3SGTE Gen 2 How much boost?

[fivebob]

It's actually the intake manifold.

Actually I don't think it is the manifold.

How the manifold distributes air when tested with constant airflow of a flowbench bears about 5/8 of fsck all relevance to how the air flows under real life tubulent conditions of valves opening and closing, generating flow reversals etc.

If it was the manifold then perhaps you'd care to explain why the revised centre entry Gen III manifold still blows the same cylinders, as does the side entry Gen IV manifold.

[fivebob]

Pistons are crap and crack ringlands,

Yes they break ringlands when they detonate, but that doesn't mean the pistons are crap. Most pistons will break ringlands when repeated detonation occurs.

oil pumps seize

First I've heard of it, certainly isn't a common problem

and bearings dont handel the jandel.

Urban legend...see above

[Akane]

It's actually the intake manifold.

Actually I don't think it is the manifold.

How the manifold distributes air when tested with constant airflow of a flowbench bears about 5/8 of fsck all relevance to how the air flows under real life tubulent conditions of valves opening and closing, generating flow reversals etc.

If it was the manifold then perhaps you'd care to explain why the revised centre entry Gen III manifold still blows the same cylinders, as does the side entry Gen IV manifold.

If the manifold does not distribute air evenly even on a synthetic test bench then what makes you being so sure everything will fix itself in real world applications, your arguement goes both ways.

The revised manifold has T-VIS deleted, runner length and manifold chamber is all revised, even with different throttle bodies. Nobody knows what exactly toyota has done and what they've done has fixed, but at least synthetic flow bench shows it does not suffer (as much?) as the Gen 2 when it comes to even air distribution. Which IMO, is a start in the right direction.

As to coolant not routing through the correct passages, as others have put 4 seperate EGT probe on each of the exhaust runners, it has shown that 2 & 3 does run considerably hotter. I wonder the tempreature of the flame/exhaust gas could rise that much from spending 0.01 sec inside a cylinder that's only ever slightly warmer than their next door neighbours.

[fivebob]

If the manifold does not distribute air evenly even on a synthetic test bench then what makes you being so sure everything will fix itself in real world applications, your arguement goes both ways.

Nope the argument only goes one way.i.e. a flow bench does not replicate what actually happens inside the manifold of a running engine. Whether or not fluctuations in the manifold pressure (which IIRC is around 4-6psi per cycle) "correct" differences is another argument altogether. Personally I think differences in the exhaust manifold runners have more to do with potential cylinder charge imbalance than any static differences in the intake manifold flow.

The revised manifold has T-VIS deleted, runner length and manifold chamber is all revised, even with different throttle bodies. Nobody knows what exactly toyota has done and what they've done has fixed, but at least synthetic flow bench shows it does not suffer (as much?) as the Gen 2 when it comes to even air distribution. Which IMO, is a start in the right direction.

Thank you for proving my point...If it's such and improvement them why does the Gen III still blow #2 pistons with great regularity, and why does the Gen IV do the same with it's side entry manifold. The fact that the mode of failure hasn't changed even though the manifolds have been radically changed indicates, at least to me, that the manifold isn't the issue.

As to coolant not routing through the correct passages, as others have put 4 seperate EGT probe on each of the exhaust runners, it has shown that 2 & 3 does run considerably hotter.

References please!! All the examples I have seen indicate that the cylinders run at approx the same temperature +/- 1-2%. Unless the EGT probes are placed accurately in each runner, so that they are exactly in the same position with respect the the valves, then the data is meaningless. A lot of the installations I have seen place the EGT probes in convienient locations for the installer, not the same position for all cylinders.

I'm not a big fan of EGT sensors providing much in the way of useful information, IMO they're really only an indicator of something wrong in the engine if they're greatly outside the normal operatring range. I'd be much more convinced if somebody actually place 4 WBO2 sensors in the runners and measured the AFR differences between cylinders directly.

