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High compression head for 28 Std Six


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Hi again boys, Let me start off by saying I believe in keeping these cars as original as possible for future generations to enjoy and all modifications I have made are 100% reversible and all original parts are kept with the car. That being said, I enjoy my car and drive it as much as I can, lots of time in the White Mountains of NH where sometimes a little more power is required to stay with the flow of traffic and not be a hazard. Now if I was the only one on the road I would love to just drop down to second gear and enjoy the ride at 20 mph 🙂.  I decided to raise the compression above  5 to 1  in order to improve the efficiency  and gain some power and fuel mileage. I could mill the head and gain maybe one point of compression to around 6 to 1 but the head is perfectly good and straight just the way it is and that metal can't be put back on later if desired, haha. SOOOO I decided to make my own , I thought you guys and gals might like some pictures because we all like pictures, haha  I'll download some of the key ones because i have lots, I have put about 500 miles on it so far and its fantastic. I also had to change the advance curve in the distributor because with increased compression less advance is required. Enjoy, Ken

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Went from roughly 100 cc original combustion chambers to 55cc that calculates  to roughly 7.7 to 1 ( I didn’t calculate the exact head gasket volume so that may not be 100% accurate but real close. 😬 For some reason i don't have a fully assembled picture I'll get one tomorrow .

Edited by Kenendcindyc (see edit history)
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With the generator on that side of the engine, that looks to be a '28 or earlier Chrysler engine ?

 

It could be parallax error, but your valves look to be on angle to the block face? 

 

Awesome work on the cylinder head. Just love it.

 

 

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3 minutes ago, maok said:

With the generator on that side of the engine, that looks to be a '28 or earlier Chrysler engine ?

 

It could be parallax error, but your valves look to be on angle to the block face? 

 

Awesome work on the cylinder head. Just love it.

 

 

 

Maybe I should read the thread title....lol

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I have not made the distributor body, yet (it is the last of the white metal on my engine but so far no cracks). My distributor is a type 1-0836 and it is two pieces made up of a main body and a upper points plate. The points plate was starting to crack badly around the pin that the points pivot on. So I did make a new upper plate that uses a very common modern set of points. 

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  • 4 weeks later...

Nice work. Please let us know how it runs.  In the photo of the water-jacket plate on your kitchen table, I can't see the inlet hole on the underside view, but it is there on the top view. Please tell me what I am missing.

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3 hours ago, JB-ed said:

Nice work. Please let us know how it runs.  In the photo of the water-jacket plate on your kitchen table, I can't see the inlet hole on the underside view, but it is there on the top view. Please tell me what I am missing.

Jb-Ed ,if your asking about the last two pictures of the completed head that’s on my table then what your seeing is both the “top plate” and the lower head assembly together. I had to make it in two pieces in order to machine coolant passages, if it was a casting it would be one piece with coolant passages cast in. I have about a thousand miles on it so far and it’s running fantastic ,hills I used to pull at full throttle I can now pull at about 1/2 throttle. Fuel mileage went from about 14-15 to 20 mpg. 👍🏻

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3 hours ago, Spinneyhill said:

Very impressive piece of work very well done.

 

Did you make the vertical spark plug connectors? I need some of them for my Dodge 8.

Yes I did. The ones I had on the original style plugs treaded onto the plugs. The new head I used modern 14mm plugs so I made those “connectors”. What style do you need?

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23 minutes ago, Kenendcindyc said:

Jb-Ed ,if your asking about the last two pictures of the completed head that’s on my table then what your seeing is both the “top plate” and the lower head assembly together. I had to make it in two pieces in order to machine coolant passages, if it was a casting it would be one piece with coolant passages cast in. I have about a thousand miles on it so far and it’s running fantastic ,hills I used to pull at full throttle I can now pull at about 1/2 throttle. Fuel mileage went from about 14-15 to 20 mpg. 👍🏻

Yes,its amazing what a boost in compression can do for torque. I only use 2nd &3rd gears now. My fuel economy has dramatically improved.

