1953 SPEED MECHANICS MAGAZINE - Summary Performance Improvements Measured on a 1953 Plymouth 4 Door

[Semmerling]

This is just the summary of used speed parts and their results. 

 

[Loren]

An analytical look at this table shows you exactly what Barney Navarro said in his advertisement of the same era.

Compression is what makes horse power.

Some things make zero horse power but are worth having for reliability such as Dual point ignition.

Grouping the Sharp head and the Mallory coil, condenser and Dyna-Flyte dual point breaker plate together is a perfect example of compression carrying the weight. ( omitting the ignition stuff would have not reduced the power output )

The intake manifold and dual carburetors added to the Sharp head added very little in example B until you got higher up in the rpm range. A good example of the horse power vs torque debate. In a long stroke flathead six low end grunt is a whole lot more useful than high rpm horse power. You can use that more of the time than bearing hammering rpm. 

Navarro of course doesn't mention manifolds because he sold them too and I am certain he liked to sell you heads and a manifold as a package.

Example C shows how exhaust can free up the breathing of an engine. Again compression is the magic that makes it work and that is why the Sharp cylinder head was the first thing they did.

 

You will note there are no mention of camshafts.

Navarro penned a two part article titled "The truth about Camshafts" along about the same time. In it the editor says that Barney had Ed Winfield look the article over before publication. Winfield and Navarro were friends of course having shops nearby. ( Navarro at the end of Lake St, Winfield on Lake St. in Glendale. You could stand at Winfield's door look south and see Navarro's shop on the cross street ) It is a pretty deep dive into the subject but it basically says other than the sound effects there's not much use for a "hot cam" in a street car. "Sound effects" seem to be real important to the car culture now days. Kong Jackson was a friend of my Dad and I ( the inventor of the Jackson gear drive for camshafts ) his son ran brother Pete Jackson's shop and produced the gear drives in two flavors, silent and noisy. Oddly the noisy ones sold very well! They sound like a blower and the guys buying them liked that.

 

So in conclusion what should we take away from this?

If you want more power the most cost effective way is to bump up the compression, either by a new head or milling your old one. Every other mod is incremental to compression or only additive to reliability.

[Sniper]

Couple of points to mention. 

 

Dual exhaust might have improved exhaling, but what would have been the difference if the intake breathing hadn't already been improved?

 

Camshaft theory, understanding and design have come a very long way since those days.  Not saying anyone is applying that to cams for our engines, but the blanket statement "not much use for a "hot cam" in a street car" is as outdated as the cam tech of that era is.

 

Finally, the article is valid if you are using the stuff they tested.  Otherwise, not so much.  Of the commonly available new dual 1bbl intakes today, the Offy is probably the worst of the bunch.  Dual exhaust is nice, but a well setup single can flow as well or better than the one tested.  I'd pass on points, dual or single, convert to electronic ignition.  

 

 

[Dave72dt]

That was a cumulative test.  I'd like to have seen tests where the parts were added individually to the stock engine or cumulative where the high comp head was added last for comparison..

[Loren]

If one were building a very well prepared engine, one could easily run an experiment.

Put everything you want into it, electronic ignition ( zero horse power ) dual carbs or fuel injection, the cam du jour and any exhaust that meets one's fancy, everything except more compression.

Then see how it performs.

Certainly there should be some improvement.

If I were to guess a well designed exhaust would help the most closely followed by dual carburetors.

Nothing will work by itself as well as more compression.

So once there is a reading on horse power, then change the cylinder head.

I think the results will speak for themselves.

There is one and only one proviso, side valve engines have a limitation to efforts to raise compression.

If you make the combustion chamber too small, it restricts the valves and the engine can't breathe.

This is why overhead valve engines took over after the war.

It is also why Barney Navarro sold Detroit Diesel 71 series supercharger kits for flathead Fords.

 

So how does compression work?

Imagine gun powder, spill it out on the floor and light it with a match and it burns very hot and slowly.

Put it in tightly wound paper and it burns just as hot but very quickly, so much so it goes BANG.

Compressing the fuel air mixture does exactly the same thing. More compression means more effective and complete burning.

One of the side effects is better fuel mileage too.

 

On camshafts, there has been some tinkering on individual engines over the decades since side valve engines ruled.

However, you'd really be surprised at how little has changed since Ed Winfield taught Isky, Crower and others how to grind cams.

 

[47 dodge 1.5 ton]

Nice information to read. I’d really like to know if the 265 truck motor was changed (cam, compression,head) over the 119hp motor when the dual carb/exhaust was an option for the 136hp. Also question if the torque showed improvement at the low rpm range? From this example, possibly not? 

[Dave72dt]

There is no torque info in the posted chart or RPM.  It was good for selling parts though.

