Why did my sr20 blow?? Need your opinions.

[civicej8]

Hey guys. Here's my setup:

S13 sr20det.45k miles,
Gt30r twin scroll at 19psi
Arp studs
Tomei gasket

Setup was professionally tuned. Tune was verified to be running safely. I've had the setup running absolutely great for 3 weeks. Went to the track. Did one run, and there goes my rod bearings. Drained the oil, and found gold tint. So I know that it's the rod bearings.

What I don't get is why did it ruin my bearings? Can knock kill a motor that fast. I was running about 19 on the fc when doing a wot pull. Oil pressure was great.

It's now making me think that the sr20s physics just can't handle the pressure. Car ran perfect before.

[Kingtal0n]

Did you run a heavy weight oil and repeatedly bang 7200rpm?

Or you had 15* btdc of timing at 18psi of boost, and it ate the rod bearings.

Or it starved for oil, check if the oil pan is dented up into the pickup. In fact sometimes it completely falls off on redtops. You have to tear down and inspect for clues. Everybody knows you need an S14 bolt on pickup for the redtop- wheres yours?

[civicej8]

Did you run a heavy weight oil and repeatedly bang 7200rpm?

Or you had 15* btdc of timing at 18psi of boost, and it ate the rod bearings.

Or it starved for oil, check if the oil pan is dented up into the pickup. In fact sometimes it completely falls off on redtops. You have to tear down and inspect for clues. Everybody knows you need an S14 bolt on pickup for the redtop- wheres yours?
I have a greddy oil pan and s14 pickup tube.

I think only my idle is 15 btdc at idle.

I ran synthetic 5w30 and I wouldn't hit the rev limiter. But my tuner said 8k redline would be okay since I have upgraded springs and cams.

[civicej8]

And to add this was a strict street car. Didn't do any tracking with it. The metal in the oil was so small we needed a light to see the gold tint. Which to me means that maybe it was slowly degrading.

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[zombiewolf513]

Went to the track. Did one run, and there goes my rod bearings.

And to add this was a strict street car. Didn't do any tracking with it.

So what really happened

[civicej8]

Ha-ha. Well. I meant before I went there lol. It was one 1/4 mile run. Just a plain run. And started hearing some ticking. That's it.

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[Kingtal0n]

last piece of the puzzle. check your timing map for 14-15* btdc during boost.

[civicej8]

last piece of the puzzle. check your timing map for 14-15* btdc during boost.
So basically your saying that knock killed the motor? Can knock kill your rod bearings to wear out faster ?

[Croustibat]

Are you seriously asking why your engine blew ? On a forum ?

Reminders :
-we know absolutely nothing about your engine. Who built it, what machining was done, what parts are in.
-what did you got "3 weeks ago" ?
-stock SR20DET, 45k miles ? Sorry, i don't believe it.
-gt30, 19psi, stock pistons ? Yup, PEBKAC.
-we know absolutely nothing about how it was used, except it "was a strict street car until you decided to track it" which tells us... well, nothing.
-do you have anything at all to monitor your engine ? like AFR gauge, EGT, fuel pressure ?


So far it can range from clearance / machining error to PEBKAC.

[civicej8]

Are you seriously asking why your engine blew ? On a forum ?

Reminders :
-we know absolutely nothing about your engine. Who built it, what machining was done, what parts are in.
-what did you got "3 weeks ago" ?
-stock SR20DET, 45k miles ? Sorry, i don't believe it.
-gt30, 19psi, stock pistons ? Yup, PEBKAC.
-we know absolutely nothing about how it was used, except it "was a strict street car until you decided to track it" which tells us... well, nothing.
-do you have anything at all to monitor your engine ? like AFR gauge, EGT, fuel pressure ?


So far it can range from clearance / machining error to PEBKAC.
The bottom of the engine is stock. Drove in the engine before buying it.

I have aem wideband and verify my air/fuels constantly.

Car is tuned on a apexi fc d detro.

Made 380whp on a mustang dyno.

I think all the hype about having a sr at that power level last is bullshit. I would hope the experts would say something. Thanks

[jorge1190]

My stock rebuild SR made those power levels for like 2 years before blowing due to a boost controller malfunction.

Why are you running 5w-30?

[Croustibat]

19psi from a gt30 on stock bottom end is a bit asking for trouble. Stock pistons are weak on ringlands, they usually break there from very few det. If the bearings are gone and they have been done recently, then it is related to bad clearances.

You won't know what has gone until you tear that engine down, so i suggest you start there. Maybe the oil pump got problems and the bottom end was starved, too.

