Diesel Cam

I have a '63 4000 with 172 diesel. I have checked my cam, and it's no good. Some of the lobes are worn down.

The cam has Diesel stamped on it, along with the Ford logo. It is stamped 310377. Yet every cam that is listed for sale for those numbers, say "Not for diesel"

What cam do I get? Why do they say it's not for diesel?

Thanks, Pat

Hey Pat, I have seen some cams with diesel cast into them. You might want to check your rear cam bearing bore against the specs of a good cam. I have some kin who "swapped" one of our diesel motors and It has a rattle to it. I thought it was the hydraulic pump shaft or gear loose but when I pried against the gear a little I found that it would lift up and down. So either the cam is worn out or the block or both. I'll be on here about 15 minutes more if you want to call. Time 9:43 PM.

Apparently there is a difference between the gas and diesel cam with regards to the clocking of the distributor/injection pump drive gear.
Putting a gas cam in a diesel engine does not allow the injection pump to be timed correctly. There was a discussion here about a month or
two ago about this very topic.

River,
Sorry, I shut down my pc before I got your reply. I'm busy this mourning. I'll give you a tonight (Saturday).

Thanks, Pat

Bern,
I have been trying to find out if they are, or not that same. Everything I have found on them, say's that same part number. But every where I find that cam for sale say's "Not for a diesel.

I started talking about not being able to get my pump timed on here for almost a year now. I have gone through my pump, Dieseltech checked my pump shaft, and the governor plate timing marks for me, and replaced them both. It did not fix the timing. my timing is off by 23 degrees. I finally found, and had a earlier ford diesel mechanic look at it, and he told me that it was not, in my pump, but in the block. That is why I have my cam out of the engine now. I am checking for something twisted, because it has signs of the hyd pump seized, and wrecking the original cam gear. It was all replaced by P.O. Everything looks good, and on the money, except for the cam gear key. I can not get the gear off, with heat & a gear puller. It will not budge. That's when I mic'd the cam, and found it has worn lobes, anyways. I still need to press the gear off, just to see if the key is twisted or not. To see if it is, why the timing is off.

My cam say's diesel on it. and the number on it say's 310377. But look up that number. It say's not for a diesel.

I can not find a cam any where, I have looked that is, for a early diesel. After '64, they say they are the same cam, but they are not the same for the earlier ones.

I did not see, or find a post about talking about the cam. Least not one that said they know where to get, or info on such a cam for one.

I really need to know where to get a cam that's for a early diesel.

Thanks, Pat

I started talking about not being able to get my pump timed on here for almost a year now.

Click to expand...

Was it working properly prior to that?

I just know the CNH website gives the same number for gas or diesel. Bern, it really wouldnt make much sense for Ford to change just the distributor drive gear only on a cam. It would make more sense to change the distributor gear. Pat, you might want to call Messicks and ask for someone in their shop who knows these tractors from one end to the other. They might give you a number for one of their retired mechanics who knows the info you need. I would try a few different dealers and write down what each shop mechanic says on the same subject. Someone on here should know a mechanic that knows these 4 bangers. Oh yea, Tony Jacobs should know what you need. Post a message to him. Perseverance my friend.

(quoted from post at 09:49:36 07/28/18)

I started talking about not being able to get my pump timed on here for almost a year now.

Click to expand...

Was it working properly prior to that?

Click to expand...

I bought it not running. It had sat 15 years, because the owner had died then. I bought it from his son-inlaw. You could tell that it had been running. When I took it apart to check the cyl's, and paint everything, it had a shims under the injector pump & drive gear. When I reassemble it I could not get the timing mark near the center, with, or with out the shims. It is 23 degrees off to the right. If I put the engine on DTC, and drop the pump on, they line right up.

I have gone through, and done everything anyone has suggested to check & do. Still no luck.

Thanks, Pat

Many years ago a guy brought me a 172 diesel to work on. He had put it together using some miscellaneous used parts, as he was working on a tight budget. The only reason he brought it to me was because he could not properly install his injection pump, and he was at his wits end - he needed another set of eyes to look at it. The engine was otherwise completely together.

