diesel to gas conversion?

Discuss (and cuss) the Nissan LD-series OHC Six diesel engine, popularly available in the US in 1981-83 Datsun/Nissan Maxima Sedans & Wagons.

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olie05
Posts: 7
Joined: 15 years ago

diesel to gas conversion?

#1

Post by olie05 »

Hey everyone,

I will soon have a diesel engine in my posession, and My plans for it are to make a long-rod stroker motor for a z-car.

There aren't too many guys over at hybridz.org that know alot about the diesel engine so I thought i'd post here.

What would it take to convert to a gas engine?

I'm already planning on using a P-90 cylinder head, and converting to a rear sump pan. Anything else I should be watching out for?

conversly, is there anything in/on the diesel engine I would want to keep for this kind of conversion? (I've heard the starter is really powerful!)

thanks!
-Oliver
83_maxima
Posts: 423
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Location: Denver

#2

Post by 83_maxima »

Why would you take one of these already rare engines and build it to run on gas???

L28 blocks are everywhere and can be had for cheap. I have 2. Put a P90 head on one of them and find a stroker crank - thereyahgo...

You'll also have to change the rods, to lower the compression. hmmmmmm.

I guess if you are going to go ahead with this, make the diesel injection components available to the members of this forum. Seems like more trouble than it's worth and takes another one of these great diesel motors out of existence but it's your choice.

Just painful for a diesel head...
olie05
Posts: 7
Joined: 15 years ago

reasons...

#3

Post by olie05 »

Well, I didn't think I would have to justify myself, but I guess I should since this is not a performance oriented forum.

My goal is performance, with no provision for fuel economy. (yes i know most of you are opposite, with a slight provision for performance)

the Idea is that the LD28 block is taller than the L28, and can accomodate a longer rod. Accompanied by low pin height pistons and the diesel crank, this makes for an engine that holds the piston at TDC for longer. That is the point of using the LD28 block.

I will be sure to post all the extra parts that I don't use ( I promise to handle them with care ) and make them all available for this forum before I stick them on ebay.

I came here to seek the advice of people who are very familiar with the LD28, since I am only familiar with its gasoline variant.

please educate me. Thanks
-Oliver
83_maxima
Posts: 423
Joined: 15 years ago
Location: Denver

#4

Post by 83_maxima »

No need to justify yourself, it's just that most all of the regulars around here are interested in the diesel technology of this engine and that's what they know about - though I speak only for myself.

The extent of performance mods that have been done (AFAIK) is turbocharging the LD28 by dslsmoke.

My interest in these engines stems from my love for the 1st gen Maximas and secondly my desire to own one of these rare and reliable (albeit somewhat eclectic) diesel engines. The others have their own reasons for owing these cars/engines and most do because of the engine and not the car.

You must also realize that buttons are pushed when people take these engines, strip them down, trash the parts and sell the cranks. This is no reflection on you, but many of these motors in otherwise good condition have gone to the recycler because someone wanted the crank...

As far as information that may contribute to your cause...there is probably very little you can use beside the block and possibly the starter. Everything else is unique to the diesel and does not cross-over to any of the other L-series engines. I am uncertain about the internals, but would think that they would need to be changed to accommodate gasoline.
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asavage
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#5

Post by asavage »

It's an intriguing idea, converting from diesel to gasoline. One hurdle would be retrofit of the front timing chain cover. You need a gasser cover to drive the distributor. An option would be a crank-triggered ignition system. Those things have gotten a lot cheaper, esp. if you're going to use aftermarket fuel injection too.

Off the top of my head, I'd think it would be easier to use the L28 block and the LD28 crank & intake, the well-trod path.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
olie05
Posts: 7
Joined: 15 years ago

#6

Post by olie05 »

Thanks for the replies!

83_maxima,
I hear you on the eclectic-ness of the engine. I'm sure the feeling is the one I have for someday owning an S20 engine, in a fairlady Z.

As far as stripping down the engine, now that I know that there is a group of enthusiasts for the diesel, I will definitely post up the parts that I don't use. Hopefully it will help complete someone's diesel project.

asavage,
I have heard that the L20B front cover can be used, since that block had the same deck-height as the LD28. Your idea does intrigue me, because that would be one clean DIS installation. The current procedure includes fitting a freeze plug in the hole where the distributor used to live.
I think i will keep the intake :)
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asavage
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#7

Post by asavage »

olie05 wrote:I have heard that the L20B front cover can be used, since that block had the same deck-height as the LD28.
Oh, Ho! Who knew? Not I. It's amazing, the collection of info that can now be shared.
that would be one clean DIS installation. The current procedure includes fitting a freeze plug in the hole where the distributor used to live.
Ah, so you're familiar with DIS, good.

