Why? more moving parts usually means less reliability over time. No timing belt to break in a pushrod engine.

In reality most engines are eningeered and tested to last 150,000-250,000+. Truck engine a eningeered to last longer than car engines. I read GM test truck engines up to 250,000 while Honda does cars to 200,000, other brands to cars to 150,000.

 

no but i still see no proof. i can show you carb cars that make more hp than fuel injected cars. it doesnt mean that its better tho. so please show me some facts that prove it does.

and OHC cant be reliable? ever seen hondas with 500k+ miles on them?

 

In trucks the pushrods are king. The smallest pushrod still beats out the bigger OHC engines.

Ford 5.4L SOHC = 300HP
Nissan 5.6L DOHC = 305HP
Chevy 5.3L pushrod V8 = 310HP
Dodge 5.66L pushrod V8 = 345HP

In all fairness a lot of it comes down to tuning.

I've never seen one, but I'll take your word for it. I4 Hondas are well built and designed engines, nothing to do with OHC. Chevy V8s last a long time too, but with most engines, any thing over 200,000 usually depends on how the owner takes care of it.

 

It's one thing comparing Carb to Fuel injection, but it's quite another OHC to OHV. Out of 4 cylinder engines, Honda's are the best (or used to be) when it comes to power out of small displacement, tuning, etc... On average, they probably last longer than other engines, although I have seen ones that didn't last past 150K miles (our Integra included).

Having said that, I would like to give example of Honda's 3.2 V6 in their Acura CL. The car weighs about 3450 lbs and has 3.2L engine producing 260 HP. An admirable number, but the fuel consumption of the car is actually the same as LS1 fbody, 2.5L more displacement and 2 more cylinders, and having 340 - 350 HP.

As a matter of fact, I have yet to see an import V8, which are SOHC/DOHC, that produce similar outputs to LS1 (not even LS2) and have similar fuel economy. Audi, BMW, MB... all have their fuel consumption rated higher.

edit: edited for correct weight of CL

 

If you don't replace the timing belt on a Honda 4 cyl it won't last much past 90,000. I know of no pushrod V8s that require a major internal component be replaced as a "regular maintenance item" to keep the engine going.

In that respect, I've seen small blocks go 200K+ without even so much as pulling a valve cover.

That's not to say that you couldn't design an OHC motor with a chain rather than a belt (aka 4.6L ford), but the point is simplicity=fewer moving parts=less to break. If all else is equal, this will bear out every time. OHC motor manufacturers go out of their way to ensure reliability so they add emphasis on durability that a pushrod motor doesn't need to = the same longevity.

 

The stress on components overall seems to be more spread out than on an OHV. Like I said its completely baseless, thats just the image I've had for a while.