Blown turbos help

[Oddamannen97]

Hey guys,

 

My precious rb26 blew its stock turbos on my way home earlier this summer. R33 gt-r 95mod.

I just did a compression test now (cold engine), and got these readings:

 

Cylinder 1: 155 psi

Cylinder 2: 155 psi

Cylinder 3: 160 psi

Cylinder 4: 145 psi

Cylinder 5: 140 psi

Cylinder 6: 135 psi

 

Now keep in mind the engine is cold.

I’d like to hear your opinion on these readings? 

[Duncan]

Sorry but it doesn't look good. When the exhaust wheel lets got at 150,000rpm, ceramic pieces have enough velocity to travel against the exhaust gas, through the open exhaust valve, and scratch the shit out of the cylinder bores. Happened to me when I first got my car, and I guess it has just happened to you.

A borescope could be used through the spark plug hole to inspect the bore for scratches.

If that has occurred, you need engine out bottom end rebuild, with bored out cylinders and oversize pistons. Expensive, but not compared to GTR prices these days....

[TurboTapin]

Blown turbo doesn't automatically mean his turbine wheel grenaded. Now with that said, the difference you have in compression between cylinders isn't great. Report back on a warm engine.  

[Oddamannen97]

Alright guys, thanks for the quick reply! I’ll give you an update within a day or two on a warm engine. I appreciate it!
 

[GTSBoy]

Buy this.

https://www.ebay.com.au/itm/8MM-HD-WiFi-Endoscope-Inspection-Camera-Waterproof-for-iPhone-PC-iPad-Samsung-AU/163440076341?_trkparms=ispr%3D1&hash=item260dc9a635:g:ofMAAOSwsPNcGhBL&amdata=enc%3AAQAFAAACcBaobrjLl8XobRIiIML1V4Imu%252Fn%252BzU5L90Z278x5ickkfOCvCjTOBWK8pwriaolq5l3YoyuRM1%252B5hQF96Q9VN70RMc3%252BYWb9Tsc4TGw41eT3TQyUnv930nBOYpCpeC0DLYi7CxMTZyPioOoOXgQasbGPlG6QtpP4pYAS6Fwp8lyvvZts9%252BMI7tKcAxRtSZg3PJaSRXesma1BQe9Y7Kk0x3lSKjtYvm8qvSbcGe6Le3XGCKqKt5N5%252BpmvMtHRRXcSMV7vH6cH2a1pfxad7lFk9REJ%252Fs9T%252FxkpiEeVzDso%252FxydMWoLVe1u58T95RoHmLBtO7UIuxhfvPW3Iwi0mSO1EhyhN%252BoIO%252FymShnXkKaBlgrverdWmmwCbiAxDdOJF9aVLKX3JZUC%252BRtHPIhIDYo9ycOshD%252B5hpeoZWH6aXXeWU%252Fi2T33k3JYi9Ww5oOdwTKLoigaAHGwopMekvh6MThpmeZVA0yFlG7%252FjqbXqMJtd%252FmENiHbwrQXc1QUAnEZr7dGv6vpcB3sHdkcVM67Xnr%252F%252FH3yBsbLHavof5BBTxjSoagT2C2akfcq8wyteFQCNP%252BE8eM2CNqVwN4mUDoYlN5f2Q1WbTtdXKDtkB7V%252BsuNLiZTPLCpyBR%252BubPJeKl1SsS%252FQLpW7nlSkqYn%252B82yIyrazSiJyR4QI%252BZpMZjKEdD8nPgDFbaKcvPK86w2c9Xtx1G4%252FkI6lHclPYp097es4WMhHReOO4KjHTLfLU8wtmotJTjP7q4pHEWo6lXcmHLGEHVVAyK%252BJ5mdYoG%252Fc6nO7DO48l8qMbgdbmxaWLlzkT78ScXaWWCP9FklM%252B8LYCnKMqZUBg%253D%253D%7Ccksum%3A163440076341da5adf177ea64ed6b78adc0d6112fd23%7Campid%3APL_CLK%7Cclp%3A2334524

 

[joshuaho96]

As a general rule if you hurt a cylinder it will be cylinder 6 because it runs the hottest. Gets the most air, worst cooling.

[Oddamannen97]

Got it! Thanks for the info guys.

[Duncan]

6 hours ago, TurboTapin said:

Blown turbo doesn't automatically mean his turbine wheel grenaded. Now with that said, the difference you have in compression between cylinders isn't great. Report back on a warm engine.  

Agreed, but the concern is all 3 rear cylinders are well down which matches an issue with the rear turbo affecting cylinders 4-6

[Oddamannen97]

Guys,

 

As i’m quite new to this, please excuse me if my questions are «stupid».

 

I thought about doing a compression test with a warm motor. But seeing as there might be a chance i have ceramic dust in my engine, wouldn’t it be damaging (or cause more damage) running the engine till it’s warm?

[Duncan]

don't worry about it mate. if that is the issue you won't make it worse warming it up.

back to an earlier question what did you mean when you said the turbos were "blown". potentially an overboost issue could end up with ring land problems on the rear 3 cylinders too, but either way it is the same solution (pull engine and tear it down)

[Oddamannen97]

Alright, thanks.

What happened is i did a small pull, probably overboosted and the rear (i assume) turbo said farewell. It cut boost during the pull, and it started coming blue smoke from the exhaust. 

 

Seeing as i intend on keeping her for a while, an engine rebuild wouldn’t be so bad i guess  

[TurboTapin]

16 hours ago, Duncan said:

Agreed, but the concern is all 3 rear cylinders are well down which matches an issue with the rear turbo affecting cylinders 4-6

 Touché sir. 

[Oddamannen97]

Hello again,

 

Sorry about the late update, i’ve been busy due to work.

I did another compression test today with the engine warmed up, and i got these results:

 

Cylinder 1: 168psi

Cylinder 2: 171 psi

Cylinder 3: 170psi

Cylinder 4: 165psi

Cylinder 5: 155psi

Cylinder 6: 158psi

 

What are your thoughts?

[TurboTapin]

3 hours ago, Oddamannen97 said:

Hello again,

 

Sorry about the late update, i’ve been busy due to work.

I did another compression test today with the engine warmed up, and i got these results:

 

Cylinder 1: 168psi

Cylinder 2: 171 psi

Cylinder 3: 170psi

Cylinder 4: 165psi

Cylinder 5: 155psi

Cylinder 6: 158psi

 

What are your thoughts?

That looks good to me!

[GTSBoy]

3 hours ago, TurboTapin said:

That looks good to me!

Yup. A little bit variable, but up at the healthy end of the scale.

[Oddamannen97]

Alright, thanks. Is it necessary to do a leakdown test as well?

[Piggaz]

Just drive it.

[trel]

1 hour ago, Oddamannen97 said:

Alright, thanks. Is it necessary to do a leakdown test as well?

It's a while you're there deal, you might as well to give you a little better insight as to the state of your engine. But nonetheless the numbers look good.

Edited September 2, 2020 by trel

[Dose Pipe Sutututu]

Looks good to me, ARP studs in, single twin scroll turbo, and send it.

[Oddamannen97]

Alright guys, i really appreciate the response from all of you. Thanks again