No witty come back.

But building 10, 9 or even an 8 second car proves what? That I spent the time and/or money doing it, WOW.

So come on prove me wrong, how quick was a STOCK LT1 Corvette in the 1/4 mile???? What did it trap??? Was it really as fast as a STOCK LT5????

Come on if I don't know CORRECT me, don't just bash because someone has said something you don't like. ANSWER IT!!!!!!!!!!!!!!!!!!!!!!!!!!

I only complain when FOOLS think just because they own something it AUTOMATICALLY becomes the best thing. TAKE a frigging look at my sig, EVERY car listed in it has a PUSH ROD ENGINE.

Really looks like the sort of cars someone who hates OHV would own

And what do you know of me? or my past, how do you know what I have or have not done, what parts I've broken, fixed, customised or built.

You don't have a frigging clue.

As for a 10 second steet machine, yeah right they are 10 a penny here in the UK - NOT

Different culture, drag racing is almost non existant here and practically no one cares about it (I say practically because some like me, do!). But engineering and physics and LOGIC are the same regardless of which continent you are standing on.

 

Because they have taxes on displacement and displacement-limited racing classes.

HP/liter doesn't mean sh*t. I couldn't care less how many HP/liter a motor makes because that doesn't get the car down the road, or down the track: HP/pound of engine weight DOES and the LS1 is LIGHTER than equivalent OHC rivals.

 

But what has this got to do with production cost per unit??


Actually it means a lot. Can a 4.8 push rod V8 really produce lots more power than a 4.4 DOHC V8? Or is it more likely the other way round. Ascari use the BMW 4.4 with with 500bhp STOCK and full emissions legal.

Well it does, it's just you don't see many large displacement DOHC engines, for several reasons, they are generally used outside the American market principly. And there really is no need for large displacements as a 4.0-5.0 litre engine can acheive all that is "reasonably" needed from a production engine.

Yes the LS1 is a great compact and lightweight unit, but so are some DOHC units. A lot of you guys seem to think the only DOHC V8 is the Ford modular motor, don't know why I guess just the availability of them makes you a little short sighted. But engines like the Jaguar AJV8 are not that disimilar to the LS1 in size or weight.

As for lb/hp, well yes overall vehicle weight is important. But if you could get another 15-30% more power from an engine only weighing some 150lb more I think it's a pretty good trade off.

Also there really isn't a current production DOHC engine equiverlent to the LS1.

How many 5.7 llitre DOHC engines do you know of?

This kind of argument can go on for ever, but at the end of the day a multivalve engine can produce more power over a wider rpm range on a like for like basis.

If you want a comprison of OHV and DOHC this is the best I can come up with.

LS7 hand built engine based of a race development program.

7.0 V8 OHV push rod all aluminium engine, dry sump n/a
512bhp SAE Net, this equals 73.14bhp/litre

TVR V12 hand built engine based of a race development program.

7.7 V12 DOHC all aluminium engine, dry sump n/a
880bhp DIN this equals 114.28bhp/litre

And yes I am well aware you can add long tubes and a cam and so on to a LS7, but you can do the same to the TVR engine as well.

 

I can tell, we can all tell your the usual internet posser, PhD of all you survey, savior of the unknowing and ignorant... WITH NO first hand experience but TONS of adviceon how we are all F'd... Take your Internet genius somewhere it can be appreciated. I here narcissist forums are all the rage now...

Hey If I am wrong post some pics of you tearing something apart…

 

When you are talking about efficiency thats all that matters. And seeing as how this is an engine based thread not one about the whole car it seems that efficeincy would be what we are talking about. So the LS7 that all of you love so much makes 505hp with 7 liters the BMW M5 V-10 does it with only 5 liters.

 

Simple....Overall size and weight of a DOHC setup is usually larger and ALWAYS more expensive than a cam in block OHV config......If you try to get the DOHC cam engine down to the physical size of the cam in block engine it will be exponentially more expensive. For the funds accomplishing that feat you could have already been making a smaller, lighter, cheaper and more powerful increased cube cam in block engine.

 

If you would like to measure something... measure the distance that the Aston Martins finished behind the Corvettes at last years 24hr Le Mans and the other ALMS races..or for that matter the distance the Ferrari's finished behind the Corvettes in prior years of ALMS racing..the distance was so far that they quit racing against the Corvettes..I can't blame them they got shut out for the whole series the last year that they competed...they were getting beaten so badly they didn't even show up for the Petit Le Mans in 2004 ...you can measure that as a total *** kicking of your Euro cars using DOHC 4 VPC technology.. ....the next schedualed *** kicking is March 18th..The 12 Hours of Sebring..go Corvette Racing ..go USA!!

 

Will this be on TV?

 

Yes it will be broadcast on the SPEED CHANNEL..


