How short-lived are stroker engines?

[Cannoball888]

I've read that the more strokage on an engine the shorter it's lifespan due to greater lateral forces on the piston. Anyone have any idea how long the life of a stroked engine vs non-stroked with all other parameters being the same?

 

[jerry S]

I've read that the more strokage on an engine the shorter it's lifespan due to greater lateral forces on the piston. Anyone have any idea how long the life of a stroked engine vs non-stroked with all other parameters being the same?

It will depend on how and how much you drive it. When I was having my engine rebuilt, I asked about this from the shop doing the work. It told me that the whether the 347 has a propensity for accelerated decrepitude or not is an open question but a 393W stroker should last as long as I have my car assuming it is not a daily driver or a dedicated racer. My car comes out of the garage on sunny days in Spring and Summer and I put 3000 miles a year on it tops. In my circumstance, the 393W would have lasted forever. The 408W and above, I was told, might have some longevity issues.

 

[rbohm]

longevity depends on so many things that it is hard to say. how the engine is maintained, how hard is it run on a regular basis, how it was built, what parts were used in building it, etc. given equal quality parts, service, maintenance, etc. if a 302 would go say 150k miles, a 331 would generally get close to that, and a 347 would get close to a 331. each within say 20k miles of the other. but that is a general figure, your mileage may vary as for the larger windsor based stroker, same thing applies.

 

[68RustBucket]

I once spoke to a very well known (race) engine builder in Trenton, NJ. He gave me a quote of about $7k for a very well built 347. After asking about the lifespan of his previously built 347's, he told me that he builds them to last as long as a correctly built 302 or 351. I guess it really does have a lot to do with the parts you use and the care given to the build process.

But, you could pay a hefty sum for a really well built motor that'll last you a while and still give you the power you need

 

[Max Power]

Keep in mind very few people build stroker motors as service replacement engines. They are performance engines that are used as such, and performance engines in general don't last as long as service engines.

It's pretty much a non-issue to me.

 

[LMan]

Mine hasnt failed yet (5 years) so I dont know

 

[57fairlane]

the 347 oil consumption/longevity issue is just an internet myth fueled by someone who makes more profit on 331s than a 347 kit.

The problems with any motor are directly related to the person who assembled the motor and to a lesser extent the quality of parts and how hard you use it.

 

[Cannoball888]

Keep in mind very few people build stroker motors as service replacement engines. They are performance engines that are used as such, and performance engines in general don't last as long as service engines.

It's pretty much a non-issue to me.

I think you misunderstand the question. Given two performance motors EVERYTHING being the same (compression, intake, timing, USE of motor) except one is stroked for more c.u. Is there a decrease in lifespan depending on the amount of strokage and if so how much.

The reason I asked is because a friend of mine at NPD said a 427 stroked motor from a small block won't last as long as a 427 big block. The severe strokage on the 351W block puts greater lateral forces on the cylinder walls via the extreme angle of the connecting rods and will wear the motor out quicker.

 

[SoCalCruising]

I think it is fairly safe to say that, all other things being equal, the higher the rod ratio, the longer the engine life. That is not hard and fast, but a general rule of thumb, which also implies a reasonable compression height and other stuff. I went 331 because I could choose from at least three piston makers who would supply pistons without piston pins encroaching into the lower oil land. Some think that isn't important, but it was to me. These pistons also have 1.175" between the pin and piston top (c-h) which give them just a bit more stability than a 347 piston. These are small considerations, but enough for me to choose 331 over 347 - let's not start a debate on this.

There are also different ways to build a given stroked displacement. A 331 can be built with 5.4" rods, or with 289 rods (5.155"). Rod ratio will vary and while both will make great power, the longer rod motor will probably last a bit longer. This may not matter much if you only drive a few thousand miles a year, but it should matter when building a daily driver than will see some spirited driving (hi revs).

This is not a statement about power. Short rod, long rod, they all can make great power when properly built. The question was about longevity. I hope I didn't step on anyone's toes.

 

[rbohm]

the 347 oil consumption/longevity issue is just an internet myth fueled by someone who makes more profit on 331s than a 347 kit.

actually not true. the early 347's did have problems with oil consumption and longevity. many of those problems were fixed by using a slightly shorter rod, and different pistons rings in street engines. even today though 347's have some longevity issues, but they are far better than they were in the early days. the problem though comes in that most 347 builders still build the engines as more for the track than the street, and most people are disappointed in how the engines run. with a street design ring set, and street cam design, there is no reason a 347 cant last nearly as long, and still make good power, as a similar 302.

 

[Max Power]

I think you misunderstand the question. Given two performance motors EVERYTHING being the same (compression, intake, timing, USE of motor) except one is stroked for more c.u. Is there a decrease in lifespan depending on the amount of strokage and if so how much.

The reason I asked is because a friend of mine at NPD said a 427 stroked motor from a small block won't last as long as a 427 big block. The severe strokage on the 351W block puts greater lateral forces on the cylinder walls via the extreme angle of the connecting rods and will wear the motor out quicker.

I would tend to agree with your friend. 427 is the upper limits of the 351 block, and the FE was designed that way with a shorter stroke.

Other than that, your initial question has far too many variables to give a definitive answer.

 

[ddonaca351]

I think it is fairly safe to say that, all other things being equal, the higher the rod ratio, the longer the engine life. That is not hard and fast, but a general rule of thumb, which also implies a reasonable compression height and other stuff. I went 331 because I could choose from at least three piston makers who would supply pistons without piston pins encroaching into the lower oil land. Some think that isn't important, but it was to me. These pistons also have 1.175" between the pin and piston top (c-h) which give them just a bit more stability than a 347 piston. These are small considerations, but enough for me to choose 331 over 347 - let's not start a debate on this.

There are also different ways to build a given stroked displacement. A 331 can be built with 5.4" rods, or with 289 rods (5.155"). Rod ratio will vary and while both will make great power, the longer rod motor will probably last a bit longer. This may not matter much if you only drive a few thousand miles a year, but it should matter when building a daily driver than will see some spirited driving (hi revs).

This is not a statement about power. Short rod, long rod, they all can make great power when properly built. The question was about longevity. I hope I didn't step on anyone's toes.

Well said...

DD