Actual Horsepower Of '60s/'70s Muscle Cars

[Fleet 500]

Hightower, don't automatically assume that the tolerance for the internal engine parts of the Honda are the same (or closer) than the Cadillac's.

Also, you didn't mention the compression ratio of that Honda engine, but if it was high-compression, it would most likely also knock on today's fuel.

[454MAG]

Horsepower dropped in 1972 so did compression on all muscle cars sad but true!

[Matra et Alpine]

Hightower, don't automatically assume that the tolerance for the internal engine parts of the Honda are the same (or closer) than the Cadillac's.

Well being realistic, Fleet getting 45hp from <500cc and 80ish from the 690cc engine isn't possible without MUCH Closer tolerances
Different materials and smaller block size DOES mean that Honda probably woulnd't have had to put in as much effort as Cadillac in maintaining temperature in a large block, but that's just "smarter" engineering
Not taking a sledge hammer to the nut !!

Also, you didn't mention the compression ratio of that Honda engine, but if it was high-compression, it would most likely also knock on today's fuel.

Possibly, but it also was very high gas flow rates and small chamber size so actually LESS likely
What I could't say though is how efficient it would have been at cooling and so pre-ignition from hot-spots is possible.
But what has knocking to do with tolerance ?

[Fleet 500]

Well being realistic, Fleet getting 45hp from <500cc and 80ish from the 690cc engine isn't possible without MUCH Closer tolerances
Different materials and smaller block size DOES mean that Honda probably woulnd't have had to put in as much effort as Cadillac in maintaining temperature in a large block, but that's just "smarter" engineering
Not taking a sledge hammer to the nut !!

Yes, but it would depend on what the actual tolerance figures are.

Possibly, but it also was very high gas flow rates and small chamber size so actually LESS likely
What I could't say though is how efficient it would have been at cooling and so pre-ignition from hot-spots is possible.
But what has knocking to do with tolerance ?

I was pointing out the fact that just because a high-compression engine knocks on regular fuel does not mean it has "poor" combustion chambers as Mr. Hightower claims.

I do remember something my dad did years ago with his '69 Cadillac (10.5:1 compression). He once said that he made adjustments on the carburetor so it could run on regular fuel. He never really said what exactly he did and I don't even know if it really worked (I was only about 15 years old at the time). Who know? Maybe he just set the timing way back!

[hightower99]

I was pointing out the fact that just because a high-compression engine knocks on regular fuel does not mean it has "poor" combustion chambers as Mr. Hightower claims.

No you were not. You where trying to claim that several 60's american V8s knock only because "they where designed for 1960's fuel" which unless you mean leaded fuel means nothing...

I am saying that part of the reason why they have such a hard time with today's pump gas (including 91 octane premium) is because of outdated combustion chamber design.

[henk4]

I am saying that part of the reason why they have such a hard time with today's pump gas (including 91 octane premium) is because of outdated combustion chamber design.

in the mid seventies a Dodge Charger and a Camaro participated in the 24 Hours Le Mans race. (or at least tried to..). They could not deal with the prescribed lower octane fuel and both suffered engine damage. There was nothing wrong with the combustion design chamber, the cars were simply tuned to higher octane fuel. A replica of the Charger now runs in the Classic Endurance Races and has more handling than engine problems

[hightower99]

in the mid seventies a Dodge Charger and a Camaro participated in the 24 Hours Le Mans race. (or at least tried to..). They could not deal with the prescribed lower octane fuel and both suffered engine damage. There was nothing wrong with the combustion design chamber, the cars were simply tuned to higher octane fuel. A replica of the Charger now runs in the Classic Endurance Races and has more handling than engine problems

Explain to me then how you "design" an engine including combustion chamber design, for a high octane? Nothing in the designs back then are more extreme (i.e require a higher octane to stop knock) than many modern cars that run on today's pump gas.

They had low knock limits and part of the reason/fault is combustion chamber design.

[henk4]

They had low knock limits and part of the reason/fault is combustion chamber design.

they had a high compression ratio......which you can achieve with any design.

[Fleet 500]

No you were not. You where trying to claim that several 60's american V8s knock only because "they where designed for 1960's fuel" which unless you mean leaded fuel means nothing...

It means what it says; nothing more, nothing less.

I am saying that part of the reason why they have such a hard time with today's pump gas (including 91 octane premium) is because of outdated combustion chamber design.

Outdated combustion chambers and poor combustion chambers are two different things.

Also, '60s engines with lower compression ratios, like 9.0:1 or 8.5:1 ran fine on regular. Where their combustion chambers better than those on the high-compression engines? I don't think so.

[hightower99]

they had a high compression ratio......which you can achieve with any design.

But there are several modern engines with just as high compression ratios and some with even higher that run just fine on premium pump gas.

Why is it that a 1960's american V8 with a static CR of 11:1-12:1 can't handle today's 91 octane premium pump gas when today's engines can?

It means what it says; nothing more, nothing less.

Well I bet you don't know what you are talking about. Explain how you design an engine to run on 1960's fuel? and how that is any different from how you design engines to run on today's fuel.

