HP limit of stock girdled block

Is the crank for a 3.25 main, or 3".I didnt think they made a forged crank for the 455 unless it was for 3" main.

 

I don't know about crank size. If you are serious give Crower a call.

On the 4-7 swap. To my knowledge it was never about HP, but less stress on the crank. Some swear it can help the "stealing aspect" of fuel distribution in a single plane intake. I prefer it because I don't like the 5 firing right before the 7. The passenger side is the hottest part of the motor and if you burn a hole it is generally on the passenger side in the corners on a nitrous deal. The ICT on todays boxes helps the situation but it is better if you don't have to compensate as much with taking timing out.

 

Standard firing order 1-8-4-3-6-5-7-2 or the 4/7 swap order 1-8-7-3-6-5-4-2

Well, it looks like to me that the 4/7 swap is trading the rear driver's side corner to be hotter to the front passenger's side corner to be hotter with the 4 and 2 firing sequentially.

We can't even use a cam that incorporates an LS firing order of 1-8-7-2-6-5-4-3 because even that firing order puts the 3 and 1 next to each other!

That being said, the lesser of the 3 devils would be to have one of the front corners of the engine have the 2 firing next to each other because of a bit more space around the front and the coolant will hit that area first so not as bad. The better front hotter corner would depend on the car and how crowded either corner is.


Derek

 

Let me clarify, when I say hot, I am talking about how fast a cylinder burns the combustion not actual cooling temps. I have only melted one plug strap in my lifetime on my old 455 and it was on the passenger side. However everytime I have seen somebody melt a strap on the drivers side they always have taken out one or more on the passenger side. Years ago before all this ICT stuff some guys would stick a .010 thicker head gasket on the passenger side to compensate this problem.

 

I knew what you meant, combustion chamber heat is what you were referring to of the 2 sequential cylinders firing. Not sure why the 5/7 on the driver's side is causing the passenger side to run hotter though. Are you from across the pond with a right hand drive?

Derek

 

That for the laugh for the across the pond comment. I guess that is what I get for typing all of this through my phone and not fully reading it before posting. I meant to say I don't like the 5-7 firing together for coolant issues since you are igniting two inside cylinders one after another.