Ive had a 4.6 before in a grand marquis. It seems more reliable. But which one is more durable? it seems that an all Cast iron motor would last longer than an aluminium motor but if you look at ebay it seems that there are more fords with higher milage. I saw a lincoln with 650000+ miles on it!! (but it ran on propane)
Either are great motors if they're well maintained. The LT1 is a tried and true small-block Chevy that will do hundreds of thousands of miles if you maintain it properly, so is the 4.6. The optispark on the LT1 maybe even makes it more reliable. Either are good motors, I don't know if I'd say there's a better engine between the two. As far as wear and tear, the 4.6 needs to spend more of its life in the higher RPM's, so the basic laws of engine wear say the 4.6 has more wear and tear on it than an LT1 if they have the same number of miles, but I wouldn't put one ahead of the other.
Automobile(s): 1992 Town Car Cartier & 2014 Accord LX MTX
Re: 5.7 lt1 VS. FORD 4.6 which is more durable
Both are great engines, very very durable motors, probably the most durable modern american V8's ever. The LT1 does have that optispark, which is very reliable, but it's costly to repair. The early SOHC 4.6's have an oil burning issue because the valves don't seal all the way. Between the two of them, I'd probably say that the 350 is more reliable, but only very slightly more.
yeah the valve seals were bad on the 92-95 engines, but the 96- were equipped with a plastink manifold that was prone to crack. Annoying repairs but not devastating sort of like the , exhaust bolts and waterpump/distributor on the LT.
Since we are comparing to the LT1, we'd have to use the older 4.6's to compare. are we comparing engines or drivetrains?
I had 2 buddies, between them, 3 Grand Marquis. Yes, strange. 2 1992's and 1 1993.
1 1992 had 150,000 on it. Was a huge problem car. Plagued from the start. Many thousands of dollars into the transmission. It was done twice. I always found Ford's trannies to be their weakness....
The oil pan rusted through
Numeruous vacuum leaks
Lots of failed sensors
The other '92 had only 70,000 on it.
Same thing, numerous vacuum leaks
oil pan rusted through on this one as well
Overdrive never shifted correctly, but the rest of the tranny seemed fine
Wow, now that I am listing this stuff, these guys had identical problems, I never even realized it.
Both used oil
However, the 1993 was a trouble free car. That one never had a problem while he had it. Sold it at 103,000 or something like that. He gave it up for a 2000 Grand Marquis
I can only list problems I've seen with the 4.6 because I never knew anyone with an LT1... so yeah
I have 209K on my ride. Eng has no evidence of ever being opened, and for sure not since I have had it in the last 60K. Trans is stock, rear end is stock (but has a pair of badly worn axle shafts thanks to GM installing the wrong diff gasket). The only real issues that this car ever had before I got it was AC compressor. Factory one died in 2002 and replacement was bad and had to be replaced less than 1 year later.
Engine itself, almost untouched for 209K. Even factory water pump and distributor/cap/rotor.
Mine is a 94 Cadillac Fleetwood Brougham with the factory V4P 7000# towing package.
My distributor is under the water pump (Optispark). It has a huge cap and has a bad rap for failures. But most are at 150K+ before they do. Most cars can't even ponder going 100K on a factory cap/rotor and these cars commonly do it. I am sure it NEEDS it, but it is a major job to do it. I need to get a water pump, timing set (209K it needs it too), and distributor (common to replace with a new GM unit). Katshot said statistically they replaced them all at 142K miles for a reliability standpoint.
Automobile(s): 1994 Cadillac Fleetwood Brougham (some show and some go!)
Re: 5.7 lt1 VS. FORD 4.6 which is more durable
Not familiar with the 4.6 so can't comment.
But the iron-headed LT1 engine is in livery Fleetwoods, taxi cab Caprices & 9C1 cop cars.
I have a pal who went 297,000 miles on his ex-cop car AND ex-taxi use vehicle. Engine failure occurred because he decided to do a 100mph jaunt on the highway when the oil pump failed (taking out the engine in the process). He could of went much longer on that stock 300K mile abused multiple fleet service engine had the oil pump been replaced at some point!
To Fords credit...ahem... my father has a transporation business with several town cars. One was retired a while ago but is still in use is a '98 town car with around 200k, other than tranny problems the car rides and runs like silk. Before that we had the 5.0 lincolns and they ran forever to with proper maintenance. The I prefer a ford 5.0 over their 4.6 for their cast iron construction, cheapness to fix and sheer simplicity. GM small blocks carry my same preference, they are so easy and usually cheap to fix especially gen I's Not to mention they outlast anything given proper care ;-)