Unofficial How Many Times You've Blown Up Your Engine Thread

[MvM]

Oh no!! That is horrible news.... Just yesterday I finished my CTSC installation from last years GB. This morning I booked with the dyno guy to check the fuel pressures and AFR's on Thursday. Now I am worried!! Sound like a ring failure maybe?? Have you any idea how the AFR was low? Do you mean rich or lean? Have you been driving your car really hard? Seems odd if a lot of the US guys can drive with no issues, even on the track that this should happen so quickly.

Not sure what else to say... Good luck with getting it fixed. Will you keep the blower on now or is that a scare to far?

Yes, it is very bad news

It took me a long time to decide on the CTSC and when decided to do it to take some precautions, like the Zeitronix unit to monitor my AFR and fuel pressure gauge.
With the stock fuel pump and CTSC voltage booster, the car had always run fine. I have plenty of AFR logs that don't point to any problems.
Am not sure what is causing the problem, probably piston rings.
When I picked up the car a few weeks ago with the Walbro installed, AFR were low and at times very jumpy, as in running extremely rich, like 10.0 or sometimes even lower. At that moment, I blamed it on the new pump and higher fuel pressures.
Probably, the problem was already there, but now surfaced.
And yes, I have been driving the car on the track, and when doing that, I was pushing it.

At this point, I'm not sure on what to do. Let's first find what the problem is and what caused it.
To be honest, driving the NSX with CTSC is quite a thrill compared to a stock car. With the SC, it's quite easy to keep with basically new cars like the R8, 911, M3 or M5.

All I can say is that I thought I was doing things carefully. Not so it seems now

 

[goldNSX]

Seems odd if a lot of the US guys can drive with no issues, even on the track that this should happen so quickly.

MvM opened a thread recently about his engine running too rich in boost and after it has been in boost. My guess was that the fuel system was overwelmed with fuel after a boosting period and the FPR could not cope with it. From the data I didn't see it running too lean. So I don't think this was the problem.
Compared to my car I didn't see this behaviour but mine is a 91 and MvM has a NA2. I've the newer Lysholm unit, MvM has the Autorotor. Maybe there are changes in FPR and electronics too.

Well, there have been very few blown engines with the Autorotor if you look 5 or 6 years back on the Forum (Autorotor GB). But I've not heard of any newer Lysholms going bad. But in the meantime a lot of people went with a cheaper turbo and didn't install the CTSC except for the GB last year. Or you simply don't hear from the blown engines.

I'm very sad to hear the bad news and hope MvM is able to sort it out.

 

[NetViper]

Yes, it is very bad news

It took me a long time to decide on the CTSC and when decided to do it to take some precautions, like the Zeitronix unit to monitor my AFR and fuel pressure gauge.
With the stock fuel pump and CTSC voltage booster, the car had always run fine. I have plenty of AFR logs that don't point to any problems.
Am not sure what is causing the problem, probably piston rings.
When I picked up the car a few weeks ago with the Walbro installed, AFR were low and at times very jumpy, as in running extremely rich, like 10.0 or sometimes even lower. At that moment, I blamed it on the new pump and higher fuel pressures.
Probably, the problem was already there, but now surfaced.
And yes, I have been driving the car on the track, and when doing that, I was pushing it.

At this point, I'm not sure on what to do. Let's first find what the problem is and what caused it.
To be honest, driving the NSX with CTSC is quite a thrill compared to a stock car. With the SC, it's quite easy to keep with basically new cars like the R8, 911, M3 or M5.

All I can say is that I thought I was doing things carefully. Not so it seems now

This is really unusual. The AFR is typically rich especially with a better fuel pump. Do you know what your numbers were?

 

[Hagasan]

Yes, it is very bad news

It took me a long time to decide on the CTSC and when decided to do it to take some precautions, like the Zeitronix unit to monitor my AFR and fuel pressure gauge.
With the stock fuel pump and CTSC voltage booster, the car had always run fine. I have plenty of AFR logs that don't point to any problems.
Am not sure what is causing the problem, probably piston rings.
When I picked up the car a few weeks ago with the Walbro installed, AFR were low and at times very jumpy, as in running extremely rich, like 10.0 or sometimes even lower. At that moment, I blamed it on the new pump and higher fuel pressures.
Probably, the problem was already there, but now surfaced.
And yes, I have been driving the car on the track, and when doing that, I was pushing it.

At this point, I'm not sure on what to do. Let's first find what the problem is and what caused it.
To be honest, driving the NSX with CTSC is quite a thrill compared to a stock car. With the SC, it's quite easy to keep with basically new cars like the R8, 911, M3 or M5.