I wonder the tempreature of the flame/exhaust gas could rise that much from spending 0.01 sec inside a cylinder that's only ever slightly warmer than their next door neighbours.

How much is "that much"???

It doesn't take that much increase in cy;linder temp to make one cylinder more prone to detonation.

Anyway I think the coolant circulation theory is based on removing possible hotspots, not reducing the overall cylinder temp.

[Akane]

Nope the argument only goes one way.i.e. a flow bench does not replicate what actually happens inside the manifold of a running engine. Whether or not fluctuations in the manifold pressure (which IIRC is around 4-6psi per cycle) "correct" differences is another argument altogether. Personally I think differences in the exhaust manifold runners have more to do with potential cylinder charge imbalance than any static differences in the intake manifold flow.

How can the argument only go one way? You're saying nope the flow bench means nothing because a running engine's real flow would be different than a flow bench. But don't you think it could be so different it could actually amplify the flow differences? That is something you do not know neither, no public information to show that it does or does not so far, hence, it's a two way street. You're saying it could only get better in real world running engine situations, due to this 4-6psi per cycle fluctuations, show us the data?

Thank you for proving my point...If it's such and improvement them why does the Gen III still blow #2 pistons with great regularity, and why does the Gen IV do the same with it's side entry manifold. The fact that the mode of failure hasn't changed even though the manifolds have been radically changed indicates, at least to me, that the manifold isn't the issue.

I'm not seeing as much blown up Gen 3's as there is Gen 2's (actually I havn't seen/read/heard any Gen 3's cylinder 2/3 failures), mainly due to the lesser sample size of the said engine, there's a lot less Gen 3's than Gen 2's out there as well. Argument invalid? you tell me, all I see is dead Gen 2's, havn't seen dead gen 3's yet due to said problem.

References please!! All the examples I have seen indicate that the cylinders run at approx the same temperature +/- 1-2%. Unless the EGT probes are placed accurately in each runner, so that they are exactly in the same position with respect the the valves, then the data is meaningless. A lot of the installations I have seen place the EGT probes in convienient locations for the installer, not the same position for all cylinders.

I'm not a big fan of EGT sensors providing much in the way of useful information, IMO they're really only an indicator of something wrong in the engine if they're greatly outside the normal operatring range. I'd be much more convinced if somebody actually place 4 WBO2 sensors in the runners and measured the AFR differences between cylinders directly.

I do recall a member of mr2oc (Yes the people you dislike) did the 4xEGT probe test, as close to the cylinder head as possible with the same distance as possible to each other, they recorded a 50F to 100F differences on a mildy tuned Gen 2, that's a lotta temp difference and it could mean just barely made it or a blown up engine, which is a lot more than your said 1-2% +/-

You might not be a big fan of EGT but EGT is directly proportional to A/F ratio, they go hand in hand like yourself and your ability to find random car data.

If cylinder 2/3 problem is that much related to exhaust manifold, I'm sure people would've been much better off with custom exhaust manifolds, but the truth is they're just as proune to blow things up as the next guy. Yet people have found that once they've installed a custom intake manifold, things *seemed* to improve, ofcourse there's no way to record data, nobody has unlimited budget and destroy thousands of engines to take a decent sample size.

How much is "that much"???
It doesn't take that much increase in cy;linder temp to make one cylinder more prone to detonation.

Exactly, that 50F ~ 100F difference is all it takes as I've stated above, pretty crazy stuff huh?

Anyway I think the coolant circulation theory is based on removing possible hotspots, not reducing the overall cylinder temp.

Certainly helps, hotspots is the main cause, those crazy japs already found a bandaid solution before we've even heard of 3S-GTE's, but reducing the overall cylinder temp is a side effect of trying to remove possible hotspots. Metal is a good conductor of heat last time I checked, making the overall cylinder temp lower is a good thing ... I guess?



So.. What is exactly your reasoning behind why this is all happening? Because after reading all these posts, I still have no idea which camp you're at. Yet you're just dishing out red cards, the usual fivebob way. Educate us.

