How do I calculate the new stroke when going from the stock LS rod of 5.394" to a longer 5.967" rod? In mm that is 137.0076 mm up to 151.5618 mm.

I am guessing I would be going from a 89 mm stroke to a 95 mm stroke?

I am trying to figure out what my compression will be on this thing - https://honda-tech.com/zerothread?id=1660368 - any compression geeks feel free to jump up!

I am trying to use the c-speed calculator.

Thanks a bunch

 

Using a longer rod wont change the stroke, that's determined by the crank throw. A longer rod will raise the piston height, making more compression.

 

ya- I knew that, was just being an idiot and forgetting what i knew.

I guess what I really need to figure out is the piston to deck height -

The stock height should be .020".
The new rods are .573" longer.
I am adding .75" to the deck - so I should have:
.75-.573=.177 of additional clearance - right???
add that to the stock clearance already there .177+.020=.197 of total piston to deck height - right???

This doesnt work right, that sounds like to much clearance and lowers the compression too much according to the c-speed calculator.

I figured this out using specs for B20 block - since Im using a B18 crank and 84 mm pistons, my arias pistons have a -12cc dome displacement, GSR head, .197" deck height and everything else should be standard - this gives me 6.7:1 compression and 2 liters of displacement.

Some expert insert accurate knowledge here please.

 

anyone???