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04-24-2014, 09:15 AM | #1 |
Former Vendor
Member#: 383547
Join Date: Mar 2014
Location: Danville Virginia
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Line boring Subaru's, with pics
With the recent discussion about King possibly making oversize od main bearings, the ability to save cases would be a big plus for lots of builds. I have been line boring them for several years now and feel that I have perfected the best method to do this. I've admittedly harped on this topic before, but I feel strongly that line honing a Subaru is a crap shoot at best. You get taper, out of round, varying tunnel diameters. Don't get me wrong, I have a line hone also, it's a great tool but has it's limits. Suby's need to line bored and the shape of the block makes them difficult to bore on a traditional line boring machine. I've done them on mine but the set-up is awkward and most shops would probably not attempt it. I now do them on my CNC and it bores an absolutely straight round hole. Step #1 is measuring the cases to determine the amount that needs to be machined off the halves. In this case, pic 1 shows that #2 is worn .005", as shown on the gage. This means that .005" needs to be taken off both cases, as my research has shown that the measured wear is normally all on one side. Pic 2 shows the block being shaved the .005", after it has been indicated to less than .0005". Pic 3 shows the optical tool setting fixture that is used to adjust the boring tool to the correct diameter. It is basically a laser that measures how far from center the tip of the cutting tool is, thereby determining what size hole it will bore. Pic 4 shows the set-up on the CNC with the tool about to start a cut. Again, I indicate the top and bottom main to within .0005". I charge $350 for this process, the price would be less if King starts to make oversize bearings as that would eliminate the need to cut the halves. So vote early and vote often for that. I'll post a video on the next post I made with an earlier slightly different set-up, but it shows how the program works.
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04-24-2014, 09:19 AM | #2 |
Former Vendor
Member#: 383547
Join Date: Mar 2014
Location: Danville Virginia
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04-24-2014, 11:18 AM | #3 |
Scooby Guru
Member#: 108051
Join Date: Feb 2006
Chapter/Region:
AKIC
Location: Oneonta, NY
Vehicle:2005 WRX STi WRB |
How much are you cutting off the halves? You don't mention this but you're pushing the piston up further into the bore. So TDC is now moving up closer to the cylinder head. :/
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04-24-2014, 11:56 AM | #4 |
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Yes it does bring the piston closer to the deck by the amount that gets removed from the parting surface. This block for instance had .006" cut off each side. So if the block was at zero deck before, then .006" needs to be milled off the domes. If it's a large amount, I've taken as much as .012" off each side, then a thicker gasket might be easier.
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04-24-2014, 01:47 PM | #5 |
Scooby Specialist
Member#: 250152
Join Date: Jun 2010
Chapter/Region:
MAIC
Location: Pennsylvania
Vehicle:2006 WRX Limited OBP |
Subscribed to both this thread and your youtube acct. Next time you do a sleeve installation could you put that on youtube? I think people should see what entails sleeving a Subaru block before they jump to having their block sleeved, especially with the onset of the block insert success
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04-24-2014, 04:19 PM | #6 |
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I always love when people with real actual knowledge chime in!
Man i bet you wish you had a 5 axis to do those on. Can do everything in one shot with the cases all bolted and torqued together. Bore cylinders then bore the mains all in one setup! I guess you could make a 4th axis fixture to do them all at once so everything is true to eachother tho ..... Got a new 5 axis here at work a while ago. Hopefully in the future i'll be able to make some suby parts on it. I see billet blocks in my future....why...cause we can! https://www.youtube.com/watch?v=POzRrMISYgE |
04-24-2014, 04:31 PM | #7 | |
Former Vendor
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Join Date: Mar 2014
Location: Danville Virginia
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04-24-2014, 04:49 PM | #8 | |
Former Vendor
Member#: 383547
Join Date: Mar 2014
Location: Danville Virginia
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Quote:
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04-24-2014, 05:45 PM | #9 | |
Scooby Specialist
Member#: 250152
Join Date: Jun 2010
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Vehicle:2006 WRX Limited OBP |
Quote:
It was worth a shot :-/ I dont mind long vids... I have watched hour long ones before lol |
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04-24-2014, 06:41 PM | #10 | |
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Quote:
Thinking if you rotated the other way you can get the mains and bores in one setup on the 4th. Not sure if it would be worth the hassle plus you'd probably have to jack up the rotary table even more and be relying on the oil pan surface to be parallel to the mains so more trouble than its worth! sorry for the brain diarrhea. Looks like you got it all pretty dialed already tho! Keep up the good work! |
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04-24-2014, 07:50 PM | #11 |
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Thanks for this...
