Average motor life?

Hey guys.

I'm now buying a motor for the tbird. Long story.

Anyways the replacement motor has higher mileage on it as it sits but is much too cheap to pass up. What kinda mileage do these motors (especially bearings and piston rings) tend to start wearing out?

Neill

Lots, but it can depend on if those are hard miles or not? How many miles on the 'new' engine? Can you do an compression test on it or is it already out?

Just get the engine regardless. Then, do what I said in your other post. Newer engines like these have more nickel in them and keep their cross hatch for a long time. Unless the engine has had water sitting in it or oil not changed for LONG time, rings are probably good. When you have the oil pan off, roll the engine over and look for scrapes and polished spots on cylinder walls. If the engines been sitting a while, I would replace the valve springs. They're cheap. Take the oil pump apart. Look for grooves on the housings and pitting in the gears. All that would be easy to do with the engine out, and head off any potential problems. It would be fine.

First car I got with 125k. Changed the oil religiously. Blew hg at 150k. Spun a couple bearings at 215k.

Second car , got with 150k and mud for oil. Changed oil religiously, locked up on way to work 165k. I beat both of these cars hard. I could see a good used engine going to 300k if the bearings and oil pump were fine, or replaced when you looked it over. Oh, and not overheated!

HwyStar said:

Just get the engine regardless. Then, do what I said in your other post. Newer engines like these have more nickel in them and keep their cross hatch for a long time. Unless the engine has had water sitting in it or oil not changed for LONG time, rings are probably good. When you have the oil pan off, roll the engine over and look for scrapes and polished spots on cylinder walls. If the engines been sitting a while, I would replace the valve springs. They're cheap. Take the oil pump apart. Look for grooves on the housings and pitting in the gears. All that would be easy to do with the engine out, and head off any potential problems. It would be fine.

First car I got with 125k. Changed the oil religiously. Blew hg at 150k. Spun a couple bearings at 215k.

Second car , got with 150k and mud for oil. Changed oil religiously, locked up on way to work 165k. I beat both of these cars hard. I could see a good used engine going to 300k if the bearings and oil pump were fine, or replaced when you looked it over. Oh, and not overheated!

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this motor is already apart, but was removed just days ago and was a running driving no smoke no knock motor. this will make checking the above a much simpler process. headgaskets (and all other gaskets) will be replaced also.

this is a pretty comprehensive list too, thanks buddy! wasnt sure whether to get a bearing set with it. wouldnt like to break something that isnt broke so i guess ill let it ride out. i doubt i will be doing a huge amount of miles in it anyway so not much of an issue.

if i were to install bearings, this new motor has no knocking or noises of any kind. am i correct in thinking that standard sized bearings are to be used and no crank work needed? or does it all depend on the physical condition rather than going by noise alone?

Neill

Ah, the 'ol longevity question! You know, there are times where I'd almost want an odometer on the engine, coupled with some sort of meter for the driver's habits (ie: typically driven hard, or typically driven normally).

I would suggest rebuilding the heads--new springs and seals at least.

Yeah, that's a good idea while the heads are off.

If you took the main and rod caps off and found damage of any kind , you could get a single new rod/ main bearing set out the set in in place of the old and plastigage it to see if you are in tolerance. It's been my experience that as long as the grooves didn't catch your finger nail, it has a good chance of living. I've had to do this for a lot of customers. I worked a high volume shop on the poor side of town, so this came up a lot!

Like you said, it's probably fine based on what you've seen. Another thing to check that's cheap to replace is the timing chain. With the synchronizer sensor off, turn the crank by hand back and forth to see when the synchronizer just starts to move. What is acceptable, 5-10*? I'm on the ship, I don't have my books..... Someone know off the top of their head?

my first supercoupes were a pair i bought from jersey

black 90 odo broke so no idea but I only put 9k miles on it and it spilt the crank
red 90 130k s&s reman engine, 8k miles and popped a headgasket

titanium 91 hg blew at 140k new hgs and aod went out at 145k, new 4r70w swap and engine locked up at 149k

black 90 -pulled engine for power build 190k going strong

blue 92 slave cylinder went out at 120k when i was 3hrs from home, then hg went 2 weeks later

Orange 93, hg blew at 119k

black 94 hg blew at 88k

purple 95 4r70w went out at 68k, then engine locked up at 74k, new engine with wiseco pistons lost junk gapless rings at 7k

I dont have good luck at all with supercoupes

Mine is the original engine as far as I know. HGs replaced by me around 170k. Still going strong at over 200k. No signs of trouble whatsoever.

Let's see...... what is it now, three engines in 6 years? maybe about 1000 miles on each.....

Doesn't say much for longevity does it

See, from almost everything I'm reading these things are absolute unreliable heaps.

