Car and Driver pulled up some interesting numbers about "low tech" engines.

[Demon-Xanth]

My entire point with bringing up the Celica was bang/buck. It HAS all the "high tech" doohickeys and such that make it cost $25k, while other cars that DON'T have it that cost $25k are faster. Signifigantly faster. I'll compare vehicles on thier price and capabilities. How they get there isn't as important. I'm a big fan of torque+RWD, but would I drive an SRT-4 if I had the chance? Hell yeah I would. It pulls the numbers that it should. It's a small car, I probably wouldn't trade it for mine for every day driving, but if I had $40k to get a car, I might get both. (aww hell, I'd end up in a Magnum or GTO)

A 5.7L V8 is physically SMALLER than the 4.5 and 4.6L DOHC engines used in the example. So displacement!=weight nor exterior volume. Just because it has an extra liter of displacement does not automatically mean it's heavy. Almost everyone who ever mentions "specific output" forgets that. That was the whole point of this thread.

 

[ElFenix]

Originally posted by: Howard

Originally posted by: ElFenix

Originally posted by: Zenmervolt

Originally posted by: ElFenix
so does less displacement

Only if power output remains the same, which it typically doesn't. Four valve heads give extra power to an engine without having to up-size the block.

power output can go down, just at a lower rate than volume.

Which means that by reducing displacement you increase the specific output... But that isn't always true.

right, but there are exceptions to everything. still doesn't make his statement about maintaining constant power output true. truth is, you can get astronomical specific outputs out of tiny engines, but the briggs and straton is still only making 5 hp.

 

[Eli]

Originally posted by: ElFenix

Originally posted by: Eli

The pushrod engine is old technology.

so is OHC and variable valve timing...

Details, details.

Let's face it, Internal Combustion Engines are old technology. Anything we can do to improve its efficiency is a good thing.

VVT is here to stay. I just can't wait until they come out with engines that have both InfininatelyVVT and IVVL. Can you say electromagnetic valvetrain?

 

[PlatinumGold]

Originally posted by: Howard

Originally posted by: PlatinumGold

Originally posted by: Howard

Originally posted by: OS

Originally posted by: PlatinumGold
if you go back and read his thread, there was a point relevant to the OP. that having a complex DOHC engine with VVT etc does not necessarily make a faster vehicle. but you are too busy getting defensive to read what other people post.

Hey dumbf*ck, the mustang doesn't even have an OHV head

On the contrary, the valves in the Mustang's engine are above the heads, therefore the valves are over the heads (OHV). Perhaps you meant OHC?

Anyways, PGold, I must be stupid or something because I can't comprehend your statement. I was only referring to his first sentence anyway. (D-X said the Celica GTS was slow, but the engine is only 1 factor of many that contribute to that "slowness")

read my post above.

I'm confused...

i was quoting demon-xanth. i just tired of OS's inability to keep things non personal, but then he started to attack me instead. oh well. that's life.

 

[OS]

Originally posted by: PlatinumGold
i was quoting demon-xanth. i just tired of OS's inability to keep things non personal, but then he started to attack me instead. oh well. that's life.

Yeah that's life with the "he started it" line.

 

[Zenmervolt]

Originally posted by: ElFenix

Originally posted by: Zenmervolt

Originally posted by: ElFenix
so does less displacement

Only if power output remains the same, which it typically doesn't. Four valve heads give extra power to an engine without having to up-size the block.

power output can go down, just at a lower rate than volume.

True, but you'll note that they only mention certain dimensions, not overall exterior volume and that they only compare weight with the Caddy's engine.

ZV

hmmm... where are those guys with the bmw engine swap...

Well, when you're picking up a hundred HP or so over the original engine, even 100 lbs of extra weight isn't going to be enough to counteract the extra power.

Yes one can get great power out of a pushrod engine, I don't mean to dispute that. But all else being equal, an OHC engine will develop more power.

ZV

 

[Demon-Xanth]

Zemmer: usually "all else being equal" doesn't mean weight or external dimensions. Often if the weight and external dimensions are the same, the pushrod has a much higher displacement.

 

[Iron Woode]

Originally posted by: OS

Originally posted by: PlatinumGold
if you go back and read his thread, there was a point relevant to the OP. that having a complex DOHC engine with VVT etc does not necessarily make a faster vehicle. but you are too busy getting defensive to read what other people post.

Hey dumbf*ck, the mustang doesn't even have an OHV head

You should really edit that statement.

It makes you look very stupid.

OHV = Over Head Valve. That means the valves are in the cylinder head instead of the block. The term flat head comes to mind.

Since about 1954 all V8s in America are OHV.

