Chevy 350 gas to 6.2L diesel conversion

Hi everyone,

I'm new to the site and new to diesels. I have a 1985 k5 blazer which currently has a 350 chevy gas motor in it. I took on a school project of swapping in a diesel motor as it will get better fuel economy. I don't have very much time to do it(two months or so) so I chose the 6.2L to swap in as I am assuming it is the easiest. I have read through and searched almost all the forums relating to the swap but am still a little unsure on exactly what needs to be done.

So far I purchased the 6.2L diesel which came with a started and flywheel alone with all the front end parts necessary. The wiring attached to the motor has seen better days and will most likely need to be replaced. The k5 has a 3-speed standard with granny low tranny currently. I am aware that all of this will bolt right in but i'm more concerned about the smaller details. I know i need a bigger radiator. Whats the process for swapping to hydroboost brake system? how should the glo plugs be wired? fuel return line? dual batteries? everything else?...

It would be nice if anyone has a link to a 6.2 manual which describes all of the wires and plug that are currently hanging off my motor that i have no idea what to do with.

Any help would be greatly appreciated.

Welcome to the board!

This link, http://www.thedieselpageforums.com/t...ad.php?t=27827 , will give you the high points of what needs to be done.

I recommend acquiring a parts donor vehicle to help you with both cost and parts location. A hydroboost, for example, can cost upwards of $500 if buying new. A new radiator can cost $200-500 as well. A donor can get you going quickly, even if the parts may need to be replaced sometime in the future.

We offer a "6.2L/6.5L Diesel Troubleshooting & Repair Guide" that can help answer most of your questions, and help you get it running with the least drama - including the glow system. You can view a table of contents and learn more about it here: http://www.thedieselpage.com/t&rguide.htm

Fuel return lines.... I recommend acquiring the fuel tank sender package that was originally found on a diesel equipped vehicle like yours. Then, the plumbing becomes easy... Jim

Thank you for the help. Ill start the search for a donor vehicle. Not only will it make it cheaper but it'll be a nice reference.

Well Sam, I hate to rain on your parade, but have you checked the price of diesel fuel lately? Don't think you're gunna be saving too many bucks in that dept. You did mention you were looking for fuel mileage.
But as a learning project, it could be rewarding. And for off roading, (should you choose to take your blazer 4 wheeling), you won't have to worry about getting your dist. wet. Don't forget about your gearing also. It'll have to match your intended usage. Good luck and Welcome to the forum.

I've done this more than once.....


Love my 6.2's. My carb'd K-5 with a 350 got 13 mpg on a good day. The 6.2 powered K20 Suburban got 18 doing the same commute.

Now that K20 Suburban's motor is in the K-5, and it's got oversized tires. I use substantially less fuel than anybody I go wheeling with. And I'm on bigger tires than most of them.

18 MPGs? My 6.2 can barely muster 10, (on a good day), but it does have 4.10s with no OD. But your point is valid, depending on tune and gearing Mark. Here in Ct tho, reg fuel is about $3.70 a gal. and diesel is way over $4. Haven't figured out the difference, but just a little food for thought, when using this reason, and this reason only as an incentive to going thru the aggravation of a conversion. But the diesel does have it's own "other" advantages, besides MPGs.

...... And gasser exhaust just smells wrong.

Joe,

I think there's something wrong with your 6.2....Our K30 3+3 dually, with a turbo 400 and 4.10's still got 16 on the highway empty, and with 4 2000lb horses in a gooseneck trailer got almost 10.

Bet your injectors are about shot.

In my experience, I saw about a 5-mpg difference between a truck without an OD trans and one with. Plus, an OD makes the truck a lot more useful, quieter and more pleasurable to drive. Jim

Quote:

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Originally Posted by AKMark

Joe,

I think there's something wrong with your 6.2....Our K30 3+3 dually, with a turbo 400 and 4.10's still got 16 on the highway empty, and with 4 2000lb horses in a gooseneck trailer got almost 10.

