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Ej20 Subaru bearings

Posted: Wed Apr 07, 2021 6:42 am
by gunt
Hi

So I always try and keep the mains fairly tight under 2 thou and the factory calls for well under that , I can get anybody to hone the mains , all measures up fine and checked with plastic gauge , so clamped up feel a little tight in places , open it up and see for yourselves , I can loosen
4C2A8F3D-1148-4A18-AAA0-4722CD40AF9F.jpeg
bearings to over 2 thou but don’t want to

Re: Ej20 Subaru bearings

Posted: Wed Apr 07, 2021 7:25 am
by BillK
Is the crankshaft the correct size and straight and round ? I would never trust plastigage for anything other than a quick check. Use a dial bore gauge.

Re: Ej20 Subaru bearings

Posted: Wed Apr 07, 2021 10:13 am
by gunt
Hi

no its dial bore gauge and checked with plastic , the crank [ ill check again ] the block is new to the build but used , the crank came out of the car and all bearings were nice in the original block , id more so say it the block

Re: Ej20 Subaru bearings

Posted: Wed Apr 07, 2021 12:31 pm
by BillK
How about the bearings themselves ? Have you compared them to the old ones as far as thickness goes ? I have seen some pretty sad parts lately.

Re: Ej20 Subaru bearings

Posted: Wed Apr 07, 2021 2:55 pm
by gunt
I have what acl call std , which has some clearance built in and have built this with some thigter ones to get clearance under 2 thou ,

so on a journal measure in 3 places i have

.0016
.0009
.0015

.0022
.0011
.0020

.0017
.0009
.0010

you get the idea , but i have contact ? when opened , no rods, just crank in there

Re: Ej20 Subaru bearings

Posted: Wed Apr 07, 2021 7:38 pm
by modok
#4 main tends to go out of alignment.

Re: Ej20 Subaru bearings

Posted: Wed Apr 07, 2021 8:31 pm
by Cubic_Cleveland
gunt wrote: Wed Apr 07, 2021 2:55 pm I have what acl call std , which has some clearance built in and have built this with some thigter ones to get clearance under 2 thou ,

so on a journal measure in 3 places i have

.0016
.0009
.0015

.0022
.0011
.0020

.0017
.0009
.0010

you get the idea , but i have contact ? when opened , no rods, just crank in there
I don’t really understand.
Have you had the cases align bored/honed?
What are these measurements? Clearance on one journal? Is one component out of round or barrel/hourglass shaped?

Re: Ej20 Subaru bearings

Posted: Thu Apr 08, 2021 5:35 am
by gunt
no one to line hone on these blocks , currently buying the equipment my self , its bearing clearance at 3 different points in each journal

Re: Ej20 Subaru bearings

Posted: Thu Apr 08, 2021 9:10 am
by MotionMachine
Hopefully you're not buying a line hone because IMO no one should line hone a Subaru. You just cannot get consistently sized bores with no taper or out of round. Line bore yes, I've done it several hundred times (always with deck plates attached), every hole to the tenth with no issues.

Re: Ej20 Subaru bearings

Posted: Thu Apr 08, 2021 12:42 pm
by agertz1
From outside of the forest ? Not being an auto machinist but lifetime conventional and CNC., horizontal mandrel for honing ? Why ?
I have heard stories with "short" length blocks, of these honing problems. Too much mandrel weight and inertial of moving parts, to be accurately
controlled in "short" blocks. Dumb question, rig tooling to mount these problem blocks, vertically in a CK10/etc. ?
Art of no forest. :?:

Re: Ej20 Subaru bearings

Posted: Thu Apr 08, 2021 3:18 pm
by MotionMachine
agertz1 wrote: Thu Apr 08, 2021 12:42 pm From outside of the forest ? Not being an auto machinist but lifetime conventional and CNC., horizontal mandrel for honing ? Why ?
I have heard stories with "short" length blocks, of these honing problems. Too much mandrel weight and inertial of moving parts, to be accurately
controlled in "short" blocks. Dumb question, rig tooling to mount these problem blocks, vertically in a CK10/etc. ?
Art of no forest. :?:
To answer your question:
https://www.youtube.com/watch?v=h8fOAgrKM0E

Re: Ej20 Subaru bearings

Posted: Thu Apr 08, 2021 5:26 pm
by agertz1
Thanks, seems like a good method for all boxer 4 cylinders ?

Re: Ej20 Subaru bearings

Posted: Thu Apr 08, 2021 9:04 pm
by modok
That is not line-boring, it's just regular boring.


There are many different kinds of honing and boring tools.
If honing aluminum does not work, you are using the wrong tool for the job, or the wrong operator.
But of course, we cannot own every conceivable tool that ever could exist.
Smoke em if you got em.
We both have more than 5 different ways to do it, I'll use whichever way works best for the price point.

Re: Ej20 Subaru bearings

Posted: Thu Apr 08, 2021 9:10 pm
by modok
But it also depends on the condition of the bores.
in many cases the hole is just too big, yet within .001" of round, and that will hone nicely.
But I have also seen them .004 out of round or worse, which I would prefer to bore.

Re: Ej20 Subaru bearings

Posted: Fri Apr 09, 2021 6:39 am
by leahymtsps
modok wrote: Thu Apr 08, 2021 9:04 pm That is not line-boring, it's just regular boring.


Exactly what is your definition of line boring?
Did he not bore multiple holes in a straight line?
Are the mains not in a straight line?

Tom