[andyd]

The specs I have seen for the last of the 230 engines in the late 1950's(1957 onwards) show that with 8.00 : 1 compression it generated 132hp,and thats with a Carter BBS single barrel carby........I would think that with a finned head of say, 8.5-9.0: 1, twin carbys, twin outlet exhaust or headers & flow thru exhaust, uprated ignition, maybe cleaned up ports, some sort of cam grind and a decent balance of the reciprocating parts, ie, pistons, rods, crank & flywheel a hp figure of 170-180 should be possible........but thats just a guessimate..........lol...........andyd    

[RNR1957NYer]

All this technical information is very interesting and useful, but is silent on the overriding reason for installing multiple carburetion:  it  just plain looks cool!

Can’t see the squeeze…. 

[Loren]

In keeping with this thread I uploaded to the Download section of this site Barney Navarro's October 1952 Hop Up magazine article "The truth about cams" parts 1 and 2.

It includes some great period advertisements that some of us might remember from our Dad's car magazines ( as none of us are that old, right? )

[Semmerling]

There is not much head snap in any of this, but there may very well be some strong pull up a hill that would simply not be there prior to some or all of the mods mentioned. I would agree with the idea that compression leads the parade. As I had mentioned elsewhere, IMO the next in line would be fixing the known design or production limiters that impact the stock engine. One would want to follow the flow. There we would find the exhaust manifold of the earlier 6's, mine certainly is there. Whether one exhaust pipe or two is, as Sniper points out, dependent on diameter of those pipes, muffler, etc. etc. Both the original fuel pump and the single carbs on many are all one would need at one atmosphere. The case for two or three might come into play for efficiency or response.

 

As has been proven in countless multicarb Static Racing event, there is little doubt that attributable horsepower gains appear to be proportional to three important things. First, if the hood is up. Second the number of people looking at the engine under that hood and lastly the alcohol content or anyone speaking. But, when we add additional atmospheres, carburation is imperative. Probably the best case Fi or a new crank and ignition starts about there too. And then Octane says hello. And only then, when all that is accomplished is one really in a position to answer the Big Question, namely "Is Using a Stand Alone Intake without Exhaust Heat responsible for the Ice Typhoon Winter Storms we now see?"  I know a couple of people who if given enough time can make a pretty compelling argument that the answer is YES! How do I know about all this and speak with such authority? I read it in a magazine or maybe it was here...honestly I really don't remember. Aside from that.....whatever Loren says is OK by me. 

 

Edited January 16, 2023 by Semmerling

[Los_Control]

Pretty sure it was a wise man who once said, speed kills ... drive a flathead & live forever.

[Sniper]

I was watching an episode of Engine Masters, season 3 episode 1, the other day and they were testing E85 vs gasoline.  When looking at the latent heat of vaporization, the intake air temperature got down to 47F using E85 with an ambient temp of 87F.  Gasoline was at 51F with ambient at 90F.

 

The carb icing issue appears to be related to cold and humid days.  Ask any pilot about carb icing if you don;t think it's a thing.

[Sniper]

1 hour ago, Loren said:

In keeping with this thread I uploaded to the Download section of this site Barney Navarro's October 1952 Hop Up magazine article "The truth about cams" parts 1 and 2.

It includes some great period advertisements that some of us might remember from our Dad's car magazines ( as none of us are that old, right? )

 

Link to download

 

 

[Booger]

 Pop Mechanics May 1953. 

Edited January 16, 2023 by Booger
File too large!

[Booger]

18 minutes ago, Booger said:

 Pop Mechanics May 1953. 

whose got a 53 Plymmie? yours if you want it. Good condition. Nice fly fishing cover

[Semmerling]

On 1/16/2023 at 4:59 PM, Sniper said:

I was watching an episode of Engine Masters, season 3 episode 1, the other day and they were testing E85 vs gasoline.  When looking at the latent heat of vaporization, the intake air temperature got down to 47F using E85 with an ambient temp of 87F.  Gasoline was at 51F with ambient at 90F.

 

The carb icing issue appears to be related to cold and humid days.  Ask any pilot about carb icing if you don;t think it's a thing.

 

Very helpful, I was wondering if it had to  do with being really high. Duly noted, thanks for clearing the air. 

 

 

[Sam Buchanan]

Yep, carb ice is a real thing but having the intake manifold attached to the exhaust manifold probably minimizes the problem for our flatties. But would it be more probable with aftermarket intake and exhaust manifolds? Ice is much more likely at low throttle setting than wide open due to the venturi effect and accumulation on the throttle plate. The chart below shows how ice can occur even on warm days if the humidity is high enough. I've had ice form on a small Continental on a warm day while taxiing to the runway but it has a carb that is slung below the crankcase and doesn't get much warming from the engine.

 

Edited February 10, 2023 by Sam Buchanan