Allpar Forums banner

318 to a 360 in a B250

4224 Views 4 Replies 2 Participants Last post by  Bas Nossent
Having a 1985 Dodge B250 is not something to brag about, but I love the van and drive it on a daily base. I also use it to camp out and transport just about everything. It runs on LPG (combination of Propane and Butane) which, in Holland, cost about half the price of regular gas.
Standard equipped with a 318 and a std duty 727 it ran well and had descent power for such a small block. But it was using a lot of oil by leaking and burning it. Because the engine is inside the cabin, every leak can be detected instantly by smell of oil.
Time for a change and a challenge so I decided to buy a 360 and rebuild it. I found one for €400. It looked like an honest engine meaning that it was never touched before. It was a 360 from 1977. Once I got it in my shed, I took it apart. It was, of course, a very low compression engine with pistons that lay so deep that I could hardly find them. On top of that, the pistons were dished. So they had to go and be replaced by KB’s. Just about the only pistons with a raised compression height for a descent price.
The cam was in good shape but standard. Crank shaft was reusable after some polishing. I had the short block machined to 0.030. The heads were open chamber type (of course) but I decided to port them anyway to get the max out of them. Afterwards I found the 318 that was in the van had nice 302 heads with closed chamber heads !! But afterwards we are all winners.

So I assembled the engine with new pistons, camshaft, lifters, time chain etc., oil pump, damper, and of course all new bearings and gaskets. Including a new seal for the oil filter adapter plate. Having the engine complete it was now waiting for the right moment to swap the engines. That moment came during the spring holiday and it took me and my 9 year old son 3 days to get the job done. It is a Van remember ? So what went wrong ? well, the lifting eye of crane broke of causing the old engine to fall back into its place after lifting it from its engine mounts. No further damage but I had to make an new lifting eye. To be able to reach the engine from the front with a crane, I had to extent the crane arm by welding a piece on to the arm. That seemed to work fine until I got the new engine at height. Slowly the crane arm started to fold up. I had an old tire at hand and actually had plenty of time to put that under the new engine for it to make a soft landing. Strange experience. After some grinding and welding, I could lift the new engine again and mate it with the car. Except for the right engine mount, all is the same as the 318.
So. all went pretty good until the first start. It fired up very well but after a few seconds my son screamed at me and signaled to stop the engine. I didn’t know what was the problem until I looked under the Van and saw a major oil leak. Not just dripping but oil pouring out. It came from somewhere around the oil filter. The leak was so bad that I couldn’t see where it was coming from. I decided that it could only come from the filter seal so I replaced the filter. Started the engine but again oil was pouring out. I was thinking of a blocked oil channel so I checked that by blowing air through the different bores but all seemed to be free. Checked the oil filter seal again but all seemed to be ok. After 4 hours I took a break and fell asleep on the couch. When I woke up I had this brilliant flashback; When I cleaned the block before bringing it to the machine shop, I took out the gasket that seals the oil filter adapter to the engine block. I remember this gasket being very thick. Maybe even 3mm. The new gasket was not even 1mm thick. During installation of the adapter plate with the new gasket I tightened the central hollow nut to specs, not realizing that the outer gasket hardly toughed the engine block. All felt and looked well but in fact wasn’t.
So I took out the adapter plate, bend it a little under a press so that during installation the outer gasket would seal first before the central nut was tight to spec. That solved the problem and I was a happy man. For the moment.

Then strange sound appeared from somewhere around the first cylinder spark plug. A pneumatic leaking sound. An hour later I figured that the leak came from the sparkplug. The plug didn’t seal enough onto the cylinder head. These heads require the big threat plugs which have a tapered flange that makes it seal. I didn’t and the head actually required machining to get it to seal again. This meant taking of the heads. Not an option so I tried some copper washers. That worked fine. And I am going to replace the heads in the future anyway so this solution will work for now.

Running in the engine (flat tappets etc.) I found another leak. This time the oil came out from under the intake manifold. On the front side of the engine. I knew this could be a problem, so when I assembled the engine I tossed out the old cork gasket and applied thick coat of sealant. Apparently not thick enough. Because of the airco compressor and the fact that the engine lays so deep in the engine compartment I couldn’t get to it and decided to take the manifold of. This time I used the crock gasket plus a thick layer of sealant. It did the job. Now it was just a matter of waiting for the next challenge.

This came when I was just on my way for a long trip to the north. About 200 miles and a good moment to check the mileage. I was 15 minutes away from home at a point where the engine temperature should stabilize. Instead, the meter went up and up. I parked and checked the temperature with my new toy, an infrared temperature device. Very handy and I recommend this to everyone that reads this. The measured values were obvious, above the thermostat it was cool, below it was red hot. A stuck thermostat !!! It was brand new !!! And during all the test drives it worked fine !! What was the message in all this ? I didn’t get it. So it took me 2 hours to get back instead of 15 minutes to get there. Stopping every ½ mile or so to let the engine cool down. With 2 kids in the back that were very understanding. At least for the first 2 miles. After that they offered several times to start walking home. I usually threaten them with walking home when they are being little devils during a long trip, now they threatened me with walking home…..
Fixed the thermostat and waited for the next thing to happen. That came a few weeks ago when the ignition started to play up. I used to have a Mallory HEI ignition but that did not really fit under the hood. It was scraping the isolation. So I took that out some time ago and installed the old distribution, connected to a GM module and a VW coil. Very good strong spark but the distribution was getting old. The magnetic force was getting weak and was too weak when I was on my way in Germany. Luckily I had a spare distribution that was also not very good but it still worked. It took me to where I had to go and back home. Engines that run on LPG are very sensitive on the ignition. On the other hand you can get away with more advance in the lower rpm range.

When I look down my street, and see all the new, modern cars, I sometimes question myself: why I do all this to myself. But it is good to read all the other stories and to know that I am not the only one struggling to keep the old stuff on the road. I learn a lot from it and it teaches my sons that there is more to life then just comfort and computer games.
Thank you for you time

Bas Nossent
The Netherlands


1 - 5 of 5 Posts

· Premium Member
6,103 Posts
Very nice, and glad you have been able to diagnose and fix problems as they occur. I am hoping that you have done the counterbalance weight on the torque converter given the 318 is internally balanced and the 360 is externally balanced. If not, the counterbalance that can be tack welded onto the existing torque converter is available and saves the hassle of actually pulling the engine or transmission to change.

· Premium Member
6,103 Posts
OK. So she is running good now, so how is the mileage and power compared to the 318?

· Registered
4 Posts
Discussion Starter · #5 ·
mileage is the same, power is up, torque is way up. I wanted to swap the 727 for a 518 46RH to get the mileage up. But since the dutch government is going to introduce road tax on cars like mine (oldtimers) based on weight, it becomes too expensive to drive a car like this anyway. About $3000 !!! per year. Just road tax. So I have to sell it. But nobody wants to buy it. Anyone over there that might be interested ? It was imported from California 4 years ago. I might take it with me when I leave this :censored: country.
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.