why not put a 6.2 or 6.5 in an FSJ??

[83 chif]

some people have told me that the 6.2 and the 6.5 are the worst and loudest diesels out there. others praise them. does anyone have any evidence or first hand accounts to testify?

the power to wieght ratio isn't suppose to be too great with the GM diesels, but they look better than the Ford international diesels ratios. besides, my jeep is not a hot rod, right now it has a 4.2.

is the 6.2 a gas engine converted to diesel? I thought that that Buick 350 diesel was, and i've heard bad things about putting them in trucks, but i didn't know about the 6.2.

[Wagabond]

THE 6.2 is loud,rattly and not very powerful. But seeing as the 360 only has144 horsepower, it couldn't be much worse. I think it is the most doable diesel swap because of the TH400, and of it's relatively light weight.

The Dodge Cummins is very long and the 6.9/ 7.3 fords, the best truck diesels IMO, are way too heavy.

The 6.2 is a diesel from the oilpan up. There was a Converted Olds 350 that GM tried to dieselize, but as soon as they sobered up it was gone.

[grand_wag_85]

I've heard both sides of the story, most say that the 6.2's and 6.5's are just diesled 350's and are absolute crud...As you probably know there's a few here who've swapped the 6.2's and 6.5's in. There's several forums out there that deal just with 6.2 and 6.5 diesel swaps, but i can't think of the names right off the top of my head right now. I'm sure those guys have heard the argument and can tell you exactly what ya wanna know.

[83 chif]

yea, i know i won't go with a ford diesel because of their size, and if i went cummins it would be a 4bt, but they are sooo expensive compared to the 6.2 and 6.5's that i found. i was looking into a Nissan SD-33, but they are even less powerful than my 4.2L is, it would be a better swap for a baby jeep, and VW, Volvo, Toyota, all those diesels are too tiny too. So i'm pretty much left with the option of a 6.2 or a 6.5.

if the 6.2 is rattly and loud, is the 6.5 the same way?? Is there a difference between the 6.2 and the 6.5 as far as how reliable they are? I'm checking out sources too, but i know there are people here who have done the GM diesels and I am wondering what led them to the GM diesels as opposed to something else. Thanks for the info peoples....

[ohioj20]

The GMC 6.2 is a copy of a Detriot Diesel 6.2, just manufactured by GMC. They have power, but aren't beasts. Though, I'm not sure how well a Cummins would be without its turbo.

[rustywagoneers_com]

6.2 / 6.5 diesels were designed as a diesel from day one and are not based on any gasoline engine. they are metric inside and out, and allegedly there was a large amount of design input from detroit diesel (which was part of GM at the time). they have the same bellhousing bolt pattern, motor mount patterns and locations as big block and small block chevy V8's. weight is roughly equal to a big block, and when they are in good health the power is pretty fair. fast, no. but decent. i have owned a scout with the nissan SD-33 and it was definitely NOT fast, but it did go down the road just fine. i have owned 4 benz diesels, 2 of them turbocharged 300D / 300SD cars, one non-turbo 300D and a (non-turbo) 240D (all stock 240D's are non-turbo) the 240D is my current daily driver, it was a 500 dollar car and gets 33 mpg all the time. it was born in 1982 with 67 hp and it weighs 3620 lbs (weighed it yesterday) 3.69 gears and tiny little tires makes it go down the road at 3421 RPM for 60 mph, and i have had it (and the non-turbo 300D with the same 3.69 axle) going 85 mph before. the 6.2 GM uses essentially the same injector and nearly same chamber shape as the benzes and i am told that one of the easiest upgrades for a 6.2 / 6.5 with a turbo is to use the benz 300 turbo diesel injectors.

my 6.2 is in a suburban and got 19 mpg pretty consistent... though i believe i have now broken a piston skirt (200K plus miles of very very very hard use and abuse) and the thing is parked for now, though i test drove a replacement engine yesterday, which will get the banks turbo setup off my suburban and will go into one of my various waggy projects... prolly to make a waggy work truck / trailer puller for me out of a pretty fair 86 i recently picked up....

really wanna learn more about 6.2's, go hang out at steel soldiers web forum for a while, and then there are a couple good diesel forums out there as most are aware...

when the body of my 240D rusts away bad enough, i will transplant that engine and trans into a stripped down waggy and choose the gear / tire combo to give the same cruise RPM (7.50-16's and 5.13's probably)

don't be scared of the 6.2 / 6.5 family. and honestly, the 350 olds diesels were pretty decent after a few serious problems were corrected...

peace
Dave

[DieselSJ]

For 6.2/6.5 info, start at the forums here - http://www.thedieselpageforums.com/tdpforum

As for swapping one into a FSJ, several of us have done it. I am very happy with the swap. The turbo makes all the difference in the world - I outran a new F350 PSD getting onto the freeway earlier this week. It will spin the tires whenever I want. Plus I get better than 22mpg on the freeway, and just a tick over 20mpg in daily driving.