All I can say is that I thought I was doing things carefully. Not so it seems now

Hmm, I'm no expert obviously but....

could it be that running too rich caused to much fuel to be dumped down the cylinders and dilute the oil causing the rings to eventually break through overheating/partial seizing/borewash?

Or that, if I remember correctly? When you installed the Walbro pump the pressure was too high and you reduced it a bit. Could this reduction in pressure have meant that on full boost there was not enough fuel and you were runnig too lean?

I hope it's not too crazy a price for fixing. Hopefully minimal parts on top of labor? Does that rule you out of the Euro Trip for sure? I couldn't commit at the time but may still be able to go. I'll know in about two weeks time..

 

[Stephen@NCAutoUSA]

Hopefully you get things figured out.

If the cylinder walls were washed then there would be other problems I'd think like blow by and crankcase pressure.

 

[MvM]

This is really unusual. The AFR is typically rich especially with a better fuel pump. Do you know what your numbers were?

AFR with the Walbro WAS indeed high, sometimes below 10.0.
However, it is probable that I already had this problem with the pistons, because when I picked up the car, it was already running rich.
Unfortunateky, I blamed the car running rich on the Walbro and the high fuel pressure.
Turned out not be the cause as far as we can tell now

Engine is going to be taken out this week for further analysis.
Like said before, shows that even if you take precautions and think you are being careful, things can still go wrong..

 

[docjohn]

welcome to our club!:frown:

 

[E-Nough Logic]

I don't think the zeitronix reads much below 10.0 if at all so it could have been even more rich than you saw. Were your AFR's under 10 at idle, part throttle, or full throttle, or all?

 

[RYU]

I'm not going to say the Walbro was the cause of MvM's blown motor but oh sweet Jesus the Walbro 255 I bought from SOS almost blew my motor on the Dyno. We started noticing the AFR log looked funny. Then the fuel pressure was jumpy sometimes rich.. sometimes really lean on the same dyno pull. Then the pump just started to lose pressure at the higher RPMs. Overally it was unpredictable. I will never install another Walbro ever. The Supra Denso pump i'm using now is super solid. (btw.. Yes, I rewired the entire system when installing the Walbro)

Another possible problem to funky fuel pressure is quite simply... a faulty fuel pressure regulator. Sometimes it's as simple as a cracked or leaky vacuum line going into the FPR.

 

[MvM]

I'm not going to say the Walbro was the cause of MvM's blown motor but oh sweet Jesus the Walbro 255 I bought from SOS almost blew my motor on the Dyno. We started noticing the AFR log looked funny. Then the fuel pressure was jumpy sometimes rich.. sometimes really lean on the same dyno pull. Then the pump just started to lose pressure at the higher RPMs. Overally it was unpredictable. I will never install another Walbro ever. The Supra Denso pump i'm using now is super solid. (btw.. Yes, I rewired the entire system when installing the Walbro)

Another possible problem to funky fuel pressure is quite simply... a faulty fuel pressure regulator. Sometimes it's as simple as a cracked or leaky vacuum line going into the FPR.

That REALLY would be something
I replaced the OEM fuel pump just to AVOID problems with fuel delivery, especially under WOT and high RPM's.

Would be a very sad, sad thing if just BECAUSE I wanted to avoid any (future) problems, my actions to PREVENT them would in the end causing them :frown:
At this point however, that's very hard to say. As far as I know, the car was running fine when I brought it in early december.
With the Walbro, I have only done something like 300 miles and even that was mostly easy driving as I noticed my AFR was too rich right from the start. That's when I started adjusting the fuel pressure to see if the FPR was causing it.
Then, after a week of fiddling and talking to SOS and CT, I adjusted it back to 50 PSI at idle and brought the car in.

 

[goldNSX]

I'm not going to say the Walbro was the cause of MvM's blown motor but oh sweet Jesus the Walbro 255 I bought from SOS almost blew my motor on the Dyno. We started noticing the AFR log looked funny. Then the fuel pressure was jumpy sometimes rich.. sometimes really lean on the same dyno pull. Then the pump just started to lose pressure at the higher RPMs. Overally it was unpredictable. I will never install another Walbro ever. The Supra Denso pump i'm using now is super solid. (btw.. Yes, I rewired the entire system when installing the Walbro)

Another possible problem to funky fuel pressure is quite simply... a faulty fuel pressure regulator. Sometimes it's as simple as a cracked or leaky vacuum line going into the FPR.

That's the first post ever here on prime where I've read that the Walbro can be faulty. They are said to be sometimes noisy but have been regarded as the 'best bang for the buck'. i also suspected the FPR and asked myself if the one that came with the Autorotor was the latest version.

