I've said it before and I'll say it again: my '04 V10 gets better mileage than the '10 F250 diesel we have at work. Might wanna do some research before regurgitating the old mileage arguement...
As for pushrod engines being superior...puh-leeze. Don't get me wrong, I love the simplicity of the older engines, but they don't make anywhere near the power nor get the mileage of newer generation OHC motors.

 

I would love to have a new V-10 SD F-250...................but every-time I read the $50,000 sticker price, my 93 460 F-250 with 27,000 miles looks better and better!...........My first 3bdrm 2 bath house only cost $39,000!!!

 

What makes push rods so great?

 

Generally pushrod engines can be much more compact then an OHC engine, but other then that there is no real advantage.

 

[quote=Sand_Man;8881360]I've said it before and I'll say it again: my '04 V10 gets better mileage than the '10 F250 diesel we have at work. Might wanna do some research before regurgitating the old mileage arguement...quote]


Come on Sandman... Comparing your 04' V10 to a 2010 6.4. with a DPF system? Doesnt sound like a very fair comparison. I have heard that with a DPF delete and a tuner, upwards of 20 mpg is possible.

I'd say my 7.3 or the 6.0 would be a better comparison for mileage, and we both know who comes out on top with that one. PSD all the way!!

 

And in the same fashion an old flathead is more compact than an OHV engine.

And a Briggs & Strattan lawmower engine is even smaller.

Not sure what's to like about a pushrod engine. Chevy makes some decent power out of them, but for the most part most engines with a high specific HP are SOHC or DOHC designs with some form of variable valve timing.

 

Chrysler makes good power out of their 2 valve pushrod Hemi as well. There was a company that just the other day announced they had gotten 600HP N/A out of a 6.1 Hemi stroked+bored to a 7.0. The car even still had cats.

I know GM at least has VCT on their pushrod V8s. Chrysler has fully independent intake/exhaust valve timing on their pushrod Hemi and Viper V10 (crazy how they did it, its a camshaft within a camshaft)

 

There are some great, modern push rod engines but they have all the complexity of an OHC motor.

I don't see what makes old push rod 460s better than the V10 though, and I have both.
Might end up selling my 460. Its lack of pulling power and poor fuel mileage keep me from ever using it.

 

well i think his point was the 460 is paid for the new v10 is 50k . in this case the 460 wins hands down!!! bseg barry

 

What makes the mod motors have good low end power as well as good higher rpm power is that they have a really long stroke as well as 3v high flowing heads. It has nothing to do with them being OHC. Look at the new 6.2 and 5.0. They are OHC engines but have the same torque curve as the old pushrod engines. That's the nature of a short stroke, big bore engine.

Under the most extreme conditions, OHC's are immensely better than push rods. No doubt about that. But for what 99% of us use our trucks for, there is no difference in push rod and OHC engines. If you are talking Formula 1 cars turning 18,000 rpm's, then there is no way a push rod engine can do that and an OHC is the only way to go. For normal driving, hydraulic lifters will limit your rpm's before the disadvantages of a push rod engine become evident.


My 91 5.0 had 225 hp and got 26 mpg's. The new 5.0 has over 400 hp and gets 26 mpg's. I did nothing but mild head, intake, cam, and fuel mods and was putting out 400 hp but only getting 18 mpg's. So I do agree with you that the OHC and new technology gets better mpg's per hp. But just because they were a dog in stock form doesn't mean there isn't a lot of potential and big power that can be made with them.

 

I see what you're saying, Josh, and I agree with your facts. Chevy and Dodge both make some pretty amazing power out of modern pushrod engines.

So I guess my question is then why would a manufacturer go through the expense to design a more complex OHC system? As I'm not an engineer I can't say, but I'm pretty sure there is a reason there. What do you guys think?

 

You want my honest opinion? If not I am going to give it to you anyways It's their way of convincing people that their product is the most advanced/best on the market and is something that they have to have. Like nitrogen in tires. If people think it is better, they will buy it. Whether or not it is actually beneficial for what they use it for.

Keep in mind that the OHC v8 has been in production for decades and isn't new technology(427 SOHC of the 60's for one). What is beneficial for a car that needs to turn 10-12k rpm all day long isn't going to help a truck that turns 2-3k rpm, but it sure makes people feel better to have something that is on a race car. That being said, you can get a push rod engine to turn 10-12k rpm all day long too, you just aren't going to ge the 18k out of it like you can an OHC engine.

 

The modular OHC engine actually has fewer moving parts than the old pushrod windsors.It's stupid simple, and far more reliable over the long term.
JL

 

I don't know, Josh...

The Cummins ISX is a DOHC motor. Not something they advertise though. This is a 15L inline 6 turbodiesel with a 2,000 RPM rev limiter.

If it were only needed for high revving engines, why would this class 8 highway motor be DOHC?

 

Broken dinosaur mentality.
"OHC engines are for high revving,and don't work for torque".
I see it constantly, and it's flat wrong.
The location of the camshaft(s) has absolutely no bearing on the RPM range and torque output of an engine.
JL