Cylinder Head
The 2.6L head has larger inlet and exhaust ports. When i find my verniers i will put up the measurements. Heres some comparison pics.
E1 on top D1 underneath.
Inlet.
Exhaust.
Heres the C1 Na shuttle manifold on the left and the E1 on the right.
The reason i mention the 2.6L head is for two reasons. The ports and valves are slightly larger and the combustion chamber is also larger. Depending on what forged pistons can be got hold of there might be a need for the compression drop to compensate for higher comp pistons.
EFI Inlet manifold
For a comparison to the Piazza inlet the Rodeo manifold has bigger runners, handy if you want to get a bit of port work done to you Piazza head.
I dont have a Piazza manifold here thats stripped to do any comparisons to side by side. Its on the car and im loath to pull it off for the sake of it. Heres the Rodeo manifold compare it to what youve got.
The Rodeo manifold has two seperate water parts in the inlet manifold. The thermostat housing and then the chamber under the runners. They are connected by a hose. The hose comes form the thermostat housing to the chamber under the plenum then the water goes off thru the heater system.
Im not sure how similar the Piazza manifold is to this so check it out before you go pulling stuff to bits. I can only find pics of underside of the lower half of the Piazza manifold and they arent the YB ones.
Save as and you can shrink em a bit with a picture veiwer so they come up full screen. lol. sorry to the dial uppers..
Colours mean the same as in the first pic.
If you switched to one of these manifolds for the port size benifit there could also be some gain from the water side of this set up too. If you motor is modded and your running high boost/intake temps if you dont run the water thru the lower half of the manifold you can gain a few HP there thru not adding to the intake temps.
Ive also been told that the Piazza plenum will drop right on the Rodeo runners as the holes at the plenum are the same size.
Valves
There is a difference but its only a 1mm on both the exhaust and inlets. Measurements and pics to come.
Cheers. Bob