[gmarblestone]

but really.. how much is involved? Money and time wise?

[FSJeeper]

but really.. how much is involved? Money and time wise?

Swapping in a GM diesel is about the same effort as a SBC or BBC. They weigh about the same as a BBC.

There are few mods you can do to bump power up to a very nice level and also quiet the engine down. Generally speaking, mods made to make a diesel more efficient and powerful, also raise gas mileage and do not hurt reliabilty.

In terms of what is needed for the swap besides the diesel GM drivetrain, you'll need GM to FSJ motor mounts available from at least 3 sources but I like the AA ones the best. Have used Novak and AA both. You'll need at least a 4 core FSJ radiator with the rad hose locations swapped on it, or an aftermarket radiator. The GM throttle cable works on our FSJ's. Banks turbo will require a 3" body lift or mods to the passengerside fenderwell to clear. GM turbo fits without mods. If your front springs are saggy, you may need new ones or a least a helper spring. The FSJ rear trans mount works good with minor mods depending on which trans/tcase you use. Front and rear shafts will need to be cut/lengthened to fit. You'll need a new exhaust system.
Power brakes will work with the vacuum pump on the GM diesel but the hydroboost system swaps in easy.

Parts or the cheapest among the diesels and readily available on ebay or military surplus houses.

20 MPG is easily attainable.

[710 Burner]

Most of the negativity I have heard is from truckers that don't like Detroit Diesel. Yes they are a bit loud, but so is a 98 Cummins. Personally I think they sound like testosterone.

[JeepNOFEAR]

I use to work at a engine machine shop and one day we were taking about motors that are rare to find without cracked heads and I think I remember those motors being two of them. I'm not completey sure, it's just something I remember in the back of my head. I'd look into it if you planned on rebuilding one.

[scotty]

i have a 6.2 in my project tow rig. i like it for what it is. it will never have the potential power of a 12v cummins,but definately dont overlook it for a reliable,economical daily driver. they had some issues,but are overall a good motor and a good design. the mechanical injection of the 6.2 and early 6.5 is very reliable.

the mechanical 6.2 is also a very easy swap.

the olds 5.7 got a bad rap,much like the 6.2. contrary to popular belief,it is NOT a converted gas engine. its a high nickel block that was cast for being a diesel. it is true that it shares the oil pan,valvecovers,and a couple other parts as the olds gas engine but that doesnt mean its a gas block with diesel heads on it.

a 5.7 is alittle more compact,and lighter than a 6.2 and will be compareable in power and maybe slightly better economy to a 6.2. only prollem with them is that so many people didnt understand them that they were replaced with gas engines and are getting harder to find. ive got one im going to rebuild and put into my 87 suburban.

great source of info for gm diesels:
http://www.gm-diesel.com/

a 5.7 site,they have quite a devoted following,not unlike us and our FSJs ;) :
http://www.olds-diesel.com/

let me know if you have any "gas to diesel" conversion questions,i just went thru it :)

[gmarblestone]

so i am really considering this swap, but dont know if i have the skill or money. What is the actual money that is involved... and if i brought it to a shop to do what do you think it would cost? Would love to drive it as a dd, but need better gas mileage.

G

[DieselSJ]

What is the actual money that is involved...

As with any swap, it all depends on how you approach it. Finding a used 6.2/6.5,700R4 and GM tcase with the correct drop for your rig will certainly be less expensive than a rebuilt engine, new trans and adapter to your existing tcase. It really depends on what you want. Figure out how much you have to spend and that will tell you a lot about what parts you can afford. With a used engine and trans and matching xfer case, probably plan on $3-5K for everything by the time you are done, and add labor if you are paying someone.

