Life Expectancy of your Engine?

[Bob Hess]

Just curious. What are your expectations of your high performance engine? I have a 351W stroker (408) that was built by a Superformance dealer in Ohio. It has all the right stuff in it. I maintain it properly, use only Brad Penn oil, warm it up thoroughly before gettin' on it and usually keep it below 5K RPM. I have 14,000 miles on the car and expect that the motor will last much, much longer. I have very little experience with this type of motor and would like some opinions on how long you think a motor like this should last.


Happy holidays

[1795]

As long as the motor is not over built, it should last for a long time as long as you perform proper maintenance and keep the rpms at a reasonable level. What decreases the longevity of an engine, other than a lousy build, is when we try to squeeze too many horsepower out of an engine. That just places a lot of strain on the engine. People who race will over build an engine because they are not planning on using the engine often and are going to rebuild the engine each year.

Just make sure that you are using adequate rpms to keep your oil pressure up and enjoy the car.

[DAVID GAGNARD]

Originally Posted by Bob Hess

Just curious. What are your expectations of your high performance engine? I have a 351W stroker (408) that was built by a Superformance dealer in Ohio. It has all the right stuff in it. I maintain it properly, use only Brad Penn oil, warm it up thoroughly before gettin' on it and usually keep it below 5K RPM. I have 14,000 miles on the car and expect that the motor will last much, much longer. I have very little experience with this type of motor and would like some opinions on how long you think a motor like this should last.


Happy holidays

Not knowing the specifics of your build,but you seem to be right on track with taking care of it,good oil,letting it warm up before getting on it and keeping the rpms within reason, 50,000+ miles should be no problem......probably more like 75,000 + would be more accurate.......

Long time ago I built a 351-W, used stock crank/rods/block/heads (lot of head work though), beat the heck out of it........over 200 drag strip passes shifting at 6,000 rpms, 2,500 miles on 3 road courses running from 3,000 to 6,000 rpms for 30 minutes at a time and then 38,000 street/highway miles........
A buddy just have to have the engine for his old hunting 4x4 and I wanted to build a 331 stroker anyway,he made me an indecent proposal and I sold him the engine, lock/stock and barrel.......he beat the do-do out of it in his 4x4 in the mud for a couple of years then sold the truck, last I heard, it's still running, granted,using a "little" oil now, but still running fine.......

David

[CBattaglia]

If your engine was built by Eric at Performance Engineering your engine could fail at any time. When mine blew at a few thousand miles what I saw when i tore it down was disgusting. A complete mess inside. Pm me and I'll tell you all about it.

[120mm]

I've built a few small block Fords, and they are easily capable of 100,000+ miles, if well maintained and not abused. While I'm not running a 408W in a Cobra, here are the things that might hurt that longevity, assuming a competent build:

1. Cooling. Improper cooling because of bad installation and poor airflow will kill any engine.

2. Rust. If the car sits for long periods of time, rust can form inside the engine.

3. Lubrication. If you start it and don't allow it to run at operating temp for say, 20 minutes, sludge caused by byproduct of combustion will build up in your oil. This is also why a well-operating PCV system is necessary. It's also why I like running a hot thermostat. The thermostat allows the engine to get to temp quicker than running it open.

4. Abuse. These are race cars. If you race them, they will wear faster.

I won't run someone else's engine in my car. I don't think anyone else cares more that my engine is built correctly than myself.

[blykins]

From an engine builder's standpoint, your carb tune will play the biggest role in how long your engine lasts.

Back in the 60's-70's when carburetors were still the primo way of fuel delivery, you couldn't expect an engine to last more than 40-50k miles. Anytime the choke is on, or anytime the A/F mixture is rich, it will wreak havoc on the condition of the cylinder walls. Fuel injected engines, on the other hand, will generally last much, much longer.

Gotta keep an eye on your fuel pressure (too high of fuel pressure can cause issues, most carbs like 5-6 psi) and gotta keep an eye on the idle A/F ratio, as well as the A/F ratio at WOT. Remember, different pump gas formulations can cause problems, even something like changing an air cleaner can disturb the A/F ratio. Excessive amounts of fuel will wash the oil off the cylinder walls.

Otherwise, the other guys listed some very good things to watch out for. Also, generally speaking, the more radical the engine, the shorter the life expectancy, due to higher cam lift, parts flexing due to high horsepower, etc, etc.

[redmt]

Hey Brent not to disagree but I will. Back in the 60's and 70's (before you were born) I built engines that were still alive up until I tore the last one down 2 years ago. My last was a 428 built in I think around 1974-76. I tore it down 2 years ago and it has .007 wear in the worst cylinder. The old school engines didn't have to contend with lousy gas and ridiculous smog restrictions. The engines were 'happy' and they ran that way. Another thing is we didn't have all this bolt on hp available that incorrectly installed will be the short term death of the 'modern' engine.
As far as the OP's question, a properly built, well maintained and not abused engine should last near forever.

[Joe's Garage]

Then there comes the debate on whether a pre-oiler makes sense on prolonging engine life, particularly with a very high end/expensive motor. The argument being real wear & tear occurs during cold startups when oil protection has to be pumped to the bearings and other critical areas which are essentially dry until oil pressure wets the engine. Some believe it, some don't - seems to be a personal preference thing, just sayin'.

[redmt]

Speaking of oil,,,, and not wanting to start a debate that wanders off the original topic, your choice of oil will have a HUGE bearing on how long an engine is protected. I have run Rotella T longer than I can remember and have NEVER had an oil related failure. Most of your decent diesel spec oils are higher in good stuff than whatever else there is available. Take it for what it's worth but I personally have put over a million miles on various truck engines with NEVER an oil related failure.

