Dodge Challenger Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
3,881 Posts
Discussion Starter #1
Well I finally gave in and built an Iron 440 for a customer. Jim has wanted a 440 for a while and I am very much against building them due to the inherent flaws with crankshaft overlap, compression height, and rod/stroke ratio. Dont get me wrong, the 440 is a bad mutha, but it does give up longevity in doing so.

What we did was different than every other 440 that I have seen. I will not get into specifics, but it does involve a 1-off custom crank, 1-off custom rods, and 1-off custom pistons. If we are happy with the performance/longevity of the motor, we will begin offering these to everyone else.

Pistons and crank will be here by Friday and I will get some pics up then, but for now, here is the block that we finished today.

Step 1:


Step 2:


Step 3:
 

·
Registered
Joined
·
3,881 Posts
Discussion Starter #7
Here are the custom pistons we made for this 440.

Please notice that we no longer use a generic round dish. By taking a mold of the combustion chamber, we can apply a dish that is a mirror image of the chamber. This forces all the fuel/air to the center of the combustion chamber where the spark plugs are for a more complete burn. Also, you can see that we now shave down the crown of the piston at the intake relief and exhaust relief in order to minimize the thin area that would normally be there due to the valve reliefs. We also have a longer skirt to give this piston more stability and increased strength which aids in the integrity of the motor. That last thing you want with a long stroke motor is a short skirt. The longer the skirt, the more stable it is.



 

·
Registered
Joined
·
302 Posts
Shwiiiiing!!!!!!
 

·
Premium Member
Joined
·
2,091 Posts
I like the longer skirt to help distribute side pressure due to any increase in stroke. The change in the piston design for better combustion is also a great improvement. Can't help but wonder what more can be done.

I've always wondered if our 2 valve set-ups could somehow replicate Suzuki's very successful TSCC.

Abbreviation: Twin Swirl Combustion Chamber
Definition

Twin Swirl Combustion Chamber (abbreviated: TSCC) (Noun, Suzuki Marketing Terminology). A specific design of the intake tract and intake valves in a four-valve-per-cylinder engine, whereby one or more venturi effects in the intake tract is/are used to intentionally create a pair of very high speed counter-rotating swirls (think mini-tornado's) within the combustion chamber, which will last through detonation and into the exhaust phase.
All 1988 - 2006 Suzuki GSXF series use TSCC, as do most or all four-valve-per-cylinder non-cruiser street motorcycle engines produced by Suzuki between the introduction of TSCC and the present day.
Typically, some form of fuel-air charge "spinning" is mandatory to being able to design small form-factor engines with very high RPM limits.
Purpose

The very high speed rotation provides several benefits:
  • Provides a faster flame-front popagation at time of spark plug firing, because the flame is carried around the cylinder;
  • Provides increase turbulence for more complete burn of the fuel-air mixture for reduced pollution and maximum power gain from the fuel-air mixture;
  • Provides higher exit speeds for exhaust gases, because the flow patterns will match the positions of the exhaust valves.
  • Permits use of Overlapping Valve Timing and Intake-Overlap to increase compression ratios within the cylinder at peak torque.
Retrieved from "Twin Swirl Combustion Chamber - Katana Wiki"
 

·
Registered
Joined
·
3,881 Posts
Discussion Starter #12
I would like to see 555rwhp/550rwtq but we will have to wait and see what happens.

I would rather not list what the bore/stroke combo is on the Iron 440 for now. The aluminum 440 has a larger bore, shorter stroke. It is a better combo, but it also costs $4500 more than the iron 440 basically.
 
1 - 12 of 12 Posts
Top