At the end of the 2005 season the Corvettes had this record in the ALMS

45 class wins in 66 races

5 consecutive ALMS Manufacturers Chanpionships

24 hours of Le Mans Class Champions 2001, 2002, 2004, 2005

 

That wasn’t an answer to your question on production cost (although taxes do factor in…); it was an answer to your question of “if OHV is so great then why don’t all these euro/jap manufactures use it?” The answer is because they have silly rules imposed on them, not because of engineering reasons.

No, it means nothing. As I said, I don’t CARE how many liters an engine is; I care how much it weighs and how much power it makes. Period. “efficiency” doesn’t win anything in the real world. If I pull up to a a guy at a light with his 300hp/L 1.0L and I have my 100HP/L 5.7L, then (all other things being equal), who wins the race? The guy with more power or the guy with “efficiency?”

I swear, I’ve heard few things quite as retarded as rating motors on HP/L. It makes no sense unless you’re racing in displacement-limited classes. Last time I checked, there was no such rule on the street.

Well, you can keep using what you “reasonably” need and I’ll keep winning, thankyouverymuch.

Show me an engine that can compete with the LS1 (hell, the LS2 since it’s out now) that has an advantage in power/weight and cost. And I don’t give a flying f*ck about displacement. Sure, Jag’s AJV8 may be close in size and weight, but what about cost? And power output across the rev range? Sorry, but the LS1/LS2 wins.

I’m not saying that it’s the be-all-end-all motor, but for a relatively inexpensive, lightweight production motor it has few that can rival it.

Well, the Ford modular units are meant to compete, but… they don’t really succeed in that so you’re right.

And your little “comparison” is useless. HP/L means nothing. That’s like comparing engines based on HP/valve. WTF does it matter?
Here, let me answer you with an equally useless comparison:

7.0 V8 OHV push rod all aluminum engine, dry sump n/a
512bhp SAE Net, this equals 32bhp/valve

TVR V12 hand built engine based of a race development program.

7.7 V12 DOHC all aluminum engine, dry sump n/a
880bhp DIN this equals 18.33bhp/valve

OMG LOOK HOW MUCH THE LS7 PWNS JOO!!!

Do you see my point? HP/L doesn’t mean anything more in the real world than hp/valve. Like I said, better metrics are hp/pound and production cost because these things matter out in reality, which is where I like to drive.

(Oh and BTW my spell check fixed your typos: “Aluminum” only has one “I.” That’s a joke, limey.)

 

I said engine weight, ********. "Efficiency" doesn't mean sh*t out in the real world.

 

Ok ignoring the fact that I hold a degree, am an engineer by profession and have worked for an aero aviation company. I am also a keen enthusiast and petrol head. I mainly compete in off road competition trials and rallys but do do a small degree of drag racing also.

Here's some pics of my TR7 that I rebuilt and converted from a 2.0 to a V8, only remaining stock parts are the doors and boot lid. As you can see by the pic in my sig it looks a bit different know. This currently off the road having blown the diff up on it while using it as my DD last summer covering 120 miles per trip each time in it. Future plans include swapping the Rover V8 out for a Jagaur Supercharged unit producing 550+bhp, which in a 1150kg car should go pretty well.

This is also the 2nd TR7 as I ripped the axle off the 1st one and twisted the chassis, that was also modified and had a replacement engine (2.0).

The Discovery is currently under going an engine rebuild by ME at my Dad's workshop after I accidently blew it up due to over fueling and other tweaks/mods that you can do on a diesel engine. As you can see from the picture it is NOT a STOCK Land Rover Discovery.

The other Land Rovers are also evidently NOT stock, the white one runs a V8.

In the past I have also restored a 1978 MGB GT, a Jaguar XJS V12 which I sold at Christmas and had owned for 5 years which had custom parts to the intake and exhaust that I did and have worked on and carried maintanance and repairs to all of my vehicles (20+) since 1997 (when I passed my test (17 years old for UK)).

Oh and not forgetting the Z28 which is also in my sig, fairly stock at present, just free mods (FRA, ported TB, bump stop) and a LM exhaust. But I've not had it all that long and parts are harder to get for Fbody's in the UK.

 

one more.

 

Ok so they have the same amount of HP (rated at the FLYWHEEL), but show me a dyno where they make the same to the wheels, lets see the power curve on the two, whats the M5 rated at, sub 400 TQ at the FLYWHEEL? You cant just look at the HP ratings from the factory and say its equivalent...and using your ricer math the LS7 might be 2 liters bigger, but the M5 need 2 MORE CYLINDERS, so there!

 

But that's partly my point.

Are OHV really cheaper to make. Is this FACT or just what people claim based on ZERO facts.

Size is important, but if you can get a LS1 in the engine bay 'most' DOHC V8's would also fit.

lol

I think the LeMans thing was really bad fuel managment as the Aston was winning and only ran out of fuel. Plus in FIA GT Championship the Aston has done fine.