[TheRealSy90]

15w-50 or bust :) that's what the FSM calls for.

[Kingtal0n]

So basically your saying that knock killed the motor? Can knock kill your rod bearings to wear out faster ?

I have seen lots of rod bearing failure in sr20det engines. The most common causes I have already had the honor of outlining for you.

As to this new question, yes, it is common for "tuners" to set the ignition timing too far advanced, as much as 15* btdc for boost situations in the 9-19psi range. The knock sensor will typically report nothing is wrong. Meanwhile, this timing setting will eat up the rod bearings over time, gradually wearing them out and causing failure. You will find the bottom halves of the bearings scored as if you need more proof that the piston were prematurely being forced down.

http://i9.photobucket.com/albums/a90/kingtal0n/Recent_tune/tune2_zpslofaceiz.jpg (http://s9.photobucket.com/user/kingtal0n/media/Recent_tune/tune2_zpslofaceiz.jpg.html)

[TheRealSy90]

I'm curious, what about the guys that run e85? I've always heard one benefit is being able to run more ignition timing, but in reality you couldn't run much more timing regardless of the fuel because of the wear on the rod bearings right?

[Croustibat]

15w-50 or bust :) that's what the FSM calls for.

Absolutely not. The FSM gives you pressure targets when cold and hot, at idle and 3000 (or 3500)rpm.

Hot, 3000rpm pressure is a WINDOW, too much pressure is bad too. Our oil pump regulation is pressure based, more pressure = less flow, so you really want the thinnest oil that gets you in that pressure window while maintaining idle pressure above threshold (as long as your engine does not eat it) at oil operating temp.

Basically, unless you live in dubai, if you need 15w50 to get that pressure range, your oil pump is worn. Change your oil pump before the lack of flow makes further damage.

I went that way too, ended up using 10w50 then 10w60 to get the correct pressure, but oil was heating more, thinning and wearing even faster. And then i replaced the pump. Now i can use 5w40, heat problems are gone (oil hardly reach 110° on track when i used to stop at 130° before, after 10mins), the oil is still good after 2000 miles, and the cost per littre is halved ...

[Croustibat]

I'm curious, what about the guys that run e85? I've always heard one benefit is being able to run more ignition timing, but in reality you couldn't run much more timing regardless of the fuel because of the wear on the rod bearings right?

You are right, we can run (much) more timing.

When there is too much gnition advance like kingtal0n says, the engine kind of "knocks", it vibrates badly and has less power (this is not det). You can't miss it.

E85 guys stop under that "lower power" threshold, and it is way higher than what you get with 93 octane. My CA has more than 20° @ WOT with 18psi of boost for example. I start feeling that "knocking" around 30°.

[TheRealSy90]

So what's the timing threshold in boost on e85, if 91 is around 8-9 degrees?


Also this is incorrect? From the fsm. Where I live it's between 60-120 year round.
http://i118.photobucket.com/albums/o107/Silvia_Convertible/Oil.jpg
http://i118.photobucket.com/albums/o107/Silvia_Convertible/Oil.jpg

[Javi802]

15w-50 or bust :) that's what the FSM calls for.

I thought it called for 10w30? Or are you being sarcastic??

[TheRealSy90]

I thought it called for 10w30? Or are you being sarcastic??

I really wasn't, refer to my previous post. I've been running 15w50 in my sr for 6 years and it still runs as good as it did when I first swapped it in '09.

[civicej8]

I really wasn't, refer to my previous post. I've been running 15w50 in my sr for 6 years and it still runs as good as it did when I first swapped it in '09.
So just the mere fact I was running 5w30 in 90 degree weather resulted in worn bearings? I mean I understand that can happen. But in my opinion unless your really pushing the motor hard then I can see engine wear. A few wot pulls a day I couldnt see.


I guess the conclusion I'm going with is maybe my oil pressure was low causing bearing failure.

Im proly going to build the block and see how long the motor will last at 500whp. Then I'll go back to a ls1 if it doesn't stand up to it.

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[TheRealSy90]

I don't see it lasting long at all unless you have it built by someone knowledgeable in bearing clearances etc.

[jr_ss]

I run 15w-40 in my VET. I also live in a hot humid climate where those viscosities are acceptable.

There's a multitude of reasons your motor could've popped. More than likely though, your motor was about to shit the bed anyway, the drag strip was just the final nail in the coffin. A tear down is in order to inspect everything.

[cotbu]

I change oil viscosity and tunes, according to the weather!

It's tear down season!!!

