Claim of 25% HP bump true?

[47topless]

Just purchased a nice '31 Victoria. My first "running" Model A. Long in FH Ford V8's.
Going through a local Dealer's parts catalogue, I noticed a claim of gaining 25% HP with their milled, high compression head. While I do not question the integrity of this company, or this offering, it seems too damned easy!
Can the increased compression, achieved in such a simple way, really bump the HP to that incredible degree?
Phil

[Y-Blockhead]

Well, when you are starting with the mighty 40hp... 10% is only a 4hp increase.

[Marshall V. Daut]

Consider that the 1932 Model B four-cylinder engine was basically a beefed-up Model A engine. The main differences - aside from a large journal crankshaft that was later counterbalanced - the Model B engine featured a slightly more aggressive camshaft, a larger CFM carburetor with a wider intake manifold and a 4.6:1 cylinder head. That 4.6:1 ratio is only slightly more aggressive than the Model A's 4.2. This engine was rated at 50 horsepower, meaning 10 more than the Model A. That equates to a 25% increase in horsepower. Sound familiar?
The "high compression" cylinder heads being produced today for Model A's and B's are at least 5.0:1. A couple are 6.0 and some even 7.0+. It's not just the compression ratio that makes the extra horsepower. It is also the design of the head's combustion chambers that creates the right turbulence and spark travel that help improve performance. These heads will definitely increase horsepower AND torque. I should think that the 5.0 head might not supply the extra 25% increase (10 HP), but the 6.0 and above heads will give a closer approximation. If the advertised head is one of the heads I described with at least 6.0:1 CR, the horsepower improvement claim is in the ballpark with a little fudge factor allowed.
Marshall

[Ernie Vitucci]

Good Evening...Ad a Model B intake and Carburetor and the 5.0 head or higher and you will be right on the edge of 50 HP. Ernie in Arizona

[Bob Bidonde]

I run 5.5:1 and 6:1 compression cylinder heads on my Model A's. The stock looking 6:1 cast iron cylinder head currently available is the way to go. I notice more power & torque and much better gas mileage.

[mach0415]

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I noticed a significant torque increase with my 6.5:1 Snyder’s cylinder head. I also went with a Vortex dual updraft intake. I’m satisfied with my ‘28’s performance. Everyone commenting in the increase is correct. Even 10hp more is very noticeable.

[Jim Brierley]

The quickest, easiest and cheapest way to more HP on the Model A is to increase compression and add a larger carb. The results will amaze you!

[Synchro909]

Originally Posted by jim brierley

the quickest, easiest and cheapest way to more hp on the model a is to increase compression and add a larger carb. The results will amaze you!

x2!

[47topless]

Originally Posted by Jim Brierley

The quickest, easiest and cheapest way to more HP on the Model A is to increase compression and add a larger carb. The results will amaze you!

...and that settles that! Check please."

[Rob Doe]

Jim Brierley, post #7,

Would a Model B carb and a machined out intake be a good choice?

[brito36]

With all the conversations on increased compression, larger carburetors, and intake manifolds, I would make sure that my lower end could handle all these improvements.

[47topless]

Originally Posted by brito36

With all the conversations on increased compression, larger carburetors, and intake manifolds, I would make sure that my lower end could handle all these improvements.

Good suggestion. I'll start the Imodium right now.
But seriously, how would a person go about testing the integrity of the lower end engine components?
Thank you,
Phil

[Dodge]

Rob Doe,

Yes, its done all the time. If your going to run a B carb you need either a B manifold
or a bored out Model A manifold. The B manifold sets the carb at a different angle but can be corrected with ovaling the holes in the manifold out or using smaller bolts.

[Synchro909]

Originally Posted by Dodge

Rob Doe,

Yes, its done all the time. If your going to run a B carb you need either a B manifold
or a bored out Model A manifold. The B manifold sets the carb at a different angle but can be corrected with ovaling the holes in the manifold out or using smaller bolts.

Live and learn. I didn't know that. It might explain why my B carburettor cuts out when braking to a stop. The problem with a RHD car is the lug on the intake manifold for the ignition advance mechanism which is present on an A manifold but missing on a B because they supposedly had automatic advance in the distributor.
I am guessing here but does the change lower the intake or raise it. Details would be very welcome.

[Dodge]

The difference is the carburetor sitting at a different angle side to side not front to back or up and down.
Your carb cutting out might be fuel shoshing, might be float level.

[1928 Sport Coupe]

Originally Posted by brito36

With all the conversations on increased compression, larger carburetors, and intake manifolds, I would make sure that my lower end could handle all these improvements.

I would like to install a High Compression head in either 5.5:1 or 6:1 such as Snyders, a "B" cam, a "B" carb, and a bored out "A" intake. If I were to use new poured Babbitt mains and rods would that be sufficient for the improvements I want to do? Which head would be the better choice, the 5.5:1 or 6:1? I have been told any HC head could destroy the center main bearing if you drive it at all aggressively. I would just like to be able to keep up with traffic when needed.
As far as I know this is the original 35K miles engine in the car (1930 Town Sedan) and I would like to keep it in the car. This way I could always return it to stock.

Thanks

[AzBob]

Old wives tale about a 5.5:1 or 6:1 high compression head taking out the bearings. I run a 6:1 Snyders head and get better mileage more power and a cooler running engine.

