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Old 08-29-2012, 11:40 AM   #1
Mojambo
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Default ASP motor build....it's time

Hey,

So this past weekend at the Canadian Nats I blew out yet an other ring land. Happened in the Test & Tune, but didn't know until the next morning on startup.

My co-driver and I got 1 run each, but the intake was sucking up all the oil and it was getting messy.

I managed to get it home over 300 miles away.

So time to re build!

Car: 06 STI, built for ASP.

objective: Rebuild to *SP legal specs with forged pistons without blowing up the bank account. As always, raising the rev limiter to 7600

Budget: as limited as possible, but willing to replace what needs to be replaced.

The motor has 55K miles. Cyl #4 was redone at 53K miles for a broken ring land under warranty

-----

My thoughts on what I will do:
-tear engine down and split short block
-inspect bores to see if they are still good.
-inspect bottom main bearings for clearance and check crank/rods
-possibly rebuild heads with new seals while I'm in there
-new timing belt and pullies..etc while I'm there

what I'm not sure if I should do:
-New oil pump? 11mm, 12mm?...do I need more oil in the pan and will it help the oiling at 7600?
-water pump?
-fancy crank pulley(Fluid damper)??
-do I HAVE to get the crank re-polished if I use new OEM bearings if it is found to be in good condition?
-Get the bottom rotating assembly balanced(assuming it can be done by balancing the 3 heaviest rod/piston combo?
-re-hone and/or rebore? 0.020?..$$$ for what gains...


conclusion:

I can easily not split the block and just drop in the OEM/spec forged pistons and re-assemble. This is a cost VS. gain thing, so it's about picking the right things for me.

Any thoughts or advice would be appreciated.

Thank you

Eric
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Last edited by Mojambo; 09-11-2012 at 11:41 AM.
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Old 08-29-2012, 12:55 PM   #2
subydude
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If the bearings have been living with 7,600 rpm for a while that means the current clearances are working ok. I wouldn't mess with it in that regard. Dropping in some forged pistons is an option, but you'll probably get some not optimal PTW clearances. If you can get good PTW numbers I would just drop and go.

If you're splitting the block, then a hone and fitment for new pistons is all I'd do. Can balance it as well, but make sure you have the OE specs to make it within tolerances. Re-use the OE oil pump, it's fine for what you're doing, and IIRC you can't replace the oil pan in SP so no dice there.

If we knew the budget we could say what to do. If you're looking at under $1k, then don't split the block. If you're looking at $2k and up, then split the block and triple check all the clearances/set them yourself to a good number.
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Old 08-29-2012, 03:08 PM   #3
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^^^thanks

you can change the oil pan and pump in SP. The 7600 has only been this year and for a few events only, so there is not much miles at that RPM, so longevity is unknown.

I called Crawford and talked to them about the SCCA certified pistons they are selling. I'm told they are made for my exact reason. Identical OEM replicas and are made to drop in.
I asked about the PTW with the forged units and was told they were meant to drop in. So I'm wondering what type of material they are made of...? no rings either, so I'd buy some new OEM rings and gap them as per spec. that's $1k right there.

I think the biggest factor right now is going to be how the bores look. if my bores are all messed, then I'll have to see if a hone can clean them up and if I need an overbore. For the price of a bore, I can get a used SB with clean bores from a friend. 10k miles on the SB. he had slight rod knock, so I can get it for real cheap.

I think that $2k would be realistic. pistons, rings, main/rod bearings, hone, gaskets and new timing belt kit.

I'm emailing other piston makers to see what they would charge for this type of custom piston.

Can I shim the 10mm pump for a little more flow? I may do some lapping with it too, so I should probably look into a bigger oilpan. In that case would that warrant a bigger oil pump?

Thanks
Eric
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Old 08-29-2012, 04:10 PM   #4
subydude
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Stick with the 10mm and if you feel the need for higher pressure, shim it. The shim doesn't increase flow, it increases pressure. The 11mm pumps are what most people shim since their relief valve opens earlier than the 10mm pumps. For peace of mind, all the Ver7 and Ver8 EJ207's come with the 10mm pump and rev happily to 8k+ unshimmed.

