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Poll: High compression turbo life


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52 replies to this topic

#26 kingbobdole

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Posted 11 February 2007 - 10:17 PM

whats a 28 wagon?


A typo. its fixed.

#27 GeneralDisorder

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Posted 12 February 2007 - 12:53 AM

Doesnt the swift share parts with the Geo Metro??


The Swift is the Suzuki branded version of the Chevy Sprint, which was originally named the Chevy Sprint Metro. When the swift went through a body change in 89?, the Chevy version wasn't updated till 91?, and at that time the name was changed to the Chevy Metro, or Geo Metro depending on how it was badged. So asking that is a bit like asing if an EA81 shares some parts with an EA82.... they are essentially the same car that underwent a body change. And depending on year, many parts will probably interchange.

GD

#28 robm

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Posted 12 February 2007 - 03:46 PM

Actually, Justy = Suzuki, just not around here.

http://en.wikipedia....ki/Subaru_Justy

#29 Gravityman

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Posted 12 February 2007 - 08:28 PM

well cryo treating cast aluminum improves its resistance to deformation under high temperatures. I've not heard much about its use with cylinder heads, but with cast pistons the gains are great enough that you can run tighter tolerances in some cases.
also maybe some copper head gaskets?
also why not just have the block or the heads decked or make a custom copper head gasket to get you into the mid to low 8's with the 7.7:1 pistons? mid 9's and turbo with a known weak engine like the ea82 just seems like way more trouble than its worth.


Funny you mention that, I am doing just this but for my ER27. Already have the copper head gasket custom built. Brand new pistons will be here tomarrow or wednesday. The pistons, rings, valves and head will be getting cryo-treated and ceramic coated and moly coating on the piston skirts. The cyl block is getting o-ringed (its at the machine shop right now). Heads are getting ported. Trying to source a set of studs but might have to stick with bolts.....Need I go on? I hate to say that I am trying to set a new benchmark. :banana: :headbang: :clap:

BUT I know that I will not be able to accomplish this without everyones support. Thanks!

I pick H - Turboing a 7.7-1 will be 8.0-1 not high compression but plan on making it last MORE then 2 years before any major maintnance issues. When i say major i mean minor issues.

#30 4x4_Welder

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Posted 13 February 2007 - 12:40 AM

Actually, Justy = Suzuki, just not around here.

http://en.wikipedia....ki/Subaru_Justy


Ok, so from 94 on, the Justy was a Suzuki. But, was it beforehand, or straight Subaru?
Japanese manufacturers shared so many components through the late 90's, I would have to take a look at the two engines side by side to see if they are different.
I do know that there was a 3cyl turbo version of the Suzuki Swift, 1.0l, but even with the turbo it was slow. The only way I have seen that engine move quick was in a go-cart.

#31 GeneralDisorder

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Posted 13 February 2007 - 02:07 AM

It's straight Subaru. There's no Suzuki in the *real* Justy. Later on they may have used the name, but it's not even close in design. The suzuki 1.0 Liter engine was a SOHC, 6 valve. The Justy uses a 1.2 (or 1.0 JDM) SOHC, 9 valve arrangment. It's a bit more powerful as well due to it's higher performance valve setup.

GD

#32 Snowman

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Posted 13 February 2007 - 02:49 AM

Didn't WJM's 9.5:1 wagon run for like 20,000 miles?

The first thing that comes to mind on this issue is that you should remember that anybody who actually builds a high compression EA82T is going to beat the living snot out of their engine.

The second thing that I would be curious about is how many people who have done it started out with NEW or otherwise PERFECT heads and a block that hadn't seen much abuse, which I think would be a requirement to get any longevity out of a hopped up EA engine.

#33 daeron

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Posted 13 February 2007 - 05:08 AM

Didn't WJM's 9.5:1 wagon run for like 20,000 miles?

The first thing that comes to mind on this issue is that you should remember that anybody who actually builds a high compression EA82T is going to beat the living snot out of their engine.

The second thing that I would be curious about is how many people who have done it started out with NEW or otherwise PERFECT heads and a block that hadn't seen much abuse, which I think would be a requirement to get any longevity out of a hopped up EA engine.