Besides winning like this is the WHOLE package and TEAM and bears little relavance to DOHC vs OHV debate.



There is no such thing at all. I mean GM sell the C6 all across Europe and they did with the C5 and the Z28 also (I own one!!!!).


eh??

Well if the 1.0 is a bike then probably them.

Or how about you pull upto someone who also has a 5.7 but makes upto 30% more power than you?


I agree the street is different, but you where not saying that, you where implying that OHV is better - period. Which is flawed as it is only better when it has the displacement advantage.


Winning what?


Cost??? Jaguar is a much smaller company than GM and doesn't have the same resources of finances. I am willing to bet the LSx engines cost as much or more to develop than the AJV8 did.

Low end grunt is attained by displacement or FI. The 4.2 supercharged Jagaur engine easily matches the LS2 yet is also only in amild state of tune. Jaguars are designed for refinement.

How about the 6.0 DOHC V12 that Aston Martin uses? A development of the commonal Ford V6 as found in the Mondeo.

Itproduces 525bhp STOCK and meeting all noise and emissions regulations. Makes the 400bhp from the LS2 look pretty low by direct comparison of a production engine.

No I agree I LOVE the Lsx engine. Hence I bought one. I mean I could have got a Mustang or TVR, Lotus or Jaguar or BMW. But I didn't I bought the Z28 because since I saw a 77 Trans Am years back I always wanted an Fbody. And the fact that the Z28 had the LS1. Plus I like the looks and they way it drives. But I bought it based on what it is.


Compete in market place maybe, but Ford have never gone head to head with the LS1 else they would have used the 5.4 in the Stsang not the 4.6

Except the the TVR is the more efficent motor in terms of specific output and TOTAL BHP. You simply can not ignore these facts.

Total HP is important. But that is a DIFFERENT issue to technical ability.

 

More cylinders don't mean more power. It just allows a lower rotaing mass per cylinder. So a shorter stroke is often common which allows higher rpms. But short stroke engines typically produce less torque low in the rpms. This is true for 4,8 10, 12, 16 cylinder engines.

More cubes and a longer stroke engine are not so high rpm friendly as a rule but will make more low end grunt.

 

There is so such a thing. Europe has a TAX on engine displacement. Look it up. GM never sold C5’s or Z28’s in any kind of volume over there. It cost less to just pay the tax than to re-design their engines, so they just paid the tax.

I said “all other things being equal.” You’re dancing around, trying to avoid my point: the driver doesn’t have any reason to care what the HP/L of his engine is. He cares about HP/pound and final output. That’s it. An engine with more HP/L may be more “technically advanced,” but that matters exactly zero to the guy who’s pushing on the gas pedal.

Do you see what I am saying?

I’ve been talking about the street all along. What I said wasn’t that OHV was better – period… what I said was that it provided superior power to weight and power per dollar. If you want an all-out race motor on an unlimited budget where package size is no issue, then there are better configurations to choose.

No I don’t have a bunch of statistics to show the cost of OHV vs OHC. That knowledge is second-hand so feel free to prove me wrong. Do you have any proof?

Winning against retards in Hondas who think that because they have more HP/L than me that it will somehow make them any faster.

Pardon my ignorance, but which motor exactly is the AJV8? What is its output and what does it weigh?

And it’s… HOW heavy and HOW expensive?

And technical ability needs to be judged by the REAL WORLD facts about how an engine performs (HP/weight and cost), not based on its complexity.

 

So, you are saying that GM can't figure out how to make it fit? I would have to disagree with you there.

 

Hay English dude..one A M ran out of gas and the other broke down at Le Mans..What about at 1000 miles at Petite Le Mans or any other ALMS race..I stood there and watched them get their *** kicked..as far as size you can't build a DOHC 4 VPC that is as small as the LS series engine with the same displacement...it will not fit in the engine compartment of the Corvette...more moving parts, more weight, and more cost..your 4 vavle per cyl. engine make its horse power up on the top..they do not make comparable HP and TQ numbers in the low or mid range like OHV engines do...before Pro Drive started using the A M they used the Ferarri and the Corvettes kicked their *** too..so bad they quit the ALMS series..look at the record..the OHV Corvette has been kicking what ever brand of DOHC automobile the Euros threw at them for the last 5 years..if you ask me your lucky one A M ran out of gas at le Mans..as least you have a half *** excuse that way...66 races and 45 wins tell me which is superior in eudurance road racing..STAY TUNED to the SPEED CHANNEL on the 18th of next month your going to get another dose of American OHV Iron kicking Euro DOHC ***..

 

Go and get your tape measure and see what an LT5 motor is and then measure the LS series motor and you will see what we are talking about..big difference in the size of those two power plants..