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Cummins/Onan 6at3.4

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'94 12 valve to '03 24v

Cummins powered Jeep Wrangler

Hi,

Dad and I are putting an Cummins 6at3. 4, aka an Onan L series, motor into our 65 land rover 109. I have foudn a source in Long Beach for running take outs from UPS trucks. The motors supposodly have around 100K on them and I have seen them first hand and they look pretty good. My question is, what should I do before I put this thing into the Rover? Head gasket? Other seals? I don't want to be doing anything to it besides gauges when it is in the rover. Let me know. Also is this the same VE pump on my first gen or is a a similar VE?

Thanks in advance,

Jamie Hastings
 
I wouldnt do anything to it, put it in your rover and hope for the best. If you can get a spare engine cheep I would recomend it, parts for these engines are getting hard to find, and expensive. Gaskets and seals are probably readily available though. I put one in a 70 chevy I had & it worked good. It was also out of a ups truck, I had about 10 to chose from so I just took the one that looked the cleanest & it ran fine. Good luck with your project. Oh one more thing they sound real nice with a 3'' straight pipe, you can really hear the turbo whistle. :cool:
 
I remember these engines from way back in the 80's. When we used them for repowers, get ready for a larger radiator. High cooling requirements.
 
Yep, That is in the plans right now. The original Rover radiator wasn't much since it just had to cool a little "petrol" 4 banger. We are planning on electric fans too.

Jamie
 
If you are looking to run more boost I would look at getting head studs. You might even look into a kit to rebuild it and do it right from the beginning.
 
I think we are going to keep it stock for now, plus we need to watch the budget and are planning on spending a little money for air lockers front + Rear and a couple of other things.
 
Yep, I actually give them a call last year, and we wre going to get a rebuilt motor from them, but it was pretty dang expesive and the man has or had and illness so we were skeptical about ordering a motor. Really nice guy though. John I think.
 
You know I am not sure if he did or not. I just went ot Long Beach today and picked up another 6AT since our first one turned out to be bad, but it was an old modle with an Onan data plate still on it so it was from the 80's. The one I got today has a Cummins data plate, so it is probably from the 90's, plus it has hydraulic lifters i believe. I am going to take off the timing cover, check out the cam and all the gears, replacve the seal, adjust the valves, and call it good. Lewdon is where I got it. Lew is a heck of a nice guy and let us do a straight swap for the Onan since it was no good. He has tons of them that come with starters, clutches, and bellhousings. $1250 and he runs them for you.

Jamie
 
When you adjust your valves it may be a good idea to check the interference nuts on the rocker levers. One of mine had lost its interference fit and backed off. It was no big deal the engine just missed on one hole till I got it readjusted. I ordered a new nut and put it on & then decided to check the rest of them and several of them were loose. Since I only had the one new nut I just put the old ones in the vice and squeezed them a little to make an interference fit. Just a heads up, I don't know if this is a common problem or not. My engine was a 1990 model.
 
RWood said:
take a look at this website http://www2.itexas.net/~peaksale/index.htm it has some good information, you might give them a call.



I stumbled across that site years ago, the owner/sales rep was a great person to talk to. I was all set to buy parts from them after we finished our relocation to MT. I ran into Kenny at Autoworld a few months after the move and lost the contact info for Peak sales.

Thanks for posting their link, I'm going to give them a ring next week. There are some parts I remember they had that would make certain conversion much easier. I was given the impression they were a small mom and pop outift which in my book is more important than anything else when buying parts/ consumer goods. I'd rather have a direct dialogue with a small business than deal with a regional parts store who doesn't even feel like giving me the time of day. :(
 
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Jamie -

You said the first engine you picked up was bad... What was wrong with it? Was it a blown head gasket? How far along with the conversion are you?



Thanks Ben
 
Well here is the deal. The first engine I picked up was an Onan engine and it had a few differences. First and foremost, it did not have hydraulic lifters. On top of that, the oil pump drive gear was totally shot. In addition the little tabs that are on top of the valve reatainers that rest against the rocker arms were also totally shot so there was enough wrong to where we just took it back and grabbed another one. It is my understanding that the later motors by Cummins have hydraulic lifters, at least that is what it looks like in the shop manual that i got. Somone with more experience also might want to chime in. We are about to rip into this motor to look it over and relace seals with our buddy who is helping us along with some of our fab work. Right now it is just a bare frame. Yesterday I put all new bushings in the frame and leaf springs and axles hsould be beneath it in the next week or two. Then I need to weld up some motor mounts and the motor, nv4500, and stock Land Rover transfer case are in. I will try to keep this thing updated with a few pictures too if i can.

Jamie
 
jamie if you need any specific info, "Simon" on pirate4x4.com/forum hangs out in the Land Rover section and did a 6AT into a 109. You can tell him I specifically referred you to him. Good luck with it...
 
Well, we talked to John down at peak sales. He is really not in good health, but we bought a BRAND NEW long block from him. We also bought a new injection pump too. Pretty reasonable I think and it is all new so hopefully we will be set to go now.
 
Jamie -



What happened this time to the engine?

How much was the injection pump?

How much was the long block?

Hope you have better luck this time.



Thanks, Ben
 
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