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04-24-2014, 09:27 PM | #12 | |
Scooby Guru
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Vehicle:2005 WRX STi WRB |
Quote:
Ahh interesting. Is that safe to have the pistons raised above deck hight? What about milling the chambers? Would deff tighten the quench pad up some. Just thinking outside of the box (ways to avoid thicker head gaskets) they're scary esp when making power. You'll also need adjustable cam gears to get valve timing into spec. Sounds like fun. Oh then tuning sounds like the most fun |
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04-24-2014, 09:29 PM | #13 | |
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That's sounds like fun!! |
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04-24-2014, 09:32 PM | #14 | |
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I wish I had money for a machine, I'd have to learn this stuff for myself sounds like a good time |
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04-25-2014, 01:12 AM | #15 | |
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04-27-2014, 01:19 AM | #16 |
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04-27-2014, 08:36 AM | #17 |
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I briefly spoke with you about some machine work and have heard other say the mains are little tight on new blocks.
Do you ever hone them at all to adjust for clearances? I bought bearings already and have 2 sets of std size ones and a set of .001 extra clearance ones to mix and match shells as that seems to be the way most people get their ideal clearances. |
04-27-2014, 01:05 PM | #18 | |
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04-28-2014, 12:43 AM | #19 |
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Vehicle:2005 forester STI |
^^ forgive my newness to the machining world but would you still do this with the softer aluminum oem bearings? Or because of the nature of the material in the oem sti bearings (say on a dd build) would clearances on the tighter side be a good thing?
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04-28-2014, 08:54 AM | #20 |
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Tight clearance on a stock rebuild is fine. Many many years ago I did a lot of work for the local Subaru dealer. I'm talking about early EA 1.4 and 1.6 motors. I would grind the crank on the high side to tighten up the clearances overall, but the center journal I would grind so that there was .0000" to .0005" clearance. That is what Subaru wanted, zero clearance. We never went to zero, kept it to .0005" and it got rid of the noise and low oil pressure on a rebuild. The bearing material has nothing to do with making sure the line bore is straight. Most shops want between .0015" and .002" main clearance and line honing or line boring on the top side of the spec give you straight and equally sized bores and give you that little extra clearance without using +.001" bearings. But don't forget, the size of the mainline is only 1 of 3 things that determine your final clearance. Bearing thickness and journal diameter are the other 2. Here's a pic of a block I just line bored.
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04-28-2014, 11:42 AM | #21 |
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^^ spoke to dale at Motion Machine this morning. WOW. Bigtime knowledge coming out of this guy, and very easy to talk to.
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04-28-2014, 12:51 PM | #22 |
Scooby Guru
Member#: 108051
Join Date: Feb 2006
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Location: Oneonta, NY
Vehicle:2005 WRX STi WRB |
How much does line boring the block narrow the oiling area for the bearings. And can you bring that back into spec? I'm guessing the back end of a micro meter can give this spec?
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04-28-2014, 02:51 PM | #23 |
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I'm not sure what you're talking about. Do you mean what affect does milling the cases have on the oil groove depth maybe? I suppose the overall surface area of the groove is affected by the amount that is cut off the block but it is such a small amount it's negligible. A better question is why Subaru offsets that groove depth toward the pan side of the motor. It is not the same depth all the way around the bearing. I noticed this when I first measured the blocks for steel inserts in the center 3 mains, something I will have to duplicate in the design I guess.
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12-02-2015, 07:38 PM | #24 |
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Do you still offer line boring?
I have an EJ22T I am trying to assemble with ARP case bolts. |
12-02-2015, 09:30 PM | #25 |
Former Vendor
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yes I do, return pm sent
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