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Discussion Starter · #1 · (Edited)
The car died on the worst possible place, the Palisades Interstate Parkway, which is only two narrow lanes, no shoulders & restricted access, so no AAA towing. I had no choice but to stay on the roadway. Thankfully, the State Troopers came quickly & blocked off the lane I was stuck in, so I didn't get nailed by one of the cars trying to cut the line building in the right lane.

Once I got it home, I put the scanner on it & got this:

I replaced the exhaust cam sensor, no start, so I replaced the crank sensor, (I had spares of all three) no start. Tach doesn't move, so no signal clearly. I did that first because it only took 10 minutes.

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ECU still communicates with the Tuner software, so I don't think the ECU is cooked. Tomorrow I'll have to run through the diagnostic.

Just curious if anyone has any experience with it - online searches mostly came back with crap YT videos

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Discussion Starter · #2 ·
Checked voltages and ground circuits at both CMP sensors, and the CRP sensor. Have 12v input and 5v signal voltage for all three. Still no rpm/tach pulse when cranking.

At this point I have to assume it's the ECU, as according to the fault tracing, the engine would still run if it were just the cam.angle sensor. Don't understand why there is no codes besides the cam sensor though
 

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Discussion Starter · #6 ·
I pulled the valve cover, just for the hell of it, couldn't find anything wrong elsewhere.

Cam pickups are fine

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What's not fine is the timing chain - how the fuck do links break like this

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chain snapped in two

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So, I presume I may have bent valves & chewed up timing gears, etc.... Anyone else seen this?
 

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I am sorry to see this failure, it is not everyday I see this.

I purchased a Toda Heavy duty timing chain. I would suggest them same. I also upgraded to a Inline Pro Timing chain tensioner. I just sent Jeremy a email about Drag Cartel's timing chain guides.

@Bjorn I just bought something from HiOctaneDirect in AU, so far the customer service has been good and they are getting the part out to me this week . Hardrace Inner Tie Rods.
 

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Discussion Starter · #9 ·
I am sorry to see this failure, it is not everyday I see this.

I purchased a Toda Heavy duty timing chain. I would suggest them same. I also upgraded to a Inline Pro Timing chain tensioner. I just sent Jeremy a email about Drag Cartel's timing chain guides.

@Bjorn I just bought something from HiOctaneDirect in AU, so far the customer service has been good and they are getting the part out to me this week . Hardrace Inner Tie Rods.
Thanks for the suggestions

I actually just ordered a new OEM-packaged chain, the one in there was one of those aftermarket kits.

original build pic - pre 40º cam gear install
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The tensioner you mention is just better quality than OEM? This K24/K20z3 motor is not a screamer, so I don't know how overboard I need to go on components. I'd like it to hold up, obviously.

It's gonna be sometime before I can drop the drivetrain & see what's what. Any ideas what carnage I can expect to find from a broken chain? bent valves? piston damage? casing damage up front? It made no mechanical crunchy noises went it went, just a 'pop' like it lost fuel/ign.
 

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Arouse the DAMPFHAMMER!
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So, I presume I may have bent valves & chewed up timing gears, etc.... Anyone else seen this?
Oh no, I am so sorry to read this. What a mess, which would be the last to be expected. I see this for the first time.

I actually just ordered a new OEM-packaged chain, the one in there was one of those aftermarket kits.
Which aftermarket brand is it and do you find any origin fabricator stamps on it?

Any ideas what carnage I can expect to find from a broken chain? bent valves? piston damage?
As long as it happened in low speed cam operation you may have luck not to see much damage beside some bend valves. As the cams are free to turn they my hammered per valves in a lowest issue position. But bent valves is something I would definitely expect. Really worse it gets when rods are bent, but there is a bigger chance they are good. A deck height measurement and comparison with blue print data will give you an answer to that question.
 

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Arouse the DAMPFHAMMER!
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chain snapped in two
I really would investigate why the heck those get broken. There is no cause single chain links brake beside material failure when only operational load is on it. Otherwise the broken surface looks like a immediate cut load, this would lead to the conclusion there was a very hard stop or immediate massive friction increase of the valvetrain or of the crankshaft for some reason. The chain link looks like it may was to much hardened and therefore brittle instead of hardened and reglowed like I would expect it with having non-tool steel material.
 

