Turbo rebuild and upgrade to 20g questions

[Spoolingaround]

Hey all

Recently my 14b gave out on me and gave me the dreaded turbo shriek. Im currently using a borrowed 14b turbo and the owner needs it back soon.

My first question is: Is there any chance that I could have damaged the cartridge (the housing for the bearings and all the components excect the two wheels and covers) and that it would not be useful at all? I called a turbo rebuild shop and they said that there is a good chance that its completely worthless if it was shrieking which I thought was suspicious especially cause the guy seemed to be trying to sell me on a garrett turbo.

Secondly, I am pretty confident I want to go with a 20G with a billet wheel. I haven't decided on the specific compressor wheel yet but no worries. I have read a little bit about the 20G tending to surge with the factory compressor housing (ported to fit a 20G wheel). Short of buying a $400 anti surge housing, what are my options to limit this? I was planning on using the td05 turbine wheel from my 14b with an 8cm housing i was using on my 14b. Keep in mind I will be using internally gated and low boost for a while until I have more $ to upgrade my injectors which are currently evo 560s.

 

[92AWDHX40]

Turbo making noises that's not good.

 

[Joethefallen23]

Open her up and look at the journal surfaces. If they're all scratched and groved up, it's pretty much junk.

 

[JusMX141]

I've never heard of anyone having issues with a 20G surging, and I've built a PILE of them over the years.

Those claiming they've suffered surge are pushing the compressor way beyond the map and should probably upgrade to a larger turbine to slow spool down a bit (reducing surge at the onset of boost) as well as pick up some much-needed turbine flow.

 

[Spoolingaround]

So i am in the midst of tearing it down now. I got the turbine wheel separated from the compressor wheel and I have two concerns. First, the compressor wheel definitely came into contact with the housing as there is visible damage on the wheel and housing, which likely led to small metal fragments going into the engine

As soon as I heard the noise I babied it home without spooling the turbo to the best of my ability (~15 miles) then it didn't run again until i swapped the turbo, changed the oil and the oil filter. What are the chances that there was any damage by these metal fragments or that there are still some flying around in there?


Second
I may end up rebuilding the borrowed 14b as a 16g as a favor for letting me borrow it (not paying for the parts) in the near future. Is a right hand threaded turbine wheel ill advised for a 16g?

Thanks.

 

[JusMX141]

First, the compressor wheel definitely came into contact with the housing as there is visible damage on the wheel and housing, which likely led to small metal fragments going into the engine

Yeah, a thrust failure. Any large particles would be caught in the intercooler.

Also, it's VERY rare that a 14B develops thrust wear unless something is blocking the oiling hole in the thrust plate. Hopefully it's not metal from within the engine's oil supply.

I may end up rebuilding the borrowed 14b as a 16g as a favor for letting me borrow it (not paying for the parts) in the near future. Is a right hand threaded turbine wheel ill advised for a 16g?

What exactly do you mean by "rebuilding a 14B as a 16G"? Does this mean you'll be replacing the compressor wheel, getting the compressor cover machined, getting the center housing machined, and replacing the 6cm2 housing with a 7cm2 housing?

 

[Spoolingaround]

What exactly do you mean by "rebuilding a 14B as a 16G"? Does this mean you'll be replacing the compressor wheel, getting the compressor cover machined, getting the center housing machined, and replacing the 6cm2 housing with a 7cm2 housing?

Yes. Buying the complete superback rebuild kit for 16, 18 and 20g from G-Pop Shop :: Mitsubishi TD05/TD05H/TD06 Complete Superback and EVO Rebuild Kit | I was unaware that the center section had to be machined, I thought the only thing for 14b to 16g swap was the machining on the housing, the wheel and the thrust plate (flatback to superback design)

Although I may just try heavily porting the 6 cm2 housing. I have a friend who works at a machine shop so getting stuff machined is discounted for me


So but for a 20g I know I would have to have the center housing machined then.

Yeah, a thrust failure. Any large particles would be caught in the intercooler.

Also, it's VERY rare that a 14B develops thrust wear unless something is blocking the oiling hole in the thrust plate. Hopefully it's not metal from within the engine's oil supply.

