em and threw em in the trash i guess the new rods where a little too small from the factroy

BASSETT IROC 85

iTrader: (2)

I agree with lukn4trbl. Are you using a mic to read clearance are you using Plastigage? Plastigage can be wrong. Either way groved bearings wont work. Pack it up and take it to a machine shop and have them mic everything for you.

ljnowell

if you are running less than .001 on the rods, thats way to tight. You need to look closer here. Possibly swap some of the inserts around and see if you can get it to somewhere around .002 or so. You can run it as tight as .0015 and probably be ok. you cant just stick the bearing inserts in and expect them to be right though, most always you need to swap them around to get it right. DONT TRUST PLASTIGAUGE. when it gets old, it gets even worse.

lukn4trbl

I agree about the plastigauge, you really should be checking the clearances
with a dial, but I understand most home hobby guys don't have that equipment.

As for swapping bearings around to achieve proper clearance, that would mean
the crank wasn't ground properly, or the bearing QA from the factory failed.

If your grinder can't get the journals to within 0.0002", then it's time to find
a new guy.

Seriously, get that crank back to a shop for precise measurements. Also check
the part number of the bearings as you may have the wrong size.

ljnowell

[QUOTE=lukn4trbl;3690277]
As for swapping bearings around to achieve proper clearance, that would mean
the crank wasn't ground properly, or the bearing QA from the factory failed.

If your grinder can't get the journals to within 0.0002", then it's time to find
a new guy.

QUOTE]

I flat disagree. Its not even a matter of the machinist. There are tolerances everywhere. They all add up. If you think its uncommon to swap bearings around to get the proper clearance, then I have to say that you dont buiild very many engines. I dont mean to be rude or condescending, please dont take it that way.

lukn4trbl

Not many engines? I don't take offense to that at all. I mean, in the past
16+ years and having my own shop I must have built, raced and tuned more
motors than most of the members on this board combined.

In all of those years, and any engine school or builder I've come across,
we've never swapped bearings around to get proper clearances.

Normally, you machine the parts. Measure and mock up the assembly and
it's bang on. Very rarely are adjustments needed.

jtrescot

If I am reading this correctly he has basically a stock crank, with stock bearing journal sizes. Assuming the rod bearings are standard as well, how in the world do you come out with too little clearance? I could understand a little too much - if the crank was polished, but too LITTLE? How are you measuring the clearance?

jerryd87

iTrader: (2)

i was using plastigage im guessing the new rods i got where slightly too small(they where the scat oem replacement ones with the waveloc bolts) went home last night and polished the crank some more to open the clearences to right about .002 and kept changing gloves and wiping everything down and spraying the rags with brake clean so there was no chance of dirt and it went togeather np nows it rewraped with plastic wrap waiting for the machine shop to get down with the heads *shrug* seemed like no one ive talked to ran into the same problem as i did before

ljnowell

Once again, I disagree. I really dont care what you have done in the past 16 years. In the time you have been on here you have done nothing but argue textbook facts with people who deal with real world problems. Swapping around bearing halves is a perfectly normal occurance. Sort of like adjusting valves with the engine running.

lukn4trbl

You can disagree all you want. I love how you try to intimidate me with
impossible data.

There is no chance in hell you will find 0.0065" variance by swapping bearing
halves.

Runout on a crankshaft is less than 0.001"; variance on a bearing is less than
0.0001"

If you are personally finding the proper clearance by swapping bearings
around, you either have faultly warped bearings and/or the crank is screwed...or you're measuring incorrectly...or you're dreaming.

Pick one, or two, or three.

As for the argument comment, I think you should get your facts straight.
Read my posts and see how many people I"ve helped. For the record,
I never started a fight with anyone. The person/thread you are thinking
is easily found and you can see the history. I'd rather not stir that pot
as it seems our differences have been resolved.

Now, you can continue to waste the OP's time and have him swap bearings
and re-torque his bolts over and over....to find nothing in clearance improvements,
or you can learn the proper method and save his motor, and his time.

We'll let the OP decided.

ljnowell

Actually, I didnt recomend that he take those bearings and swap them, read my post a little closer. I was actually telling him that when tolerances get too close you can swap them around. No where in my post did Itell him to swap them and get .0065 clearance. He said he was running .0009. Where I come from, that is much less than the recommended .002 or so. I recommended swaping around bearing inserts to see if he could gain the extra .0005, which is a common procedure. Argue all you want. I dont really care. Preach about who you help, you wanna see my inbox? I wont argue with you anymore, as its an obvious waste of time.

lukn4trbl

Do you realize how absurd your logic is? You are telling him to mix bearings
around until he finds a good match.