I'd wager a guess that the crawfords are 4032 since it expands less. If it's 2618, then it'll expand more. I'd still measure in triplicate for a drop in and decide from there if a hone is needed. One thing that I'd like to note here, a set of off the shelf pistons is $500 with rings. They also look a lot like the OE pistons. I'm not advocating cheating, but in this case it's a mostly identical part for hundreds less. But, that's my opinion and if you want to be 100% legal then crawford is the only game I'm aware of. I would be wary of their statement that they're drop and go when they don't give numbers.

One thing I've noticed in the cars that cracked ringlands, the ring gap on the OE pistons was rather tight. Several people I've talked to mentioned a possibility of the rings closing and that cracking the ringland. I found that somewhat interesting, and thought I'd pass it on.

If you can do oil pan and pickup I'd roll with a killer b setup. I have it, I like it, it's an extra quart in the pan and a nice pickup to boot.

If the bore is messed up, it might be worth looking into the first overbore (99.75mm) and finding a set of pistons for it. Would guarantee correct PTW clearances.

If you split, check what the OE clearances were on the main/rod bearings just for reference. I'm using 14-15 thou on the mains and 19-20 thou on the rods. The key here is consistency of clearances with the #3 main being slightly looser as it's feeding the #2 and #3 rod bearing.

If you're doing a new timing belt, do the water pump at the same time. It's not that expensive, and it's definitely a peace of mind deal. Plus, I don't like taking the t-belt off more than I have to!

Last edited by subydude; 08-29-2012 at 06:00 PM.
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Old 08-29-2012, 05:38 PM   #5
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fantastic advise. I was thinking Crawford was making the Pistons out of 4032 for the same reason. I doubt the PIC on the Crawford website is accurate. It doesn't look like a OEM piston to me. (no valve reliefs)

I realize the price diff compared to other drop ins, but I do want to be legal 100%. Otherwise my friend has a perfect set of Wossners for me. For the price diff reason, I've contacted a few Piston makers to see what they can do. I know for a fact CP has made them before.

10mm it is. Good point on them being on the 8k JDM's.

I'll check the ring gaps and compare to what the OE specs are. I can always gap to the higher tolerance.

I've got the killer B pickup already, but the OEM oil pan.

For the PTW, I'll see what the other mfg's have in mind and go from there. My buddy has all the right measuring tools to check all the specs on the block, so I'll check everything out all over.


Would you guys recommend the OEM complete kit? I've heard that you can have alot left over after the re-build.

thanks
Eric
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Old 08-29-2012, 06:09 PM   #6
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Quote:
Originally Posted by Mojambo View Post
fantastic advise. I was thinking Crawford was making the Pistons out of 4032 for the same reason. I doubt the PIC on the Crawford website is accurate. It doesn't look like a OEM piston to me. (no valve reliefs)

I realize the price diff compared to other drop ins, but I do want to be legal 100%. Otherwise my friend has a perfect set of Wossners for me. For the price diff reason, I've contacted a few Piston makers to see what they can do. I know for a fact CP has made them before.

10mm it is. Good point on them being on the 8k JDM's.

I'll check the ring gaps and compare to what the OE specs are. I can always gap to the higher tolerance.

I've got the killer B pickup already, but the OEM oil pan.

For the PTW, I'll see what the other mfg's have in mind and go from there. My buddy has all the right measuring tools to check all the specs on the block, so I'll check everything out all over.


Would you guys recommend the OEM complete kit? I've heard that you can have alot left over after the re-build.

thanks
Eric
Maybe talk to Micah (3MI Racing/HomemadeWRX) and ask about the pistons. He seems to have a good grasp of what's being made out in the "custom" world.

Get the pan to match the pickup, it's good juju.

If you're doing 4032 PTW should be around 25-30 thou. 2618 would be 30-40. These are just suggestions though, go with what the maker suggests.

OEM gasket complete kit is nice if only because you know everything is there and you don't have to worry about it. I have a few things left over, but probably less than 1/3 when it was all said and done.
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Old 08-30-2012, 10:04 AM   #7
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I thought in SP you couldn't mess with the engine internals? What can you legally do here?

Interested as i've been thinking of campaigning a V8. I know all the real go fast parts are restricted like cams, bore/stroke.
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Old 08-30-2012, 10:23 AM   #8
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The only things you can touch are a factory overbore or 0.020 if not listed. Deck the head to factory spec or 0.010 if not listed.