[scotty]

as for economy,i was getting 18-19 in my 7000# truck when i first put the engine in. unfortunately, ultra-low sulphur diesel in all the pumps now has dropped it 2-3 mpg. :mad: still not too bad for a heavy dually with 4.10 gears.

as for cost,it depends largely on how lucky/crafty you are at scrounging parts and how much work you do yourself.

i bought a rusty k5 blazer for $400. since i was swapping it into another chevy truck,and doing all the work myself,i didnt need conversion mounts or any custom parts,so i really didnt spend much more than that. $100 or so for an aftermarket oil cooler(dont use the factory "oil heaters" in the radiator. for engine oil or tranny fluid) and maybe another $100 or so for new hydroboost hose,new oil,filter,and speedo cable since i forgot to keep the one from the donor.

at any rate,if you locate a whole donor 4wd truck for $1000 or less,the swap will be much easier,and it should be quite feasible to find one for that much that runs good. add to that cost the motormount kit to swap in a small block chevy if you do not think you have the skill level to fab mounts. a 4wd truck will come with a 700r/208 so add the cost of swapping the gm 208 input gear into a jeep 208 if you do not think you have the skill to disassemble a transfer case.

you definately will want to use the OD with the diesel,so the input gear swap is a cheap,easy way to use it and end up with a compatible drop transfer case.

another thing that to keep in mind is that a diesel makes no vaccum on its own and must use a pump to run any vaccum operated accessories. i have heard of people doing it,but most folks seem to think that the rear mounted vaccum pump is not really capable of powering your brake booster.

the option of swapping on hydroboost brakes to deal with the vaccum issue makes your donor truck that much more valuable ;)

the other option would be swapping on a belt driven pump,from something like an 80s ford 6.9 or 7.3.

in a nutshell, using the chevy tranny with a jeep t case makes mounting the engine in your chassis the hardest part of the swap,IMO. once you have it sitting there,its easy it wire it up and get it running.

almost forgot-youll prolly have to swap out your gas filler neck. first time i went to get gas was almost a bad situation,as the diesel pumpo wouldnt fit into my gas filler neck :eek: good thing i still had the diesel filler from the donor k5 at home!

further questions? :)

[JpX]

almost forgot-youll prolly have to swap out your gas filler neck. first time i went to get gas was almost a bad situation,as the diesel pumpo wouldnt fit into my gas filler neck :eek: good thing i still had the diesel filler from the donor k5 at home!

further questions? :)

There were at least 5 different times in my build when I had already told myself "I don't need the donor truck or shortblock anymore." Each time I was wrong and glad I kept the donor parts and shortblock until I am done.

I'm swapping a 6.3 (383 SBC) but I don't think I'll be getting anywhere the mileage of a diesel. I used the Novak mounts since I'm not in a good position to fab mounts and get them welded. If somehow you could get ahold of the ISUZU Diesels Chevy uses now they are the quietest large displacement diesels I've heard yet. By a long shot.

4BT would be my diesel of choice too late to change in my project though.

[AlsChopShop]

some people have told me that the 6.2 and the 6.5 are the worst and loudest diesels out there. those people have never been around a cummins or powerstroke! the 6.2 and 6.5 aren't that loud, and they somehow got a bad rap just like GMs 700r4 transmission, not a fair one!

IIRC the 6.5 was the earlier version, and cracked heads were common. the later 6.2 was a different design and did not have any cracking problems like the earlier 6.5. but somehow the 6.2 got the bad rap that it was the same as the 6.5, as well as the rumor of being designed from a gasser! not true at all! while these motors don't have the power of the newer diesels that have come out, they can still be built to be good powerhorses for whatever you throw at them.

is it a good canidate for a swap into a fsj? sure. its cheaper than a cummins, and the size and wieght is very close to a sbc.

go for it!

Al

[jepj2000]

I think it was the 6.2 that came out first and then the 6.5turbo was next. I wish I had a 6.5td in a wagon for dd a sometimes tow rig. I would eventually want a 4 door Jtruck with a diesel though. Man that would be great.

Rankin

[J4000Guy]

i have a 6.2 in my project tow rig. i like it for what it is. it will never have the potential power of a 12v cummins,but definately dont overlook it for a reliable,economical daily driver. they had some issues,but are overall a good motor and a good design. the mechanical injection of the 6.2 and early 6.5 is very reliable.

the mechanical 6.2 is also a very easy swap.

the olds 5.7 got a bad rap,much like the 6.2. contrary to popular belief,it is NOT a converted gas engine. its a high nickel block that was cast for being a diesel. it is true that it shares the oil pan,valvecovers,and a couple other parts as the olds gas engine but that doesnt mean its a gas block with diesel heads on it.