Doesn't bode well considering how much needs spending on it.

Had my 98 cobra for 7 years and it's let me down once. Had the bird 6 days and blew the motor. Head gaskets are a prone failure, there are videos all over YouTube of them blown...

Anyone with anything good to say about these motors or is that it? Horror stories?

People are happy to report bad experiences because misery loves company. For some reason it is also kinda cool in this club to denigrate the motors. However, the fact is that behind nearly every engine failure is a story of neglect, abuse, misuse, or misfortune or a all of the above. The motors are not prone to failure any more than any other pushrod Ford. In fact the 3.8L V6 is arguably the best pushrod motor Ford has built. It's not the most popular, but it's I think it just might be the best.

But if you are starting out doubting it's worth, then it's probably best to do something else because most likely you'll never believe in it anyway.

My personal experience is that my XR7 which I bought in it's production year (1990) never did fail other than head gaskets which is common with any and ALL forced induction motors. That motor saw over 200K miles, a LOT of drag racing, street racing, towing, and just plain idiot driving at HP levels ranging from stock to well over 400rwhp. But for any good testimony you'll find a bunch more negative ones so I guess you have to decide for yourself for your own reasons.

These motors don't cost that much either. Sure you can buy a lot more cheap Chinese parts to put in/on a 5.0L than you will a 3.8L, but if you build both motors using similar quality parts you will spend approximately the same money either way. It's more a matter of what you want than how much it costs.

A cars value to me isn't down to overall cost it's down to how long it lasts, how much you can build of it yourself. My belief is in all honesty, I will mess this up. I had a 2.3 fox mustang that had 125k on it when it died from rust. I then spent around £3000 buying parts, rebuilding axles, swapping sheet metal etc. day two of the build and a crack appeared in the screen. Paid another 400 for a new screen and it cracked that one too. All that money wasted. In total it was around $5300 when converted. Hence me wanting to junk this car and forget about it. It's my girlfriend that's the driving force behind it. She wants to learn, build and be rewarded for her labours. She feels it will make us stronger too.

I have every confidence in fords products. I used to work for them, own a crap ton of ford branded clothing, wallets etc. the doubt lies in my rookie building skills.

I would prefer an untouched motor but hey, they aren't around. This motor needs head gaskets and an oil pan gasket and it's good to go. But seeing as it's done 180k miles I figured bearings would help the longevity some.

XR7 Dave said:

People are happy to report bad experiences because misery loves company. For some reason it is also kinda cool in this club to denigrate the motors. However, the fact is that behind nearly every engine failure is a story of neglect, abuse, misuse, or misfortune or a all of the above. The motors are not prone to failure any more than any other pushrod Ford. In fact the 3.8L V6 is arguably the best pushrod motor Ford has built. It's not the most popular, but it's I think it just might be the best.

But if you are starting out doubting it's worth, then it's probably best to do something else because most likely you'll never believe in it anyway.

My personal experience is that my XR7 which I bought in it's production year (1990) never did fail other than head gaskets which is common with any and ALL forced induction motors. That motor saw over 200K miles, a LOT of drag racing, street racing, towing, and just plain idiot driving at HP levels ranging from stock to well over 400rwhp. But for any good testimony you'll find a bunch more negative ones so I guess you have to decide for yourself for your own reasons.

These motors don't cost that much either. Sure you can buy a lot more cheap Chinese parts to put in/on a 5.0L than you will a 3.8L, but if you build both motors using similar quality parts you will spend approximately the same money either way. It's more a matter of what you want than how much it costs.

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Some great points, Dave.

I also have to wonder in each individual case of where the engines have problems, whether 87 octane was used (and how often) without pulling the octane plug, and/ or how often coolant changes and oil changes were done. Those sorts of things will reduce the life of any engine, but the heat inherent in the SC motors will just kill it quicker than a non FI car.

I can see why auto manufacturers had largely grown wary of turbocharging/ supercharging cars, after the 80's/ early 90's. There's not the knowledge by most of the average customer base, which includes the maintenance of a different type of engine. Turbocharging and supercharging has made a comeback (with engineering that is designed to take more abuse from negligent owners), and is more efficient. But I can understand why the craze died down after the 80's, initially.