 

[PlatinumGold]

Originally posted by: OS

Originally posted by: PlatinumGold
i was quoting demon-xanth. i just tired of OS's inability to keep things non personal, but then he started to attack me instead. oh well. that's life.

Yeah that's life with the "he started it" line.

show me where i said anything personal about you?

show me anywhere in this thread where i claimed to know more than you about engines, i probably don't.

i do know when i read something i understand what it is i read. i do know that there is a certain logic involved in discussions. i do know that sometimes points are made and people attack the peripheral not knowing that it has nothing to do with the point made.

btw, does the mustang gt have an OHV or not?

 

[ElFenix]

Originally posted by: Zenmervolt Well, when you're picking up a hundred HP or so over the original engine, even 100 lbs of extra weight isn't going to be enough to counteract the extra power.

ZV

yeah, but those guys thought that the LS1 was gonna weigh about the same as the BMW motor (well, maybe not the 4 banger they ripped out of the 318, but one of the typical I6s with the massive cross flow heads).

 

[Iron Woode]

Originally posted by: Zenmervolt

Originally posted by: ElFenix

Originally posted by: Zenmervolt

Originally posted by: ElFenix
so does less displacement

Only if power output remains the same, which it typically doesn't. Four valve heads give extra power to an engine without having to up-size the block.

power output can go down, just at a lower rate than volume.

True, but you'll note that they only mention certain dimensions, not overall exterior volume and that they only compare weight with the Caddy's engine.

ZV

hmmm... where are those guys with the bmw engine swap...

Well, when you're picking up a hundred HP or so over the original engine, even 100 lbs of extra weight isn't going to be enough to counteract the extra power.

Yes one can get great power out of a pushrod engine, I don't mean to dispute that. But all else being equal, an OHC engine will develop more power.

ZV

If all else is equall then the 2 engines would make the same power.

 

[Bulk Beef]

Well, this is turning out to be a very emotional thread.

 

[PlatinumGold]

Originally posted by: Iron Woode

Originally posted by: Zenmervolt

Originally posted by: ElFenix

Originally posted by: Zenmervolt

Originally posted by: ElFenix
so does less displacement

Only if power output remains the same, which it typically doesn't. Four valve heads give extra power to an engine without having to up-size the block.

power output can go down, just at a lower rate than volume.

True, but you'll note that they only mention certain dimensions, not overall exterior volume and that they only compare weight with the Caddy's engine.

ZV

hmmm... where are those guys with the bmw engine swap...

Well, when you're picking up a hundred HP or so over the original engine, even 100 lbs of extra weight isn't going to be enough to counteract the extra power.

Yes one can get great power out of a pushrod engine, I don't mean to dispute that. But all else being equal, an OHC engine will develop more power.

ZV

If all else is equall then the 2 engines would make the same power.

really?

i'm assuming that ZV means all else being equal except the difference that OHC can make vs a Push Rod, so, it can't be completely equal. given that difference wouldn't the OHC put out more power?

 

[Iron Woode]

Originally posted by: PlatinumGold

Originally posted by: Iron Woode

Originally posted by: Zenmervolt

Originally posted by: ElFenix

Originally posted by: Zenmervolt

Originally posted by: ElFenix
so does less displacement

Only if power output remains the same, which it typically doesn't. Four valve heads give extra power to an engine without having to up-size the block.

power output can go down, just at a lower rate than volume.

True, but you'll note that they only mention certain dimensions, not overall exterior volume and that they only compare weight with the Caddy's engine.

ZV

hmmm... where are those guys with the bmw engine swap...

Well, when you're picking up a hundred HP or so over the original engine, even 100 lbs of extra weight isn't going to be enough to counteract the extra power.

Yes one can get great power out of a pushrod engine, I don't mean to dispute that. But all else being equal, an OHC engine will develop more power.

ZV

If all else is equall then the 2 engines would make the same power.

really?

i'm assuming that ZV means all else being equal except the difference that OHC can make vs a Push Rod, so, it can't be completely equal. given that difference wouldn't the OHC put out more power?

For reason of brevity, I won't go into details as to why a conversion to OHC will not increase power. Suffice it to say there are serious differences in cam design from in block to OHC. If the OHC cam gives identical lift and duration specs to the in block cam, there is no reason why the OHC conversion will make more power. But this is not the case and the cam(s) will deliver more power.

Cliff notes: in block cam and OHC cams have very different lift and duration specs. Also the heads would have to be modified as well. Will this mean more air-flow? Better air-flow? These are the factors affecting this type of mod.

