SsgLattig
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- Morris County, NJ
The 3100 series is a great engine family, and from what I remember 2350 is the recommended top rpm, depending on the variation though, but lots of guys say they run them past 2900. Most likely all of the crappy tachs in these trucks are off. Not saying they can't be run at 2900+, but being a former Army mechanic (63T) & still hold the 91M MOS secondary to my 11B, as well as a Cat certified guy, I can tell you the gages in military vehicles are crap. Back in the day I used to change them out in my BN daily on this vehicle or that. Cat has a really cool old piece of gear called CAT-ID that displays all engine info (from electronic engines), and guys used to love that because they found their gages were off so they could always look at that and see that their engine was fine. The problem with overspeeding any diesel engine is that the valves will "float" or not close fast enough and the pistons will hit them, break them off into pieces, and then they get chewed up in the combustion chamber and spit pieces out the exhaust, through the turbo (if applicable), and now you need a head, piston, turbo, and maybe a block since these are dry sleeve blocks. They aren't "throw away" engines, regardless of what anyone here says, and they can be bored and sleeved. I've done it many many times, and they go on living a long life. You don't want to overheat them though because then you cause warping & all kinds of other potentially unrepairable damage like cracking. That'll make any engine a "throw away". The throw away Cat is the 3208, and yes I know there's a guy on here that put one in his Deuce, and I don't hate the engine, but they are really a throw away because it's cheaper to buy another one and usually aren't rebuildable without lots of $$. There's another thread on here on the subject of rpm's on a 3116 titled "M35A3 Cat 3116 Max Operating RPM" with some more info as well.Thanks for the info! My A3 purrs right now. I will have a CAT Technician perform all the work it will need. I can fiddle with a big block or a Briggs&Stratton or even a 6.2 but I'll leave the CAT to the men with the tools. The engine runs so well I'd like to keep it that way.
I have decided that since it is my farm offroad toy, I don't like to over rev the engine above about 1,900-2,200 RPM even though it will rev pretty high (2,700). What RPM is too much for these engines in your opinion?
So, IMHO I can only tell you what I know from my experience. Aside from that, people will do whatever they want, which is totally fine, but I don't have a lot of $$ to fix my stupid choices so I tend to take it easy on equipment these days