[Jim Brierley]

Originally Posted by Rob Doe

Jim Brierley, post #7,

Would a Model B carb and a machined out intake be a good choice?

Of course it would but a 2-throat downdraft would be better.

[Jim Brierley]

Originally Posted by brito36

With all the conversations on increased compression, larger carburetors, and intake manifolds, I would make sure that my lower end could handle all these improvements.

Always a good idea, I have always run Model B engines, and they are strong, bigger bearings and better oiling system, but A engines are very strong and reliable too.

[Jim Brierley]

Originally Posted by 1928 Sport Coupe

I would like to install a High Compression head in either 5.5:1 or 6:1 such as Snyders, a "B" cam, a "B" carb, and a bored out "A" intake. If I were to use new poured Babbitt mains and rods would that be sufficient for the improvements I want to do? Which head would be the better choice, the 5.5:1 or 6:1? I have been told any HC head could destroy the center main bearing if you drive it at all aggressively. I would just like to be able to keep up with traffic when needed.
As far as I know this is the original 35K miles engine in the car (1930 Town Sedan) and I would like to keep it in the car. This way I could always return it to stock.

Thanks

Higher compression and other things that make more power CAN be harder on bearings, BUT don't if you ease back on the ignition timing a bit, which does 2 things. 1) it prevents detonation and 2) is needed because the fuel will be burning faster so is more apt to knock (detonate) Also, driving down the road takes exactly as much power with or without more power, so most driving will not affect the babbitt or anything else.

[31a]

he parts suppliers have a small a adapter kit that allows the B carb to align properly.

[Fullraceflathead]

If you think of the engine as half of a 400 cubic " V8 it's easy to see how under carburetor the engine actually is!

[47topless]

Great point! Maybe I should look for a four banger blower. Now we're talkin' SLEEPER

[nkaminar]

Dyno tests are here: https://www.modelaparts.net/dynoshee...ynosheets.html

[Terry Burtz, Calif]

Originally Posted by 47topless

Great point! Maybe I should look for a four banger blower. Now we're talkin' SLEEPER

Check this out https://www.facebook.com/groups/1123...1121704006913/

Blowers are available from Aaron Loveless https://frenzelsuperchargers.com/pro...VUJygiHVLnUsd8

[old31]

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Talking about HP.

Does anyone know the difference in the Burtz 6.5 HP vs Snyder's 6.1HP?

[nkaminar]

From my experience there is a little boost going from the Snyder's 5.5 to the Burtz 6.5. In my opinion, the Snyder's 6.1 head has a better combustion chamber design than the Snyder's 5.5 or the Burtz 6.5 so it might be better than either of those, but I don't have any data to back that up.

[Big hammer]

Synder’s 6.1 head is 6.0 compression ( in their catalog 6:1) and their 5.5:1 if anyone cares

[Cape Codder]

years ago I bought a 5.5 head from Snyder's only to find it was approx. 1/8"-3/16" too short in front and rear. I'm just wondering if this still exists? Of course they refunded my money and paid for shipping both ways!

[tony1940]

Originally Posted by Jim Brierley

The quickest, easiest and cheapest way to more HP on the Model A is to increase compression and add a larger carb. The results will amaze you!

Hi, just checking HP threads, what carb would you add with a Synder 6:1 head. This engine has 2k miles on it from it's complete rebuild. thanks!

[Ruth]

Originally Posted by Cape Codder

years ago I bought a 5.5 head from Snyder's only to find it was approx. 1/8"-3/16" too short in front and rear. I'm just wondering if this still exists? Of course they refunded my money and paid for shipping both ways!

Yes

[Bruce of MN]

Originally Posted by tony1940

Hi, just checking HP threads, what carb would you add with a Synder 6:1 head. This engine has 2k miles on it from it's complete rebuild. thanks!

I like the way mine runs with a Tillotson. It is my only experience, so it could be mediocre in reality.

[Jim Brierley]

Originally Posted by tony1940

Hi, just checking HP threads, what carb would you add with a Synder 6:1 head. This engine has 2k miles on it from it's complete rebuild. thanks!

Either a Stromberg 81 or 97 or the Weber that is commonly used today. I once ran the Auburn hill climb in my '30 tudor. I had run it first with a stock B engine with stock A carb. A few months later I changed to a Winfield 6:1 head, the time was a full second quicker up the hill. That same day I switched to a Stromberg 81, times were almost another second quicker. The next time I ran that hill I had changed to a 97 carb, times were 3/10s of a second quicker. I love to experiment like that. That car got really quick when I installed my 4-port Riley in it!

[Charlie Stephens]

Originally Posted by brito36

With all the conversations on increased compression, larger carburetors, and intake manifolds, I would make sure that my lower end could handle all these improvements.

I was just going to post to watch out for the top end. Be sure there is adequate clearance between the head and the piston. The original and many reproductions had a recess in the head above the piston. Many high compression heads lack this recess. If the top of your block has been machined a couple of times you could have a problem when the piston pops up above the block..

Charlie Stephens

[Synchro909]

Originally Posted by brito36

With all the conversations on increased compression, larger carburetors, and intake manifolds, I would make sure that my lower end could handle all these improvements.

Easy fix. Wear a diaper.