Thinking of getting more ponies out of my ntc-bciii. cpl 531. already done the fuel line modification. what do you guys recommend I'm about 24-27 psi boost. Pyro about 800 pre turbo I believe believe. thinking 10% up injectors. bigger button or have pump calibrated and resealed. and putting on ht60 turbo. what modifications did you guys need to do to put on a ht60? any other supporting mods? can I change the pump to a 1" or 1.25" without a pump shop?
Send the pump and injectors to Premco in Las Pasas Texas, I don't/didn't use any other pump shop. They only do PT pumps for large Cummins. Set it no more than 14/15% over fuel with ** ratio set 10% over. Anymore than that and the stress to cam injector lobe is way too high. HT60 turbo to use is #3804502, straight bolt up, oil drain & pressure inlet is basically the same. * There is no need to change pump gear size. The reason for sending to Premco is Pump & injectors need a matched flow rate. The injector flow is key. Being a 531 it is the same basic engine CPL as a 625 CPL. The only major thing that can make a difference is where the injector timing was set originally .69 is fast, .70 is nominal, .71 is slow, timing is preferred on the slow side. I normally set at 71 to 72 thousands pushrod travel, I always set to slow timing because it gives a slight bit of hang time between shifts, torque. But with that said, it's a bunch of work to retime one, so unless it's a complete inframe or out of frame it's not worth the time. Power gained from your change over about 50 to 55 hp and 100 lbs torque gain, no more than that. * I see your eastern Oregon, I live in Walla Walla. Last one I built below about one year ago. *
hey that looks really nice! I'm new to timing these have done a couple p pumps. can someone put me in the right direction for an injector timing tool and the literature for it. we've got about 8 of these engines and would like to slowly get them tuned better. what would be the easiest way to retard the timing? do a step key? I'd be willing to drive pay $$ and bring an engine some time to someone if they'll show me the ins and outs.
I'm in the baker city area but actually going to walla walla in the next couple weeks to grab a seed drill. small world!
The standard cam gear key used for CPL 531/625 is 1596 for a 3/4" key flangeless cam which is the most common type cam. Gear has to be properly supported to remove with press, gear can only be heated in a oven {no other means} to 450* for a drop in place fit using inferred gun to check temp. But to change timing everything from rocker boxes up plus injectors has to be removed, along with accessory drive, compressor, pump to gain access to cam followers. A lot of work for a minimal gain in timing, that's probably already at 70 nominal. Plus after the cam is removed Cam bushings need to be inspected because unless any of these engines are recon replacements the cam bearings are more than likely original, and very tired. And to replace cam bearings in frame is a major job, requiring a special puller for #7. Plus installing new bearings in frame is a b---h. #2,4,6 have multiple feed holes to line up and you can't miss. Best to leave it where it's timed until a major out of frame overhaul. I have a timing tool and have timed I don't know how many, but I don't loan that timing tool.
would you be able to get the numbers on the timing tool? we've got 3 855 small and large cams that need rebuilt and a l10. thanks for all the insight guys. what do you guys recommend for a button until I can send this off to get calibrated. I think I have a 15 or 17 in there right now. and max rail pressure and not eat cams? anybody have a favorite injector flow in cc for about 500?
There is only one guy here at this time. Monaco Tools makes and sells a nice timing tool. Monaco Tools is in Eugene Ore. It more than likely had a #27 or so for stock button, #22 is 10% over, if it has a 15 to 17 it's already 15% plus over fuel. Stock rail pressure is in the 160 range, Max rail is 200 before cam damage occurs. 15% over fuel is roughly 195 to 200. Now This is where the hot rodding destroys 855's real fast--trying to push 500 hp out of a fixed timed Cummins. If you have been reading crud on face book or youtube about 500 hp 855's that last--that's totally mistaken, Pittsburg Power that's their way of selling parts. I suggest if your looking for that kind of power you buy factory rated N14's, Series 60's or Cat 3406/C15's. The Big Cam's were not capable of creating long term engine life twisted that far from stock form. It isn't a 5.9 and never will be. * Truck Shop.
just looking for a bit more snout. this will be my personal truck. occasional 500 when the weather is cold. I'll get a gauge ordered and see where I'm at on pressure. would just like to build her up see what it can do then tame it back down with the throttle shaft screw for employees to drive.
For your time and money you could get a n14 and have way more power at every rpm. Everyone loves a red head
id rather the old school mechanical big cam.