So...that means all of the other journals have to be off ground +/- x.xxx"
and he'll need the same offset mismatch in the box of bearings to ensure
that every bearing falls within clearance...or he can have a few that are
perfect, a few that are too tight, and some that are too loose?

Well I hope that his crank and all the bearings in the box happen to have
enough variance to match his crankshaft imperfections...or he'll have to
buy another box of bearings and begin to swap them around.

You are not going to find more than 0.000 1" variance across bearing
thickness. If you do, they are faulty.

What's in your inbox that's going to validate swapping bearings as a method
to correct improper clearances?

Why don't you forward those messages in your inbox to a few other engine
builders and let them evaluate your process.

Quote their name, their company and message when you reply. I'd love to
see what I'm missing.

ljnowell

Once again, a sorry attempt at flame baiting. No one said you would get more than a thousandth. If he is running at .001 and needs to get .0005, that can sometimes be had by swapping shells. I guess you will tell me that they dont make .001 under bearings, to be used for this purpose? Give it up. Continue to post your replies, argue all you want. The poster needs a solution, not your argument of, your machinist sucks. He needs his problem solved, which at the moment is his rod bearings are too tight, running at .0009. That being said, TO THE ORIGINAL POSTER:

you can swap bearing inserts around, one half of the insert that is and see if you can get the needed clearance. Otherwise, you can get bearings that are .001 over, and use one half of the bearing to get 1/2 of the amount or both to get the desired .002 clearance. Please disregard any above argument. I hope this solves your problem, others are beyond help.

lukn4trbl

YOu better check your numbers. He's running 0.000 9"

Typical clearnace is 0.002 5"

Even if he uses your method by swapping half of the bearings, the best he
can achieve is 0.001 4"

That's assuming you can find a bearing that has a variace of 0.000 5"

A bi-metal Clevite bearing is produced to within 0.000 3". It's on their site.
Go and check it out. I beg you to take out your measuring device and a
digital camera. Post up a some pictures of a bearing that you can find
with up to 0.000 5" in a set.

Please show all of us your wisdom. You are certainly not fooling me, and
I have no idea where you found information on swapping bearings halves.

I didn't say that. Nobody else said that...I think you're fishing for words
that are not on this page.

Jerryd87, or anyone else:

If you were to swap bearings around and check them you would find no
more than a difference of 0.000 3" (typically 0.000 1") between
bearings.

The best you can achieve is 0.001 2" (0.000 9 + 0.000 3) which is still
too tight.

Basically, you are wasting your time.

As was mentioned near the top of this thread, you need to check the
crank measurements, or check the bearings for proper size. Something
is definitely not right.

But don't take my word for it. Here are two links from the MFG, Dana/Clevite/Malhe
which tell you the allowable crank, rod and bearing tolerances.

Page 2:
http://mahleclevite.com/publications/CL77-3-402.pdf
Page 3:
http://mahleclevite.com/publications/CL77-2-402.pdf

ljnowell

With your kind of quoting, I think you could work for the hillary campaign! Once again, you are trying to weasel out of something. Read my above post, the one you posted in reply to and you will see that I did in fact say .0009. So, thank you for quoting a different post and pretending that I am not smart enough to know the difference. YOu obviously have problems admitting that other people know a way to fix something that your textbooks tell you isnt right. Sorry. Now, are we going to have the valve argument all over again with bearings, or can you leave it alone and act like a big kid?

lukn4trbl

You are SOOOOOOOOOOO missing the most important aspect of that quote
that it's humourous.

It's not the matter of 0.001, or 0.0009"...because if you read the entire
reply you can clearly see I used 0.000 9" for the simple math.

There's nothing to weasel out of...in fact, if you still don't understand
that you can't achieve the required clearnace from the math I posted,
then you better run back to grade one and pay more attention.

Sorry, but you have yet to show me, or anyone else here that your method
exists, or works.

I've already posted links from the manufacturer's site that states the
tolerances of the bearings, and the recommended crank and rod clearances.