Sent from a Highly Tuned Note 4.5!!!

[civicej8]

I change oil viscosity and tunes, according to the weather!

It's tear down season!!!

Sent from a Highly Tuned Note 4.5!!!
It might have been the 5w30. I mean I was running it through 90-100 degree weather. Maybe the oil was too thin causing it to wear fast. Yes. It's true that I could of been running on a hurt motor. I'm gonna look into building the block and seeing how that goes. I just wanted some clarification of things that can kill any motor. I'm aware that knock. Running lean. All of that can kill a motor fast. But rod bearings for me have always been running low on oil. Which I made sure not to do. You gotta pay to play.

[Croustibat]

So what's the timing threshold in boost on e85, if 91 is around 8-9 degrees?


Also this is incorrect? From the fsm. Where I live it's between 60-120 year round.
http://i118.photobucket.com/albums/o107/Silvia_Convertible/Oil.jpg
http://i118.photobucket.com/albums/o107/Silvia_Convertible/Oil.jpg

timing : i can't tell, it depends on many things.

As far as the oil go, i don't know what FSM you are talking about, but here is the S14 SR20DET one.
http://www.240edge.com/manuals/s14_sr20det.pdf

Look at page LC5 (numbered 122 in the pdf file)
oil pressure when hot at 3200 = 3.14 to 3.92bar, period. Chose you oil accordingly, if you need 10w50 to be in that window and don't live in a very hot country, you need a new oil pump.

So just the mere fact I was running 5w30 in 90 degree weather resulted in worn bearings? I mean I understand that can happen. But in my opinion unless your really pushing the motor hard then I can see engine wear. A few wot pulls a day I couldnt see.


I guess the conclusion I'm going with is maybe my oil pressure was low causing bearing failure.

Im proly going to build the block and see how long the motor will last at 500whp. Then I'll go back to a ls1 if it doesn't stand up to it.

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If you didn't have the right oil pressure, then yes, it could, but it could be million of things as said before. Bad clearances, out of round crank and so on.

You won't see how long the motor will last because the transmission will be long gone at that power level. You will start breaking gearboxes from 350hp with sticky tyres, or even lower depending on how you drive the car.

You need a stronger gearbox. Easiest route is the Z32 gearbox conversion, but they are kind of old, crappy and have loooooooooooooooooong gearing ... Z33 conversion is much better in every aspect. But it is more expensive, and you will need some massaging work (with a bigass hammer) on the firewall and tunnel.
But it really is worth it. GB is very smooth, precise, supports high revs shifting, and has an interesting gearing.

[civicej8]

timing : i can't tell, it depends on many things.

As far as the oil go, i don't know what FSM you are talking about, but here is the S14 SR20DET one.
http://www.240edge.com/manuals/s14_sr20det.pdf

Look at page LC5 (numbered 122 in the pdf file)
oil pressure when hot at 3200 = 3.14 to 3.92bar, period. Chose you oil accordingly, if you need 10w50 to be in that window and don't live in a very hot country, you need a new oil pump.



If you didn't have the right oil pressure, then yes, it could, but it could be million of things as said before. Bad clearances, out of round crank and so on.

You won't see how long the motor will last because the transmission will be long gone at that power level. You will start breaking gearboxes from 350hp with sticky tyres, or even lower depending on how you drive the car.

You need a stronger gearbox. Easiest route is the Z32 gearbox conversion, but they are kind of old, crappy and have loooooooooooooooooong gearing ... Z33 conversion is much better in every aspect. But it is more expensive, and you will need some massaging work (with a bigass hammer) on the firewall and tunnel.
But it really is worth it. GB is very smooth, precise, supports high revs shifting, and has an interesting gearing.
Thanks for your input bro. I think I've seen the z33/conv for 1300. Not sure how much it is. I know alot of people say this but I baby the car. That's why I was so surprised it failed lol.

I wish there were more people pushing good power with sr20s that lasted a while for them. For competition I mean go for the most reliable setup. But time attack cars like scorch s15 and motive s14 have been having good luck with them so hopefully they can stand up to the abuse.

[2muchboost]

Let me guess spun bearing on #3? If so there is a solid explanation for it as I have seen almost every SR with a spun bearing be piston 3 while drag racing.

[civicej8]

Let me guess spun bearing on #3? If so there is a solid explanation for it as I have seen almost every SR with a spun bearing be piston 3 while drag racing.
Not sure I haven't tore it down yet. I'll definitely update.