a 5.7 is alittle more compact,and lighter than a 6.2 and will be compareable in power and maybe slightly better economy to a 6.2. only prollem with them is that so many people didnt understand them that they were replaced with gas engines and are getting harder to find. ive got one im going to rebuild and put into my 87 suburban.

great source of info for gm diesels:
http://www.gm-diesel.com/

a 5.7 site,they have quite a devoted following,not unlike us and our FSJs ;) :
http://www.olds-diesel.com/

let me know if you have any "gas to diesel" conversion questions,i just went thru it :)

that's interesting I have an associate that was given a 70's olds with that diesel engine/tranny......he hates diesels with a passion and is looking for a 350 to put in.....might be worth my time to see how much he wants for it.....probably not much.....

[tndonor]

I had a 6.2 in my one ton J10. I wasnt overly loud. It was DECENT for power. Got good mileage (20ish). My 6.2 was the early design (82-84) which had several weaknesses. I ended up throwing a rod through the oil pan and cracking the block.

If you are wnating some power, I would suggest skipping the GM diesels all together. The reason is they have a high compression ratio and require lower compression pistons to use more boost. They are a little heavy. Tipping near the 1000 pound mark. I had Stans diesel headers on mine too to help. It wouldnt maintain highways speeds uphill. Early International and Navistar motors had their share of TSBs and all out failures.

I went with a 4cyl Cummins in my Jeep. Its just like the 6 cyl Cummin just two short. They are getting 25 mpg in vehicles. EXCEPTIONAL service life, power, and reliability.

I have the buildup under 4BTA in my J10 if you want to see how one fits. It is much more peppy that the 6.2 could EVER be.

[billyrb]

I understand folks swapping to diesels for reliability or more torque, but not as much for mileage (note, I'm talking about the various quotes of folks getting 19-20mpg after their swaps). If you spend around $2,500 for a swap (ballpark), and you gain 7mpg over the gas engine, it'll take you over 4.5 YEARS to break even. Seems to me that money would be better spent on other things, and give the vehicle a proper tune, stay in the rpm band of the motor & slow down on the highways, and keeping the tires properly inflated. But then again, that's only if we're talking about doing it for mileage reasons. And yes, I do like the benefits of diesels.

Now, if the swap netted around a 15-20mpg gain, putting the FSJ at 30 or higher MPG, then I'd see it as a good financial decision.

[JeepinPete]

I'm assuming 10k miles a year, 12 mpg for the stock 360, and 20 mpg for a diesel swap, and regular unleaded and diesel both at $3 a gallon (current prices in my neck of the woods), you would recoup that $2500 in 2.5 years...

[GWChris]

I understand folks swapping to diesels for reliability or more torque, but not as much for mileage (note, I'm talking about the various quotes of folks getting 19-20mpg after their swaps). If you spend around $2,500 for a swap (ballpark), and you gain 7mpg over the gas engine, it'll take you over 4.5 YEARS to break even. Seems to me that money would be better spent on other things, and give the vehicle a proper tune, stay in the rpm band of the motor & slow down on the highways, and keeping the tires properly inflated. But then again, that's only if we're talking about doing it for mileage reasons. And yes, I do like the benefits of diesels.

Now, if the swap netted around a 15-20mpg gain, putting the FSJ at 30 or higher MPG, then I'd see it as a good financial decision.
I tend to agree, especially as diesel will remain more expensive than gasoline, and Suburbans with diesels in them are available. I had a chance to pick up an '88 Sububurban diesel for $4k, but I passed on it. I'm doing what I can to get the mileage of the Wagoneer up, and that will cost a lot less - it's not like I use it for daily transportation.

[ohioj20]

I am well aware that I may never recoop my money spent in my swap, but there are several reasons why I did it.


More reliable
Longer driving range went from 10 MPG to 24 MPG
You will RARELY see diesel FSJ
Sounds too cool and turns many heads!

[Wagabond]

I tend to agree, especially as diesel will remain more expensive than gasoline, and Suburbans with diesels in them are available. I had a chance to pick up an '88 Sububurban diesel for $4k, but I passed on it. I'm doing what I can to get the mileage of the Wagoneer up, and that will cost a lot less - it's not like I use it for daily transportation.

It's cheaper than gas here. Plus we probably have hippies at ASU brewing Bio. If I can keep it to a gallon a day I actually might get it free from work.

Does anybody know if the SBC/TF 727 adapters would work? I've got a nice tax return coming, and I'm bored. I might do this deed.

