[40 Deluxe]

Originally Posted by Desoto291Hemi

My plans are to do a complete rebuild and add some power at the same time.
Nothing radical,,,just a strong engine
As a matter of fact,,,I will just go ahead and lay out my plan now.

1.
Get the block serviced and see that it is good.
Bore it somewhat,,,,not to the max,,,just a good oversize.
Deck it and clean up all the machined surfaces.
I am not sure yet about relieving the block for more flow,,still reading up on that.

2.
Clean and check the crank,,,see if the journals are okay,,,service as needed.
Balance assembly after the rods and pistons have been weighed for the bobweight.
Use good quality bearings throughout the assembly.

3.
Rods,,,,clean and check,,,shotpeen for strength,,,,resize and check for any defects.

4.
Pistons,,,,,I want to use a good brand of pistons,,,not the most expensive,,this is not a racing engine,,,just a nice hot engine.
I don’t think I will use the 4 ring system,,,I believe 3 rings will be fine.
Being that the pistons will be a modern aluminum piston and will be machined with a barrel shape to fit better in the bore ,and not prone to a lot of skirt movement.

5.
The camshaft will probably be a nice Isky grind,,,not sure yet.
I have looked at some,,somewhere in the .365 range maybe,,,not sure ,,,still early.
I would like to use the adjustable lifters if I can,,,,is that a good idea,,,I have just began to read about them.

6.
Valves,,,,,I would like to use a good stainless valve to be safe.
I would like to go bigger than stock,,,if I can?
I am considering going with a1.625 intake if I can make it fit?
The exhaust would probably be a 1.57,,,,I am still in the thinking stage with this.
I know most engines always used a slightly larger intake being that the mass of the fuel and the air is not as great after the combustion cycle,,,,no fuel droplets in the exhaust.

7.
The heads,,,,, I am thinking about a nice aluminum head,,,with a better chamber shaped to increase compression. I believe that compression within reason is free horsepower.
The aluminum ones have added capacity for more cooling water flow and fins to increase the cooling ability,,,,especially after the shutdown,(act as a heat sink),,,to help remove heat from the deck surface?
Although it uses bolts right now,,I plan to upgrade to studs for strength .

8.
Intake,,,,still don’t have a good direction there yet,,,but I am just starting here.
I am thinking a dual carb or single 4 barrel,,,,,not a bunch of carbs,,,,too much to keep up with I think.

9.
Ignition,,,planning on adapting a SBC dual point distributor,,I like dual points and believe that it will work great. I have a nice Accel dual point,,and several others,,,just plan on the Accel at this point.

That is about as far as I have gotten so far,,,still thinking and studying my options.

I am still in the planning stage here,,,any ideas?

Tommy

Some 'bench racing' thoughts:
1. No need to relieve. You'll just lose compression and won't gain airflow unless you have a large engine at high RPM, and a radical cam (plus a super trick porting job). Air has mass, therefore has inertia and resists changing direction (which hinders flow). So air is flowing upward as it enters the cylinder, then through the transfer area and down into the cylinder. If we can change its direction gradually the flow will be greater. Forcing the air to make a sharp turn out of the port, through the relief, and another sharp turn into the cylinder will hinder flow. Since you lost compression to make the relief, and won't have much extra flow through the relief, you end up with a net loss at normal street engine speeds.
6. Larger valves. Will the ports flow good enough to take advantage of
the larger valves? Most of the reading I've done indicates the ports are the limiting factor in airflow, not the valves.
7. Aluminum heads. They look pretty, but they take heat out of the combustion chamber and put it into the cooling system so quickly that some efficiency and power are lost.
9. Since this is a street engine, make sure your Accel unit has vacuum advance for better fuel mileage.