Well... I had used this turbo on my old block that threw a rod and there were definitely metal pieces flying around then. But that was three years ago, it sat for three years and since then I put a fresh 6 bolt in it and its been running well for about 4k miles. Also I knew the turbo had significant shaft play but I just didn't really have the funds to replace it at the time... And it was running at 25lbs... So basically I shoulda seen this coming...

 

[JusMX141]

I was unaware that the center section had to be machined, I thought the only thing for 14b to 16g swap was the machining on the housing, the wheel and the thrust plate (flatback to superback design)

Nope...center housing needs machined, too.

Although I may just try heavily porting the 6 cm2 housing. I have a friend who works at a machine shop so getting stuff machined is discounted for me

Doesn't matter how big you port the inlet- you're not changing the physical a/r ratio of the housing. You can't port a 6cm2 housing into a 7cm2 housing- it's no different than trying to port a 2.0L into a 2.4L.

So but for a 20g I know I would have to have the center housing machined then.

Small 16G would need the center housing opened up to roughly 61.5mm, and a Big 16G / 18G / 20G would need the center housing opened up to about 69.5mm.

Well... I had used this turbo on my old block that threw a rod and there were definitely metal pieces flying around then. But that was three years ago, it sat for three years and since then I put a fresh 6 bolt in it and its been running well for about 4k miles. Also I knew the turbo had significant shaft play but I just didn't really have the funds to replace it at the time... And it was running at 25lbs... So basically I shoulda seen this coming...

Never use a turbo from a blown motor without rebuilding it first as all of the metal from the failed engine is packed into the turbo's oil supply.

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[Spoolingaround]

Never use a turbo from a blown motor without rebuilding it first as all of the metal from the failed engine is packed into the turbo's oil supply.

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Well i just died a little on the inside

What are the chances that I still have metal fragments floating around in my engine/oil and what can I do about it?

I just send some drawings and dimensions out to get quoted for machining, but in the meantime here are some pictures on the inside of the journal. What do you guys think? Rebuild-able or not?

 

[JusMX141]

Those journals are junk- grooved terribly from oil contamination, plus there are clearly high and low spots as noted by the wear pattern.

You can get it honed to the next-available oversize, but the cost of the labor and the oversize bearings as well as getting it machined for whatever compressor wheel you want to use would offset the cost of a replacement center housing.

 

[Spoolingaround]

Alright. I'll toss it out. I'll be looking for a 20G to buy then.

My main question is still do you guys think there is much risk of fragments getting into the intake and causing damage?

 

[Spoolingaround]

My main question is still do you guys think there is much risk of fragments getting into the intake and causing damage?

Well crap... I noticed blue smoke from the exhaust. Sure enough im burning a little oil, from what I first thought would be the borrowed turbo because it was old and had a lot of miles on it. Did a compression test and I found about 110-120 psi across the board.

The motor only had about 4k miles on it...

 

[JusMX141]

No metal fragments small enough to reach the engine could cause damage serious enough to cause low compression. Anything large will get stuck in the intercooler.

 

[Seamus]

A leaking turbo generally smokes under boost. If ## getting smoke at idle or low loads its engine related. Also are you doing the compression test correctly? People often seem to so them wrong and get inaccurate results. Oil smoke and low compression are often unrelated.

 

[Spoolingaround]

Also are you doing the compression test correctly? People often seem to so them wrong and get inaccurate results. Oil smoke and low compression are often unrelated.

Well, I pulled out all the plugs which were very fouled with oil (especially since they only have about 4k miles on them) Then I disconnected the fuel injectors, screwed in the testing unit to each cylinder and cranked it over with the throttle wide open. Only read 110-120 across the board.

So I know that there is oil getting into the combustion chamber (as you can see by the plugs) which I am really really hoping is from the turbo alone (not the motor as well).

Why could I be getting such low compression numbers the if low compression and burning oil aren't usually related? WTF

I just purchased a new 20g from one of the guys on the forum and I was planning to put it on in about two weeks when I take the car home to Cincinnati and I have access to my shop, however now I am a little leery.

