This is a completely rebuilt SOHC 1500 cylinder head with performance cam applicable to fuel injected 1981-85 Fiat and Bertone X1/9s with a 10-bolt 10mm engine block. Also applicable to fuel injected Fiat Strada and Ritmo SOHC 1981-On.
(Not applicable to 1980 1/2 10-Bolt, or 1986-88 14-Bolt blocks).
This is the entire cylinder head assembly with camshaft, shimmed to spec and ready to bolt onto the block. The other guys don't do that. Be sure to check out the multiple pictures!
PLEASE NOTE: No core is assessed, but we will issue $100 as store credit if you send your existing, rebuildable 1981-85 cylinder head to Midwest-Bayless as a core.
Due to availability of cores, we may require your original cylinder head prior to commencing the job. Please call us for verification at 614-784-8870. In such cases, the cost of the assembly will immediately have core cost credited ($100 discount) prior to purchase.
When milled -.075, it increases compression nearly 10:1. Throw in a hot cam, and a good valve job, and this unit will really wake up the performance of your car.
We start with a very good condition 1500 fuel injected head, with 10mm head bolt holes. All threads / stud holes are intact, and clean coolant passages absent of corrosion or enlarged openings. All spark plug and coolant sensor holes have clean threads, and we replace any valve guide whose measurements are out of spec.
We mill the head to completely remove the combustion chamber "dish" and mill the cam tower to accommodate the smaller base circle of the aftermarket cam.
Removing this much material does affect cam timing, but generally it indexes the camshaft between 3-4 degrees advanced, and will operate correctly with the stock cam belt pulley. An adjustable cam timing gear is recommended, however to optimize performance through proper cam and crank timing.
A 1300-style cam belt tensioner bracket and bearing will be required to correctly tension the timing belt.
We tap and plug all emissions ports, and tap the intake manifold coolant holes with a 5/16 x 20 thread so that they can be easily blocked if desired. New (not used) valves and provide a trick three-angle valve cut on the seats which has been flowbench proven to increase flow by nearly 40%! New competition valve springs with stock retainers are used, which are guaranteed to put up with a high RPM beating up to 9K RPM without danger of valve float.
Midwest then fits a fresh performance camshaft with 223 degree (at .050 lift) duration, 10.2mm lift, fully set-up and shimmed to spec.
Higher-duration camshafts often require an aftermarket EFI controller.
A new set of 10x1.25 head bolts must be purchased separately, and five are pre-fitted to the short-side prior to installation of the cam box.
The job is finished up by fitting a new cam seal, gaskets, and a cam box cover with excellent condition springs and bushings that are cleaned and freshly re-assembled.
Condition: Freshly Rebuilt
Allow 15 working days to produce.