Therefore your suggested idea of mixing bearing halves cannot , and will
not make a difference.

Do you understand that much?

This isn't text book talk, or bench racing (much like your theory). If you'd
like I can post pics of my shop, and a few of the engine's I have built...
but that probably wont impress you?

Maybe if I told you that next month alone I'll be building no less than three engines
that might impress you? How about the estimation that over the last four
years I have successfully built and tuned no less than 60 engines.

How about the auto school I have taken, or the fact that I'm an
administrator for Speed Talk to show that I have a slight idea of
what I'm talking about.

Please post a picture of the tool YOU use to measure bearing thickness
down to 0.000 5" precision.

Please post a link to a credible site that explains short block assembly
using the "musical chairs swapping bearing halves" method.

Please do SOMETHING besides repeat your theory to show that you
actually build reliable motors and that your method is credible.

It so clear that you don't have the tools to measure this because IF
you did have tools and you ACTUALLY MEASURED, you would know
there's no difference.

Gotta Love the bench racing and magazine mechanic mentality.

PLease prove me wrong with a link, or some photos of your "stuff".

BASSETT IROC 85

iTrader: (2)

I have a friend that is a former NASCAR engine builder that has showed me that changing inserts to get the clearance you want is acceptable. In one case he used a +1 insert on top and a standard insert on bottom to get the clearance he wanted. Some times changing bearing manufactures will give you the clearance you want.

lukn4trbl

Exactly. He needs to change the set to achieve the required clearance.

Swapping them around isn't going to do a thing.

ljnowell

ahh, read above completely, he said in one instance, he in fact does swap them around to get the desired #. I really dont care how many engines you say you build. I build engines for a living too. And transmissions, differentials, and any other component of a car you can think of. You can post pictures all day of your shop it wont change anything. I can post pictures of the dealership I work in, and my home shop, if that matters much to you. I can post pictures of my micrometers, dial bore gauge, dial calipers, dial indicator, snap gauges, and all of the other tools that I own that I use to work on engines, it wont matter. You arent the only one here that works on cars. I have my ase certs I know what I am doing.


If you cant see how changing around inserts can gain clearance, then I cant help you. You are arguing against fact that has existed since people started building engines. Just like setting lash on a hydro cam will wipe lobes.

lukn4trbl

Please do

If you're lucky enough to find up to 0.000 3" difference.

So you have 16 bearing halves. You need proper clearance on all 8 rods.

How do you get all of them correct by swapping them around?

I didn't insist on regrinding the crank. I said to measure it, and check
the bearing part number as it may be incorrect.

You are pretty stubborn and poor at taking in all the details. In his case
changing inserts could not possibly work. He would end up with one correct
rod, and the rest would be off...unless you only measure one rod out of eight?

No it doesn't exist. YOu still haven't proven that. Link me for the third time!

You can change bearing sets, but you are not going to find enough variance
in ONE set to make all eight rods proper. It's mathematically and logically
impossible!

Sonix

iTrader: (1)

My machinist also told me I could mix and match bearings to get the proper clearance. I think he was talking more-so about doing half a set of .011" undersize bearings and half .010" undersize.

lukn4trbl, you really are looking to argue aren't you? Everyone on the internet manages a speed shop and has their own race team. Every 18yr old joker on here has there own "racing club" with a fancy emblem. Where's your fancy emblem eh? I'm just joking around here, but in all seriousness, I wouldn't spout out your accomplishments in order to make yourself seem more "right". Simply stating your experience and how it's worked for you in the past is all that's needed. If someone else doesn't want to take your advice, just move on - arguing online is a waste of everyones time.

lukn4trbl

Trust me Sonix, I don't look for arguments. I thought my initial reply to
ljnowell was very polite and civil.

I agreed with part of his post, and stated why mixing the bearings wasn't
an option.

Even in the follow up reply I didn't say anything toward him, and yet I was
attacked again with a procedure that doesn't make sense.

Now, if this makes me the one to start fights, I'm sorry. I'm just trying to
help out, however I wont be displaced by a theory that doesn't hold water.

I'm all up for learning and trying new things, but there are certain ideas that
just don't/can't work.

Peace and love and all that Internet stuff

ljnowell

hmmm, its funny how it doesnt work in your shop, but does work everywhere else in the world. Bearings dont care which rod they end up with. If you can squeeze out that last little bit of clearance you need, or tighten it up that last little bit by swapping them around, it should be done.

