K-20 conversion

[dieselcrawler]

Hey all...
I have a K-20 350/TH350/NP203 (kinda like Merle's, a multi-yearcombonation) that I would like to change over to a 6.2L. I have a compleat motor that my uncle gave me, (I think it's a J motor, out of a '90 1 ton tow truck) but it's been out of the truck for at least 3 years. And setting outside. Somewhat covered. (Keeps getting worse... *grin*) So, what kind of things should I be prepaired to do to swap this into my gasser K-20? I think I have the hardware (fuel filter, etc) that is diesel specific, but with a motor that has set for that long, will I be able to get it to fire up? I know that rebuilding the IP would be a good thing to do, but don't want to sink the money into it unless I know for sure the dang thing is gonna run ok. So, I'd like to at least hear it run a little. And the radiator... for test reasons, I would think that the one I have would work to keep things cool for a little while, enough to test drive it anyway, right? I'll be keeping my eyes out for a larger one in the meanwhile.
Anyone else had any luck with this before? Let me know... Thanks...

Greg

[arveetek]

I basically did the same thing to my '81. I bought an engine that had been sitting outside for a while, covered up by an old car hood. I tore the engine down and rebuilt it before installing it.

It's all the little items that nickel and dime ya to death. The alternator, ps pump, and a/c brackets are all different, as well as the radiator (don't forget the engine oil cooler lines), starter, and other minor parts. Otherwise, the engine should bolt up just fine.

I wouldn't attempt to install that motor without tearing it apart first. Why was the it pulled in the first place? As long as it's been sitting, the cylinders probably have rust in them. Mine did. However, I was simply able to hone the cylinders and install new rings, and I was good to go.

Casey

[dieselcrawler]

The motor came out because my uncle found a big block to put in the tow truck, and he never was fond of diesels.

Oil cooler: can I use an aux tranny cooler, like you might find in a summit catalog? Any other sugjestions?

I don't really mind a little extra work, and would like to just stick the motor in and see if it will run... don't really have the cash to rebuild it now, and have to keep it low-buck. It's not like it's gonna hurt much, just trying to make it run the way it is, if it's gonna need rebuilt anyway...

Thanks...
Greg

[Craig M]

While I know it is not good practice, I have left various diesel engine unused for many years. Put a fresh set of batteries in and most will fire right up. Rubber parts may tend to deteriorate over time, but steel and aluminum do not.

[CleviteKid]

A big transmission cooler will work just fine as an engine oil cooler, but in the winter you will lose the benefit of the Dexcool helping warm up the oil for easier flow. I only mention this because I have been in West Virginia in January, and it was MUCH colder than Miami, FL.

Dr. Lee :cool:

[dieselcrawler]

What about the motor mounts? Can I use the ones from the 350, or what? How diffrent are they?
What about the hydro boost for the brakes? I assume I'll need to change that, guess I'll have to start calling junk yards for that one. Hadn't really thought of it till just now...
How diffrent are the tork converters for the trans? I would think that the stall speed would be the diffrence, but how much? I have a stock one for a gasser now, maybe 1200 rpm... what is the diesel stall speed?
Any how, it's all still in the planing stages, thanks for the input.
Greg

[C.K. Piquup]

It would be nice if somebody could right an article on gas to diesel swap,answering all related questions.It`s always simplest to do with a complete diesel donor vehicle,but that`s not always possible.Also,like your case,what do we do with the motors left over from diesel to gas swaps?

[dieselcrawler]

That's easy, the donor (my uncle's tow truck) gave up it's 6.2L N/A, let it set outside for 3 years, and then gave it to me, cause I got another truck with a 6.2L and loved it. Too bad he left the hydro-boost stuff on the tow truck!
I have thought of looking for a 6.2L powered truck for cheap, and doing the swap that way, but I'm just not sure where I'm gonna put ONE MORE DEAD TRUCK... I have alot more junk than I have room for now. My ol' man just doesn't seem to understand why I feel I have a right to store stuff at his farm in the back field. Oh well.

'Till next time,
Greg

[arveetek]

You can use your vacuum assist brakes with a good, well-functioning vacuum pump on the 6.2L and an aux. vacuum reservoir. I'm still using the vacuum assist on my '81.

You can use the gasser tranny TC. I'm running one behind my 6.2L.

350 motor mounts should also work just fine.

Casey

[jcomp]

A hydroboost setup shouldn't be too hard to find. I believe that all 1-tons from the late 70s to late 80s all used it, even the gassers. The hydroboost on my FJ40 came off a 2WD 1-ton gasser, and the junkyards seem to always have a couple.

[big swifty]

I had issues of the exhaust getting too intimate with the Frame after my conversion. I changed to Poly 454 MM's and the difference was incredible-a much better feel and the Rubbing was Taken care of too! When you have the engine out anyway-may as well do the Mounts.