engine health+propane Q's

Propane, Butane, LPG, GPL, C3H8, C4H10
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Joined: Sun Mar 20, 2011 12:15 am

engine health+propane Q's

Post by volaredon » Fri Apr 15, 2011 10:38 pm

this is on a 318 in an 83 D 250. 150K miles, orig unrebuilt short block.
I have not really noticed a difference in performance, (runs as good as always) but a couple times over the winter when I'd start it up in the driveway, I noticed more blue smoke than it used to put out back when it still had the old heads/worn out guides; I put a brand new set of EQ Magnum heads on there same thing as Hughes "Iron Ram's"; drilled for the "LA" series mopar smallblock intake. (carb'd)

having a teen son that I am trying to teach some semblance of maintenance, I have delegated the last few oil changes his way; so I have not been under the hood as much as I used to be, nor as much as I should be. Well I was the other day, and it was an "uh oh moment". 2100 on oil chg, and it's down a bit, will be a qt when change time comes at 3K miles. I have had lots of engines that used more than a qt/3000 and no blue smoke. That don't bother me as much as the oil getting into the air breather housing. I'm hoping that since I have been driving it less that it is condensation related, I do have new air filter new breather element and PCV valve to put on tomorrow, hoping that one may be "bad" but I am fearing "shot" rings.

I have most of the makings of a fresh Magnum short block that I can assemble while still using the truck; fresh machined block crank pistons rings bearings etc; I'm short a T chain, an oil pickup tube and a set of head gaskets. I have the rest. the truck has seen much "reduced" use especially since I started back to school, for which I have been using my Wrangler for the daily 80 mile round trip. My hopes were to switch the truck over and switch to the truck as the daily driver like it used to be when gas was cheaper, only once converted fuel would again be cheaper since I'd be running it on propane.

Thats the back story; As a "backup vehicle"" the signs of weakening engine would not bother me, just drive it til it dies; but being "promoted" back to main driver status once converted, it does bother me; I do have another bare 318 Magnum block here, that since it needs bored anyway I had thoughts/hopes of building into a 390 cu in "stroker" for the truck.
The 318 has always been plenty for my needs, it has done well; and has proven extremely dependable. beyond my expectations. To a point that I'd drive it to Florida tomorrow on a moments notice if need be;
MY QUESTION IS; If I do a leakdown on it and see that the rings/cyls are tired, how would it take to a propane conversion?
I had other plans for that 318 shortblock that I could build up and swap in there (a project Volare resto mod that is "on ice" for now) and I want to build a 390 for the truck for when I tow, but $$$ isn't there right now for that to happen. so I see 3 choices; I could build the motor intended for the car, put it in the truck and worry about building another motor later for the car. Not like the body work has progressed to a point of that car seeing the light of day under its own power for a couple years anyway.
OR; I know where there is a lo mile 70s 318 (almost 100K less than what is on the truck) that with a pan and oil pickup swap would go right in, and cheap.
OR; run it as is til it dies. Part of me wants to see how long it will run, kind of an endurance/torture test. with any of these options would still add propane conversion to.
All that said this truck is going no where. Unless the frame rots out from under it, or it gets nailed by a semi. It's been "that" good to me. how would that enter into what "you" would do?

One more; If I build the fresh 318 Magnum block, put the Magnum heads from my current motor on there, (only 29K miles on them from new, I put those on this truck a couple years ago) how would a Mopar Perf RT+10 cam work in there as a "work truck" with carb/gas power and again same question with propane power?
Would you cam an engine differently for gas than propane? and, Yes I know about the short Crank Snout precluding my putting a mech fuel pump onto it. I have the "adapter" from Hughes that would allow me to run an eccentric on that cam.

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