 

[Howard]

Originally posted by: Iron Woode

Originally posted by: OS

Originally posted by: PlatinumGold
if you go back and read his thread, there was a point relevant to the OP. that having a complex DOHC engine with VVT etc does not necessarily make a faster vehicle. but you are too busy getting defensive to read what other people post.

Hey dumbf*ck, the mustang doesn't even have an OHV head

You should really edit that statement.

It makes you look very stupid.

OHV = Over Head Valve. That means the valves are in the cylinder head instead of the block. The term flat head comes to mind.

Since about 1954 all V8s in America are OHV.

Toooooo slow!

 

[Howard]

Cliff notes: in block cam and OHC cams have very different lift and duration specs. Also the heads would have to be modified as well. Will this mean more air-flow? Better air-flow? These are the factors affecting this type of mod.

How are the lift and duration different?

 

[Eli]

Originally posted by: Iron Woode

Originally posted by: PlatinumGold

Originally posted by: Iron Woode

Originally posted by: Zenmervolt

Originally posted by: ElFenix

Originally posted by: Zenmervolt

Originally posted by: ElFenix
so does less displacement

Only if power output remains the same, which it typically doesn't. Four valve heads give extra power to an engine without having to up-size the block.

power output can go down, just at a lower rate than volume.

True, but you'll note that they only mention certain dimensions, not overall exterior volume and that they only compare weight with the Caddy's engine.

ZV

hmmm... where are those guys with the bmw engine swap...

Well, when you're picking up a hundred HP or so over the original engine, even 100 lbs of extra weight isn't going to be enough to counteract the extra power.

Yes one can get great power out of a pushrod engine, I don't mean to dispute that. But all else being equal, an OHC engine will develop more power.

ZV

If all else is equall then the 2 engines would make the same power.

really?

i'm assuming that ZV means all else being equal except the difference that OHC can make vs a Push Rod, so, it can't be completely equal. given that difference wouldn't the OHC put out more power?

For reason of brevity, I won't go into details as to why a conversion to OHC will not increase power. Suffice it to say there are serious differences in cam design from in block to OHC. If the OHC cam gives identical lift and duration specs to the in block cam, there is no reason why the OHC conversion will make more power. But this is not the case and the cam(s) will deliver more power.

Cliff notes: in block cam and OHC cams have very different lift and duration specs. Also the heads would have to be modified as well. Will this mean more air-flow? Better air-flow? These are the factors affecting this type of mod.

Why would where the cam is affect the cam's profile?

That's up to the engine's designer, not where the cam/valves are. I don't think you can say that statement applies to all engines.

 

[Zenmervolt]

Originally posted by: Iron Woode

Originally posted by: PlatinumGold

Originally posted by: Iron Woode

Originally posted by: Zenmervolt

Originally posted by: ElFenix

Originally posted by: Zenmervolt

Originally posted by: ElFenix
so does less displacement

Only if power output remains the same, which it typically doesn't. Four valve heads give extra power to an engine without having to up-size the block.

power output can go down, just at a lower rate than volume.

True, but you'll note that they only mention certain dimensions, not overall exterior volume and that they only compare weight with the Caddy's engine.

ZV

hmmm... where are those guys with the bmw engine swap...

Well, when you're picking up a hundred HP or so over the original engine, even 100 lbs of extra weight isn't going to be enough to counteract the extra power.

Yes one can get great power out of a pushrod engine, I don't mean to dispute that. But all else being equal, an OHC engine will develop more power.

ZV

If all else is equall then the 2 engines would make the same power.

really?

i'm assuming that ZV means all else being equal except the difference that OHC can make vs a Push Rod, so, it can't be completely equal. given that difference wouldn't the OHC put out more power?

For reason of brevity, I won't go into details as to why a conversion to OHC will not increase power. Suffice it to say there are serious differences in cam design from in block to OHC. If the OHC cam gives identical lift and duration specs to the in block cam, there is no reason why the OHC conversion will make more power. But this is not the case and the cam(s) will deliver more power.

Cliff notes: in block cam and OHC cams have very different lift and duration specs. Also the heads would have to be modified as well. Will this mean more air-flow? Better air-flow? These are the factors affecting this type of mod.

My bad. The assumption I was making was that the OHC engine would have >2 vlaves per cylinder whereas the pushrod engine would have =2 vlaves per cylinder. You're right, of course, that if both have the same 2 vlave heads they will make the same power.

ZV

 

[Iron Woode]

Originally posted by: Howard

Cliff notes: in block cam and OHC cams have very different lift and duration specs. Also the heads would have to be modified as well. Will this mean more air-flow? Better air-flow? These are the factors affecting this type of mod.

How are the lift and duration different?