I'll admit, I'm the hardest test driver god has ever created, throttle state is either on or off theres no such thought of part throttle existance in any of my personal cars, just speak of it and youe liable to catch a wrap to the throat

One thing I'll say about the supercoupes, Ive never had one fail without advanced noticed other than a slave cylinder failure

My five speed SC is bone stock and had the HG's replaced at 110k at the first sign of leakage by the previous owner. He did new o2's new water pump all new hoses had a valve job heads pressure tested and surfaced did it all right. I'm at 170k now drive it every day and it does not use a drop of ANY fluids and runs like a new car. However my auto 93 spun a rod bearing at 110k It was a one owner car when i bought it years ago and by all means looks alot better and has always been garaged since new. When i initially tore into that car i discovered that the heads had been replaced with reman's a year before i bought it. I'd say that they had a catostrophic HG failure which resulted in coolant in the oil and did dammage then. I've seen 5/6 SC's with spun #3 rod bearing shortly after HG failure. PO of my DD replaced HG at the first sign of steam out the exhaust and therfore its never had any issues! I still have the original balancer too knock on wood. Jeff Bratton has 300k and never been into his motor original balancer too! and he has been around 300rwhp for YEARS pretty tough engines IMO but you can't blow the HG's to the point of coolant going into the oil and expect it to live much longer.

If it's just about head gaskets, there is a poll on year & trans type: http://www.sccoa.com/forums/showthr...and-Type-of-Tranny&highlight=head+gasket+poll

Annual coolant flushes and frequest oil changes are key

FWIW, I have yet to do a HG job in 25 years of having 9 different SCs and I do flog 'em but not as much like Dicepia I guess.

The one without an engine I currently have came to my hands with a damaged block from the #4 piston breaking (detonation maybe) and snapping the rod in half and out through the side of the oil pan. However, when I pulled the heads they did not show any damage and head gaskets were complete and free of fissures.

My bomber mule, the '90, has over 130K and the entire drivetrain is untouched but for lots of mods added. Original radiator, water pump, clutch, HB, trans and and diff. It sees high boost 11-15 PSI consistently with a late blower, 36#, bigger MAF and TB, MP plenum and a very open exhaust to save the day. The original radiator still cools well and I am sure I have not had to do HG on it thanks to annual coolant flushes and new antifreeze. I plan on going 200K before she gives up on me. As DD stated, preventive maintenance (or lack of it with neglected driving in the heat) is what dooms these otherwise amazing V6 motors. Not the smoothest motor FORD has made but considering how it pulls like a truck, I'd say they are something special.

Cheers

superpoop said:

I would prefer an untouched motor but hey, they aren't around. This motor needs head gaskets and an oil pan gasket and it's good to go. But seeing as it's done 180k miles I figured bearings would help the longevity some.

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In your situation - since the motor will have to come out at least part way to do the oil pan gasket - and since head gaskets will be half as difficult with the motor out - you should strongly consider at least a refreshment of all bearings, including cam bearings, and valve train parts. New pistons may or may not be required, depending on compression test results.

I've owned a number of SCs over the years, as well as 5.0 and 4.6 powered tbirds and other cars. I have also used all 3 powerplants in daily drivers, and blown engines in all 3. While the 5.0 and 4.6 do have better durability, the SC isn't bad in this department, just not quite as durable as the others. I suppose it shouldn't be any surprise that a supercharged V6 making 210-230hp in stock form isn't as durable as a naturally aspirated V8 making 200-205hp. I personally have had a 5.0 car and 2 4.6 cars with over 250K miles that the valve covers had never been off. I can't say that for the SCs. The highest mileage I ever had on an SC without anything engine-wise having been taken apart is 178K, and that was in an 89XR7 when it spun a rod bearing. That motor never popped a head gasket, and was beaten on daily for over 2 years when it finally failed, even with the spun the bearing, I was still able to drive it home over 300 miles with the engine knocking away, so it didn't even leave me stranded. Most bottom end failures on SCs that I have seen have been spun rod bearings, and I think the fact that the cars are supercharged puts more strain on those bearings, so even in a very well maintained car, that is likely to fail eventually. With that being said, I have seen stock bottom ends with over 200K on them, so you can't really call a spun bearing at that mileage a design fault or a weak point, it is just a wear item that will eventually need to be replaced. Head gaskets are more common on these cars than on other engines, but again you have a supercharged car, and I have seen a number of SCs, especially 94/95s, with over 200K miles on stock head gaskets, so they aren't guaranteed to fail, and I think as XR7Dave said, most failures can be attributed to neglect or abuse, or both. It really depends what you are looking for. If you just want a cheap reliable daily driver, I would say go for a 4.6 bird. They are cheaper, easier to maintain, easier to get parts for, and more durable, but they are nowhere near as fast or as fun, unless you spend a bunch of money on them, in which case their reliability goes down, just like the SCs. If you want something that will be a weekend car, a project, and will surprise a lot of people, then get an SC, take the time to rebuild the engine correctly, new head gaskets with ARP studs instead of the bolts, and keep up on the oil changes and coolant flushes, and you should be able to get 150K+ reliable miles out of it without a problem, which will take you a long time to rack up on a weekend only car.