New Engine Ideas - LX-450

Viper

Member
Hi all, currently driving a 1996 LX-450 - 139K on the clock. Other than running hot on long pulls, engine is solid. However, she's underpowered as all hell and more and more that is becoming an issue. Toying with the idea of getting a new engine - maybe a VORTEC v-6 or some V-8. I will have a pro mount it - beyond me to do it. Any ideas on the most mountable engine type that requires the least amount of fabrication and will be the most hassle free? I appreciate any advice!
 
Have you had your head gasket checked? Have you had the coolant flushed and replaced or is it the original?

Mine has the same mileage and runs cool all day long. I have replaced the thermostat at 120,000 and just had the PHH done.

Do you have a lift, bigger tires, etc? If you have like 35s and have not changed the gearing, this will affect performance, maybe causing it to run warm.

You might also check on ih8mud for input. A lot of 80 series knowledge on that forum.

A vortec V6 will probably struggle and not do much better with mpg than what you have now. A V8 swap would probably work the best, but again money and fabrication and headaches come into play.

The upshot is, almost any engine swap into an 80 series will involve a lot of money, time, and fabrication. Personally, I feel the factory 4.5 I6 engine is the right engine for an 80 series.
 
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LexusAllTerrain

Expedition Leader
Plus, replace muffler, catalytic converter, oxygen sensors, spark plugs, wires, radiator cap and you will see an improvement right away!

Give us more information and maybe we can help troubleshoot!

I pull a trailer and have lift, 33's, and alot other stuff and I run at 75 to 80mph with no problems at all and I have 150k on the odometer!
 

Viper

Member
Great input, thanks! The thermostat was replaced, but at that time, the engine was overheating, not merely running a bit hot.

I am running 35s and the gearing is still factory settings - great point and will look at that. I didn't give the muffler any thought, ruled out a blown head gasket and mud-clogged radiator.

Good starting points!

Thank you!
 

Pokey

Adventurer
depends what your intended purpose is:

if you plan to go deep into backcountry where theres no AAA - id stick with 1fz....change fan clutch, rad, cooling system houses, pm headgasket and definitely do 4.56 or 4.88 gears. This is hands down the most reliable , get you there and back setup if properly pre- maintainenanced and setup gearing wise. No vortec or other engine save a toyota diesel will get you the drop dead reliability of a 1fz. All i see on craigslist is tons of these for sale with 350k miles+.

if you are doing stuff within range of AAA - with occasional offroad but not too far off the cellphone range........vortec would be zippy for merging onto freeway- and zipping around for groceries.

the trick with the 1fz setup is to keep your weight as close to stock as possible. removing things like heavy leather seats for oem cloth ones is not only 300lbs lighter.......but can offset add ons like winch bumpers etc. if you like 80mph travels- 4.56 gears would probably suit you better than 4.88s..........which with 35s are more offroad centric and make 2400rpm 65mph a nice cruising speed for fuel efficiency and engine wear. You can build a very capable rig with awesome dependability if you resist all the heavy- and i would say- pointless bolts ons which impact the driveability and durability of the 1fz platform.

with 35s - a good target weight is sub 5000lbs and you will be maintaining the stock durability that these are famous for and with synthetic fluids should pull close to stock mpgs. Putting your swap money into dialing in your gearing and maintenance is the way to go imho. Vortec is ideally suited if you are going waay beyond the stock platform with 37"+ tires- heavier axles-and mods tipping the scales above 6000lbs.
 
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One other thing I might add, the temperature gage on the 80 series is not known for being on the money in terms of accuracy. The sending unit might be going bad, or maybe you could look into some way of verifying your engine temps independent of the factory gage.
 

redthies

Renaissance Redneck
One other thing I might add, the temperature gage on the 80 series is not known for being on the money in terms of accuracy. The sending unit might be going bad, or maybe you could look into some way of verifying your engine temps independent of the factory gage.

This is good advice, as is most of what has been posted. I had a '96 LX450 and ran it on both 33" and 35" tires with stock gears. I live in mountains where it is in the upper 90*s a lot in summer. Never had any heat issues, or found it lacking in power either. I also had a drawer system with close to 300 lbs in it most of the time.

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kletzenklueffer

Adventurer
I've had two quotes for pro installed vortec v8's and transmissions in my 80. You're looking at over $20K and a couple months of downtime. For me it's kind of hard to put that kind of dough in a $5-8K truck. You can supercharge it if you can find the TRD blower ($3-4K) or turbocharge it for around the same.

If you're running oversized tires, regear it. It'll cost around $1200, and will give it more go. My 4runner is faster off the line, but the 80 with 4.88's and 35's will move o.k. I can pass in it, but it take a bit more planning than the 4runner.
 

rabbiporkchop

Adventurer
I'm kind of partial to the Vortec 5.3 swap idea, simply because it is what I had done to my 95 Tahoe.
Google the 1996 LF9 LX450. Same basic idea
 

VuickB6

What is this I don't even
With an adapter from Mark's 4WD you can swap in a GM Vortec or LS engine fairly easy. I'll be swapping to a 6.0L next year since I plan to tow a travel trailer with mine and don't want problems at elevation.
 
20k??? no freakin way dude, they either saw you coming or pumped up the price as they may have been intimidated by the install..........somethings wrong..
 

kletzenklueffer

Adventurer
The $20K quote came from two different reputable installers on the east coast. I'm sure the finished product looks like a factory install, but it's more than I'd put into the truck.
 

murphy744

Adventurer
Make sure the top end (head gasket) is solid, go through the cooling system, then see if you can locate a supercharger. Go over on MUD. Tons of guys have superchargers on their 80's/450's. It totally wakes the motor up. Last I checked a supercharger runs about $3500. My Toyota mechanic quoted me about 8hrs to install it, but others I know have done it in the driveway over a weekend. For the money you would be spending on a V8 swap, you would be better off getting a 100 series. My 2 cents:)
 

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