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Discussion Starter · #1 ·
Ok guys,

Im the newbee!

Here is my sob story.

71' 302 30over 268cam 650holley

Built a nice starting stand for this baby and finally got around to statring her this weekend. After correcting a little timing issue, she started and ran really sweet.
About 20 min in to the break in (2000rpm+/-) i started to play with the throtle. everything is huming along:).

Then, my son notice a walk of the balancer when i would feed it.
After checking tightness of everything. (Nothing lose) fired her up again.

Puring like a pist off lion! Evrything sounding and looking good. Except the crank walk.

Ok, here is my question?
It has nothing on the back end excpet the flywheel. Does adding the converter and tranny help with the walk?

Or should i tear her apart to check thrust bearing?

I would say its about a 3/16 to 1/4 walk. But stays steady at what ever RPM you stop at. Just quick (rapping) do you notice it.

Please help

Thanks
Doug
 

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If you can move the crank front to back with a pry that much you have a bad thrust bearing.
 

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Discussion Starter · #3 ·
Yea i already new the answer!
Just wishing i was wrong.

The only concern is this is a fresh build. I can see the thrust bearing goin that fast. (maybe 30 min)

I really got that gut fealing its a bad crank.
 

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Did you check end play after you installed the crank?
 

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Crank end-play is just one of many clearance checks done during a basic engine build. Grab a manual and check as many of the others as possible during your crank check, such as cam end-play. It can save you a bunch of time, money and frustration later.
:tup:
David

Here is my crank end-play being measured with a dial indicator at .007". Feeler gauges can also be used to get reasonably accurate numbers:

 

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Discussion Starter · #7 ·
Thanks PSIG

I knew (know) better. But getting old sucks! My memory forgets some times!
I really didnt even think about it. Ive built a few engines in my day! (Gas, Marine, desiels, etc.)

No rookie, but i cant beleive i did it. or should i say didnt do it.

Better to catch it now than in the car down the road:)
 

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I've see crank thrust surfaces that were rough and not true wipe a thrust bearing in short order.
 

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Discussion Starter · #9 ·
Well,
Ill start the depressing job of tearing the bottom open this aftrnoon.
Should know for sure soon.

Ill post what i find!

Fingers crossed
 

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Discussion Starter · #10 ·
OK all,

Here is the diagnoses!

Wrong thrust bearing in the main kit!
After contacting Federal Mugol and giving the part number on the bearing, it was wrong for the motor. (seems it was for a chavey)
Luckly, crank seems fine, as well as the other bearings.
Deal indicator showed about .47 of play.

Bearing look as if they was a mismatch from factory.
So, getting a repalcement set from Oriely (at their cost) along with gaskets, oil, filter, etc.

Sure wish i could have afforded to pay more attention when assembling.

Thanks again.
 

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Funny thing is, if you LEFT OFF the thrust bearing you would BARELY just clear 1/4" of movement, if you got 3/16 to 1/4 movement I'm thinking the thrust bearing is NOT in the correct spot or it's altogether fully wiped out which don't happen on a break in. There's nothing there to cause this to happen that I can think of.

Wiping a thrust bearing with no miles on an engine is unheard of to me.
 

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OK all,

Here is the diagnoses!

Wrong thrust bearing in the main kit!
After contacting Federal Mugol and giving the part number on the bearing, it was wrong for the motor. (seems it was for a chavey)
Luckly, crank seems fine, as well as the other bearings.
Deal indicator showed about .47 of play.

Bearing look as if they was a mismatch from factory.
So, getting a repalcement set from Oriely (at their cost) along with gaskets, oil, filter, etc.

Sure wish i could have afforded to pay more attention when assembling.

Thanks again.
for a chevy ????

why don't I believe this ?. .47" play .

OP , tell me how thick the flange is on the correct bearing'
whats really going on ?
 

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Dan is right. The Chevy bearing is about twice as wide.
 

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I have experienced a brand new set of bearings have one mis-matched new in the box. After that and an almost disaster, I always check every piece of every bearing now before I try and use them.
 

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OK all,

Here is the diagnoses!

Wrong thrust bearing in the main kit!
After contacting Federal Mugol and giving the part number on the bearing, it was wrong for the motor. (seems it was for a chavey)
Luckly, crank seems fine, as well as the other bearings.
Deal indicator showed about .47 of play.

Bearing look as if they was a mismatch from factory.
So, getting a repalcement set from Oriely (at their cost) along with gaskets, oil, filter, etc.

Sure wish i could have afforded to pay more attention when assembling.

Thanks again.
fe , put bthe bottle down or pick it up ... you were right the first time .
 

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aaaaahhhhhhh OK I'm not drinking now and can see my not noticing it was in the hundredths... LOL
FE , see the above post . .470 is to the 1/1000 but is in the 1/10 ... four hundred seventy thousands

you need to be on the bottle. lol
 
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