Golden Jubilee
Posts: 5188
Joined: Thu Nov 29, 2012 9:28 pm
Location: Lyman, IA
My '89 9670 build
I purchased this truck back in '95 with just over 600K on the clock. I put another 800K or there abouts on it before I retired it in 2006. Well its time has come.
I'm starting out by installing a set of used IHC 472's in the back 3.73 ratio. It came with SQ100's 3.42 ratio but heavy hauling wore them out to the point the housing were shot. I installed the 472 housings from a parts truck and put a 3.55 rear in the front housing and ran it a single drive with a tag for the last 100K I drove it. I'm cleaning up a set 3.73 for it.
I have several engines for it, but all are in need of attention. The original Cummins CPL 838 which I uprated to 840 (350hp). I wore it out and while it runs, it leaks so much from every gasket that I pulled it.
I had a CPL 676 (400 hp) that came from a junkyard, but I found it has a crack in the cooling jacket. I could try and seal the crack but it would be hard to do it right in the chassie. It was caused by someone trying to remove the big plug in the back of the block.
I just bought a "running core". It is a Big Cam 1 CPL 324. The junkyard pulled one head to replace the headgasket, then gave up and sold as a core!
The engine came from a '79 4300. I believe the engine had a Luberfiner bypass filter. WHen they pulled the engine and did the work, rather then plug the lines to luberfiner, they connected the supply to the return. If they ran the engine, there would be no oil pressure. I think this is what happened, and they cut there losses and sold as a core, not realizing their mistake. When I got it, there were new filters and new waterpump belt. The waterpump was shot. I've got a new one coming. When it gets here I am going to make up block-off plates for the outlets, fill the cooling jacket and pressure test to 50 psi.
WHy so high you ask? well Big Cam Cummins run up to 50 psi BLOCK pressure, the radiator is much lower, 4-7 PSI cap. The block runs a much high pressure to prevent liner cavitation pitting. The smaller outlets in the head to the upper waterrail effectively drops the water pressure down to less the 10 psi in the radiator.
My small Cabover detailed in another thread shows why you must pressure test the block. It doesn't leak any coolant while sitting or idleing, but when running down the road, it leaks between the block and head. I need to pull the heads and take care of this leak, but I am using it right now, when I get the '89 up and running, I'll pull the heads on this one.
Ever since I owned it the right door was hard to open. On close inspection, the door itself is bowed. Fortunately, I saved the door from the parts truck, so I am going to send it to the bodyshop to be refinished in the correct livery for this truck.
Its kind of "a labor or love" as this was the 1st big truck I owned. (I now have many) With so many miles, and hard miles at that, sometime grossing as much 168,000 lbs, shows how well made these older IHC's are.