Maybe we should be telling the gasser folks about the clean-lines LD28 front cover, for DIS conversions :twisted:
I think i will keep the intake :)

I've been hearing of folks using the LD28 intake on the gasser, but I wouldn't think the air velocity would be optimized for low speed. Diesels flow the maximum amount of air for any given RPM, gassers don't. If'n I was looking for an intake upgrade, maybe I'd look into the tuned intake system tech that switches in and out different runner sections at different RPM.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
goglio704
Posts: 726
Joined: 15 years ago
Location: East Tennessee

#8

Post by goglio704 »

Captain,

It appears we've been boarded by a crank pirate! :shock: :wink:
Matt B.

83 Maxima Sedan, LD28, 5 speed, white, 130k miles. My original Maxima.
83 Maxima Sedan converted from gasser, LD28, 5 speed, 2 tone blue, 230k miles
82 Maxima Sedan, LD28, 3 speed auto, 2 tone Gray/Silver, 140k miles
81 810 Sedan, LD28, 3 speed auto, rust, rust, and more rust!

2005 Jeep Liberty CRD
olie05
Posts: 7
Joined: 15 years ago

#9

Post by olie05 »

goglio704 wrote:Captain,

It appears we've been boarded by a crank pirate! :shock: :wink:
that's crank and block pirate to you, sir.
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asavage
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#10

Post by asavage »

Urban definition

crank-pirate
Function: noun
Etymology: ND-speak, circa 2005, from crank, crankshaft [also crank, as in crackpot, "an annoyingly eccentric person; also : one that is overly enthusiastic about a particular subject or activity"; no relation to the drug: powdered methamphetamine] + pirate, the unauthorized use of another's production, invention, or conception . . .
Oliver, you are the first out-of-the-closet crank-pirate we've had in our short six month existence, so some good-natured ribbing is to be expected. However you want to use your LD is OK with me; my "highest and best use" (pun intended; if you don't get it, re-read the definition above!) may not be yours, but I think I can tolerate the destruction mutation of an LD into something non-diesel . . . IF you never tell me that you scrapped the remainder of the engine, because it was "in the way", or "I moved", or "garage cleaning" or some other lame-ass excuse for not properly recycling the remains -- or at least making a real attempt at keeping the other parts of this increasingly-rare engine from becoming landfill and Chinese-made toaster ovens.

Or something like that. One would think that having lived as long as I, one would learn not to try to express ideas subtlely after consuming certain potent consumables. But at least I didn't incorrectly use an apostrophe (apostrophe: award to the cat with the best ass) in the word its . . . to all of you who were cutting class that day, the apostrophe ("single quote") in it's always indicates the contraction, "it is", and never shows possession. Hence (examples):

o "A room with a view is its own reward."
o "It's never too late to say you're sorry."

Reading UtahBiodieselSupply is a real downer, for all its inappropriate "it's".

[*hic*]
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
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asavage
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Location: Duvall, Wash.
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#11

Post by asavage »

But seriously, how 'bout something completely different?

** Gas 3.1l, turbo, propane fuelled **

Seriously . . . figure normal propane mixes (commercial propane in the US isn't nearly 100% propane, but is a combination of various igniteable hydrocarbons) is around, oh, 110 octane. Ditch the gasoline carbs and high-tech FI hardware and go combo-retro:
  • IMPCO VFF30 Fuel lockoff & filter, $25 on eBay
  • IMPCO Model E Regulator/Vapouriser, $50 on eBay
  • IMPCO Model 225 mixer ("carb"), $50 on eBay
  • Autotronics/DualCurve Model 5918 (or 4046, or any one of several other models) mixture controller, $100 on eBay, $200 brand-new
  • Appropriate LPG fuel tank & special hose
  • O2 sensor
  • High-energy ignition system, electrics in good shape
The tank is the only hard/expensive part -- really.

With a consisent fuel octane of 110 or more, you can build your motor 12:1 compression or even higher with no detonation, optimising the thermal efficiency of the hardware to match the fuel, also offsetting somewhat LPG's lower energy density. LPG burns super-clean, doesn't require cold-start enrichment (or choke), doesn't require cold-start fast idle, does not soil the lube oil at even 1/4 the rate of gasoline, and is cheaper per gallon than gasoline almost everywhere.