[budojeepr]

Hmm. Just a bit of math opinion...if I'm going to swap engines anyway, then I'd have to compare the costs between swapping one vs. the other. Thus an engine swap for $2500 for the diesel might end up only being $500 more than a gas engine swap or rebuilding the stocker.

My Wag is a my DD, so I'd love the mileage and torque to go along with the reliability. I'm keeping my eyes peeled for the right deal...

[DieselSJ]

I tend to agree, especially as diesel will remain more expensive than gasoline...

Regular here is right at $3/gal. Just filled the diesel tank for $2.77/gal. Mileage is hovering right around 21 for daily commute. I have even a bigger benefit in that about 1/2 of my overall mileage is reimbursed at 42.5cents/mile by my work.

Honestly, mileage was not the top reason for the swap. I did it because it is Great Googley MoogleyGreat Googley MoogleyGreat Googley MoogleyGreat Googley Moogleying cool.

[GWChris]

Looks like I'm wrong about the price difference - but that may be more due to local taxes. What I meant to say is that diesel now costs more to make than gasoline. Now it takes both the crude oil it always did to make it, plus hydrogen that comes from natural gas to remove the sulphur. It's a built-in cost disadvantage.

Anyway, I like diesels and wish that the Wagoneer already had one, and if you are doing a swap already it might make sense. But to just swap out a good running gas engine for a diesel would be hard to justify.

[scotty]

Does anybody know if the SBC/TF 727 adapters would work? I've got a nice tax return coming, and I'm bored. I might do this deed.

they might(bell bolt pattern is same,not sure about crank pilot). however,your 727 has no OD. as much as i hate the 700r it makes alot more sense to find a 4wd 6.2/700r/208 and use that. adapter cost=$0 :D if youre installing it into a pre80 rig,you can use it as-is. if its going into a post80 truck, the gm 208 input gear is an easy swap into the jeep 208.

[ohioj20]

Does anybody know if the SBC/TF 727 adapters would work? I've got a nice tax return coming, and I'm bored. I might do this deed.

I think starters are in opposite sides, plus your TH 727 would have to have some changes to its insides. Gas tranny's are different that diesel tranny's. shift at different RPMS and a govnor

[Carl Rasmussen]

I am thinking about the 6BT in my GW. I know it is a tight fight but I have seen them done and running. since I get 20MPG + in my Ram 3500 I would hope I could get at least that or more in a GW. I would go with 4bt but I waht to really Juice up the power at a later date.

[motox-010]

Not like it will be availible for sale anytime soon, but I have heard rumors that Ford it putting a diesel into the f-150 for the 2009 year models. I have read it is a 4.4. Dunno how much power that would put out but itll probally get very good mileage. And it will also be extremely expensive to buy then part it out for the engine.

[billyrb]

I am well aware that I may never recoop my money spent in my swap, but there are several reasons why I did it.


More reliable
Longer driving range went from 10 MPG to 24 MPG
You will RARELY see diesel FSJ
Sounds too cool and turns many heads!


That's totally cool and I could agree with that. Those are the reasons I swapped to my LT-1, knowing I wouldn't recoup the costs for a long while.

[scotty]

I think starters are in opposite sides, plus your TH 727 would have to have some changes to its insides. Gas tranny's are different that diesel tranny's. shift at different RPMS and a govnor

both starters are on the passenger side. the olds diesel has a driver side starter,but the 6.2 is just like any other chevy v8 with it on the passenger side and bolting to the block,not the tranny.

very good points on the trannies innards,however. another good reason to not waste your hard earned tax $$ on an engine adapter.

[scotty]

I am thinking about the 6BT in my GW. I know it is a tight fight but I have seen them done and running. since I get 20MPG + in my Ram 3500 I would hope I could get at least that or more in a GW. I would go with 4bt but I waht to really Juice up the power at a later date.

dont forget the 4bt is as tough as his big brother. you can add turbos,intercoolers,nitrous,propane,and anything you can think of to increase power.

a guy in the local jeep club has a twin turboed 4bt in a wrangler :eek: ill have to ask him what kind of power it makes.

at any rate you should easily be able to get "built small block" power from the 4bt,and more if you want it.

there is a guy here with a 4bt in an m715 who gets,IIRC,24 mpg with it. not sure to what degree he has it turned up.

not saying the 6bt swap is a bad idea,but the 4bt swap will definately be easier,and possibly a cheaper donor can be found,so definately dont rule it out.