Board Logo

T1 dual v single port engines
Dak-Dak-68 - February 5th, 2011 at 11:20 PM

any information on the pros and cons


bajachris88 - February 6th, 2011 at 01:36 AM

single port = more bottom torque. (smaller port cross sectional area, therefore greater air intake velocity, natural supercharging effect etc)
dual port better top end. (better breathing for high revs)

dual port was initially encorporated for vw's fuel injection implementation and not necessarily any performance increase.

If you can encorporate both with variable intake cross sectional areas (smaller cross section for low rev) then activate a vacuum based actuator to open it up for high revs for large cross section, you can get the best of both worlds. Just like toyota's old fashioned TVIS from the 80's :tu: (had dual intake runners per cylinder, had a rev based valve switch that opened a vacuum canister to operate an actuator which in turn open and closed 1 of the two intake runners on each cylinder when it was required... depending on the rev range of course.)

thats it in a nut shell :)


68AutoBug - February 6th, 2011 at 02:47 PM

Quote:
Originally posted by Dak-Dak-68
any information on the pros and cons



I still have My original single port engine in My beetle...
was 1500 now 1600 and I replaced both heads with single ports

I'm very pleased with its performance....

Lee