ZR-1 ZR-1 ZR-1 ZR-1 ZR-1 ZR-1 ZR-1
Haibeck Automotive Technology
Cylinder Head Porting
We port cylinder heads with the following features:
The intake ports are opened up from 33 to 36 mm for an increase in port volume of 19%.
The valves are unshrouded. The intake valve seats are blended into the roof of the combustion chamber.
The valve seats receive a three angle finish. The intake valves are back-cut.
The dyno chart shows the incremental power increase from the addition of cylinder head porting on an engine with top end porting. The subject engine is a '93 that also has headers. Note that low speed torque is maintained.
The cylinder head porting process includes; removal of the engine, disassembly of the top of the engine, porting, combustion chamber work, refinish the valves and seats, time the camshafts to I114/E110 +/- .5 degree, reassembly of the top of the engine, reinstallation of the engine in the car, and Dynojet tuning. $6798.
'90 cylinder heads can be upgraded to add valve stem seals on the exhaust valves. $150
Cylinder heads can be shipped in for porting. Disassembly and reassembly of the heads is included. $2912.