What I am trying to convey in my post is that not everyone has impeccable machine work, and getting better work may not be possible. Also, in the real world, people dont always have a crank turned on a rebuild. Sometimes they are in good shape, but are just a little off. In this case, swapping bearing halves around is a viable solution, and one that people use every single day. I cant help it if you cant accept that. There are lots of people here who have done that. Its definately not the first time it has been mentioned here, and not the last either.

https://www.thirdgen.org/forums/tech...clearance.html

there is the link, here is an excerpt:
I think that you guys are right I'm going to go to another shop. Today we checked the crank and it was in good shape.

CRANK #'s .010 grind
1. 2.439 main journal O.D.
2. 2.4388
3. 2.438
4. 2.439
5. 2.4388

Then we checked main bearings with an I.D. mic and not so good.

MAIN BEARING #'s .010 oversize
1. 2.4419
2. 2.4422
3. 2.4425
4. 2.4422
5. 2.442

Then we did some swaping around with the bearings and a little better but still not so good.

MAIN BEARING #'s .010 oversize (second time)
1. 2.4415
2. 2.4418
3. 2.4418
4. 2.441
5. 2.442

Well I'm really not sure about all this but do you guys think I should buy some federal mogul bearings instead of clevite 77 the bearings that are in there or what? Does anything look inconsistant or out of place.
*********
notice the amount of difference, especially on #4. hmmm, not a single person threw a fit saying this would cause death and destruction and general demoralization of the population. It didnt solve his problem but it surely illustrates my point of the ability to swap bearings. If you logic was correct, there would have been no changes at all in the measurements, because all the bearings are the same.

I wont argue any more on this topic, as it is a worthless cause.

lukn4trbl

I can't believe I have to spell this out to an "ASE" certified mechanic...

You have 16 bearing halves. They are each in spec from the MFG within
0.000 3"

Rod #1: has a clearance of 0.002 5"
Rod #2: has a clearance of 0.002 0"
Rod #3: has a clearance of 0.002 0"
Rod #4: has a clearance of 0.002 5"
Rod #5: has a clearance of 0.000 9"
Rod #6: has a clearance of 0.002 0"
Rod #7: has a clearance of 0.002 5"
Rod #8: has a clearance of 0.002 5"

The rod journals are all machined correctly. 2.100" (tolerance of 0.000 2")

All of the rods ends have been resized correctly to within 0.000 2"


You need to come up with at least 0.001 1" for #5

Please show me how you get Rod #5 in spec and keep all other 7 rods in spec?

Sonix

iTrader: (1)

I would guess if he has one at .0009" then the others probably aren't .0025" or so. Rod #6 is probably going to be pretty close eh? Otherwise there'd be a funky step on the cranks rod journal area which would stand out a bit eh?
So i'm guessing they are all in the .0014" range. He might be able to gain a few ten-thou by swapping bearing shells. I think he's probably best going to his favorite machine shop and getting a set of .001 extra clearance bearings. Well actually, get a 2-3" micrometer and measure the rod journals first, then measure the rod big end, and figure out what's up. Then go from there.

lukn4trbl

Absolutely, unless the bearing is out of spec.

I gave him 7 other rods in the range of 0.002 -0.0025 to be generous.

Likely as you stated, they would all be closer to 0.000 9" than what is listed,
but then...it would make correcting the scenario even more impossible than it already is.

ljnowell

I lik,e how you have latched onto that number. I believe I said above that it wouldnt work for him at .0009. However, your statement was that it cant be done because it wont make a difference. That was my only argument, was that it can and does make a difference. That being said, I believe this argument is all argumented out.

lukn4trbl

Why must people quote only part of the paragraph...

ljnowell

Gee thats funny, for it never changing clearances, it did. Look above for the proof. Posted. Why dont we let this one die, obvious there will be no resolution. If you are just looking for a pissing match, take it elsewhere.

pandin

Do not some bearings come .002 undersize to compensate for crank wear. I have known cases where a standard crank was matched to an undersized set of bearings it will turn but lock up when hot.

ljnowell

They do in fact make bearings like that. GM had a real probem with main bearings in the 90s, actually had a training video on replacing the bearings with the engine in the vehicle. Plastigauge and a different bearing. Not much of a repair, but its under warranty, what do you expect.