[fivebob]

How can the argument only go one way?

Simple really. I said static flow has little to do with real world flow, that's easily proven if you bother to do the calculations using wave theory.

As I said the argument that it gets better or not is an entirely different one. We're talking about a functioning system not an isolated component. There are many things that affect the volume of charge entering a cylinder, static flow of the intake manifold is only one of them, and IMHO a very minor one.

You're saying it could only get better in real world running engine situations, due to this 4-6psi per cycle fluctuations, show us the data?

Nope, never said that it got better, only that the flow bench numbers tell you little if anything about what happens inside a running engine system. You should realise that cylinder scavenging of the entire system has more to do with how the charge volume enters/exits the cylinder and the interaction of all systems components, rather than static flow measurement of one isolated component.

I'm not seeing as much blown up Gen 3's as there is Gen 2's (actually I havn't seen/read/heard any Gen 3's cylinder 2/3 failures), mainly due to the lesser sample size of the said engine, there's a lot less Gen 3's than Gen 2's out there as well. Argument invalid? you tell me, all I see is dead Gen 2's, havn't seen dead gen 3's yet due to said problem.

Then you haven't been looking, or your memory is very poor. I have two first hand examples, one blown Gen III and one Gen IV, both blown #2 pistons, though there were also broken ringlands in #3 and in one case #4 pistons, but by far the worst was #2. I know of several other Gen III & Gen IV piston failures that are the same.

I do recall a member of mr2oc (Yes the people you dislike)

That's extremely pretentious, and ill-informed, of you judging whether or not I dislike some people. I have no dislike for any members of MR2OC. I guess you just don't really understand how to form an unbiased judgement of the facts.

did the 4xEGT probe test, as close to the cylinder head as possible with the same distance as possible to each other, they recorded a 50F to 100F differences on a mildy tuned Gen 2, that's a lotta temp difference and it could mean just barely made it or a blown up engine, which is a lot more than your said 1-2% +/-

If it’s the example I’m thinking of the probes were far from equidistant and even if they were, how do you explain a 10% difference in EGT from only a 2-3% difference in flow???

You might not be a big fan of EGT but EGT is directly proportional to A/F ratio, they go hand in hand like yourself and your ability to find random car data.

Actually the relationship is not as linear as you imply and in fact past stoich the temp will probably go down not up.

If cylinder 2/3 problem is that much related to exhaust manifold, I'm sure people would've been much better off with custom exhaust manifolds, but the truth is they're just as proune to blow things up as the next guy.

References please!!!

Besides which I didn’t say it was related to the exhaust manifold either, just that the exhaust manifold layout has a greater influence on cylinder scavenging than some supposed static flow imbalance in the intake manifold.

How much is "that much"???
It doesn't take that much increase in cylinder temp to make one cylinder more prone to detonation.

Exactly, that 50F ~ 100F difference is all it takes as I've stated above, pretty crazy stuff huh?

Not really that crazy, and also not proof that the cylinders are running leaner, just that they may be running hotter. You still haven’t provided references so we can check out the validity of the claimed difference for ourselves

So.. What is exactly your reasoning behind why this is all happening? Because after reading all these posts, I still have no idea which camp you're at.

I’m not in any camp, well none of the ones you’ve mentioned anyway. I have my theories but until I get a chance to put them to the test I’ll keep them to myself.

Suffice it to say that it’s not as black and white as you maintain. i.e. The intake manifold imbalance is not the sole cause of the problem, IMO it plays a very small part, if any in the #2/3 piston failure mode evidenced in 3S-GTE engines. Like I said before if it was the only cause then you would expect to see different failure modes in Gen III & Gen IV engines, but you do not.

Educate us.

Educate yourselves. It’s much more satisfying than being told the answer

[JustinSpiderholden]

quote="Akane"]

Educate us.

