Thread: DE head package - on a budget - infotainement

To try not to increase the area too much and thereby change the air speed in the port?

it isn't likely that the fuel would puddle on the port walls, **IF* it were to puddle, it would likely be on the floor... but... because of this "aero" port, if the fuel is going to puddle, it'll puddle on the back side of the valve, or possibly just before the valve on the port floor




this is correct... although "change", should be "lower"... For to be truthful, if we can port this head AND increase the velocity (air speed), then I'm better than I think I am...

I'm not saying I can't do that.... but finding that unicorn/unobtainium spot that both increases volume and increases velocity is VERY tough to find....


speaking about increasing both volume... and velocity.....




I now have, or will have once it has been cleaned(on loan), a low port SR20 head to get some measurements and photos from.... Even before cleaning... I can EASILY tell why/how this head makes more power... 2 less than obvious changes. The obvious change is the port is low, and it is much shorter... but although both of those help... the 2 less than obvious changes are inside the port/bowl areas themselves.... 1) the stock port ID is a lot closer to 28mm (remember the highport is only 27mm), and, 2) the short radius is much better. Sometime next week I'll get this head back, and take some better photos...

until then.... a dirty head... but you should be able to see the 2 less obvious changes....





more to come.......

Not quite sure about that, I know its a guess though. But, depending on whether its a de or det, the fuel would be injected either before or after TDC of the intake stroke.

I'm glad you've obtained a lowport to compare.

Does anyone have the intake manifold runner length on a SR20DE highport? I'm looking for the measurement from the mounting flange to the plenum. Ideally I want the measurement from inside the manifold......



Can anyone tell me why I want to know???

Mr Helmholtz asks you?

Pulse wave calculations. Determines what rpm the manifold is designed to operate best at.

More specifically Helmholtz Resonance

To know how far you can open up the cylinder head before there are negative impacts. The two parts must flow evenly without disruption for better performance.

I'll go with Helmholtz.

I've just had some work done on my VE head.

He's reshaped the ports quite a bit, spent a lot of time working the bowls at the back of the valves.





There was massive almost 90deg steps in the exhaust ports that have been radiused out, they have also been mirror polished.