DOHC/OHC vs. OHV

[boxmonkeyracing]

Originally Posted by Jinx

Not to mention the LS1 was unrated. Lol. Most current Mustang GTs would be lucky to make 280 to the wheels.

under rated? lol I keep telling myself that but my G-Tech confirms that my car was close to the 305 rating. lol got below 220 hp doing a hp run on it. granted that calculates aero drag and drivetrain loss. . .

[Jinx]

Originally Posted by boxmonkeyracing

under rated? lol I keep telling myself that but my G-Tech confirms that my car was close to the 305 rating. lol got below 220 hp doing a hp run on it. granted that calculates aero drag and drivetrain loss. . .

Lol. My bad. Yes under rated.

G-Tech is as accurate as a Mood Ring. Aero Drag slows the car down, but doesnt decrease the horsepower. Drivetrain Loss is different from car to car. Well the G-Tech devices calculates acceleration (or inertia) which its applies physic equations in pre-programmed tables, you can determine lots of stats. But, when it comes to calculating HP, it gives you a figure and you calculate your car weight into that number to calculate final HP. Hence, it is not an accurate way to determine HP. It is good, however, to see if performance mods work (after mod data -baseline data = net rough estimated gain)

From a stock stand point, Ive seen most LS1 Fbodies produce 290 or a little more to the wheels. At a modest 15% drivetrain (M6) loss estimate, and 290hp to the wheels, thats roughly 333 at the flywheel. 28hp more than GM says its at.

In my opinion (or general optimism for GM products) I think the drivetrain loss is more (which means I think that the flywheel Hp is higher). I think its closer to the vettes rating of 345hp.

Here is a good read:

[wildpaws]

Originally Posted by Chocolate Apocalypse

It only started getting ridiculous when you brought purpose built race motors into the equation. Not what this thread is about.
Oh, OHV is my choice.

Depends on your definition of purpose built "race motors", I would certainly define limited production Ferrari engines as purpose built, just as the old DZ302 engines were purpose built (and by the way were able to turn 7k + in factory form). What difference does it make whether it is purpose built when you are talking about the potential of the engine design? But I digress, and as I said I'll leave the results of the argument to the forum. I'll just be happy with a good high performance OHV V-8 in the new Camaro.
Clyde

[radz28]

I've seen many more LS1s make more than 300 than less. Regardless, of that, GM way underrated them.

[Jinx]

Originally Posted by wildpaws

Depends on your definition of purpose built "race motors", I would certainly define limited production Ferrari engines as purpose built, just as the old DZ302 engines were purpose built (and by the way were able to turn 7k + in factory form). What difference does it make whether it is purpose built when you are talking about the potential of the engine design? But I digress, and as I said I'll leave the results of the argument to the forum. I'll just be happy with a good high performance OHV V-8 in the new Camaro.
Clyde

Well thats just it, a purpose built engine cost a nice penny and that factor is one of the biggest relevant factors in putting an engine in a car like the Camaro. The Camaro isnt a Ferrari or has a Ferrari price tag. And it shouldnt. If the discussion doesnt have "purpose built" (price), then we can throw in a Pratt & Whitney Jet engine design or GE engine with vectoring nozzle into the equation if we are just shooting for the best engine technology. That would pointless; so price is relevant.

"Purpose built" is usually in reference to race or limited hand built engines. Designed to operate in strict conditions or "purpose". They are usually not realistically compatable with everyday driving. Example: John Force does not drive his race car home.

Food for thought:

-5.0L Cammer Engine (400hp, 400tq)...........$29,500.00
-4.6L 4V (320hp, 320tq)...........................$6,700.00
-4.6L 3V (300hp, 320tq)............................$6,700.00

-LS7 (505hp, 470tq)..................................$17,495.00
-LS3 (430hp, 424tq).................................. $6,185.00

[boxmonkeyracing]

And the comment about chevy under rating we all know ford over rates theirs. look at the cobra line back in the 90's. . .what were they claiming was the flywheel power? but I remember they were dynoing them at 230 and with a drivetrain loss they calculated that it was nearly 50 hp off what it was rated at.