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[codyace]

Engine oil didn't hurt the engine

20 psi on a 30r did


It's stock junk, regardless of 'how it is tuned'. One little ping can ruin the day, or constant knock that you didn't (really, you can't hear in the car at speed if you're not trained) recognize smashed the rod bearings to smithereens (an already week item on these cars)

Nothing more, nothing else.

[Dboyizmlg]

Engine oil didn't hurt the engine

20 psi on a 30r did


It's stock junk, regardless of 'how it is tuned'. One little ping can ruin the day, or constant knock that you didn't (really, you can't hear in the car at speed if you're not trained) recognize smashed the rod bearings to smithereens (an already week item on these cars)

Nothing more, nothing else.

+1

Big turbo, with engine block being mostly stock can deff be the culprit

[Kingtal0n]

Keep in mind two things,

A: The rod bearing is a mechanical part, i.e. you can spin an sr20det by hand (crank it over with a start, spin it with the rear tires, or if you invented a device to spin the engine electronically all of that is possible without the turbocharger or even gasoline) And at some point, the oil pump / provided oil will be insufficient at some XXXXrpm. Also, there are mechanical limits imposed by valvetrain parts (but for the sake of this example, lets assume the valvetrain is invincible to 999999rpm). and piston velocity speed limits, and other mechanical problems with ultra high RPM. What I am getting at is, running engine or not, there is some mechanical limit imposed by the rotating assembly, its design/clearances, the oil you have chosen, and the variables associated with a running engine: temperature, frequencies, pressure settings such as oil pressure relief, and even the alignment of structures within the engine and all of the places oil is expected to slip from between parts.

That said, how fast do you think we can spin an sr20det engine with an invincible valvetrain until it spins a rod bearing? and why would the lubrication fail, is it the pump? the weight of the oil? the clearances of the engine? The type of bearing? None of this can be known, even with a full tear-down and inspection you are still making a "theory" of why the engine failed. It does not necessary have to be the real reason it came apart. The main point of A: is this then: There are many situations that can cause a rod bearing to fail which have nothing to do with the turbocharger or even combustion of gasoline, and everything to do with lubrication facility of the engine.

With this main point in mind, we will come to B:

B: there is only one way that gasoline (i.e. the turbocharger aspect of the engine) can cause a rod bearing to spin, (whereas there are several lubration aspects) and that is pre-ignition (for zealots I am being more specific: on-set of combustion pressures too rapidly, too soon) and that way is very specifically due to insufficient octane and/or too much timing advance. Ill repeat it: these are the only two aspects of the turbo that can cause rod bearing failure this one way.

One of them is due to the gasoline you put in your car, the other is due to the guy with the laptop.

[Praxis]

I have seen lots of rod bearing failure in sr20det engines. The most common causes I have already had the honor of outlining for you.

As to this new question, yes, it is common for "tuners" to set the ignition timing too far advanced, as much as 15* btdc for boost situations in the 9-19psi range. The knock sensor will typically report nothing is wrong. Meanwhile, this timing setting will eat up the rod bearings over time, gradually wearing them out and causing failure. You will find the bottom halves of the bearings scored as if you need more proof that the piston were prematurely being forced down.

http://i9.photobucket.com/albums/a90/kingtal0n/Recent_tune/tune2_zpslofaceiz.jpg (http://s9.photobucket.com/user/kingtal0n/media/Recent_tune/tune2_zpslofaceiz.jpg.html)

That timing table is terrible. The Power FC over reports knock, but it can be used during dyno tuning.

380rwhp, on a legit, un doctored Mustang Dyno is a lot of power for a stock bottom end.

Most common detonation failure I see is due to oil in the intake. Either pcv, or turbo.

[Praxis]

Number one cause of detonation in a street type car is oil.

Pcv, or turbo, rings etc. Ive even seen valve stem seals do it.

On tear down, look for oil in the intake, intercooler piping, and piston tops for burnt oil residue.

[Croustibat]

Thanks for your input bro. I think I've seen the z33/conv for 1300. Not sure how much it is. I know alot of people say this but I baby the car. That's why I was so surprised it failed lol.

I wish there were more people pushing good power with sr20s that lasted a while for them. For competition I mean go for the most reliable setup. But time attack cars like scorch s15 and motive s14 have been having good luck with them so hopefully they can stand up to the abuse.

We do, in France, because these come with stock S14 :D

It depends on what you call "good power" of course. I missed one when it went on sale, built by my tuner, 450WHP+ , z33 gb, had done 1 pro drift season, owner wanted a V8.