Educate yourselves. It’s much more satisfying than being told the answer [/quote]

Isn't that the point of a forum to share knowledge and to help educate others

BTW what high power 3sgte's have you been built with Fivebob?

[fivebob]

Im guessing Fivebob and Vegaa both went to the same school of:

"I Know it all yet can give no reasoning for my knowledge and get shitty when ever anyone questions me"

Nope not at all, I have given reasons for why I believe that it is not the manifold. Perhaps you missed that bit in your rush to judgement

And where do you get that I've been shitty. I've merely reiterated my points in a logical calm manner with no tone whatsoever... Perhaps you should read it more carefully

[JustinSpiderholden]

Im guessing Fivebob and Vegaa both went to the same school of:

"I Know it all yet can give no reasoning for my knowledge and get shitty when ever anyone questions me"

Nope not at all, I have given reasons for why I believe that it is not the manifold. Perhaps you missed that bit in your rush to judgement

And where do you get that I've been shitty. I've merely reiterated my points in a logical calm manner with no tone whatsoever... Perhaps you should read it more carefully

I jsut get annoyed at the amount of hear/say I see on forums

If you know how to built a strong 3sgte, would it not be better to simply share the answers with the rest of us

[fivebob]

Educate us.

Educate yourselves. It’s much more satisfying than being told the answer

Isn't that the point of a forum to share knowledge and to help educate others

Or are you form Vegaas school of i know all will shoot you down with out reasoning then not be helpful at all

Guess I'll have to answer that one as well as your original version.

You need to read things again. I have clearly stated my reasons why I don't believe the manifold is the sole cause of the problem, do I need to spell it out more simply???

I have shared my knowledge, but there comes a point in time that makes it a futile exercise to illucidate people any further.

If I had proof of what I believe to be the cause(s) then I would publish it. As it is now it's just a theory and doing so would just create endless reams of ill-informed debate with no proof one way or the other.

[fivebob]

I jsut get annoyed at the amount of hear/say I see on forums

Forums by their very nature will have a lot of discussion about a subject, not all of it useful or accurate. Getting annoyed about it isn't a particularly useful way to spend your time. Personally I prefer to make a reasoned judgement as to the varacity of the claims made, and, if I find the point valid or at least possibly valid, then add that to my knowledgebase for later use.

If you know how to built a strong 3sgte, would it not be better to simply share the answers with the rest of us

Building a strong motor isn't rocket science, it's all about the basics of preperation and assembly. The interesting part is where you have an issue like the #2/3 piston failures in 3S-GTE that requires that you determine what the cause of the failure is and how to avoid it. All too often I see people proposing a solution to a problem without actually defining what the problem really is. The 3S-GTE has had lots of these "solutions" proposed over the years, from dual feed fuel rails, special coolants, methanol injection, custom manifolds etc etc etc, yet I have not seen anyone ever try to prove what the cause is. they simply seem to try and justify their solution.

I have my theories, I have a large collection of data about the 3S-GTE and it's failings, I even have the data logging system and a manifold set up to take 4 WB02 Sensors and 4 EGT sensors, but I lack the time to do any real testing, so until the time I have the data to prove/disprove these theories I'll keep them to myself, rather than have someone propose a solution before they've even defined the problem.

[fivebob]

I do recall a member of mr2oc (Yes the people you dislike) did the 4xEGT probe test, as close to the cylinder head as possible with the same distance as possible to each other, they recorded a 50F to 100F differences on a mildy tuned Gen 2, that's a lotta temp difference and it could mean just barely made it or a blown up engine, which is a lot more than your said 1-2% +/-

I just did a quick search on mr2oc.com and all I could find was Shane Craddock's test which shows the sensors at random distances from the valves and gives results that are around 1-2% as I said. I'll give you the benefit of the doubt and let you post a link to the test that showed 50-100F° difference, but for now all I can see is flucuating differences that are around the margin of error

For those that can't be bothered reading the link the results are;