Exactly. suzuki or not, the justy had no turbo EA-82...

a simple poll is far from demonstrative that it is impossible.. it merely indicates what many people are finding out.. you need to build an engine out of top-notch blocks and heads... SPECIFICALLY with power in mind, as opposed to just slapping together what youve got laying around. Should you choose to simply "assemble" a high comp turbo motor, chances are longevity will be short, unfortunately.

There were two or three people, one in particular I recall, who were trying to do just this.. One person whose name totally escpaes me went through two or three new blocks before one was not defective in some way, but I can't even remember the username to search for it, :-\

Thats not to say they aint fun while they last..

#34 mikeshoup

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Posted 13 February 2007 - 08:36 AM

Phil: Any idea what happened with Noss's wagon? Has the new owner had any bad luck with it yet?

Personally, I think high compression Turbo motors are evil.

#35 mdjdc

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Posted 13 February 2007 - 09:18 AM

Hi guys:

As you all may recall I built a high comp turbo engine mid last year. I started with a brand new, not rebuilt engine. Yes, completely new engine straight from japan. Then I swapped out the pistons and dropped it into my car. I'm probably going on seven months now and the engine has not given me a single hiccup. I am getting ready to put an oil cooler on it, but I will wait until it warms up a little. I do not beat the engine because I built the baby for better low end torque while off roading. It does a nice job for me and I can keep you all updated. If it blows I'll definitely let you know what happened. I'm also running stock boost from the turbo.

I like the better throttle response and low end, but I'm not looking to make any super times.

#36 Forkspear

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Posted 15 February 2007 - 10:42 PM

I vote A C and G

I lost the rings in one cylinder so I swapped a carbed block from the junkyard. It wasnt the greatest. It had 146k I think. It lasted a couple trips to town on stock boost. About a week later I gave it 12 pounds and went for a freeway run. Got finished and it ran like crap. Not wanting to deal with it i just keep driving. I dont think it has been six months yet. It still ran a 15.6. I beat two 5.0s and a 4.6 from a roll 2 weeks ago. Being slow is annoying so im going to put rings in my old block with turbo pistons. No more of this high compression crap. Well maybe with stock boost it would be alright on something im not going to hotrod around all the time.

#37 Vanislru

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Posted 16 February 2007 - 12:09 AM

Well over a year on my high comp turbo ea82, and alot of that is abusive 4 wheeling pushing 29" tires around.

#38 carfreak85

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Posted 16 February 2007 - 12:57 PM

I'm going to try installing some carby pistons in my EA81T at some point. I think it will hold up better than the EA82s.

#39 daeron

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Posted 16 February 2007 - 08:16 PM

I'm going to try installing some carby pistons in my EA81T at some point. I think it will hold up better than the EA82s.


I thought the ring lands were deepest on the ea82 pistons????? i may be wrong, but i thought id say something.

#40 carfreak85

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Posted 08 March 2007 - 12:22 PM

I'll choose F. I just found a lead on a fully rebuilt MPFI EA82. With proper fuel management, this car should last for a while. I'll keep everyone updated.

#41 Gloyale

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Posted 08 March 2007 - 10:42 PM

I'm thinking of going the high compression route simply because the Turbo pistons are very hard to find. The machine shop thats got my engine right now can't get me a new set. Standard size or otherwise. Does anyone know where to find a set of .030 over 7.7 pistons? Anyone ever tried milling out a little of the 9:1 carb pistons to make a 8.x?

#42 crazy D

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Posted 08 March 2007 - 11:14 PM

It's straight Subaru. There's no Suzuki in the *real* Justy. Later on they may have used the name, but it's not even close in design. The suzuki 1.0 Liter engine was a SOHC, 6 valve. The Justy uses a 1.2 (or 1.0 JDM) SOHC, 9 valve arrangment. It's a bit more powerful as well due to it's higher performance valve setup.

GD



question.....the justy was a 3 cyl correct? how were the valves arrenged per cylinder and is it a flat 3? and how would that work.....wouldn't the engine be unbalanced?

