Has anyone taken advantage of the cold weather down time to derestrict the Savage exhaust port? I'm interested to know how far you can go.

Clive W  

LANCER wrote on 12/31/69 at 16:00:01:


did you take any metal out on the "roof" of the port or stick with expanding the outside at the pipe connection?

I do not recall exactly how much was removed, but I would estimate about 2 mm all around and with the bottom of the port being flat...making a D shape.  I went inside the port 25-40mm and removed some material to widen the inside of the port.  When the 2 ports coming from the exhaust valves combine into 1 port there is a good amount of room initially, but then quickly gets smaller.  I just tried to make the transition more even and smooth and a little straighter.
The header I made is 1.75" OD/1.66"ID, which should be about the best overall size for this size engine/power output and useable rpm range.  The port work was designed to try to match the pipe as well.

I did not spend a lot of time on it, at least one..,maybe two hours.  But the engine runs really well and does not like hardly any restrictions on the exhaust at all.  Too much restriction and it really shows up with rejetting required.

What can we say...GREAT MINDS !?

Savage_Greg wrote on 12/31/69 at 16:00:01:


I do not mind at all.  I do, however have some photo's of the port on this site somewhere.  I was looking for them last night but could not find them.  I will try again, and if not successful I will get some more to put up.

Thanks for finding the photos.  That's all that I need.

What about that flat casting on the inside top of the port?  Any reason not to reduce that area too?