Here we can openly discuss the 2.4 blocks.

Edit: Original question was;

 

I think Buschur has one, or is in the process of doing one.

 

Buschur and AMS i believe have them.

Chris

 

doesnt RNR also have them? i might be wrong

 

Neither Buschur or AMS sell a 2.4L block. RnR is the only one who offers a 2.4L block for the Evo. Buschur and AMS offer strocker blocks 2.3l and such. You can't go wrong with whoever you choose though.

 

The displacement of a stroker and the displacement of a 4G64 is the same.

 

Junk yards.

I wonder if there is a cylinder wall thickness difference between the 2 blocks, 4g63 evo & a 4g64?

If the wall thickness is the same, I would opt for the 2.4 block, slightly taller block = potentially longer rods if you were to use a 100mm stroke crank. Slightly larger bore, helps unshrouding the valves, besides getting another 100cc = 15 hp. Based on a 2.0L that makes 300hp.

Just depends on your goals. Even running a 2.0L crank in a 2.4 block would be awesome, just get longer rods, add piston squirters, whamo a 2.1 with a better rod ratio & the potential to flow more through the head by having the valves shrouded less. I am not sure what the rod ratio is in our evo 8's but I am certain it can be improved upon.

 

Is the 4g64 2.3l in capacity? I know that honda has a ~2.15L, but calls it a 2.2L.

Is this a similar case? I havent calculated the capacity of a 4g64 to determine its actual size, so thats why I ask.

 

Yep.

 

This is from David Buschur from another thread about 2.4 Blocks:


Here is some quick numbers I threw together this morning for cubic inch comparisons. All numbers are based on a stock bore block.

2.4 liter Mitsubishi is 142.62 cubic inches which is actually 2.337 liters.

2.0 liter Mitsubishi is 121.61 cubic inches which is actually 1.992 liters.

2.0 liter Mitsubishi with a 2.4 liter crank in it is 137.71 cubic inches which is actually 2.25 liters.

21.01 cubic inches more going from a 2.0 to a full 2.4 liter engine
16.1 cubic inches more going from a 2.0 to a stroker kit using the 2.4 liter crank.

More to come later on piston speed differences, for now I have to put an engine together.

David Buschur
www.buschurracing.com

 

Thats some good info guy's.

 

Depends on what you bore the engine out to when you stroke the 2.0L.

 

Only if you overbore the 4g63. The EVO's are so new that many people are using stock sized replacement pistons without even doing a hone let alone a rebore of the block.

Keith

 

Magnus racing in Canada sells this setup

Keith

 

Are those numbers direct quotes from Dave?

Useing displacement calculation on multiple web sites (this one for example)

http://www.straightliners.co.uk/calcs/eng-disp-calc.htm

You come up with 2.351 liters (143.4 ci) for the 86.5 mm bore 100 mm stroke engine. That rounds up to 2.4 liters with no fudgeing of the numbers by Mitsubishi.

You end up with 1.997 liters (121.9 ci) for the 85mm bore 88 mm stroke 2.0 moter.

And for the stroker you have 2.270 liters (138.5 ci) at the 85 mm bore 100 mm stroke.

This gives the 2.4 block a .081 liter advantage (4.9 ci) over the stroker if you don't do a re-bore up to 86.5 mm on the stock 2.0 block.

Also, the short stroke 2.4 block ends up with 2.069 liters (126.2 ci) of displacement using a 86.5mm bore and 88 mm stroke.

Later,

Keith