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Discussion Starter · #14 · (Edited)
I really would investigate why the heck those get broken. There is no cause single chain links brake beside material failure when only operational load is on it. Otherwise the broken surface looks like a immediate cut load, this would lead to the conclusion there was a very hard stop or immediate massive friction increase of the valvetrain or of the crankshaft for some reason. The chain link looks like it may was to much hardened and therefore brittle instead of hardened and reglowed like I would expect it with having non-tool steel material.
Yeah, pretty sure it's just defective aftermarket parts. I don't see how any load on the chain (slack tensioner, etc.,) could cause individual links the fracture like that. The brand is unknown, I bought the chain kit off eBay, and they don't keep your purchase history past 2 years. I originally assembled that motor in fall 2018, in prep for install the next year.

I bought another kit last year, to use for the spare block I bought, I can "assume" I bought from the same vendor, since I had no reason to assume there was a quality issue. There are zero product/ ID markings on the chains. Once I get it all apart I will of course document the damage.

more pics of both sides of the chain - many fractures

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Arouse the DAMPFHAMMER!
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more pics of both sides of the chain - many fractures
I never saw this even on regularly touching 10,000+ rpm engines. They got stretched in a very short time but never broke. That is totally new to me. As a German saying teaches, "Buy cheap, buy twice!". On safety parts there is no room for budget parts once one loves to have a reliable engine. Chain, oil, cams, valves, bearings and rod bolts as well as rods are parts which life affects the total engine once they fail. I am sorry you learned it the hard way, I am really sorry, imagine the mess you have now with the rebuild.

We built highly new and innovative engine stuff with budgets of 10-30 kEUR, which is pain in the ass if you don't sell them just to develop a new setup. But is is even more pain in the ass once not your failure brake it down, but a material failure of a non-brand stuff which has no service or regress on it. So never touch that products, and it can be your fault only during assembly or tuning, but that can happen during any development process, we are humans.
 

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Discussion Starter · #16 ·
I never saw this even on regularly touching 10,000+ rpm engines. They got stretched in a very short time but never broke. That is totally new to me. As a German saying teaches, "Buy cheap, buy twice!". On safety parts there is no room for budget parts once one loves to have a reliable engine. Chain, oil, cams, valves, bearings and rod bolts as well as rods are parts which life affects the total engine once they fail. I am sorry you learned it the hard way, I am really sorry, imagine the mess you have now with the rebuild.

We built highly new and innovative engine stuff with budgets of 10-30 kEUR, which is pain in the ass if you don't sell them just to develop a new setup. But is is even more pain in the ass once not your failure brake it down, but a material failure of a non-brand stuff which has no service or regress on it. So never touch that products, and it can be your fault only during assembly or tuning, but that can happen during any development process, we are humans.
Yeah, hindsight is always 20/20. Unfortunately my major experience with aftermarket is Volvo-based, and since there are few aftermarket manufacturers for parts such as timing belts, etc., typically the quality is good for such items. It was pointed out to me that the sheer volume of Honda production indicates that shameless manufacturers will produce critical components of poor quality simply because it makes a profit no matter what.

So, no more penny-pinching on critical components 🤪
 

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Arouse the DAMPFHAMMER!
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So, no more penny-pinching on critical components
I know it is hard. For example i could choose for the 11,500 rpm capability a valve spring set for 400 USD, which would would maybe survive the tuning session or buy the capable set for 900 USD, which would stand for some 50 hours of racing. But that's a simple decision. More difficult it get's, I know stock chain guides can't handle the hard shift engine speed steps during race shifting for long. There are always issues with them. Upgrading them means another 500-800 USD. Same for timing chains, valves, rods, bearings, oil pump, oil and so on. If you declinate through all with the safety googles, you came out with an red head asking yourself how to refinance this: more working, reduce money bleed on other systems like wife ;), ... while prices rises from month to month by 5-10 %. My last stop at the grocery was +12 % compared to the exact same list bought at end of May '22. Also the USD-EUR change rate get lowered from 0.88 EUR/USD to now 1.00 EUR/USD, another 12 % loss in buying power, if you buy parts from US.

You see I see also the situation for doing the right is challenging these times. Time for some innovations ;).
 

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Arouse the DAMPFHAMMER!
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due to house & family obligations taking up my time :rolleyes:
Thanks for the reply, I am too curious 😇. Good success for your other important stuff beside the engine thingy 🤫.
 
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