Warm Idle Temps
Cyl
1 950
2 950
3 930
4 925

______________________________________
4500rpm 62mph 3rd gear constant
Cyl Temp
1 1405
2 1425
3 1410
4 1405

3000rpm 56mph 4th gear constant
Cyl Temp
1 1415
2 1435
3 1420
4 1410
_______________________________________
3rd gear runs max temp shift point 7,000
Cyl Temp
1 1550
2 1575
3 1550
4 1550

4th gear runs max temp shift point 6,200
Cyl Temp
1 1550
2 1585
3 1580 (1600 reached on one pull at 7000 rpm)
4 1580

[Akane]

I see.

Naw, can't be bothered spending time digging up old archives. I'll just sit around and wait for someone to come up with a conclusion.

[dragonx]

Im guessing Fivebob and Vegaa both went to the same school of:

"I Know it all yet can give no reasoning for my knowledge and get shitty when ever anyone questions me"

Nope not at all, I have given reasons for why I believe that it is not the manifold. Perhaps you missed that bit in your rush to judgement

And where do you get that I've been shitty. I've merely reiterated my points in a logical calm manner with no tone whatsoever... Perhaps you should read it more carefully

I jsut get annoyed at the amount of hear/say I see on forums

If you know how to built a strong 3sgte, would it not be better to simply share the answers with the rest of us

Hearsay literally means information gathered by the first person from a second person concerning some event

i think the point here is that we all read lots of claims, most of them unfounded.
There are many facts, the facts we are looking at in this thread are issues around 3SGTE engines failures, for reasons not yet fully explained.

Maybe the intake plays a part, maybe the block is to blame, it maybe a combination of many things.
i agree with Mr 5BOB, i have not read that he is claiming it is one thing or another, but dispelling the idea the it has been shown to be the intake, the exhaust or somewhere in between at this point in time. i think the key word is "evidence based research", that clearly shows cause and effect.

[fivebob]

I see.

Naw, can't be bothered spending time digging up old archives.

So you lack the courage of your convictions then. Either that or you know that there is no test showing your claimed 50-100°F difference

I'll just sit around and wait for someone to come up with a conclusion.

Exactly why I said you should educate yourself. Typical Gen Y, want everything handed to you on a platter

[Akane]

So you lack the courage of your convictions then. Either that or you know that there is no test showing your claimed 50-100°F difference

Exactly why I said you should educate yourself. Typical Gen Y, want everything handed to you on a platter

I'm lazy and the whole of toyspeed knows. Would be nice if it was a silver platter too. Keep us updated on this engine failure issue tho, would like to know how toyota can let this slip, but I'm not overly bothered to be honest, I never had a problem with 12.5:1 AFR. Maybe I am just lucky, who knows? I am not extracting huge power out of my motor too, which helps.

[blitza]

How to be an e-baller on the internet for dummies. ???

any hoo, my gen III broke #4 ring lands, and had three bent rods, which i thought was a little odd. was still running fine till a bit of ring chewed its way through the bore.

[fivebob]

any hoo, my gen III broke #4 ring lands, and had three bent rods, which i thought was a little odd. was still running fine till a bit of ring chewed its way through the bore.

Gen III or Gen IV(III.5) Caldina engine. Gen IIIs don't usually bend rods.

[DriftSpecStarlet]

He could have sucked in some water and hyrdo'd the engine to bend the rods

[fivebob]

Interesting thing I have discovered about this whole 3S-GTE piston destruction saga is that while it common for one particular cylinder to fail completely, the other cylinders all have signs of detonation to some degree. e.g. My Gen IV destroyed #2 piston (compression test was 150,50,150,150) but #3 & #4 both had ring land damage to some degree, and I'm guessing that if I crack tested #1 there would probably be some damage to it as well.

So it's not really a #2/3 cylinder issue that causes the failure, as it's happening to some degree in the whole engine.

The real question is which problem do to solve first, the detonation or the piston failure because of detonation?