Factoring long term durability for a B/RB?

[b5blue]

  Is factoring long term durability part of your engine build? I see most discussion centered on building power. It's a given that machining tolerances and the quality of parts has a huge effect but what about things like valve spring pressure when compressed? Would a spring with say 40-50 more pounds pressure then stock (when the valve is open) add up to a shorter life span?
  What about cam ramp and lift? I'd think a faster ramp profile and higher lift might have increased mechanical forces that could generate wear? Could that increase side loading on valves? If you see what I mean, a rocker does not push straight down on a valve tip but slides across it.
  I chose Hyper over standard cast or forged pistons for a daily driver build after factoring that while the forged is much stronger it required a looser bore for expansion. The reasoning was in use my engine will see far more cycles of short term runs than longer runs of say over 10 minutes, I live close to work. That would add up to a lot of time forged pistons would spend loose in the bore while warming up and expanding only to stop and cool back down. The Hyper's gave me something stronger than stock cast but with a tighter bore than forged.
  I've torn down many different types of engines and always found it interesting determining why it failed when it did. There is a point where increasing power output reduces service life I'm just considering in general. I'll be installing new Sidewinder heads and it could be a good time to change my old school Resto cam to a modern cam. That had me looking at springs for the new heads and comparing loads and general specifications across components. Many here have much more experience with B/RB, I've 20 years with just my 440 and it's history but no others for comparison of what a B/RB can tolerate over the long term in daily use. (?)   

[Ghoste]

It was in mine.  But in truth, if you are building properly for power you will generally be adding durability and reliability as well.

[c00nhunterjoe]

Without turning this into a huge engineering response, putting it simply, everything is a trade off. Build it for max power and it wont last 100,000 miles, but build it to last 100,000 miles and it wont be fun to drive. You have to find a middle ground. The easiest way i have found to do this is NOT build the engine based on the hp you THINK you need. Instead, decide on what exactly you want out of the entire car. For instance, strictly a tire burner with no intentions of actually racing or going fast, an all out drag car, or a weekend cruiser on winding backroads. Each one of those options is a totaly different car, not just the engine. Long story short, you dont need to build a 700 hp engine if you plan to run a g60 14 tire.

[Ghoste]

Virtually all street builds will be a compromise of some sort though anyway.  Even if we typically only discuss heads, cams, intakes etc. on here there will be very few of us build a street engine for maximum power at the expense of durability.

[Challenger340]

Yes, this indeed could become an extremely long winded discussion, and invariably we would be discussing factors to longevity internal of an engine, that I can guarantee nobody here has even begun thinking about.
The bottom line here though... is that everyone wants "price", and there is no convincing them otherwise. You can talk at newbies until you are blue in the face, just wasted air.
That said...
IMO, the trade-offs to longevity with power levels is NOT as pronounced as many believe, and indeed it is NOT "linear" that as power goes up, reliability goes down.... FAR from it depending upon :
* How it is looked after by the owner
* and HOW it was machined / built in the first place.

I have engines out there 8-10-15 years old, 550-650 hp on pump gas, many tens of thousands of miles on them and still going strong.
One guy I built a 451 for... put it in his RoadRoach, beat it for 3 years on the street including 2 trips to Ca from Alberta Canada, then took it out and transplanted it in his A-Body to go bracket racing on "pump gas" as cheaper, and still goes 10.70's all day long at the track with it for the past 4 years !
another,
SB Stroker 408 I built 10 years ago at 600 hp on pump gas for the street, the Customer then uses a shot of Nitrous to 800 hp when outlaw street racing. The guy was so happy with it, he came back 3 years ago and wanted a pump gas 572 HEMI that could make the same power without the spray, so we did a 900+ pump gas deal.
Nonetheless,
he SOLD the sb 408 to a buddy who is STILL beating on it and running fine ! never touched or freshened !

HOW it is machined/built in the first place !
and,
HOW it is maintained by the Owner
are the 2 most important factors to longevity as power goes up.

[Challenger340]