Outdated combustion chambers and poor combustion chambers are two different things.

The design was outdated back in the day therefore they were poor for the time. I am not saying they where the worst combustion chamber designs of the day just that an overly simple design philosiphy was used.

Also, '60s engines with lower compression ratios, like 9.0:1 or 8.5:1 ran fine on regular. Where their combustion chambers better than those on the high-compression engines? I don't think so.

I doubt a 1960's american V8 with a static CR of 9:1 will run very well on today's regular pump gas. 8.5:1 sure probably but what is your point? They have a much lower CR meaning they can run on lower octane even with poor combustion chamber design.

I still want to know how the engine was designed to run on 1960's fuel and how that disproves that 1960's american V8s didn't and don't have good combustion chamber design...

[henk4]

But there are several modern engines with just as high compression ratios and some with even higher that run just fine on premium pump gas.

Why is it that a 1960's american V8 with a static CR of 11:1-12:1 can't handle today's 91 octane premium pump gas when today's engines can?

Today's HC engines run on 98 ROZ...which is possibly not the same as the American indication...

[Fleet 500]

Well I bet you don't know what you are talking about. Explain how you design an engine to run on 1960's fuel? and how that is any different from how you design engines to run on today's fuel.

I didn't say an engine should be designed to run on 1960s fuel; I'm saying (for about the third time now) that many 1960s engines can't run on today's fuel without pinging due to their high-compression. They do run okay on fuel with a high enough octane rating.

The design was outdated back in the day therefore they were poor for the time. I am not saying they where the worst combustion chamber designs of the day just that an overly simple design philosiphy was used.

They were "outdated back in the day therefore they were poor?" You mean there were absolutely NO good engine/combustion chamber designs in the 1960s or earlier?

I doubt a 1960's american V8 with a static CR of 9:1 will run very well on today's regular pump gas. 8.5:1 sure probably but what is your point? They have a much lower CR meaning they can run on lower octane even with poor combustion chamber design.

My '66 Dart GT V-8 (8.8:1) and my brother's '66 Plymouth Fury III (9.0:1) ran on modern fuel without knocking or pinging. And will you stop saying all '60s cars had poor combustion chamber designs!!! Don't blame the engines if they can't run properly on today's poor excuse for gasoline!

I still want to know how the engine was designed to run on 1960's fuel and how that disproves that 1960's american V8s didn't and don't have good combustion chamber design...

You want to know "how the engine was designed to run on 1960s fuel..." What does that mean?
The Mopar 426-Hemi has been the most successful drag racing engine ever. I believe the fastest 1/4 mile time is with a dragster with a Hemi engine, which is under the 5-second bracket. Why aren't modern engines, with their "superior combustion chambers" faster than the Hemi?

[Fleet 500]

But there are several modern engines with just as high compression ratios and some with even higher that run just fine on premium pump gas.

I thought this was answered already? It's because modern engines can automatically adjust for different octane fuel. On my Lincoln, it's called "Electronic Engine Control."

Why is it that a 1960's american V8 with a static CR of 11:1-12:1 can't handle today's 91 octane premium pump gas when today's engines can?

I think this was answered already, too. Because '60s American engines with a CR of 11.1-12.1 were meant to run on 98 to 100 octane. That's why some owners mix 91 fuel with 111 octane fuel found at some gas stations near the airports.

[hightower99]

Today's HC engines run on 98 ROZ...which is possibly not the same as the American indication...

98ROZ is roughly 93-95 american octane basically high premium pump gas.

Regular gas is 89 in america roughly 91 octane in UK/Europe
Premium is 91-92 in america roughly 95 octane in UK/Europe
High Premium is 95 in america roughly 98 octane in UK/Europe

There are many modern high CR engines that run on 95 octane (UK/Europe values) which is 91-92 in america.

I didn't say an engine should be designed to run on 1960s fuel; I'm saying (for about the third time now) that many 1960s engines can't run on today's fuel without pinging due to their high-compression. They do run okay on fuel with a high enough octane rating.

I don't know how to make myself any more clear... The CR that 1960's america V8s run does not warrant more than 92-95 octane (american values) Yet they have to be fed with fuel that is over 98 octane (american values) to run without knocking. My point is that they need too high octane values before they run well. This is in part due to bad combustion chamber design.

They were "outdated back in the day therefore they were poor?" You mean there were absolutely NO good engine/combustion chamber designs in the 1960s or earlier?

WTF!?! where did you get that from? I have been talking about 1960's "Performance" american V8s... There are many engines from the 60's from other parts of the world and even a few in america that had excellent combustion chamber design.

My '66 Dart GT V-8 (8.8:1) and my brother's '66 Plymouth Fury III (9.0:1) ran on modern fuel without knocking or pinging. And will you stop saying all '60s cars had poor combustion chamber designs!!! Don't blame the engines if they can't run properly on today's poor excuse for gasoline!

Your Dart should run on regular (ie 89 octane american) and so should your brother's Plymouth. However since you used past tense I figure they didn't run that well for long anyways Stop blaming the gas for the engines' faults!

