Ej20 Subaru bearings

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modok
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Re: Ej20 Subaru bearings

Post by modok »

Line boring kinda implies ... A line boring bar or a line boring machine.
And i was wondering what line boring machine can repeat to a tenth?!
and the answer is.......
It was a misunderstanding.
No big deal.
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Re: Ej20 Subaru bearings

Post by MotionMachine »

Update to the mainline boring process, not to be confused with actual line boring. This is a new billet block I'm doing today that shows the leveling plate I built since that previous video was taken. This makes it much easier to align the top and bottom main to a couple of tenths.
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Re: Ej20 Subaru bearings

Post by gunt »

so while i wait for the tools , what to do for now , i can loosen it up bu .0015 but that puts me out on the larger side
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Re: Ej20 Subaru bearings

Post by leahymtsps »

modok wrote: Fri Apr 09, 2021 12:47 pm Line boring kinda implies ... A line boring bar or a line boring machine.
And i was wondering what line boring machine can repeat to a tenth?!
and the answer is.......
It was a misunderstanding.
No big deal.
Look up Rottler - RMC and I'm sure there are others.

Tom
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Re: Ej20 Subaru bearings

Post by MotionMachine »

gunt wrote: Sat Apr 10, 2021 5:22 pm so while i wait for the tools , what to do for now , i can loosen it up bu .0015 but that puts me out on the larger side
Curious as to what these tools are that can repair the mainline of your block.
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Re: Ej20 Subaru bearings

Post by modok »

leahymtsps wrote: Sun Apr 11, 2021 7:12 am
modok wrote: Fri Apr 09, 2021 12:47 pm Line boring kinda implies ... A line boring bar or a line boring machine.
And i was wondering what line boring machine can repeat to a tenth?!
and the answer is.......
It was a misunderstanding.
No big deal.
Look up Rottler - RMC and I'm sure there are others.

Tom
what machine do you recommend for a subaru?
MotionMachine
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Re: Ej20 Subaru bearings

Post by MotionMachine »

I've done Subarus on both my BC4 and now my Robbi line bore. Perfectly do-able albeit very time consuming and a pita, given the oddball boxer shape with deck plates attached. What the major pita is, instead of centering the bar on a concentric main saddle like a traditional block (0,+1,0), you are dealing with an out of round hole, sometimes as much as .006" out of round. And of course you have once chance to hit the size, go over and it's a do-over. On the CNC, I can take a test cut and then another .0005" if I need to. Plus if it looks like the center needs to move a few tenths after a test bore, I can easily move the table over whatever amount in whichever direction. So CNC is the best but you need a riser in the column, so your common 3 axis mill would not accommodate doing a Subaru.
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Re: Ej20 Subaru bearings

Post by modok »

It's a great process I agree.
If the depth of a bore is not in excess of 5x the diameter, then single point boring should work, and that 5x is not a hard limit, just a rule of thumb. Basically the engines are not long enough to need to be traditionally line bored.
A type-4, type-1 or Vanagon engine is considerably more difficult to mount....
But even so I think we could do it if there was enough demand to justify making the fixture.

Could use a vertical milling machine, or a horizontal one.... as long as it has a spindle large enough and good enough.
in the past they might have been bored on a lathe, in which case, it would be kinda the same either way, just, using the tailstock or not using it. :lol:
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Re: Ej20 Subaru bearings

Post by MotionMachine »

"A type-4, type-1 or Vanagon engine is considerably more difficult to mount...."

Oddly enough, I am currently working on a fixture to line bore early 4 cyl Porsche blocks. Customer says money is no object so I decided that even at the end of my career, I have one more challenge in me. I can use existing tooling and will modify my Subaru fixture to mount the block ass end up to bore mainline and aux shaft bores, then invert to bore oil pump housing bore.
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Re: Ej20 Subaru bearings

Post by jed »

Dale I was just wondering if you are pinning the mains?? It helps a lot under high boost to keep the case haves from walking.
I like your work. :)
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Re: Ej20 Subaru bearings

Post by MotionMachine »

jed wrote: Sun Apr 18, 2021 9:56 am Dale I was just wondering if you are pinning the mains?? It helps a lot under high boost to keep the case haves from walking.
I like your work. :)
Yes, I've pinned a lot of them. But now I limit myself to doing Subaru blocks for only one race team and they buy semi finished billets only now, which come already pinned.
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