 Is factoring long term durability part of your engine build? It should always be the MOST important factor to any buildI see most discussion centered on building power.but only WITH durability It's a given that machining tolerancesHUGE !! and the quality of parts has a huge effecteven lesser parts longevity is enhanced dramatically with different machiming but what about things like valve spring pressure when compressed? Would a spring with say 40-50 more pounds pressure then stock (when the valve is open) add up to a shorter life span? Initial Guide clearance, Valvetrain Geometry, and It can depend hugely upon the level of knowledge and training of the owner/operator in Thermal Stabilization of parts
 What about cam ramp and lift? I'd think a faster ramp profile and higher lift might have increased mechanical forces that could generate wear?again here, level of training on the owner operator is paramount. Dimbulbs can fawk up the BEST parts in 3 seconds, while smart guys van run lesser parts forever
Could that increase side loading on valves? If you see what I mean, a rocker does not push straight down on a valve tip but slides across it.
Valve guide "wear" is directly proportional to the amount of Valve guide "clearance" initially. The more the Valve is flopping around in the guide the more and faster the guide wears. But who wants to pay for a hone-fit .001" guide clearance ? I mean the Heads are "BRAND NEW" or just "rebuilt' right ? You would be amazed at what we see on "brand new" stuff the customer thinks is GOLDEN, and then the blank stares we get when we indicate it's NOT to our standards.
 I chose Hyper over standard cast or forged pistons for a daily driver build after factoring that while the forged is much stronger it required a looser bore for expansion. 4032 Alloys on Cam & barrel designs do NOT require much(if any) more clearance, and run very quite. Using a Torque Plate when fitting is more critical. Even Hypers can be "noisey" depending upon WHO or HOW they are fit relative to safety factors
The reasoning was in use my engine will see far more cycles of short term runs than longer runs of say over 10 minutes, I live close to work. That would add up to a lot of time forged pistons would spend loose in the bore while warming up and expanding only to stop and cool back down. The Hyper's gave me something stronger than stock cast but with a tighter bore than forged. Again 2 things here.... ANY Engine, Hyper or Forged, should be allowed to warm up for 10 minutes on first start of the day REGARDLESS of Piston material. Once warm, subsequent starts a few hours later are NOT as critical sue to latent heat still retained. Nonetheless, always remember, just because the temp gauge comes up after a couple of minutes.... the Valve Springs are still COLD, they are what requires the "time"@ TEMP to conduct heat and warm up on first start. Again, subsequent starts throughout the day are not as critical... just the FIRST start from dead cold.
 I've torn down many different types of engines and always found it interesting determining why it failed when it did. There is a point where increasing power output reduces service life I'm just considering in general. Which again, IMO, is directly correlated to HOW it was initially Machined/Built for the application ? It's amazing how many guys try and build "performance" or "Stroker" Engines.... to "specs" ? Right ?
OK, show me the "spec" column for a 500 hp ? or 550 hp 440 mopar ?
See what I mean here ? There AIN'T ONE, basically because Chrysler never built one !
Without getting too long winded, I can show you 6 ways to get .0025" Vertical Bearing clearance on a 440 Mopar crank ? But which is "right" for your application depends on what your are planning to do ?
Nonetheless, it's just amazing to me that people take these "kits" to the local Machine Shop, get the "good to go" based off those stock 230hp 440 "specs" and away they go ! HEY... "shit will run" and it does obviously, just say'in.... ever wonder why ya hear so many "why's" and where-fors later ?

I'll be installing new Sidewinder heads and it could be a good time to change my old school Resto cam to a modern cam. That had me looking at springs for the new heads and comparing loads and general specifications across components.Load acceptance to wear/longevity are directly proportional to guide clearance and Valvetrain geometry setup.
Many here have much more experience with B/RB, I've 20 years with just my 440 and it's history but no others for comparison of what a B/RB can tolerate over the long term in daily use. (?)
450 hp to 550 hp/Trq on pump gas, with decent owner/operator knowledge and maintenance, Machined and built properly in the first place, should experience no problems, pretty much forever ? They are an extremely durable design at those levels

[justcruisin]

Always interesting reading your posts Bob, long winded as they are, I haven't fallen asleep reading one yet.

[b5blue]

Thanks guys! 

[Kern Dog]

I think that an engine built for torque theoretically should last longer because it will be operated at lower RPMs. Lower RPMs means fewer RPMs per mile driven.

[BSB67]

I think that an engine built for torque theoretically should last longer because it will be operated at lower RPMs. Lower RPMs means fewer RPMs per mile driven.

Which is dictated by the gear ratio.  If longevity is what you want, put a 2.76 in it.  If it is a daily driver and you want to get 100,000 + miles out of it, there are things that you don't want to do to it in search for more power.

[flyinlow]

Where do you pick the balance point between a stock 383-2bbl that goes 40years/200K. miles and a top fuel hemi that goes 1 day and 1/4 mile?  Pay your money and make your choice.

When my son and I built (assembled) the 440 we had goals of 100HP bump over a stock 440 , drivable , a 100K. mile durability and a $5000 budget.  The engine runs well and hit 40K. mile this year.

The things I think we did right:   Pick a good machine shop (Fowler) who gave us some advice and did good work. Used good parts, ARP bolts, SRP pistons , and Edelbrock heads. MSD box with a rev limiter, overdrive trans., big radiator , oil cooler and Mobil 1.  Attention to detail during assembly and proper break in.  Took advice from forum members.

The things I wonder about:   Lunati lifters (so far so good), will the shorter skirt SRP pistons cause a shorter life? Will the aluminum heads with a cam with more lift and stiffer springs go the distance?

It's a hobby car so I can write off mistakes to learning and entertainment .... as long as it does not break in front of my Chevy buddies.

[c00nhunterjoe]

Where do you pick the balance point between a stock 383-2bbl that goes 40years/200K. miles and a top fuel hemi that goes 1 day and 1/4 mile?  Pay your money and make your choice.

When my son and I built (assembled) the 440 we had goals of 100HP bump over a stock 440 , drivable , a 100K. mile durability and a $5000 budget.  The engine runs well and hit 40K. mile this year.