You want to know "how the engine was designed to run on 1960s fuel..." What does that mean?

You tell me you are the one who keeps repeating that! You keep saying that it has to do with the gas and how the engines where designed to run on 1960's fuel.

The Mopar 426-Hemi has been the most successful drag racing engine ever. I believe the fastest 1/4 mile time is with a dragster with a Hemi engine, which is under the 5-second bracket. Why aren't modern engines, with their "superior combustion chambers" faster than the Hemi?

Nope fastest time is in the 4 second bracket and is done with a chevy 500Ci engine. Now what exactly was your point? Ask yourself what is most important for a drag engine? Big displacement (set by rules at 500Ci) Strong block, and most importantly simple and easy to take apart and overhaul as this needs to be done every time you run the engine. The Combustion chamber only has to allow the most air/fuel in and exhaust out as fast as possible. Knocking is taken care of by running ultra rich mixtures and using Nitro blends.

[Fleet 500]

98ROZ is roughly 93-95 american octane basically high premium pump gas.

Back in 1971, 91 octane was classified as "regular." How do I know? Because the owner's manual for one of the Cadillacs I owned (a '71 Fleetwood with an 8.5:1 CR) said "regular fuel of at least 91 octane may be used."

There are many modern high CR engines that run on 95 octane (UK/Europe values) which is 91-92 in america.

Again, that is because modern high CR engines can automatically adjust for different octane. '60s high CR engines can run 91-92 octane, but with adjustments like setting the timing back, carb adjustments and colder spark plugs, but they really should be running higher octane.

I don't know how to make myself any more clear... The CR that 1960's america V8s run does not warrant more than 92-95 octane (american values) Yet they have to be fed with fuel that is over 98 octane (american values) to run without knocking. My point is that they need too high octane values before they run well. This is in part due to bad combustion chamber design.

That is not so. I have dozens upon dozens of '60s car mags and they said that high CR engines needed about 98 and higher octane. It is not "bad combustion design" because the octane you claim they ran on is not right. Too low!
One test of a '64 Cadillac (429-cu-in engine, 10.5:1 CR), by Autocar, said that the fuel used was "Super premium grade 100-102 octane RM."

The following is from an article from "Hot Cars" May, 1970:
Engines with a compression ratio of 9.0:1 use regular fuel having an octane rating of about 95. Premium fuel (100 octane) must be used with compression ratios of around 10.0:1. Most street/strip engines are limited to a compression ratio of about 12.5:1 because they require approximate 105 octane gas, which is about the higest superpremium available from the pump."

WTF!?! where did you get that from? I have been talking about 1960's "Performance" american V8s... There are many engines from the 60's from other parts of the world and even a few in america that had excellent combustion chamber design.

Yes, you were claiming that all '60s performance American V-8s had "poor" combustion chambers because they knock on regular fuel, but many '60s non-performance American V-8s (but with high CR) also would knock on regular fuel.
As you said, there were many engines from the '60s (and, btw, what do you mean "even a few" in American had excellent combustion chamber design? It was a lot more than "a few!") that had excellent combustion chamber design.

Your Dart should run on regular (ie 89 octane american) and so should your brother's Plymouth. However since you used past tense I figure they didn't run that well for long anyways Stop blaming the gas for the engines' faults!

Yes, because they were not high-compression, they did run okay on regular fuel. However, if my Dart had the high-compression (10.5:1) version of the 273 V-8, it would have knocked on regular.
I owned my Dart a long time, from 1979 to 2002; my brother owned his Fury from 1976 to 1998... I would say we got our money's worth out of them!!! They did run long... my Dart had about 235,000 miles and the Fury was at 250,000+. The engines in both were well-built, reliable and had good longevity. And I drove my Dart hard many times... burnouts, 2nd to 3rd shifts at 75 mph, etc.

You tell me you are the one who keeps repeating that! You keep saying that it has to do with the gas and how the engines where designed to run on 1960's fuel.

Well, isn't it? If you put 87 or even 91 octane fuel in an engine designed for 98 or 100 octane fuel, and it knocks, why blame the engine? I knew when I bought my '69 Cadillac (10.5:1 CR) that I would have to use "premium" fuel (91 octane out here) with octane boost and bigger jets in the carb.

Nope fastest time is in the 4 second bracket and is done with a chevy 500Ci engine. Now what exactly was your point? Ask yourself what is most important for a drag engine? Big displacement (set by rules at 500Ci) Strong block, and most importantly simple and easy to take apart and overhaul as this needs to be done every time you run the engine. The Combustion chamber only has to allow the most air/fuel in and exhaust out as fast as possible. Knocking is taken care of by running ultra rich mixtures and using Nitro blends.

I haven't kept up with what is currently the fastest, but I do know that the 4-second bracket was broken by a dragster with a Mopar Hemi engine. It was 4.990 seconds at Houston, Texas, in 1988. One of my muscle car mags covered it.
The NHRA does say that the engine choice for most teams is an aluminum version of the famed 426-Hemi.