Hey Tony, good choice on the 27 with those KB's and head work..If you can get your porter to work up the total package to 9.8:1 with a .030 head gasket and milling you would have a real good performer without giving up reliability. it would put your ccp right at 190. very friendly on pump gas and a nice bump off the line and then some.. Don't forget to find out where your pistons are in the hole. A .030" to .033" is an optimal squish that does make a nice improvement... I'm only suggesting because how deep your into the motor.

I ran some numbers and you would need to zero deck the cylinders and mill the heads to 81 cc just to get to 9.7:1 which still keep the ccp at 187. Anyways just throwing it out there.

I'm sure whatever you do it'll be a huge improvement... Good luck man and keep us posted....

Don't mind me I just like messin with numbers......

 

Are you using the Accelerator Pro III software by Walter's Technology?
http://walterstechnologies.com/

 

wingnut software - I have the plastic 3 X 3 inch tan plastic one ( forgot what they called that ) floppy disc maybe he sold way back

 

Sounds like you are doing it right. Asking questions is key imho. Also any piston will fail if ring gap is wrong. Great thread. Keep us posted on outcome.

 

No. RB Racing's calculations web site. Why? Do the numbers seem of?

 

I don't mind at all...I appreciate the input!


Thanks...I'll keep it updated.

 

I was just curious as to how you were running the calculations/simulations. I purchased the Walters Technology Accelerator Engine Simulation Software years ago (mid '90s) and used to fool around with it trying all sorts of different builds. My version of the software is very old and I'm not even sure it would run on my current computer system. Your comment caused me to flashback to some fun times years ago, that's all. I see that the latest version of the software is called Accelerator PRO III. I just sent the company an email to see if they offer an upgrade program. I'd like to fool around and run some simulations again .....

 

It's just a numbers plug an play like spreed sheet that RB racing has on their home web site, down at the bottom. They offer all kinds of calculators. For anything you want to motor and motorcycle related. Here's the link.
https://www.rbracing-rsr.com/calculations.htm

And yea it is fun to see how all the different builds do. You can create a data base on all the info that's offered here on the forum and apply it to create a log to know exactly how someones changes created changes in their build. Providing they other accurate info and of course a valid dyno sheet...

I have quite a bit of time, so to me it's both interesting and fun...