To start, let me warn you this may be a long read. If you want to add your input, please be as precise as possible, I will appreciate it, I need to come to some conclusions and learn from this engine failure, since, obviously something went wrong, and if I could have prevented/avoided this from happening, at least I'll have the knowledge for the next time around. It is pretty important to me because I work in my car, and drive a big deal in it, so having it healthy and reliable is essential for me.

You might first want to go and look at this thread first, it could give you additionnal info: https://honda-tech.com/zerothread?id=477618 .

Right. I'll give you a recent history of the engine and what's been done to it. In december, I swapped out the auto tranny for the 5-speed. I also installed a UR flywheel Ultra L, and a Centerforce dual friction clutch. The swap was pretty professinal, and included a good amount of parts, including a 5 speed ECU. Coming right out of the shop, I noticed the idle was shifting during cold starts from 1500 to 1800 rpm.

I didn't give it too much thought even though it bothered me a little. But as time went on, the idle shift started to occur even when the engine was warm, in fact, as soon as I would disengage the car, while still rolling, it would hold steady at 1500, then as soon as I stopped, it would shift between 1000 and 1500, and backfire a fair amount.

That started to get annoying, and that's when the ECU threw 2 codes: Bad EGR, which I was advised to ignore because it was useless anyway, and a bad distributor, because of misfire in cyl #1.

So 2 weeks ago in goes the car for extensive maintenance and a little upgrade too. Timing belt, water pump, valve adjustment, distributor, distributor cap, wiring, spark plugs, AEM cam gear (set at -4°, or -8°crank), and FPR (set at 40psi). When I drove it after, I was really impressed by the improvement in performance, and at last, the engine ran smooth too.

Except for this little shifting at cold idle of 200 rpm again. But I was thinking I could live with it, so I didn't worry more about it.

Well this tuesday, the situation I described in the thread I linked arose. So I got it checked, and the mechanic told me to set back my cam gear, distributor and FPR to Honda specs. Which I did, and all the problems before I changed the distributor came running back. Back to good ole backfiring and idle... idle. + I had lost a good amount of performance.

Now what the mechanic had noticed and not me, not having the ear trained for this, was a little valve ticking. He was thinking, "he's burning up a valve" and chose not to talk about it, because he thought it was probably too late anyways.

So off I go and drive another 600miles or so, trying to avoid the misfire range, and all, until yesterday, when, driving down a hill, and compressing in 3rd at 3500, bang! I snapped a rod and it went straight through the block. End of story for this engine.

Now we are going to tear it down to see how it looks inside, and I will take pictures and try to post them as soon as I get them.

But when the car rolled in, just by looking at the tech, I could see he knew exactly what was going on, he was expecting me (bastard). He explained to me that since my engine had over 155,000 miles on it, retarding the cams, and advancing the fire probably put too much strain on it and I burned a valve, and locked cylinder #1.

I don't know what to make of this. I would say he is rather credible, since he seemed to know what was going on, but is it the cam gear's fault? Is it because it couldn't take the heat? Is the misfiring related to it by any chance?

I need your help to understand this as clearly as possible, because if it is something other than the cam gear, I could be making warranty claims either for a bad new distributor, or bad ECU.

Now this spurs up other questions I will ask in two different threads: What engine for replacement, and what about AEM EMS? Because I need to get this car back on the road ASAP. Plus, it's soon track time! hehehe.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sauceman &raquo;</TD></TR><TR><TD CLASS="quote">AEM cam gear (set at -4°, or -8°crank)</TD></TR></TABLE>

OK, first this seems like to much, but what do you mean by -8 degrees crank?
second, your mechanic might be right.
Third, if you want reliability i guess AEM EMS is not what you need.
Fourth, my advice (if you can afford it) is get an H22A and rebuild it, that way you'll be sure it is in a "new" condition and will last longer.

and fifth, i'm really sorry for this, i know is hard for your with all this expenses that you have to deal with.

OH! BTW: did you check the wires on the distributor?

 

Yeah, the wires were ok. Thanks, forgot to respond to that on the other thread.

Edit: GZERO, I really don't know what it means either, I picked that up somewhere, but don't remember picking up the explanation. Maybe I got it all wrong too

And as for the EMS, it kinda puts it out right there. If anyone wants to comment on it I'd love to read about it, I don't know how it works.


Modified by sauceman at 12:06 AM 4/19/2003

 

you didn't have a vaccum leak in there did you ?

 

No, all the vaccuums were OK.

Is it possible that a bad valve by any chance could have caused the misfiring at partial charge between 2000 and 2600rpm?

Since VTEC engages at 2500, could it have been playing a role in preventing the misfiring to happen in higher ranges?

 

I thought V-tec came in at a higher rpm range around 4-5K

 

this has been discussed many a times, VTEC engagaement is somewhere around the mid 2000 rpm range, depending on a number of factors.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TypeSH &raquo;</TD></TR><TR><TD CLASS="quote">this has been discussed many a times, VTEC engagaement is somewhere around the mid 2000 rpm range, depending on a number of factors.</TD></TR></TABLE>
Right. I was as surprised to learn this too, and when I had the auto, I couldn't feel it, because upon acceleration there was too much torque slip under 3K to feel any shift in power, but I must admit I could feel it very distinctly with the 5-speed. And it was probably the biggest "surge" of power throughout the band, even moreso than the one at 3800.

 

I was waiting for somebody else to comment, but here goes...


How would a burned valve cause a snapped rod? I'm not trying to be an ***, i just don't see the cause/effect relationship

anyone care to 'splain it to me?

 

vtec system activation and the hi-cam crossover are two entirely different topics

 

That's what I thought, but since I only partially know engine dynamics, I have to sort out fact from BS. This is why I ask your help...