I recently ported my 6port spareengine

Im hoping to pull around 210 @ the flywheel



It will see a few trackdays and general abuse other than than its my daily driver.

I would like opinions on anything that you could think of.

Like how much could I go down(port) on the exhaustports, wetcoil reccomendations ASO

Current SPECS:

Cold Air intake

True dual exhaust

SAFC

550cc secondary injectors(I have them, just not sure if its overkill)

Euro spec motor (fully functional 5/6 ports) for low end

No emissions

Matched intake manifolds

Distributor dizzy(Euro-stock)



I have checked corner/apex seal path using the lexan trick, everything seems fine.

The new ports are 6mm and doesnt go underneath the rotorhousing.

Bridge



I simply took out the sleeves and cut away the diffuser, Ill weld in a new bottompart later

Exhaustport

looks good. exhaust needs to come down some more. and you can get a little more out of the aux eyebrow. You can also take very small polishing stone and clean up the edge on the secondary port bridge

Here are some suggestions.



The liners keep exhaust gas velocity high. The noise suppressors in the NA liners only cost a few horses, and they do cut the noise way down. So, you can use less restrictive muffling and gain back way more than what is lost to the suppressors.

Also the liners cut down the heat that the coolant must remove, and that heat stays in the exhaust gas where it belongs.



If you can clean the housings up with solvent and 400 silicone carbide paper, and then radius the chrome back all around about 1/16", there will be no bouncing, and less dragging a carbon track up the sides. This suggests that the OMP oil (sump) is not burning fully, and EGT is a bit high at WOT. For a daily driver, I would use a straight weight dino oil for better burning, (less plastic) and pre-mix a bit of high quality 2 cycle oil for the hard use weekends.



In the picture, I would leave the closing line stock. Don't really extend the open line for a timing change, but make the open line a big radius as shown. For a street engine, 3/16" to 1/4" is plenty. Radius all around the sides and closing line into the chrome about 1/16" so that the closing line right at the sealing surface is as smooth as is possible to make it. Most of the flow has exited before the apex seal gets to the closing line, and at WOT that flow is supersonic. Raising the closing line or the shape of the port above half way just adds to overlap and that just kills low end performance. Try to keep WOT max RPM EGT under 1650 degrees.





Lynn E. Hanover

Mr. Hannover - I love you https://www.nopistons.com/forums/pub...1047683894.gif



In a macho kindda way https://www.nopistons.com/forums/pub...#>/biggrin.png