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Need help verifying fit of crank, camshaft, bearings
Posted by: cwdaveroch ()
Date: July 29, 2017 05:32PM

Been working on a '63 Convertible for about 10 years. Three years ago I was done with body and ready to start the engine. I had the crankshaft and camshaft serviced at a local shop spec'd to 0.010 oversize. Bought piston/rods combo and all bearings from Lon at Corvair Underground. I used assembly lube, installed the bearings, and torqued town the bolts connecting the two engine block halves together. At that point something was wrong - the crank and cam could not turn at all - the fit was way too tight.

Then we moved. For three years I've been doing house projects and am now ready to start the engine again.

I don't know enough to figure out whether the shop work on the shafts was done correctly, the bearings are the correct ones (they didn't come in a sealed box, just loose in a cardboard box taped up - so no part #), whether I need a new torque ratchet, or what.

I've measured journals and bearings and I'm hoping someone can help me out.


Here's what I have:

Engine halves; YN One has R1 3786752, other L12 3786091

Crankshaft: #5607 Journals are 2.088, inner diameter of bearings on the block is 2.086

Camshaft: # 6255610 Journals are 1.202, except front is 1.454. Inner diameter of bearings on the block is 1.190 and front is 1.431.

I hope this all makes sense. What I'm trying to find out is do I need to have the crankshaft and camshaft re-serviced, get new bearings, both, or buy a better torque wrench and/or caliper.

I've compared everything to the junkyard primer and the engine pages in Clark's catalog. If there's someplace else where I should be looking at instead of posting in the forum, feel free to let me know. I don't mind doing research, just don't know where to start.

Also, since I've torqued the halves together, I'm assuming I'll need new bolts for the block - is that correct?


Thanks for any help.

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: RobertC ()
Date: July 29, 2017 05:51PM

Do you have the 61 shop manual and 63 supplement?

I believe all your answers are there - including how to torque the case so that the crankshaft does not bind.

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: davemotohead ()
Date: July 29, 2017 05:53PM

The easiest way to check bearing clearances is with plastigauge, place a little strip of it on the bearing surface and torque to spec, remove and check clearance, sounds like you have bearings too tight.





Email me at: Dave Motohead

Sign my guest book!
[motoheadmall.com]
-----------------------------------
Rust Free Lancaster Ca

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: Vairismo ()
Date: July 29, 2017 06:17PM

When you first assembled it, did the crank turn without the rods on it? It has been recommended to torque case bolts
in steps and get the case to 'settle' in with the persuasion of a rubber hammer if it binds up the crank movement when torquing.
You may also want to verify the markings on the bearings and or measure actual thickness of bearings.



Edited 1 time(s). Last edit at 07/29/2017 06:20PM by Vairismo.

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: dragvairclark ()
Date: July 30, 2017 04:57AM

According to your own measurements, you have .002 interference. Get the crank turned farther undersize.

Clark Hartzel, Fraser, MI
1965 Monza coupe

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: cwdaveroch ()
Date: July 30, 2017 09:06AM

Robertc ----
Yes, I have the manuals and just re-read the section and found the details about checking clearances. I used plastiguage before but can't remember the results, so I will do that again.I was assuming there were very specific measurements for each, but now see it is more of just makimg sure the fit and match is correct.

I have one question after reading. What should I be using for lubrication during the plastiguage test? Assembly lube? Motor oil? Nothing?

Im using a fairly cheap caliper from Harbor freight, Pittsburg brand. Should I get something better? Suggestions?



Edited 1 time(s). Last edit at 07/30/2017 09:12AM by cwdaveroch.

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: cwdaveroch ()
Date: July 30, 2017 09:08AM

I see -- measure the thickness of the bearings instead of the diameter. That makes a lot of sense. Thanks

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: cwdaveroch ()
Date: July 30, 2017 09:11AM

Vairismo -

I haven't had the rods on at all. By "persuading" do you mean to tap the rod end or piston to encourage crankshaft movement?



Edited 1 time(s). Last edit at 07/30/2017 09:13AM by cwdaveroch.

