turning up the old cummins 262 nhht

[Jackling54]

 OK guys ... I have an old 220 with a turbo..here are the numbers I have taken off the block and the fuel pump.
Date of man. 10-70'
engine # 758406
rpm t.c.-c
model NHHT-6      The old NHH 220 is crossed out
Smb 76804

Fuel pump:tag say NT0262
housing says USA 17776

The manifold is two pieces that fit together into one piece.
I want to get some more power but I don't want to blow it up ...so need to stay some what safe..Any and all advice is welcome..Also will be needing a good Cummin's guy in my area, Southern California, to do the upgrades..thanks guys.

[JohnEd]

Jack,

Cummins forums are your best be.  We are mostly DD savvy but there are those exceptions.  Search on cummins forums and such and that will put you into the groups(s) that you are looking for.  Welcome to our world.

John

[Geoff]

On your antique engine old timers would increase the horsepower by "putting a bigger button" in the injector pump for more fuel.  They used to overfuel their cummins so much they would not only get billowing black smoke, but flames out the stacks.  In this day and age, that would get you a ticket for exccessive smoke. 

[DaveG]

Generally a 262 was not much more than a 220 with turbo....have to check an old CPL book to find out more, but it might be hard to judge what you have even with the numbers...some guys change stuff without changing numbers.

[HB of CJ]

If you have the older 743" Cummins 220 turboed up to 262hp, what they may have done is just add the turbo and adjusted the fuel pump while leaving the injectors alone.

This MAY mean that the engine MIGHT have the stock 220 pistons (who knows) which are higher compression and may not have the necessary oil squirter nozzles.

This old iron was set up to as high as 335 hp back in the good old days, but the insides were quite different that the 220.  The older marine models had as much as 350 hp.

Since the 743 had fewer head bolts than the later, but still older, 855 small cam, the head gaskets would seep after time, usually on the rear head.  That limited the amount of power.

However....I love a good plan.  If your Cummins is out of a Crown Supercoach or Gillig, start callilng the L.A. area friendly, inexpensive, heavy truck wrecking yards for a Pancake Big Cam

Then call up the guys at Pittsburg Fuel Injection.net and ask what can be done with the older (but newer than what you have now) Cummins Big Cam engines.  The sky is the limit.

For lots of money and time, one can build up a STREET DIESEL that puts out well over 700 hp to the back drivers, plus be quite tame and streetable; until you put your foot in it.

However, then one must replace ALL the running gear with stronger stuff.  Ever see a 10 wheeler do a real burn out?  Wow!  I was going to put a Big Cam 444 into my old Crown.  HB of CJ (old coot)

[Jackling54]

Ya Ya Ya burn out that's it !!!
Well maybe after I blow this one up 
So for now I'm hoping to just turn it up with bolt-ons or changing combination's around.  I can change injectors that's not to hard..


;)Maybe I'll buy another motor and start the STREET diesel for later..

[TomC]

Couple of problems-one-the 262 NH did not have an aftercooler-whether it be the jacket water aftercooler or an air to air intercooler.  Hence the 262 was conservatively rated by the factor so not to melt down.  If you have a 10spd, then you could turn it up with the aide of a pyrometer after the turbocharger (exhaust gas temp gauge).  Personally-I would just leave well enough alone and look for a NTC400 pancake engine.  Then you'll have a decent engine with 400hp and about 1150lb/ft torque.  Good Luck, TomC

[Jackling54]

ok tom
what specifc 400 big cam 1,2,3 04 ??

[Boomer]

If you are trying to put an 855 in an older Crown that came with a 743, it ain't a straight up swap.  The accessory drive housing will necessitate notching the frame, or lowering the engine.  Then you have possible ground clearance problems.  Big Cam 400 would probably be too much snoose for the stock radiator, and not sure about the fan drive being swappable either.  A 10 speed trans would be where I would spend my money, as long as the 743 is running good.  Would vastly improve the roadability.

[Jackling54]

boomer   
I do have a ten speed,And actually the bus originally had a Hallscott..gas'er So my 743 does sit in there a little low...got a few inches from NEW" 24.5 with the bigger  then stock..motor's new only 10,000 miles on and complete rebuild.She runs like a top ...Just looking to pull a big toy box behind her now and want to pick up some extra pulling power ...I'm currently a lead foot,so going from tons of power to 250 is going to be a little boring.

[DaveG]

HB's got it right.

As far as BC 1/2/3/4 goes, seems like most 1s were upgraded to 2s, and 4s were a late model/low flow cooling so I'd stay away from them. That being said, any BC you have avail to you (pancake) will be a good start. It'll have 300hp or more to start with.

Pittsburg Diesel is the place to go for HP

BETTER GET THE 3" PYROMETER!

[JohnEd]

Well, so much for my advice

Welcome to the Cummins forum.

John

[Jackling54]

Thanks for the very thorough relays "old coot" and everyone else.
Very needed info..I great group!!

[TomC]

Just remember that the 262 and even the 220 used to pull 73,280lbs in trucks cross country.  Course they did about 20mph up a 6% grade-but they got there.  Good Luck, TomC

[Mex-Busnut]

Not to dis this great list in any way, but there is also quite a bit of Cummins info over one the school bus camper forum. It won't hurt to check them out.

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