-change pistons to OEM copies but made of a forged material.

-Port match 1" into the openings

That's it.

I'm getting a few emails back from piston makers. They are wondering if it is the PIN and Piston combo that needs to meet the OEM weight, or the piston with out Pin needs to be exact....gonna drop this one on the SCCA boards

Thanks
ERic
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Old 08-30-2012, 11:42 AM   #9
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Quote:
Originally Posted by Mojambo View Post
The only things you can touch are a factory overbore or 0.020 if not listed. Deck the head to factory spec or 0.010 if not listed.

-change pistons to OEM copies but made of a forged material.

-Port match 1" into the openings

That's it.

I'm getting a few emails back from piston makers. They are wondering if it is the PIN and Piston combo that needs to meet the OEM weight, or the piston with out Pin needs to be exact....gonna drop this one on the SCCA boards

Thanks
ERic
Piston weight to piston weight, to be accurate. of course the pins should be the same or heavier as well.

The builder I used had JE make mine. good luck!
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Old 08-30-2012, 12:10 PM   #10
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haven't heard back from JE yet. Thanks for the clarification. I posted on SCCA forum and I suspect I will get the same answer. My brain tells me piston to piston, but getting 3 emails asking questions about both weights together to meet the requirement has me thinking

Thanks!

Eric
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Old 09-02-2012, 03:27 AM   #11
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Subscribed. Been hoping someone would go on the hunt for ASP-legal pistons a'la Stompy.

Almost went that way for myself, but went the SM route as it was easier (not planning on full SM prep for my 07 STI, cracked ringlands and went with a TopSpeed shortblock, larger turbo, and support mods).
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Old 09-02-2012, 01:35 PM   #12
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I confirmed with Crawford that what they are selling are SCCA legal *SP pistons.

I've emailed various piston mfg's and they are all wanting large custom costs and are mostly unsure how they will get the forged piston to match the OEM piston weight. Crawford has done the R&D and if you price it out, they come out on top.

Eric
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Old 09-02-2012, 02:26 PM   #13
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Quote:
Originally Posted by SubieEngineer
Subscribed. Been hoping someone would go on the hunt for ASP-legal pistons a'la Stompy.

Almost went that way for myself, but went the SM route as it was easier (not planning on full SM prep for my 07 STI, cracked ringlands and went with a TopSpeed shortblock, larger turbo, and support mods).
You sound just like this guy I auto x with
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Old 09-03-2012, 03:42 PM   #14
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Quote:
Originally Posted by Mojambo View Post
I confirmed with Crawford that what they are selling are SCCA legal *SP pistons.

I've emailed various piston mfg's and they are all wanting large custom costs and are mostly unsure how they will get the forged piston to match the OEM piston weight. Crawford has done the R&D and if you price it out, they come out on top.

Eric
That's interesting... I remember reading that Crawford had them, but thought someone else did, too. Suppose not.

Quote:
Originally Posted by purplewrx View Post
You sound just like this guy I auto x with
I'm sure I sound like many STI owners out there!
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Old 09-10-2012, 01:25 PM   #15
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Little update:

I have it down to a SB with the pistons out. #2 was busted, but stayed together until I removed the rings.

Moving forward I'll be building to *SP specs and with the best accepted tolerances within the OE manual. The bores are not pretty, so I'll be getting a bore to 100mm.

parts ordered:
-OEM master gasket kit
-OEM 100mm rings
-OEM main and rod bearings
-Gates timing belt kit
-Crawford V2 AOS

Waiting on vendor:
Crawford SCCA spec pistons to 100mm overbore
Tomei EL headers

parts I'm lookin at:
Killer B oil pan/windage

Anything else I'm missing?

Plans for the build:
-Torque plate .020 bore
-0.010 off the head
-Balance rotating assembly to the lightest combo of rod/piston to 8K rpm


Seeing that the rules are specific I can't play inside the assembly

I'm the engine builder along with a machinist friend who has built a few. I have all the precision measuring tools: micrometers, dial bore gauge, dial indicator, flat granite to 0.0002 flatness.

more to come...