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: BobV66Vair ()
Date: July 30, 2017 09:13AM

Buy better bearings, in a real package. They are not that hard to find in original packages. You can get the crank polished and mic'd at the machine shop. They should be able to mic your bearing as well, or you can with the mic. Then use plastigage as Dave recommended. That will show you the actual clearance and you should know if it is all correct. Be sure to check the mains as well as the rods. Check for easy rotation with each bolt torque setting. Manual should show you the correct pattern. Clarks has the manuals and the parts.

Also check the cam carefully with plastigage. It would be unusual for that to bind but you should check it.

Did you use assembly lube? What kind? If you remember. Once you do these things, be sure to add to this thread so everyone can help more or know what happened to fix it.

Bob Vinnacombe
Sandy, Oregon
1965 Corsa 140 stock
1966 Monza Soon to be race car
1968 Monza Parts for now

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: 63turbo ()
Date: July 30, 2017 09:18AM

When you are checking clearances with plastigauge, there is no need for lubrication. Calipers, even good ones, are NOT the right measuring tool.
Either find someone that has a Vernier micrometer to measure your crank, or
buy your own. The nice thing about the plastigauge method is that you don't need a micrometer to check the clearances.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: Wagon Master ()
Date: July 30, 2017 09:33AM

BobV66Vair Wrote:
-------------------------------------------------------
>Then use plastigage as Dave recommended. Check for easy rotation with each bolt
> torque setting. Manual should show you the correct
> pattern. Clarks has the manuals and the parts.
>
> Also check the cam carefully with plastigage.

All good suggestions but DO NOT rotate the crank or cam during the plastigage measuring process. That will destroy your results.

'64 Monza Coupe 140 4 speed
'61 700 Lakewood 95 4 speed
'69 Monza Convert. 140 Auto.

Been aircooled since 1973
Northwest Ohio

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: 63turbo ()
Date: July 30, 2017 09:55AM

cwdaveroch Wrote:
-------------------------------------------------------
> Camshaft: # 6255610 Journals are 1.202, except
> front is 1.454.

If those measurements really are correct, you have a serious fit problem...
I have 2 separate cams, a brand new one and a nice used one, and both measure
1.440" on the big one, and 1.200" on the other 3 journals.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: Vairismo ()
Date: July 30, 2017 10:41AM

cwdaveroch Wrote:
-------------------------------------------------------
> Vairismo -
>
> I haven't had the rods on at all. By "persuading"
> do you mean to tap the rod end or piston to
> encourage crankshaft movement?

No I don't mean that. Use the rubber hammer to rap on various positions of the aluminum engine case so that if it is a bit mis-aligned,
it can shift and find a 'natural' alignment that allows the bearing to run as designed and not have possible binding from the small mis-alignments.
Hope I said this well enough to be clear.

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: gnvair ()
Date: July 30, 2017 12:20PM

Before assembling the crank I will typically plastigauge the camshaft to check cam to case clearance.
Then I remove the cam and install all of the main bearings dry.
I then will lay the cleaned and dried crankshaft in. I will cut 4 small pieces of plastigauge and lay it across all 4 main journals. Be careful not to turn the crank or disturb the plastigauge. I then torque the case halves.
I then unbolt and check the clearance (how much the plastigage was flattened).
If within specs I will continue.
I will then lube the crank and bearings and camshaft and next I will degree the cam or align the marks. I then reinstall the case halves and retorque turning the crank each time to make sure it still spins freely. If it locks up or gets really tight I will use the rubber mallet and beat on the case halves to try to free it up. If it doesn't I will loosen the bolts and start again. Sometimes you need to vary the torque sequence to get it where it needs to be. Once I verified that it will torque up properly I will loosen it one last time and add sealer in 3 spots to the case halves and retorque it for a final time.
You need to realize if the crank was cut .010" that means the journals are now .010" smaller. To make up for it you will use bearings that are .010" undersized which make up the difference. If the crank was cut properly you should be back within manufactures specifications. If they cut too much off the crankshaft your clearances would be bigger/larger. If they did not cut off enough they would be smaller.
All of the currently available main bearing sets are of good quality (Federal Mogul and Clarks). Clevite was preferred by many but they have been slowly phasing out all of their Corvair bearing sets.
Again these are what I do. YMMV