This was a dyno run done with a JASMA restrictor welded in the exhaust, that was removed later. 2 years ago, still running and taking abuse :D

https://vimeo.com/65543081

[TheRealSy90]

Oil pressure when hot at 3200 = 3.14 to 3.92bar, period. Chose you oil accordingly, if you need 10w50 to be in that window and don't live in a very hot country, you need a new oil pump.


So for example where I live, our coldest time of the year is high 60's, and the hottest part of the year is between 105-115 for a couple months. This would make sense to run that 10/15w50 oil even with a good condition oil pump, correct? (I don't really take the "lows" into account, because I'm not usually driving my car around at 3-5am in the winter.)


This is our yearly averages.
https://dbffkv15yp72v.cloudfront.net/production/reports/year/000/031/083/15e2d18d/daily_high_and_low_temperature_temperature_f.png

[civicej8]

Engine oil didn't hurt the engine

20 psi on a 30r did


It's stock junk, regardless of 'how it is tuned'. One little ping can ruin the day, or constant knock that you didn't (really, you can't hear in the car at speed if you're not trained) recognize smashed the rod bearings to smithereens (an already week item on these cars)

Nothing more, nothing else.
Thanks codyace. My car probably was at your cars power level.

I've read even enthaplys suggestions for built motors and he suggests stock bearings for the mains and rods. I even talked to my tuner after and he reassured me we were running a super safe tune. He said my knock count on the fc was at 19 at the highest. He said you need to be in the 70s for engine damage. Although my motor didn't seem to last long after that.

[Kingtal0n]

Thanks codyace. My car probably was at your cars power level.

I've read even enthaplys suggestions for built motors and he suggests stock bearings for the mains and rods. I even talked to my tuner after and he reassured me we were running a super safe tune. He said my knock count on the fc was at 19 at the highest. He said you need to be in the 70s for engine damage. Although my motor didn't seem to last long after that.

words

With OEM cams the knock high is 12 on the PFC, and I see an occasional 14. The number itself is not as valuable as the consistency with which it appears. For instance, when I install HKS 272 camshafts with VTC, I would see 19 on about 1/3 to 1/5 of every wot pass. If I disable the VTC, it goes back to a consistent 12 (PFC can turn off VTC at 1300rpm so it is off the entire time you drive, or just unplug the vtc solenoid). the fact that vtc can be picked up in the engine knock number should tell you that other such similar situations exist of which we are unaware which undoubtedly result in the random number that appears.

For what it is worth, it may not be apparent if you never operated the data-logit with an PFC, the default setting in the power FC for knock count to warn the driver is around 65.

[Croustibat]

So for example where I live, our coldest time [...]

No, it does not make any sense to base your oil choice on anything else than pressure when cold and at operating temp. Temperature has an influence on oil viscosity and therefore pressure, which is why the oil choice needs to be made depending mostly on oil working temperature.

The temperature VS oil thickness choice graph is something for people with no engine knowledge (nor oil pressure gauge) and standard car use.

(and i don't know how to use °F, there is an international standard, use it :D )

Basically, on these engines, if your oil working temp is around 100°C, you should be fine with 10w40 in summer and 5w40 in winter. If you are more around 110°C , 10w50 would be fine. If your oil temp reaches 120° or more... there may be something wrong, so find what and/or get an oil cooler .

Again, if you ever need 15wX oil or Xw60 on these engines, it mean something is seriously wrong, or you are living in an extremely hot country, or the engine is giving everything it has for prolonged time and can't cool correctly (like 600+ WHP)

[TheRealSy90]

(i don't know how to use °F, there is an international standard, use it :D)

It's just not the standard here, sorry I don't think to use it.


Basically, on these engines, if your oil working temp is around 100°C, you should be fine with 10w40 in summer and 5w40 in winter. If you are more around 110°C , 10w50 would be fine. If your oil temp reaches 120° or more... there may be something wrong, so find what and/or get an oil cooler .

Again, if you ever need 15wX oil or Xw60 on these engines, it mean something is seriously wrong, or you are living in an extremely hot country


Well I do live in a very hot country, we average over 40°C in the summer time during the day, and no less than 18°C in the winter to put it in perspective, we only have a couple "winter" months. Wouldn't 10w50 and 15w50 have the same effectiveness when the engine is at operating temperatures?

[Kingtal0n]

No, it does not make any sense to base your oil choice on anything else than pressure when cold and at operating temp.

Croustii, do you have any charts or diagrams of oil flow vs pressure in an engine? I've been trying for 3 minutes to find one for any random engine; it is proving more powerful than my attention span