Bet your injectors are about shot.

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That's good to hear. I really haven't gotten into the nitty gritty of tweaking the IP, and would love to be able to improve its mileage. I'm not sure how bad the injectors are. I did replace them less than 40K ago, but they could be full of crap, cause the truck mostly sits outside.(Moisture or water contamination).
That being said, I still think we're being raped on the price of fuel. For over 70 yrs, the cost of refining diesel, has always been less than the cheapest gas. Now it's more than premium fuel? What's up with that?

Quote:

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Originally Posted by joeq

For over 70 yrs, the cost of refining diesel, has always been less than the cheapest gas. Now it's more than premium fuel? What's up with that?

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Answer: Oil companies began seriously exporting diesel fuel a few years ago. The world runs on diesel fuel. Gasoline is much less an export commodity.

See: http://www.thedieselpage.com/dieselprices.htm

Interesting article Jim. I keep hearing about all this oil in our continent, and it makes all the sense in the world to me and a million other US citizens, but obviously the major oil co.s are making more money exporting, than if we were "self sufficient". And we all know about the "golden rule". I'm afraid we're beating a dead horse.:mad:

Energy independence is now an outdated notion. Once, I believed that if we could produce all of the energy we consumed our economic security would be assured.

Now, major energy companies are global entities. They sell globally. They move energy products where the market is.

Natural gas is currently cheap, but the energy companies are working feverishly to find a way to economically move that gas to overseas markets. Once that happens, natural gas prices will double or triple here at home. We produce and the world then benefits - instead of energy independence creating stable and affordable domestic prices.

This is why I'm against the Keystone pipeline. It'll be exported. This is why I'm against coal mining. We're exporting 100M tons/year.

This is why conservative groups have joined forces with crazy environmentalists in Tennessee to stop hilltop removal coal mining. It's a Chinese company behind the effort to get the coal. Tennessee's environment is being compromised mostly for the benefit of China. Think about it...

Ending coal-fired electrical generation in this country, as Obama wants, will produce even higher coal export levels. We (the government & energy companies) are exporting our economic future and spending our children's inheritance. I guess China can burn it, but global warming will benefit more if we don't... :rolleyes:

All countries that export energy and raw materials will eventually rue the day...

Quote:

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Originally Posted by Thisissam34

Hi everyone,

I'm new to the site and new to diesels. I have a 1985 k5 blazer which currently has a 350 chevy gas motor in it. I took on a school project of swapping in a diesel motor as it will get better fuel economy. I don't have very much time to do it(two months or so) so I chose the 6.2L to swap in as I am assuming it is the easiest. I have read through and searched almost all the forums relating to the swap but am still a little unsure on exactly what needs to be done.

So far I purchased the 6.2L diesel which came with a started and flywheel alone with all the front end parts necessary. The wiring attached to the motor has seen better days and will most likely need to be replaced. The k5 has a 3-speed standard with granny low tranny currently. I am aware that all of this will bolt right in but i'm more concerned about the smaller details. I know i need a bigger radiator. Whats the process for swapping to hydroboost brake system? how should the glo plugs be wired? fuel return line? dual batteries? everything else?...

It would be nice if anyone has a link to a 6.2 manual which describes all of the wires and plug that are currently hanging off my motor that i have no idea what to do with.

Any help would be greatly appreciated.

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get the 6.2 flywheel drain fuel tank use filter setup from 6.2 use glow plug relay for 82 to 84 6.2 trucks

then add momentary switch with key on power at relay and ground switched cold engine hold glow plugs 7 to 9 seconds with new 60G s 2 good batteries good alternator and starter

I found carquest has best price for starter if all are good and fuel system is up to par this engine is like a sore peter you cant beat it

You might get some ideas from www.borjan.ax.

I listed the modifications I had to do when I switched a 307 gasser to 6,5l diesel.

Have a nice day !