Lee J
Southern New Jersey near Philly.
1966 Corsa 180/4 speed
1969 Monza convertible 140/4 speed

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: thewolfe ()
Date: July 30, 2017 02:01PM

You can't measure bearing clearances with a cheapo caliper. You need a good dial bore gauge and micrometers that both measure to .0001, not .001. Or use plastigauge. Even that is not as accurate but will get you close enough.

Nate Wolfe
Portland OR
65 Corsa 180

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Re: Need help verifying fit of crank, camshaft, bearings
Date: July 30, 2017 07:23PM

Lee J has your answer in the techniques he describes to assemble the case.
Read his info along with the procedures in the Chevrolet manual.

The case bolts are re-usable. You will be taking it apart and putting it together a few times to get everything right.

To begin, take everything back apart and clean it all. inside the bores, inside the cases etc. Clean, clean, and clean again! grinning smiley

With a proper micrometer measure the crankshaft main bearing diameters and record them.
Post 'em up here. This is how you will know if the machine work on the crank was done correctly.
Take a few photos while you are at it. Let's see how well the cutting was done.
Tale a few of the bearings, too. Let's see what you've got including numbers/marks on them
Plastigage is available at most "real" auto parts stores.


Dan Davis - Pierce County, WA ~ CORSA Western Director + Corvairs NW + North Cascades Corvairs + Corvanatics
1966 Corsa Turbo coupe ~ ~ 1966 140 Corsa ~ 65 Monza 140/4 'Vert Sierra Tan/Fawn (my current driver!!)
~ 1964 Monza 'Vert ~ 65 Monza 140/4 Evening Orchid w/ ivory/black int ~ 1962 Monza Wagon 102/4
1963 Rampside/Scamper ~ 1963 Red/Greenbrier ~ 1969 Ultra Van #468

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: gnvair ()
Date: July 30, 2017 07:42PM

I buy Plastigauge at the local Napa.
Corvair engines are one of the most tedious and time consuming engines to build.
There are a lot more pieces to clean and a lot more clearances and assembly procedures to follow compared to say a small block Chevrolet.

Lee J
Southern New Jersey near Philly.
1966 Corsa 180/4 speed
1969 Monza convertible 140/4 speed

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: cwdaveroch ()
Date: July 30, 2017 10:56PM

I am truly grateful for the help. It will be Thursday or Friday before I can get back to the workshop, but I will order some fresh plastiguage and buy or borrow a good vernier micrometer.

One of the most fun parts of this project is going beyond just replacing or bolting on parts and gainimg a deeper understanding of how everything works. All the great advice will help me to do that. If/when I take the crankshaft back to the shop I will be able to carry on a better conversation than just "spec it for oversized bearings".

When I get working Thursday I will post updates. Im also going to start another thread on the rods and pistons, because I think they are not quite right either.

Again, thanks so much.

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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: cwdaveroch ()
Date: August 04, 2017 04:11PM

Lee -

Got back to the garage again and I am following your notes. I laid the camshaft in with plastiguage and the clearance looks to be between .004 and .005. According to the manual, used camshaft clearances should be between 0.002 and 0.004. I have a second camshaft, but clearances are the same. Should I go ahead or do I need to look for a better block? I'm including pictures.

BTW, I am having a blast doing this. Ome reason I started this project is the learning opportunity. Also because a 1969 Monza convertible was my first car. Thanks for pointing me back to the manual, setting my thinking straight, and giving me the confidence that if I screw it up I can get help.

Attachments:


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Re: Need help verifying fit of crank, camshaft, bearings
Posted by: Wagon Master ()
Date: August 04, 2017 04:19PM

Best I can judge by your pictures I would put the clearance between .0035 and .004. Still within the high side of the spec. range. I'd run that block.

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