[mikeinatlanta]

Aluminum 432 Windsor with a 4"stroke. .700 solid roller, 8000 rev limit.
valve spring checks are every 1000 miles. projected rebuild interval is 5000 miles.

[blykins]

Originally Posted by redmt

Hey Brent not to disagree but I will. Back in the 60's and 70's (before you were born) I built engines that were still alive up until I tore the last one down 2 years ago. My last was a 428 built in I think around 1974-76. I tore it down 2 years ago and it has .007 wear in the worst cylinder. The old school engines didn't have to contend with lousy gas and ridiculous smog restrictions. The engines were 'happy' and they ran that way. Another thing is we didn't have all this bolt on hp available that incorrectly installed will be the short term death of the 'modern' engine.
As far as the OP's question, a properly built, well maintained and not abused engine should last near forever.

How many miles were on it?

[redmt]

Originally Posted by blykins

How many miles were on it?

Wild guess would be 100 to 150,000. The speedo had flipped and quit working years ago. That particular engine was in a 1 ton, dually, 4x4, flatbed pickup. I hauled my pull truck all over the western US with it, taught both my kids to drive in it and used the snot out of it around the ranch until the body, doors and stuff either wore out or fell off.
BTW, it's the 105 I was talking to you about a cam for.

[blykins]

I'm sure you kept up on the tune. Most Cobra owners are guys who haven't seen a carburetor before or haven't touched one in decades...

That also jives with the point I was trying to make. An engine that's tired at 100k miles isn't what we're used to seeing these days. My Explorer has 185000 on it and with the exception of a valve cover leak, doesn't lose any oil. My '90 Mustang LX 5.0 had about 110k on it and when I pulled the heads to bolt on a set of GT40's, the crosshatch was still very evident, along with no cylinder ridge.

Carburetors are certainly easier to mess with, but I do think they contribute to accelerated cylinder wear. Just harder to keep up on the tune, along with keeping a constant ideal A/F ratio.

[120mm]

All throughout High School, (1978-1982) I flogged a very early hipo Mustang that still had its original engine. Never touched the carb, but it had, easy 150,000 miles on it. And I surely didn't care for it, beyond oil changes. I literally broke the gear shifter OFF the four speed (w/lockout) transmission. (I always thought it was a toploader, though I've been told recently it may have been a T10.)

These Ford engines were built real stout. Out of the 6 Mustangs I've owned, only one was a sub-100k engine, and it was a 6, which I've recently replaced with a roller motor.

[120mm]

Originally Posted by blykins

Carburetors are certainly easier to mess with, but I do think they contribute to accelerated cylinder wear. Just harder to keep up on the tune, along with keeping a constant ideal A/F ratio.

That is true. Running overly rich will wash oil off the cylinder walls.

I have a manual choke on the '67 pictured in my avatar for that reason.

[Blue66]

Originally Posted by blykins

I'm sure you kept up on the tune. Most Cobra owners are guys who haven't seen a carburetor before or haven't touched one in decades...

I fall into that category. I got use to new technology and fuel injection in 85 with the Buick V6 Turbo's. Tuning is the name of the game. We have V6s with 600/850 rwhp in a lot of my cars. They take a beating !! Just shoot for NO KNOCK.. 30 psi of boost you had better be on your game I was looking into fuel inj for the Cobra. I did get back to playing carb man an your mind starts remembering stuff from back in the 60s/70s !!

[madmaxx]

IMHO the most loaded component in a pushrod engine is the valve train, specifically the camshaft. If you have spring pressures above 300lbs I would throw some deadline breaking additive in you oil to help with the EPD additive.

[Ace23]

Originally Posted by blykins

From an engine builder's standpoint, your carb tune will play the biggest role in how long your engine lasts.

Back in the 60's-70's when carburetors were still the primo way of fuel delivery, you couldn't expect an engine to last more than 40-50k miles. Anytime the choke is on, or anytime the A/F mixture is rich, it will wreak havoc on the condition of the cylinder walls. Fuel injected engines, on the other hand, will generally last much, much longer.

Gotta keep an eye on your fuel pressure (too high of fuel pressure can cause issues, most carbs like 5-6 psi) and gotta keep an eye on the idle A/F ratio, as well as the A/F ratio at WOT. Remember, different pump gas formulations can cause problems, even something like changing an air cleaner can disturb the A/F ratio. Excessive amounts of fuel will wash the oil off the cylinder walls.

Otherwise, the other guys listed some very good things to watch out for. Also, generally speaking, the more radical the engine, the shorter the life expectancy, due to higher cam lift, parts flexing due to high horsepower, etc, etc.

Well that sucks to hear. I was just getting comfortable with the fact of accepting keeping the carb on the car! What is the ideal A/F during idle and can you achieve an ideal A/F ratio at idle when your have a more radical camshaft? When I pull my motor for the cam swap what is the recommended way to check for ring wear?

[blykins]

Nothing at all wrong with a carburetor. You just have to come at it knowing that it has to be tuned and it will require a little maintenance.

[Bernica]

Originally Posted by blykins

My Explorer has 185000 on it and with the exception of a valve cover leak, doesn't lose any oil.

A yup. My wife's 2006 Mercury Mountaineer (basically an Explorer) V8 has around 185k on it and other than an oil leak and replacing plugs, it just goes and goes....