The things I think we did right:   Pick a good machine shop (Fowler) who gave us some advice and did good work. Used good parts, ARP bolts, SRP pistons , and Edelbrock heads. MSD box with a rev limiter, overdrive trans., big radiator , oil cooler and Mobil 1.  Attention to detail during assembly and proper break in.  Took advice from forum members.

The things I wonder about:   Lunati lifters (so far so good), will the shorter skirt SRP pistons cause a shorter life? Will the aluminum heads with a cam with more lift and stiffer springs go the distance?

It's a hobby car so I can write off mistakes to learning and entertainment .... as long as it does not break in front of my Chevy buddies.

Shorter skirts such as pistons in big strokers will wear faster due to stability in the bore, but its a trade off. In my opinion, for a long term street cam, staying in the .550 lift range is the best. Once you near or peak .600, things wear of pretty quick relatively

[BSB67]

Very short skirts are common on late model stuff and, 0.60 lift in late model hp stuff too.

[Mike DC]

          
I wish there was more concern about this in the old car hobby.  But in general we just don't drive these cars much.  

Driving an old musclecar 15,000 miles in 5 years is considered a lot.  But many of us put 15,000 on a daily driver in a single year.

[b5blue]

  I'm not typical for the norm. If I can't use my 70 Charger for a daily I've no use for it. A basic bone stock big block has more torque and horsepower than I'll ever "need" and the only reason my car has a 440 is because that engine was in it when I bought the car. So for me service life of any repair is the prime objective. B body is a proven reliable, repairable platform that's remarkably rugged. 

[six-tee-nine]

I personally think that most engines you find today that need a rebiuld or trew a rod or whatever did'nt end their life because they were build on the edge of what's possible. I guess they were just build sloppy.

Its not a matter of just buying parts and putting stuff together and see how it goes.
If you respect the sequence of measuring and keeping track of all tolerances, then you'll get pretty far.

[b5blue]

The block was redone about 7 years ago and seems fine in every way.  The heads are decent just standard 346's that got checked/serviced but nothing special, new springs and hardware. I was considering a new cam to replace the resto Mopar but don't think it's going to make much difference given info here. (I'm not chasing max power.) 

[stripedelete]

  I'm not typical for the norm. If I can't use my 70 Charger for a daily I've no use for it. A basic bone stock big block has more torque and horsepower than I'll ever "need" and the only reason my car has a 440 is because that engine was in it when I bought the car. So for me service life of any repair is the prime objective. B body is a proven reliable, repairable platform that's remarkably rugged. 

Out of the norm, but, not alone.

[1974dodgecharger]

get a slant 6 make it last forever....done deal....

[b5blue]

wut? 

[firefighter3931]

From a durability standpoint a stock stroke 440 should be quite good : deep piston skirts and a 1.80:1 rod ratio are ideal for piston durability/stability and reduced side loading in the cylinders. Just run a quality lube and it should last for a very long time. 


Ron

[Kern Dog]

get a slant 6 make it last forever....done deal....

Uhhhh, it may FEEL like forever.....

[Bronzedodge]

  I chose Hyper over standard cast or forged pistons for a daily driver build after factoring that while the forged is much stronger it required a looser bore for expansion. The reasoning was in use my engine will see far more cycles of short term runs than longer runs of say over 10 minutes, I live close to work. That would add up to a lot of time forged pistons would spend loose in the bore while warming up and expanding only to stop and cool back down. The Hyper's gave me something stronger than stock cast but with a tighter bore than forged.
    

You're on the right track.  We've all read articles about the little old lady with the Max Wedge who only drove to church on Sunday.  The second owner pulls the heads and the bores are clean with a cross hatch and no ridge 'cause the motor was never hammered.  There was a guy in my neighborhood who changed his oil in his RS Camaro every 2500 miles.  Similar story - his son re gaskets the motor and it was beautiful inside.

I heard that there's good reason to use modern piston rings - less tension, less friction, and there's no compromise with lighter oils.  Pistons have to match of course.  I suppose you could balance the bottom end, maybe take the rods and pistons to the light limit with respect to the counterweights?

[b5blue]

Chuck and his Mopar specific machinist helped greatly. Even with the six pack they considered this a low power build, knowing it had to last me.  It took much longer to get the short block back from them but my patience paid off as they did a thorough job for much less than expected.    

[Morten Andre]

In my opinion for most street builds what puts most wear would be the number of cold starts seen in conjuction with thick oil used and carburetors on choke that bore wash the cylinder walls!
Generally a carb jetted for optium power that also is rich in cruising mode should be responsible for a lot of the cylinder wear due to washing the oil of the cylinder walls.
Oil can also be dilluted by fuel in such a condition. Fuel injected engines running at close to stoichiometric ratios must wear alot less cylinder walls than carbureted in my opinion.

I live in a cold country so in the season for using the Charger the temps are usually about 40 to 60 F, with warmer days like 70-75 F being more unormal than normal.
Like to daily drive the Charger in the spring unntill fall season, but have been thinking about putting in a electric coolant preheater and maybe more importantly a electric oil sump heater to lessen the cold starts.
The forged pistons sure do like to rattle a bit when cold, so I am always careful and not loading the motor hard or reving it high before it is fully warm!