Newbie here needing some quick advice. I've searched the forums as well as the internet but before I make a $$$ mistake I was wanting clarification. From what I can tell the NH250 is a high flow system. Please correct me if I'm wrong. The current engine in my 1971 Ford L9000 is the NH250. Due to a whole host of issues I am probably going to swap it out. I have found an NTA 400 which from what I can tell is the high flow as well. I guess to make this simple, as long as the water intake/exit is the large diameter pipe (which is the same as my current NH250) I can do a swap relatively easy? I just need to stay away from the engines with the small inlet/outlet radiator lines correct? Please let me know what your opinions are for an engine swap. I see several with the aftercoolers and several without. I like simple as this is just a truck that will be used from time to time. Thanks in advance for any help
Correct-Any engine that's a Big Cam VI, New Big Cam VI {small steel tube oil cooler}, NT88, 444 will be low flow cooling. The coolant flows in the bottom radiator tank is pushed to the top tank and flows back down to lower tank and back out the bottom tank. There are dividers in the top and bottom tanks to divide the tubes. Your engine is a small cam, any engine built before mid 86 is a high flow system.
Some of the 250's had an excentric water pump. Twist the pump in the block to adjust the belts. If the fan hub height and depth of your replacement engine are different that could be a problem. If you have to use your original flywheel housing there is a difference at the rear cam location. Seems I had to modify it somehow but doable. Problem could have been going the other way. Small cam for a big cam. I have done both. Do you have belt driven power steering pump? That probably won't work out. Change exhaust and air intake piping. It will work but little issues always come up.
I'm thinking It being a 71 it should have a suitcase water pump with straight drive fan. Being Ford the rear mounts are probably on the trans. Should be a Vickers pump if so it's just changing some hoses. Main thing is what year that NTA 400 is
Would he need front motor mount and possibly rear flywheel housing for big cam he's putting in? The block would be the same, but would it have a different front mount for larger balancer/ engine lean, and rear housing different for the engine leaning over? It could also have had a small box 6613/ 613, and have a smaller housing for the small box transmission. I kind of doubt the transmission behind the 250 would be able to handle the 400, but if he's not using it everyday.....
It should have a full size trans most likely a 9513 or 10. Front mount will swap, could even just be a cradle mount. The rear housing can be used with a slight modification like Tenwheeler said. And even if/ those parts are findable in a salvage yard. It's the same basic engine just aftercooled.
Will the same radiator have enough cooling capacity for the extra 150 Hp?
sure.
Thanks for the info. I think it is a water pump that adjusts the belt
It has a "newer" Eaton 10 speed. I'm assuming someone changed it out. I only assume this because the shifter is the newer model with the front bladed flip switch
That's probably just a new style A6909 shift control knob, Some photos of this stuff would be nice.
Didn't ford have a special flywheel housing since they liked to put a lean to all big bores back in the day? I remember doing an L10 swap and had to change flywheel housing and front gear case cover. Then i read oil pans, pick up tubes and cooling nozzles were even different for the Fords.
That's why photo's would help, see which mounts were used.
As I recall ,the NTA 400 that I worked with was a somewhat harder starting engine in cold weather than some of the others. Was in a 359 and had a compression release. Ran well after starting.
Any of the big cams really were not great cold weather starters, anything below 45* even on a fairly low mile engine it was best to plug them in.