Eric
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Old 09-10-2012, 02:54 PM   #16
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Has anyone else heard bad things about gates timing belts? We put one on a Ver 4 sti motor and Topspeed recommended oem.
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Old 09-10-2012, 03:06 PM   #17
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I'm looking at the Gates Kevlar belt. Supposed to be stronger if that's worth anything
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Old 09-10-2012, 03:12 PM   #18
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Yeah I put tgat one in my motor as well. But after some troubleshooting I was told not to go with them for the Ver4 motor.
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Old 09-10-2012, 06:36 PM   #19
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I used/will use it in the SM car.
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Old 09-10-2012, 09:10 PM   #20
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Since you are doing the killer b oil pan and windage tray, why not the pickup as well? Seems like a little insurance is well worth it.
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Old 09-10-2012, 09:37 PM   #21
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^^pick up is already in there. not too sure about the PAN and tray. extra $500..It's already over $3k
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Old 09-10-2012, 10:01 PM   #22
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Just finished measuring the bores for being Oval and Tapered:

the first numbers are inches then mm. Dial bore gauge was zeroed to 99.5

OEM specs:

Taper:
Standard
0.015 mm (0.0006 in)
Limit
0.050 mm (0.0020 in)
Out-of-roundness:
Standard
0.010 mm (0.0004 in)
Limit
0.050 mm (0.0020 in)


Cylinder 1
A axis (horizontal) B axis (vertical)
0.0003=0.00762 0.0006=0.01524
0.0002=0.00508 0.0002=0.00508
0.0002=0.00508 0.0002=0.00508
0.0004=0.01016 0.0001=0.00254
Cylinder 2
A axis (horizontal) B axis (vertical)
0.0004=0.01016 0.0008=0.02032
0.0007=0.01778 0.0007=0.01778
0.0007=0.01778 0.0008=0.02032
0.0011=0.02794 0.0009=0.02286
Cylinder 3
A axis (horizontal) B axis (vertical)
0.0008=0.02032 0.0006=0.01524
0.0009=0.02286 0.0005=0.0127
0.0010=0.0254 0.0006=0.01524
0.0009=0.02286 0.0009=0.02286
Cylinder 4
A axis (horizontal) B axis (vertical)
0.0003=0.00762 0.0006=0.01524
0.0005=0.0127 0.0005=0.0127
0.0003=0.00762 0.0005=0.0127
0.0009=0.02286 0.0005=0.0127



of course this is going to be bored to 100mm, but I wanted this down in this log
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Old 09-10-2012, 11:57 PM   #23
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Quote:
Originally Posted by 04trailsti View Post
Has anyone else heard bad things about gates timing belts? We put one on a Ver 4 sti motor and Topspeed recommended oem.
Having gotten my car back from TopSpeed last month, I went all OEM on the timing stuff, save the water pump (Aisin cast impeller version). I was told by a local European shop to avoid Gates belts, too. With that said, my accessory belt is OEM.
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Old 09-13-2012, 12:32 AM   #24
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I could be wrong, but I believe the OEM belt is made for Subaru by Gates. Gates manufacturers something like 85% of all OEM timing belts out there.

They standard Gates timing belt / kit is OK. The problem lies with their blue "Racing" belt. The racing belt is thicker, and the blue paint comes on. Overtime this blue paint wears off onto the pulleys, causing buildup and slowly increasing the diameter. Eventually, it can lead to jumping a tooth.

Stick with the standard Gates kit or OEM, and you'll be fine.

During my recent motor build I put on a KillerB oil pan and windage tray. My last motor failed due to a spun bearing, so it was definitely worth it, as it can only help. I can now run 6 quarts of oil instead of 5.

I'd also look into the Invidia Race Header. They have been delivering some very impressive gains lately, and TopSpeed managed to get 18whp/50wtq from their tuned stock-turbo STI. The Tomei setup also makes great gains, and Tomei includes an upipe and all needed gaskets/bolts/heat wrap too I belive.

Do you already have larger injectors and a fuel pump?
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Old 09-13-2012, 01:22 AM   #25
SubieEngineer
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^ All except the turbo-downpipe gasket are included with the Tomei ELH, oddly enough.

I seriously thought about the KB oil pan, but that was more than I wanted to spend on it at the time.
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