Think about it.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
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kassim503
Posts: 1027
Joined: 15 years ago
Location: Stony Brook, NY

#12

Post by kassim503 »

whahhht?????????????


is it really "its"

and not

"it's"??????????????????????????????????????????
'83 maxima sedan, l24e, a/t, black

227K SOLD 6/7/2012
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asavage
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Posts: 5370
Joined: 15 years ago
Location: Duvall, Wash.
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#13

Post by asavage »

it's is ALWAYS "it is".

Read that again.

The next time you type "it's" in a sentence, read it to yourself as "it is", and if the sentence still makes sense, you used the apostrophe correctly. If the sentence is now gibberish, remove the apostrophe.

Simple, no? Well, no, but it's English -- The Language.

I'm not a grammarian, but I have my limits.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
User avatar
kassim503
Posts: 1027
Joined: 15 years ago
Location: Stony Brook, NY

#14

Post by kassim503 »

asavage wrote:But seriously, how 'bout something completely different?

** Gas 3.1l, turbo, propane fuelled **

Seriously . . . figure normal propane mixes (commercial propane in the US isn't nearly 100% propane, but is a combination of various igniteable hydrocarbons) is around, oh, 110 octane. Ditch the gasoline carbs and high-tech FI hardware and go combo-retro:
  • IMPCO VFF30 Fuel lockoff & filter, $25 on eBay
  • IMPCO Model E Regulator/Vapouriser, $50 on eBay
  • IMPCO Model 225 mixer ("carb"), $50 on eBay
  • Autotronics/DualCurve Model 5918 (or 4046, or any one of several other models) mixture controller, $100 on eBay, $200 brand-new
  • Appropriate LPG fuel tank & special hose
  • O2 sensor
  • High-energy ignition system, electrics in good shape
The tank is the only hard/expensive part -- really.

With a consisent fuel octane of 110 or more, you can build your motor 12:1 compression or even higher with no detonation, optimising the thermal efficiency of the hardware to match the fuel, also offsetting somewhat LPG's lower energy density. LPG burns super-clean, doesn't require cold-start enrichment (or choke), doesn't require cold-start fast idle, does not soil the lube oil at even 1/4 the rate of gasoline, and is cheaper per gallon than gasoline almost everywhere.

Think about it.

Propane is cool, it really is


ive been around some propane run vehicles (like ford 250/350/450's and propane lawnmowers my friends beat together), propane would really surprise you.

The tanks can be found- try searching on ebay or at a propane accessory store, they sell tanks that go in cars its like a oversized forklift tank. Propane also would let you run a higher compression (like al said), and personally I think propane gets u a little more power than gasoline does, I have access to propane powered f350s at one of my jobs and it does 4wd burnouts :lol: .

Also you might be one of the first propane datsun cars around- thatll turn heads if you take your car to shows, not like some run of the mill state owned F-350
'83 maxima sedan, l24e, a/t, black

227K SOLD 6/7/2012
olie05
Posts: 7
Joined: 15 years ago

#15

Post by olie05 »

asavage wrote:
Urban definition

crank-pirate
Function: noun
Etymology: ND-speak, circa 2005, from crank, crankshaft [also crank, as in crackpot, "an annoyingly eccentric person; also : one that is overly enthusiastic about a particular subject or activity"; no relation to the drug: powdered methamphetamine] + pirate, the unauthorized use of another's production, invention, or conception . . .
Oliver, you are the first out-of-the-closet crank-pirate we've had in our short six month existence, so some good-natured ribbing is to be expected. However you want to use your LD is OK with me; my "highest and best use" (pun intended; if you don't get it, re-read the definition above!) may not be yours, but I think I can tolerate the destruction mutation of an LD into something non-diesel . . . IF you never tell me that you scrapped the remainder of the engine, because it was "in the way", or "I moved", or "garage cleaning" or some other lame-ass excuse for not properly recycling the remains -- or at least making a real attempt at keeping the other parts of this increasingly-rare engine from becoming landfill and Chinese-made toaster ovens.

Or something like that. One would think that having lived as long as I, one would learn not to try to express ideas subtlely after consuming certain potent consumables. But at least I didn't incorrectly use an apostrophe (apostrophe: award to the cat with the best ass) in the word its . . . to all of you who were cutting class that day, the apostrophe ("single quote") in it's always indicates the contraction, "it is", and never shows possession. Hence (examples):

o "A room with a view is its own reward."
o "It's never too late to say you're sorry."

Reading UtahBiodieselSupply is a real downer, for all its inappropriate "it's".

[*hic*]
:shock:

I had to read that 5 times before I started to understand parts of it.

I want what you're having, please. :D
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