All Small Six 68 small log head porting [ including preliminary DYNO RESULTS ]

[bmbm40]

I have very much enjoyed this thread and have reread it at least twice and appreciate the detailed information. If you can get 130 hp from a small log head 200 that is impressive compared to the 80 hp stock from the original dyno test which was great base info. That is a 50 hp, or 63% increase over stock!
On the provided dyno torque numbers are they represented in ft lbs like in the US?
Is your C4 stock? I have read about modifications that give it more of a performance feel such as shift points and firmer shifts.
Looking forward to hearing more.

 

[clochard68]

@bmbm40 Thank you for the kind words. I am glad you got something out of this thread.

Regarding your questions:

The torque numbers are in newton meters (so if you multiply my numbers by 0.738 you get the ft-lbs). Of course the torque numbers are so high in the beginning of the curve because of the torque converter, but it's the torque you feel on the street non the less...

I installed a Transgo shift kit into my C4 for firmer shifts, and you definitely feel it when driving, it shifts a lot quicker now.

 

[clochard68]

I finally ordered a seat cutting tool from ebay and these two Goodson cutters for my new SI 1.75 intake valves.



As soon as I got time I will be installing the bigger valves (I currently have 1.65 standard valves) and will do my best to give them a 30° backcut.
The plan is to NOT unshroud the chamber any more, but I will see once the valves are fitted.

I post this primarily to hold myself accountable to finally getting this modification done, I will keep you updated...