That REALLY would be something
I replaced the OEM fuel pump just to AVOID problems with fuel delivery, especially under WOT and high RPM's.

You have quite a lot of data with the Zeitronix. Did you see it running lean under boost for even a second?

 

[RYU]

Prime is far from the difinitive source for Walbro performance. Most of the owners here drive less than 5k miles a year. Even fewer actually monitor their fuel pressure/Afr as meticulously as we do. Just do a basic search online. The failure rate is legendary. I chose to ignore it too "because prime said it was OK"

Anyway... I truly hope you guys with walbros don't ever have a problem. It almost cost me a motor.

 

[Coolberg]

I chose to go with the aeromotive on my build. Anything bad about those?

 

[Valhalla]

There are Walbro's and then there are the imitation Walbro's. I got an imitation (thought it was the real thing) and it crapped out out on me in under 500 miles. Got a real one installed and it's been rock solid ever since. Now it does push more pressure so I had to have my engine management remapped to control the flow at the injectors, but no issues since.

 

[BATMANs]

When I blew my motor I was already prepared for the $$$, time and overall project (having done one rebuilt with the GTO and a few others with the FDs).

Even before the SOS SC I had the $$$ earmarked.

I really did want the NSX engine to blow so it could give me an excuse to change my clutch and improve the air flow and install lighter and stronger parts in and around the engine.

 

[peiserg]

uhm put me down as "renewed membership." Sigh.

 

[doc_tai]

damn what happened? i thought it'll safer e85 than 91

 

[RYU]

I suppose it is possible that SOS sold me a fake pump

I have some interesting Walbro vs. Denso pics in my build thread.

 

[MvM]

I suppose it is possible that SOS sold me a fake pump

I have some interesting Walbro vs. Denso pics in my build thread.

Will read up on your thread, looks interesting.

Well, at this point, it is all still speculation what happened. That will have to wait until the engine has been opened.
As far as I know, the engine did never run lean under boost at any time. Not with the OEM pump and not with the Walbro.
But then again, I suppose it only takes a second or so to go wrong.

 

[Dimer]

That is some really bad news Maarten!! I hope you can have it back on the road soon!

I'm at number four, in three years now... 'First' one gave up after >300k km's. Just about everything was broken. I had the engine built with new pistons, valves etc etc. 40km after break in and tune the engine failed. Rod bearing melted, drive shaft was toast, just as one of the camshafts. So I bought a used engine. We put it in the car, started it and after a couple of kilometers blew a head gasket. After inspection not only the gaskets were blown, but all the piston rings were broken.. So I sent both engines to the builder and he just finished building number four...

 

[goldNSX]

MvM, you've told me that the engine has been running rough right after you've picked up the car from your workshop after installing the Walbro, the special gaskets and other things not related to the engine like side skirts. If that is the case I think it must have happened something out of your control then. I'm not saying your workshop is bad...How do the special gaskets between the CT and the engine look like?

I suppose it is possible that SOS sold me a fake pump
I have some interesting Walbro vs. Denso pics in my build thread.

I've bought the Walbros from SoS to avoid getting a fake which are available anywhere. So I strongly hope IT IS an original Walbro.

 

[RYU]

MvM, you've told me that the engine has been running rough right after you've picked up the car from your workshop after installing the Walbro, the special gaskets and other things not related to the engine like side skirts. If that is the case I think it must have happened something out of your control then. I'm not saying your workshop is bad...How do the special gaskets between the CT and the engine look like?


I've bought the Walbros from SoS to avoid getting a fake which are available anywhere. So I strongly hope IT IS an original Walbro.

I hope it's not an original Walbro and I hope SOS swapped it out for something better like a Denso or an Aeromotive. LOL! I'm just kidding guys. I sincerely hope none of you guys have to swap out your Walbros. Removing the fuel tank is a PITA w/o a lift.

 

[MvM]

That is some really bad news Maarten!! I hope you can have it back on the road soon!

I'm at number four, in three years now... 'First' one gave up after >300k km's. Just about everything was broken. I had the engine built with new pistons, valves etc etc. 40km after break in and tune the engine failed. Rod bearing melted, drive shaft was toast, just as one of the camshafts. So I bought a used engine. We put it in the car, started it and after a couple of kilometers blew a head gasket. After inspection not only the gaskets were blown, but all the piston rings were broken.. So I sent both engines to the builder and he just finished building number four...

Well, I was hoping that I could have 300K on my engine too without too much problems.
However, getting a engine broken after a rebuild after ONLY 40 KM really sucks !!
I'm not sure I would go back to the same engine 'builder'...

Hope your new engine will last a bit longer, must be getting tiresome..