The company that grinds the cams chooses lift and duration based on various things.

Since the OHC actuates the vavles directly instead of through pushrods, the cam's timing needs to altered.

There are no rocker arms either. Less wasted motion.

On a side note: I was debating whether to change out the cam in my 318. Currently I have a 454 (gross) lift 272 duration (gross) single pattern cam. I was considering the new Extreme series from Comp Cams.

 

Pertaining to the original question at hand, would you guys like the six page extremely technical answer, the three page general summary or the six sentence overview for the mechanical illiterate ?

After viewing the votes, I will post the answer on monday.

Goodnight all.

 

[Ornery]

I don't know which is worse. Numb-nuts too lazy to crop quotes, or this damn FuseTalk 'upgrade'.

 

[Iron Woode]

Originally posted by: Roger
Pertaining to the original question at hand, would you guys like the six page extremely technical answer, the three page general summary or the six sentence overview for the mechanical illiterate ?

After viewing the votes, I will post the answer on monday.

Goodnight all.

You mean that it just doesn't matter? That is the only answer. Drive whatever you wish and be happy.

 

[vi edit]

You shouldn't make that kind of comparison.

Why not? The nissan DOHC 3L VQ from Nissan (V6), the 3.4L DOHC from GM found in the Monte Carlo Z34's, and some Oldsmobile and Pontiac midsize sedans, as well as the 2.8L DOHC engine found in my midsize VW Passat all offer superior passing power over SOHC equivalent egines. They simply have larger lungs than the alternative.

The SOHC 3.0L found in the Taurus and the SOHC 3.4L that's in the Malibu's & Impalas are gutless when it comes to passing. They work great getting around town, but when it comes to passing somebody on a two lane highway at 55-60MPH they fall flat on their face.

Even driving an Oldsmobile Intrigue with the 3.8L SOHC and the replacement 3.5L DOHC proved different on the highway. The 3.8L is fine up to about 45-50 MPH, but past that and it loses it's wings.

I'm not getting into technical merits of either design. I'm simply saying that similar cars with similar sized engines (displacement wise) have different driving dynamics.

 

[Iron Woode]

Originally posted by: vi_edit

You shouldn't make that kind of comparison.

Why not? The nissan DOHC 3L VQ from Nissan (V6), the 3.4L DOHC from GM found in the Monte Carlo Z34's, and some Oldsmobile and Pontiac midsize sedans, as well as the 2.8L DOHC engine found in my midsize VW Passat all offer superior passing power over SOHC equivalent egines. They simply have larger lungs than the alternative.

The SOHC 3.0L found in the Taurus and the SOHC 3.4L that's in the Malibu's & Impalas are gutless when it comes to passing. They work great getting around town, but when it comes to passing somebody on a two lane highway at 55-60MPH they fall flat on their face.

Even driving an Oldsmobile Intrigue with the 3.8L SOHC and the replacement 3.5L DOHC proved different on the highway. The 3.8L is fine up to about 45-50 MPH, but past that and it loses it's wings.

I'm not getting into technical merits of either design. I'm simply saying that similar cars with similar sized engines (displacement wise) have different driving dynamics.

I understand what you are saying but trying to compare completely different engine designs and then making a blanket statement is a bad idea.

Larger lungs? Like I said engine design is what the differences are. SOHC or DOHC differences should be compared on identical engines not completely different ones.

The intended applications of these angines also comes into play. It would be like me comparing the 305 in my old Caprice to the 340 in my friend's Dart. Which do you think will have better passing power at 55 mph?

 

[PlatinumGold]

Originally posted by: vi_edit

You shouldn't make that kind of comparison.

Why not? The nissan DOHC 3L VQ from Nissan (V6), the 3.4L DOHC from GM found in the Monte Carlo Z34's, and some Oldsmobile and Pontiac midsize sedans, as well as the 2.8L DOHC engine found in my midsize VW Passat all offer superior passing power over SOHC equivalent egines. They simply have larger lungs than the alternative.

The SOHC 3.0L found in the Taurus and the SOHC 3.4L that's in the Malibu's & Impalas are gutless when it comes to passing. They work great getting around town, but when it comes to passing somebody on a two lane highway at 55-60MPH they fall flat on their face.

Even driving an Oldsmobile Intrigue with the 3.8L SOHC and the replacement 3.5L DOHC proved different on the highway. The 3.8L is fine up to about 45-50 MPH, but past that and it loses it's wings.

I'm not getting into technical merits of either design. I'm simply saying that similar cars with similar sized engines (displacement wise) have different driving dynamics.

hey wait a minute. that's my Olds Intrigue you are talking about there bud.