#43 Gloyale

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Posted 08 March 2007 - 11:17 PM

question.....the justy was a 3 cyl correct? how were the valves arrenged per cylinder and is it a flat 3? and how would that work.....wouldn't the engine be unbalanced?


It is not a flat 3. It is an inline 3. Can we start a new thread for that?

I really would like to talk more about the high compression Turbo EA82 subject.
Can anyone tell me where to find aftermarket pistons?

#44 mikeshoup

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Posted 08 March 2007 - 11:19 PM

Can anyone tell me where to find aftermarket pistons?

http://ramengines.com/

#45 Gloyale

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Posted 08 March 2007 - 11:55 PM

http://ramengines.com/


Hmm.. I don't think I want to spend 500 bucks on pistons. I was just lookin for some OEM style 7.7:1's

#46 mikeshoup

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Posted 09 March 2007 - 12:19 AM

Hmm.. I don't think I want to spend 500 bucks on pistons. I was just lookin for some OEM style 7.7:1's

Give them a call, they can certainly make you OEM style cast oversized pistons. Or at least get you in touch with someone who can. RAM doesn't have everything they offer on their website.

It looks like to me, you can get a cast piston kit with rings from them for $222.50

#47 Gloyale

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Posted 09 March 2007 - 12:24 AM

Give them a call, they can certainly make you OEM style cast oversized pistons. Or at least get you in touch with someone who can. RAM doesn't have everything they offer on their website.

They are targeted towards aviation, so a lot of what they have is for higher performance.

Seems to me though, $500 isn't a bad deal. Subaru pistons go for about $65 (x4 = $260), then $200 for a ring set (= $460). Then RAM will throw in an oil pump and water pump.

Seriously though, give them a call and see what they can do.


It's a good start and I appreciate it. I have a nearly new WP and OP already. I really am thinkin more about dishing the standard 9:1s out a little. Theres got to be some meat for it, caus there's already the valve recesses. If I just went as deep as they are in a tub around the piston. When I say "I" I mean the machinist doing the work. I'm paying to make it happen so it's still "me " doin it right?

#48 4x4_Welder

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Posted 09 March 2007 - 01:12 AM

If EA82 pistons are anything like the EA81 piston I am looking at right now, there is no space for a dish. The crown of the piston is pretty thin.



#49 daeron

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Posted 09 March 2007 - 06:27 AM

I was looking at my SPFI NA cylinder heads while I had my engine apart, and it seemed to me that you could likely do a bit of cutting in the combustion chamber, maybe open the side away from the spark plug up a little bit into a kidney shape.. this would have two effects, the first being to increase combustion chamber size and lower compression to 8.x, and also it could be done in a careful manner to increase the quench design inherent in the head... which in turn allows for you to run less ignition advance without pinging, and give more power.

I couldn't tell how much could safely be ground away, because I left my valves in and just had the heads decked 0.005 to get them flat.. BUT it seemed like a REALLY viable idea for the entire high comp turbo route...

#50 Gloyale

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Posted 09 March 2007 - 12:47 PM

I was looking at my SPFI NA cylinder heads while I had my engine apart, and it seemed to me that you could likely do a bit of cutting in the combustion chamber, maybe open the side away from the spark plug up a little bit into a kidney shape.. this would have two effects, the first being to increase combustion chamber size and lower compression to 8.x, and also it could be done in a careful manner to increase the quench design inherent in the head... which in turn allows for you to run less ignition advance without pinging, and give more power.

I couldn't tell how much could safely be ground away, because I left my valves in and just had the heads decked 0.005 to get them flat.. BUT it seemed like a REALLY viable idea for the entire high comp turbo route...

I asked my machinist about this when I dropped of my heads to be surfaced and Vac tested. He seemed to think it would hurt the quench effect and may hurt performance. That is why I started thinkin about custom pistons. The "tub" in a turbo piston is about 6mm deep. I was thinkin if you mill a tub in the NA pistons about 3mm deep you'd be there. The valve relief cuts are about that deep already.




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