Pyrometer for C15 single turbo MBN; How hot is too hot?

With 2 thou liner protrousion its no wonder it blew a head gasket. Bet CAT told you the reason it blew the head gasket was because you had modified injectors in it...what a load of ####. Sure the extra fuel and boost with your big injectors and turbo problably made it happen sooner but it still would have done a head gasket anyway. I have seen more C15s and C16s than I can count with blown head gaskets and none of them were modified, I have seen a stock C16 blow a head gasket at 200000km. Its all about liner protrusion!!
Did it blow out at the front of cylinder 5 or rear of cylinder 4 , that is the most common place.

I think I would put the injectors and turbo back on, I think the marine cam has a more aggressive lift on the injector lobe, thats partly why they make more power so adding one may increase the power even furthur.
The only real way to be sure it will handle bigger power is to pull all the liners and insert the block to get the liner heights perfect, and even then you can still have gasket failure.
Remember that an engine running full load constantly with 300hp will always last longer than the same engine at full load constantly with 600hp which will last longer than same engine at full load constantly with 900hp.
The trick to having big horsepower is only use it when you need it.

That said there are other guys on here more qualified to answer questions about high horsepower cats than me. I have a hard time finding people with desire to spend money modifying there engines beond stock out here.

On the Acert thing, the jury is still out on that one...I was under the impression that the purpose of the VVAs was to reduce cylinder pressure under high boost and load also but I spent some time in a 625hp T904 Kenworth with a B-double tanker on it. 62psi going up hill under 100% load and the VVA's didint come on once (I was watching the parameters on CAT ET). Cat arent very forthcoming with info either. Backing the timing right off is the other way they could be controlling peak cylinder pressure, that would also explain the poor fuel economy they get.

 

Yes CAT did blame the mods
It was blowen in 2 places both around 4 and 5
I dont want any more power,the responce,cool temps,MPGs is enough
I thought I was easy on the boost,BUT some times it was too much when I saw a Cummins 620 sig in the distance.
It did have a cracked liner after 420k km CAT paid for the rebuild and they put it together at .002...I think they did'nt want to spend any more than what they had to so no new .003 under spacer plate ($960nzd).
Thanks very much for the info as there is know one over here doing this sort of thing its great to be able to hear it from guys like you.

 

That's the samething here in the US, nobody understands what an advantage they gain with big horsepower.

 

Thats normal for cats, the official spec is .001 to .006 acceptable range (there are also other measurements you must check, average differnece between liners and protrusion across each liner , etc. ) but most people who work with them will tell you anything under .003 is asking for trouble and if you want to do the job properly you need .005 to .006. Most cat mechanics know this but if the repair is done under warranty their hands are tied, they cant fix something thats already with cats spec.

A side note for anyone out there thinking more is better....you cannot assemble a C15 if you measure a liner height above .006, it will in most case crack the liner flange.

 

Saw that once on a 3406B. The ####### forgot to install the 3 headgaskets and ruined every BRAND NEW liner. Broken flange.

 

All depends where the probe for the pyrometer is mounted before the turbo appox 1200 max, 5" after the turbo appox 1000 degs, big difference

 

This is an old thread. Mine's mounted after the turbo and it would easily go to 1200 possibly beyond. I always backed out when it got to 1150. Didn't do any good the exhaust housing still ended up with a hairline crack at around 850k miles. Heat is just too much on these engines in stock form. It was impossible to keep daytime pyro temps below a 1000. There's only one way to fix it and I'm sure glad I found this forum a couple of years ago. Never see temps over 825 anymore even on the hottest of days.

 

MBN is a cat (bridge) engine. I had an 03' Pete with that engine. I have seen the pyro go to 1300 and above alot. It melted all the plastic off the heater hoses. Took to Dallas Pete probably 10 times, and finally they said we cant fix it. (dont forget this truck is new). Finally shop foreman said just run it, its under warranty. Long story short these engines were junk unless you changed the ecm and took the catalytic convertors off. Poor excuse for an engine. Goo news is they could be fixed.

 

good news not goo news

 

Goo news was when you blew the turbo and shards went into the motor lol