Featured Technical ***July 2025 Banger Meet Thread - Get Your Banger On The Road***

That's very kool - I never knew Gemsa produced flatheads (but I shoulda guessed...)

 

Going to share a “aha moment”, it was fun just to play around with the math as I am neither competent enough to achieve what would be required tolerances. The below only looks at the combustion chamber interface side, and is a dive into the complexities of making power.

this particular head has an un-machined combustion chamber which calc’s out to around 7.7:1 static compression. Leaving the area over the valves alone, the clearance is between the top of the piston and the center underside of the combustion chambers is as follows:

1. 0.416”
2. 0.416”
3. 0.408”
4. 0.394”

from the Interwebs, the ideal clearance to create quench is between 0.035” and 0.045”.

Careful machining out of the combustion chamber space above the piston to make everything level, and purchase a set of pop-up pistons to have the machine to the correct clearance seems to be the way to generate quench.

in achieving the above quench, the volume displaced by the piston in the cc would increase from ~49cc to ~68cc and move the static compression from 7.7:1 to 9.4:1!

math is fun.

Today, I can just look up much of this online. Imagine if you were trying to make power in the 60s with one of these, could easily end up with an engine that ran rough and tried to break itself. I am also fortunate that I can reach out to Dema, share the above, and he can design a cam that won’t “try” to blow the bottom end of the engine out.

couple years back I picked up a new Sherman heads from the gentleman who did a run out of Los Angeles. He said he put a more material over the valves and the combustion chamber. I’d feel better about having that machined down, Then trying to cut the original Gemsa up.

 

I have only seen one in 25 years, It was on George Azevedo’s “Faultless”. No clue where the engine ended up after he did the BB Rajo conversion.

So for some odd observations on the head. There was a contemporary group of speed merchants in the LA basin making the “Giant Power Head” (Which was a copy of the “Simmons Power Head”, which itself was a copy of another head, which I can’t remember at the moment.)

The physical external dimensions and the style of lettering (font) used are very similar between the Giant and the Gemsa heads. The difference being that the Gemsa has a V8 60 style combustion chamber, Whereas the Giant has a “crows foot” style. The Gemsa is done in Aluminum and the Giant is cast iron.

A few years back, I came across a T speedster that had a sticker on it for the Sherman “Giant Equipped” Racing Team. That’s the only other time I’ve come across “ Giant speed equipment”.

 

I believe the predecessor to the Giant and Simmons was the Waukesha-Ricardo

 

Edit: answered my own question…

the googles for the win (since I have a Simmons head, And the patent number is cast in the top of it)

The crowfoot combustion chamber was designed by Mr. Haibe under patent: 1645423



Harry Ricardo’s patent from 1919 (US), the UK being earlier :

 

That's not a bad idea! A member on here is selling me a Donovan one, but I didn't realize how simple it was to shape a mold out of styrofoam! I might have to do that..

A friend up in San Francisco sent me this photo, Kong made some cool ones to match the manifold.

 

Those look to be adapters to go from one size Winfield square base to another Winfield square base. Notice how the carb flanges are a different shape than the adapter surface.

On edit- picture angle does not tell the whole story- see below duh!!

 

Here's two more photos I found. Rather unique looking adapter!

 

Blast from the past, D O Fronty on a

 

Hi folks, I tried searching but had no luck, does anyone know anything about this head?

 

I may be incorrect, but I believe that is a 1930’s reproduction head. What does the combustion chamber look like?

 

Yes it does look like that, not sure if it says MFI or MF1. On the right side it says MADE : IN : USA.

I haven't taken the head off yet, will do in next few days.

 

Probably an after-market replacement head. If it has a diamond on the underside of the waterpump mounting it is a later Ford head. Does the block have a diamond on the front of the block near the timing cover?

 

Anybody seen a lower distributor shaft out of an A Banger with a 90 degree offset in the slots before? What would be the use case for one?

 

@Zax -I don't believe I've seen one of those...

@Retson the Racer. Those Kong carb adapters are cool!

 

It could have been to adapt a wico mag.
J

 

A few pages from Green Engineering Works.

 

Just making my way here to post it, and I see you already did. Thanks!

 

i was a little bummer i could not get on the linked website. i got both 'unsafe' warnings and nothing when i tried to refresh.

to get the YT channel announcements, it seems to be a paid subscription.

 

I bought a hoard of old hot rod stuff recently. I found this little gem in the mix. I hope to find the rest of it somewhere (have not yet got everything in one place).. Looks like a supercharger manifold, the tapered runners are really cool. I also dig the safety wire screws.. The carb stack is actually a radiator hose.. Nutty!

 

Not many Riley carbs out there, nice score! There were some repops made a while back… hopefully there are some extra float bowl covers left over. Might be able to use Winfield float ball, they are 2-1/8” diameter

 

Looks like a previous owner cut the bottom out of the float bowl and added that plate with the 4 bolts- wonder what that was about? There should be a serial number stamped on the top of the body near where the throttle shaft comes out the top under the throttle arm.

 

Anyone need a set of Riley 2 port valve covers with unique extra tall fins…?

https://www.jalopyjournal.com/forum...-a-riley-finned-covers.1336480/#post-15646773

 

Strip to street

 

Here is the bolt spacing for the different sizes.

 

Just checking in -been busy ,so far I have blown my cylinder head gasket at Santa Pod 1/4 mile racing and after fixing it raced at MPH 9 runs in total in one day ,4 by me 5 by my missus !!

 

Got the Burtz head on as well as a Mallory YA 11A. Fired it up last night. Throttle response is so much quicker. Can't wait to take it for a test ride this weekend

 

Checking in. I have followed for years so I should check in more often.
I moved so not a lot of time for cars. My snow tires are still on from the Flaming Gorge Resort Snow Rally. I’m set for the gravel roads I guess. Looking forward to working on cars soon.
My other bangers- The brown 30 I restored as a teenager. The black 30 was my dad’s.
The grey 32 was a recent project.
They all need attention, I have time for one. Which one gets it?