[Jinx]

Originally Posted by boxmonkeyracing

And the comment about chevy under rating we all know ford over rates theirs. look at the cobra line back in the 90's. . .what were they claiming was the flywheel power? but I remember they were dynoing them at 230 and with a drivetrain loss they calculated that it was nearly 50 hp off what it was rated at.

I agree with you there. My Mustang GT is rated at 260hp stock. I have my doubts on it even being 260hp at the flywheel.

[boxmonkeyracing]

Originally Posted by Jinx

I agree with you there. My Mustang GT is rated at 260hp stock. I have my doubts on it even being 260hp at the flywheel.

yea but they fixed that issue for 03 and 04. lol. I won't touch a cobra from those years. . .well when my camaro was running.

[Jinx]

Originally Posted by boxmonkeyracing

yea but they fixed that issue for 03 and 04. lol. I won't touch a cobra from those years. . .well when my camaro was running.

Supercharger, revamped head design, and finally growing a pair in the SVT department helped the cobra.

[boxmonkeyracing]

Originally Posted by Jinx

Supercharger, revamped head design, and finally growing a pair in the SVT department helped the cobra.

well that's the only way a mustang since the 5.0 in the fox and notches has been competitive.

[Myka]

With equal displacement, I would rather see a DOHC setup. GM, please do not use a SOHC. A 4V will always sound better and be able to flow more air then any other head. Not to mention it is more durable in race situations. I'm not saying I will hot rod my camaro all the time but it will be put through its paces. That being said, I don't want to have to worry about steel rockers and bent pushrods. Besides, Fbodfather said to "forget everything you know about engines". He also responded to someones email when they guessed about the LS3 and the LS9 being in the camaro and I believe the response was, "nope". So with all that, I can't imagine an LS3 pushrod being in there.

Maybe he was referring to the possibility of a hybrid model. I was reading an article yesterday where they were speculating that the new camaro could have a hybrid option in the first year.

[boxmonkeyracing]

Originally Posted by Myka

With equal displacement, I would rather see a DOHC setup. GM, please do not use a SOHC. A 4V will always sound better and be able to flow more air then any other head. Not to mention it is more durable in race situations. I'm not saying I will hot rod my camaro all the time but it will be put through its paces. That being said, I don't want to have to worry about steel rockers and bent pushrods. Besides, Fbodfather said to "forget everything you know about engines". He also responded to someones email when they guessed about the LS3 and the LS9 being in the camaro and I believe the response was, "nope". So with all that, I can't imagine an LS3 pushrod being in there.

Maybe he was referring to the possibility of a hybrid model. I was reading an article yesterday where they were speculating that the new camaro could have a hybrid option in the first year.

hate to say it but it's probably going to be an OHV motor. at least I hate to say it for you. personally I like my pushrods. so easy to work on.

[Myka]

Originally Posted by boxmonkeyracing

hate to say it but it's probably going to be an OHV motor. at least I hate to say it for you. personally I like my pushrods. so easy to work on.

I appreciate your sympathy. What is difficult about a 4V?

[Grape Ape]

Originally Posted by Captain Awesome

Awww come on... a topic isn't truly reached the end until someone makes a comparsion to Nazis.

Originally Posted by Myka

With equal displacement, I would rather see a DOHC setup. GM, please do not use a SOHC. A 4V will always sound better and be able to flow more air then any other head. Not to mention it is more durable in race situations. I'm not saying I will hot rod my camaro all the time but it will be put through its paces. That being said, I don't want to have to worry about steel rockers and bent pushrods. Besides, Fbodfather said to "forget everything you know about engines". He also responded to someones email when they guessed about the LS3 and the LS9 being in the camaro and I believe the response was, "nope". So with all that, I can't imagine an LS3 pushrod being in there.

Maybe he was referring to the possibility of a hybrid model. I was reading an article yesterday where they were speculating that the new camaro could have a hybrid option in the first year.

You don't need 2 cams to run 4 valves. The big advantage of DOHC or SOHC is that you can vary intake and exhaust timing separately getting you a little closer to the holy grail of having RV cam at idle and a race cam at WOT.

I’m hoping that they slip us a twin cam in block motor. That would give us the DOHC’s VVT advantage while preserving the OHV size and weight advantage. It might never rev as high as a DOHC V8, but who cares?