 

[JusMX141]

Turbo oil from the cold side rarely reaches the cylinders on cars like ours....at least not in volume enough to show up on plugs.

Low compression and oil consumption / oil on spark plugs with a fairly-new engine sounds like the rings didn't seat properly.

 

[Spoolingaround]

Turbo oil from the cold side rarely reaches the cylinders on cars like ours....at least not in volume enough to show up on plugs.

Low compression and oil consumption / oil on spark plugs with a fairly-new engine sounds like the rings didn't seat properly.

Improper break-in method?

 

[JusMX141]

That, incorrect oil used during break-in, or the cylinders were not honed correctly during the rebuild which prevented the rings from seating.

 

[Spoolingaround]

That, incorrect oil used during break-in, or the cylinders were not honed correctly during the rebuild which prevented the rings from seating.

Incorrect oil? I used conventional oil, I can't remember the brand but perhaps 5w-30 or 10w-30. I ran only about 3-5 lbs of boost for the first 500 miles, then 10 for the next 500, then 16 for the next 500, then 20 again after another 500.

I bought the rebuilt block from a shop out in california for a steal of a deal, $1600ish and I would have assumed they did a thorough job as they offered a warranty (I installed the block after the warranty ran up however, I didn't have the resources to put it in when I got it).

For a 6 bolt out of a 92, compression should at 180 right?

 

[untouchablecc]

6 bolts are usually around 168-170 on 7:8.1 pistons and 7 bolts should be around 185 on 8:5.1

 

[Spoolingaround]

So basically I am looking at having to rebuild the engine. But, the pistons and rods should still be okay to use since they only have about 4-5k miles on them right? I know I might as well replace all the seals while its apart, but would the bearings need to be replaced? Is there any change they didn't get proper oil flow due to the rings not sitting right?

So I very well be looking at having to rebuild this almost brand new block...

If I were to tear down the block, I would assume I could use the same pistons and rods since they only have about 4k miles on them. I would definitely replace all the seals as well. Would I have to replace the bearings?

 

[JusMX141]

How would any of us know what to replace inside your engine?

Tear it down, inspect things, and replace what needs replaced. I personally wouldn't pull an engine down and re-use bearings or rings, so count on replacing those at the very least. Have your block properly-honed using a ball-type hone sized for your cylinder bore and break it in properly using a non-synthetic oil.

 

[Seamus]

Only read 110-120 across the board.

So I know that there is oil getting into the combustion chamber (as you can see by the plugs) which I am really really hoping is from the turbo alone (not the motor as well).

Why could I be getting such low compression numbers the if low compression and burning oil aren't usually related? WTF

I just purchased a new 20g from one of the guys on the forum and I was planning to put it on in about two weeks when I take the car home to Cincinnati and I have access to my shop, however now I am a little leery.

Well that sucks about the compression.

Oil doesn't get from the turbo to the combustion chamber. It ends up in the intèrcoolrr and piping. Turbine side oil burns up.

I said oil burning/low compression are OFTEN unrelated with these cars.

Sounds like you need to spend that turbo money sealing up the motor. I didn't know it was just rebuilt. It may not have been a bad breaking, it could have been bad machine work or somthing- Your motor is consistantly crappy.

 

[Spoolingaround]

How would any of us know what to replace inside your engine?

I just meant is there any speculation on the condition on the bearings? Is there a known link between bad piston rings and the bearings maybe getting insufficient oil? I will most likely replace them however.

break it in properly using a non-synthetic oil.

Was there a flaw in my break in procedure mentioned in one of my previous posts? I know there are like a million posts on how to break a new engine in, but it seems like everyone has their own opinion. One thing I have gathered is that by running low/no boost for the first 500 miles I might have done the damage there. Any comments or thoughts?

Well that sucks about the compression.

Yes, yes it does.

Is there any chance at all that the piston rings may still seat properly after 4k miles?

I am moving this topic over to cylinder head and short block section as i believe thats where it now belongs. Here is the link: http://www.dsmtuners.com/forums/cyl...sion-numbers-4k-mile-motor.html#post153389685