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1 hour ago, Kenendcindyc said:

What style do you need?

They are a push-on zinc plated type with a circular spring clip to push onto the spark plug bulb at the top. I have the blanks and have to cut the slots and make the springs.

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43 minutes ago, Spinneyhill said:

They are a push-on zinc plated type with a circular spring clip to push onto the spark plug bulb at the top. I have the blanks and have to cut the slots and make the springs.

ahhhh ok, Those in the picture are just some quick ones I machined up, because after i got the head on I totally forgot my old ones wouldn't fit on  the new plugs haha.  In fact my first 10 mile test drive I had the plug wires wire tied to the side of the plugs and my fingers crossed they wouldn't melt before i got back. 😉 

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1 hour ago, Mattml430 said:

That is just beautiful work you should be very proud of that. 

How many hours work went into doing it all, or did you not want to know. Haha. 

Its just amazing. 

I have about 80-100 hrs into the project 😳 as I have very primitive machines. Some of that time includes making some tooling I needed to perform the machining. Kieth ,Surprisingly I have not performed a “ after” compression test yet as I keep forgetting to bring home my compression tester from my day job haha. But thanks for the reminder maybe this weekend 😀. I had 65psi with the original head.  

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48 minutes ago, maok said:

WoW 125psi!   I only have 85psi, up from 70, may need to take off another. 0.030" from the head.

Ya when I decided to build a head I went for the highest compression I could without shrouding the valves too much. I figured I could  allways machine the transfer section more if I needed to lower it some. Compression stayed reasonable because the piston stops about .070” below the deck on this motor and head gasket is .065” thick. If you compare the old combustion chamber with the new you will see it’s probably a little more than can be gained with a .030” shave. 😀 Note these pictures are some what deceiving because of the difference in distance that I took the pictures. The originals CC at 100 and the new head at 55cc. Combustion chambers are .750"deep on original and .370" on the new head and it has a shorter transfer section.

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Edited by Kenendcindyc (see edit history)
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Wow. Those are some serious compression gains.

Any concerns about the parts down the line? Piston rings? Piston, pins, con-rods, bearings and crank for example? Will these parts take these higher intensity blasts reliably?

Just curious on your thoughts here. Old iron is generally over engineered I suspect.

Edited by keithb7 (see edit history)
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2 hours ago, keithb7 said:

Wow. Those are some serious compression gains.

Any concerns about the parts down the line? Piston rings? Piston, pins, con-rods, bearings and crank for example? Will these parts take these higher intensity blasts reliably?

Just curious on your thoughts here. Old iron is generally over engineered I suspect.

Well time will tell, but I think it will be fine.  I'm using the same pistons as a 1930 chrysler 268 and that's a 100 hp motor, the Dodge Brothers six is a seven main bearing engine with 2.375" mains and 2.125" rod bearings and a forged steel crankshaft with full pressure lubrication. Plus I figure during normal cruse its only producing the HP required to move you down the road same as before except now your throttle is open less and your burning less fuel and making less heat. Only when your calling on it to do something it couldn't do before is it working harder and under more strain but that will be intermittent. For comparison these are the connecting rods I’m running compared to some rods from a modern 230 hp v8 and what the lower end of the Dodge looks like. So my guess is its over built enough to handle more than original HP. Crankshaft picture is Dodge Vs Model T ford  (I  raised the compression on it also and its doing fine) haha 

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Edited by Kenendcindyc (see edit history)
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It's also possible that if you switched to the Stromberg UX-2 carburetor, you may get even better performance --  if you use Glenn Smith's reproduction. Your distributor is not the stock model provided with the original engine. What is it from and how is the advance curve compared with the original. I presume you allow far less advance in timing, but how much?

 

Regarding my previous question, I understand your need to produce this in two parts, it's just that I could not see all the coolant passages (and still can't but that's my problem).

Edited by JB-ed (see edit history)
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