Claim of 25% HP bump true?

[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.

[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.

[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.

[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.

[31a]

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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

[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

[nkaminar]

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

[old31]

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!

[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