He was adamant about the fact that there was nothing wrong with the injection pump, as it was working fine before the rebuild and it was not touched while it was on the bench. He did tell me that he put a different cam in the engine from a gas 172.

After consulting the parts book as well as the service manual, we saw the same thing you did - that the cams were the same for both gas and diesel engines. Therefore, the fact that the donor cam came from a gas engine didn't concern us - we figured the problem had to be with the installation, like maybe a twisted gear key or a timing gear on backwards or something odd like that. Everything checked out fine visually.

I set up a degree wheel on the crank, along with a dial indicator to check valve event timing, and compared it against specs in the book. I even checked multiple lobes, and they all came out pretty much dead on. I was then forced to conclude that there was something different about the injection pump drive gear. I instructed the owner to find another cam out of a diesel. Once he got it and I installed it, everything fell into place.

Even though the service manual indicates that there is no difference between the two, as God is my witness, there was in the example I worked on. I don't know why it was that way, but now it makes sense to me that some parts houses say "diesel only" on the cams that they sell.

I agree that there must be a difference between a gas, and a diesel cam. even though everyone listed say's their the same, until you read their what it fit's list. Then it say's not for diesel.

The thing on this one is, it has a ford logo on the cam, and it has 310377. But it doesn't time right. But, I do need to get the cam gear off to see if it has slipped/turned on the key. I can not get it off the cam. I heated with map gas, while I had the puller on as tight as could go with a 3/8 ratchet it. I decided to take it somewhere to press it off. where I live no one with a press is open on Saturday's, without driving some 40 plus miles. So I'm going to have to wait till Monday, and kick myself again for not buying a press!

So what do you suggest for buying a new cam, since they all say, "Not for a diesel" Find a good used one, which can be risky. I do know someone that know's of a diesel 172 sitting. I do not know what's wrong with it, but it can't be worth any more then scrap weight, since he's getting rid of everything, by way of auction soon. I'll have to ask, he was a tractor mechanic. But then again, I have to pull it to check it out.


Thanks, Pat

Well Bern, two heads are better than one, the more the merrier. What about the casting numbers on the cams? Are those factory knowledge only? Pat might have had a gas cam from the start, maybe thats why the pump had the shims.

Why would it be a gas cam, with diesel stamped into?

It had "Diesel", "310377", "18-J" & "C18" on the cam.

Remember, I still need to remove the gear to check the key. But it's the last thing. Everything else has been checked, and is right. But the key is the last thing that can make the timing off.

Thanks, Pat

They probably forged a cam just for the diesel bacause they made the gas engines first.

Ok, Today I pulled the gear off the cam. I used my oxy-ace torches, and heated it hotter. I noticed a tiny crack in the spoke of the gear (see picture). So I had nothing to loose. I also noticed that there was a gap between the gear & the cam. Which means they never pushed the gear all the way on. Which is why the pump gear at the back, wore a ring into the rear cover, from the bolt heads. It pulled off hard, but came off. I found that the key was good, but the keyway in the cam was toast. When they went through the engine, they reused the cam, which had a bad keyway.

So I brought all the parts over the early Ford tractor mechanic. We came to the idea that with the gear not all the way on, aloud the pump drive gear to move back, and change the timing, which also allowed the front cam gear to move some forward, which change the gear mesh, which moved the timing marks on the flywheel. So with all this moved timing out of sink.

He is going to try to pick up a good gas cam, and a good diesel cam. We will put both of the in, to try to find out if the timing moves. He said for all the years he rebuilt these engines, he never heard anyone ask for a gas, or diesel cam. It's always been just a cam, even though it said "diesel" on the cams they pulled out.

Thanks, Pat

Funny how it show two of one picture, and not another that I had posted there, again!

You can see how loose the key fit the cam, with space next to it, but fit right into the gear.

Thanks, Pat

Also, the picture it left out.