M929 Big cam 400

[Stevepala]

Had the chance to drive it this morning. Being that the original 250 was blown this project was unknown. But after letting it shift through the gears, all seems good. Just the right amount of power. I had Pittsburg Power rebuild and increase the cummins pt pump by 25%. That made a big difference on start up and smoothness of idle. It's not meant to drag race, so I know to be easy with the Allison.

This truck was very solid but I always was second guessing it. The engine was from Matt up in Boston area and it obviously sat for some time. But after running it there is plenty of power and the smoke clears out when it's at operating temp. Thanks Matt.

Not an easy swap.

 

[Bolkbich]

It will be worth all your trouble. They are great trucks , they just need more poop. If mine pops its getting a 400 for sure.

 

[Vintage iron]

Nice job Steve. Glad I could help with the motor. I like the location of the oil filter, nice and easy change! What is the fuel filter set up that you have on the drivers side? Is that one that takes the air out of the fuel?

 

[Stevepala]

Hey Matt. That is a FASS fuel filter that does remove air and filters down to 4 micron. The best thing about it is it provides the pt pump with 12 psi all the time so start up is very fast. I have run a lot of miles with lift pumps on other trucks and the benefits are very noticeable. The biggest is throttle response in my Duramax pickup and Cummins powered RV.

Finding the spin on filter adapter for the engine took some time, but is the only way to mount it. The frame rail is to close in the standard location.

 

[Vintage iron]

interesting?

 

[m16ty]

I've been trying to talk my brother into putting a 400 in his M939 lime spreader truck. He hauls heavy loads up some big hills and sure could use some extra power.

 

[jarhead1086]

It fits without mods to the hood? My 250 is fresh but I better start saving money and learning from you all. What would this cost, ball park, for somebody having to pay for the install? These blocks are huge and beyond my current abilities. Great motivation for me, thanks for posting.

 

[Floridianson]

Did you have to rework the front motor mount?

 

[Stevepala]

Did you have to rework the front motor mount?

I had to torch cut out the top 4 inches of the cross member. Then I welded in a thick piece of steel in this cut out so the commercial truck style mount could sit on the member.

This was the hardest part of the swap because the orientation of the tail shaft of the transmission must be in the same location as with the the original motor because of the extremely short output shaft to the divorced transferr case.


Some might say this weakened the frame, but trust me, it did not. The metal I welded in is twice the thickness of the original.

 

[Stevepala]

It fits without mods to the hood? My 250 is fresh but I better start saving money and learning from you all. What would this cost, ball park, for somebody having to pay for the install? These blocks are huge and beyond my current abilities. Great motivation for me, thanks for posting.

There is enough room but the biggest fit issue was the extra height with the jake brakes fitting under the cab cowl on number 6. I ended up giving the cab and hood a 1 inch body lift to clear the valve covers.

I was quoted 4k to do the swap just in labor. Depending on the price of the motor you could easily be in for 10k. That's why I did all the work myself.

Yes these blocks are huge, must weigh over 3000 lbs with the transmission. It was quite heavy hanging from a chain on my loader trying to wiggle it in place by myself. I put it in and out a few times.

steve

 

[Floridianson]

Nice job. thanks

 

[jcappeljr]

Good fab work..

 

[bigboy44]

Good Workmanship! Could you post more pics of the hood lift.

 

[Stevepala]

The body lift is rather easy to do. I used steel plate/washers and longer bolts to lift the cab and hood at the mounting points an inch. Take a look at my first photos in the post. That cross member with the rubber bumpers in front of the radiator is bolted to the frame. You need to raise it up an inch on its mounting points to the frame. This will raise your hood an inch.

 

[Stevepala]

Had time this morning to mount the 1600 tires and wheels. What an improvement in looks and ability in mud and rough terrain. Just need to get a hard top on it.



Steve

 

[Tinydragon2001]

Very nicely done. I am looking to do a big cam 350 swap on my m925 that I converted to dump. Truck runs fine just want a little more pulling power on hills.

Any pointers on the swap? Things to expect? Any info would be greatly appreciated.

 

[MidnightDuramax]

More detail of the cut out in the front cross member would be great I have been wanting to do the same conversion. The lack of having something big enough to lift the engine in and out several times to get the mock up and fab done has been a major part of putting it off. I would have to rent a forklift or get a neighbor to help with a loader. But getting more info on the front cross member modification it can be done and then the engine dropped in in one shot. Your truck looks amazing and great fab work and skills.

 

[trooper632]

Tinydragon2001, where did you get the hydraulic dump kit for you truck, I have a very nice M923a2 that haven't been able to sell so I am thinking about making a dump out of it

 

[Naterik]

Very nicely done. I am looking to do a big cam 350 swap on my m925 that I converted to dump. Truck runs fine just want a little more pulling power on hills.

Any pointers on the swap? Things to expect? Any info would be greatly appreciated.

That's a good looking rig, I love the subframe dump hoist. I'm planning on doing the same thing to my M925A2 when I finish bobbing it. I'm going to end up with a 10.5' bed it should make the truck a lot more useful in the long run.

 

[Tinydragon2001]

I got the hoist off an old 6-7 yard single axle dump. It was an old municipal truck. Motor and cab were shot, but Hoist was still good. Sub frame is only 10ft. long, so I made a front support out of some extra cribbing I had. It will dump 10 tons no problem.