Vaeth's Rebuild Blog

As most of you might know, I blew my engine about 6 months ago while attending a track day. The cause of the blow at that time wasn't known, and there were many theories flying around. I have since brought my engine to WTF Auto for a rebuild, and as of late last week, my engine is finally out and is in the process of being rebuilt.

This thread is a blog of the rebuild process, including comments from the engine builder, my comments on things past, present and future, and hopefully some interesting photos. Feel free to comment in this thread, but lets not go too far off track:

-- Brendan

Entry 1:

Excerpt of an email from Tristan

quote:

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Hey Brendan,

Almost everything has been smooth so far. Although the rear driveshafts" welded" themselves into the hubs from rust which is very uncharacteristic of your extremely tidy car. I have a feeling that the missing centre caps combined with salt water on the trip over must have caused the problem.

Your head has copped a bit of damage, something foreign went through the inlet and started punching holes in cyl 3. Im going to have to have some of the damage welded up I think. The piston was a bit damaged too - not that it matters.

The Mahle pistons have arrived also - They're an incredibly nice piece. And they are the lightest piston/pin combination Ive come across.

I'd like to take a bit of time to tidy some bits of your motor up. A lot of things have been done 'rushed' such as the fuel rail install - instead of running a new return line, the stock half metal line
is just hanging around, scratching up your sard rail... and a couple more things here and there.

Anyway, I'll shoot you another email once I've examined the pistons

-Tristan

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It was good hearing from Tristan that my car was in overall very good condition. It is a pity that my driveshafts have rust locked, but well, that's fix-able so I'm not too worried. The bit about the rushed job regarding my fuel rail installation really urks me though. This begins the first of many grievances against the workshop that did my fuel rail installation and tuning.

The work shop that did my fuel rail installation, cams installation, and tuning was called TRIAL. They are a workshop in Osaka, Japan, and are also listed as a workshop in Gran Turismo 4. It should at this point be stated for the record that any further comment I make about TRIAL will be strictly a relation of my personal experiences with them, and my personal view of them resulting from my experiences with them. At no point should my comments be understood as a statement of fact of their business practices, conduct, quality, and so forth. It is not a purpose of my comments regarding TRIAL to affect people's perception of them, nor to affect their reputation. I am merely relating my own experience in dealing with them.

I went to TRIAL thinking that, well, yes, they are exorbitant, but at least I know I'm getting the best. After all, it's no small feat to be featured in GT4 right? Not to mention they used to be a sponsor in JGTC and some other races like that. Having paid close to $4000 for my cams, fuel rail, and tuning, it just pisses me off to hear that they didn't even bother fitting a new return line and instead left the stock one just hanging around like it is...anyway. Deep breath, ring bell, meditate.

On to the damaged head. This kinda got me down. From the sound of things, my engine was in pristine condition (see further blog entries later below). It's somewhat disapponting to hear that I damaged it. I'm not sure when this happened so no fingers being pointed anywhere here. I feel like I've ruined a famous painting though...like the Mona Lisa or something. Even if it can be fixed, it's not the same.

Anyway...now the Mahle pistons sound cool. I'm really excited about these. I've always like using something different from the norm, and to be able to test out something new as opposed to using the normal JE, Arias, etc pistons, just puts a smile on my face. Not that I'd notice the difference anyway...but well, that's my way of ricing up my car.

End Entry #1

Great idea Brendan, thanks for sharing the experience.

Entry #4

Excerpt of Email from Tristan (revised for readability by me):

quote:

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Well, the teardown is complete. Pistons 1,2 and 3 have smashed ring
lands. Given that #4, the richest cylinder survived, I'd guess that
the failure was from lean AFRs.

Pison #2 was particularly destroyed...the second ring land got smashed too, something I've not seen before on a 3S piston that wasn't melted. The top rod bearings all have wear spots where the detonation has literally hammered the rod into the crank at TDC over a pretty prolonged period (ie, longer than a few seconds). Your rod small end bushes have also been knocked out of round and -should- be replaced.

Otherwise your whole engine is in amazing condition. Oil pump is the
newest looking example Ive ever seen, bearings and pistons are
superb. This motor could have done 300,000kms plus if treated like it
has been (aside from the smashed pistons!)

On that topic, how many kms had the motor done when you got the car?
what oil have you used and how often did you change it? Im very very
interested to know.

-Tristan

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So...bad AFR's blew my engine? I understand that this is just an opinion of one engine builder, but his reasoning and justification behind his conclusion is hard to refute.

Pistons 1 - 3 are dead. The traditionally richest piston #4 is still surviving. Amazing to think that I still manage to drive my car home from the track in this condition. I was basically running on 1 good piston, 2 half pistons, and 1 truly dead piston? Talk about tough.

Anyway, I hate to point more fingers, but I'd have to say that I'm definitely pointing in the direction of TRIAL regarding the cause of my blown engine. They were the ones who tuned my engine in the first place. I am so glad that I did not go back to them to rebuild my engine. I can't help but wonder how lean the AFR was to cause 3 pistons to blow a ring. And to cause one of the pistons to blow 2 rings. Damn... Oh, I should also mention that when TRIAL did a check of my car to ascertain the damage (and how to fix it), they only mentioned that piston #2 (or #3 i forgot) was blown. They didn't menion that pistons #1 and #3 were also blown. Gees...thanks very much Murayama-san...you da man.

Deep breath, ring bell, meditate....grrrr!!!

Anyway, glad to hear more confirmation that the rest of my engine is in good nick. Gotta say a big thank you to the previous (and only) owner of my MR2 for taking such care of the car. Sorry I've blow it up...but I'll take good care of it from now on!

End Entry #4

Entry #6

Cracked Piston


Cracked Piston



Cracked Piston



Cracked Piston



Mahle v. Stock



Big end bearing wear



Hmmm...hope my crankshaft is alright. That looks like a nasty wear mark.


End Entry #6

as the compression ratio is just the ratio of the maximum volume formed in the cylinder to the minimum(clearance) volume, increasing it would have to produce more mechanical energy and a better thermal efficiency. Someone confirm?

quote:

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Originally posted by MR2Vaeth
There you go, oils ain't oils. Use only the best full-synth oils for your engine if you care about it.

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hmmm, VERY different from what Terry at Road and Track said on this issue. He said that the 3sgte doesn't like fully synthetic oil, and that people should only be using semi-synthetic oil, as the Synthetic stuff is too good for it...

quote:

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Originally posted by KrAzE

quote:

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Originally posted by MR2Vaeth
There you go, oils ain't oils. Use only the best full-synth oils for your engine if you care about it.

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hmmm, VERY different from what Terry at Road and Track said on this issue. He said that the 3sgte doesn't like fully synthetic oil, and that people should only be using semi-synthetic oil, as the Synthetic stuff is too good for it...

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I'd have to say that the proof is in the pudding Kraze. Or in this case, the proof is in the lack of pudding in my opened engine.

Only possibility I can think of of why a semi-synth would be better than a full-synth is in circumstances/situations where the engine is already not in perfect shape (i.e. it has not been service regularly, and/or has been using mineral or semi-synth oil for a while) and putting in full-synth just highlights and brings out the problems already present. A semi-synth or non-synth in this case would hide the problems and makes the engine seem smoother.

That's my guess anyway.