Just as elegant on the inside as the outside, the Fiat/Lancia DOHC cylinder head is a work of art. It's efficient straight-through air flow and hemispherical shaped chambers are a testament to the prowess of the original designers. However, like most mass-produced engine parts of its day, sacrifices were made from the original designs in order to achieve manufacturing efficiency.
These sacrifices can be overcome with a Midwest-124 performance cylinder head rebuild. Designed for each customer's unique needs, the ports can be manifold-matched and shaped to optimize air flow. Custom designed oversize valves can be used to improve top-end, and Iskenderian racing valve springs installed to allow for higher RPM's. Combustion chamber shaping and valve deshrouding is also performed as needed.
Whether you desire a bone-stock or a full race-ready level rebuild, each head is processed with the same attention to detail. Each head is stripped and thoroughly cleaned and media blasted. Valve guides are inspected/replaced and flex-honed. Regardless of the use of stock or oversized valves, each valve seat is blueprinted to the valve for optimum performance.
Below are some recent examples of customer builds.
Customer John Ovington recently gave me the unique opportunity to prepare his 2L Lancia Volumex cylinder head. There are very few of these in the US. Several features separate the Volumex head from others. 43.4mm intake valves, sodium filled exhaust valves, and additional mounting holes on the intake side for the Volumex manifold. The head as I began the work on the left. The photo in the center is a typical 41.8mm OEM valve on the left and the 43.4mm Volumex valve on the right. The photo on the far right is the #1 chamber finished with lapped valves.
Above is a 2L fuel injected Fiat 124 cylinder head. This one was built with the new Midwest-124 designed 43mm intake and 37mm exhaust valves. Head is destined for a 1756 block with large dome high compression pistons.
Above is a 2L fuel injected Lancia Beta cylinder head. This one was built with stock size valves. Head was destined for a 1756 block with large dome high compression pistons. Final CR of the engine estimated to be approximately 10:1. Chambers have been carefully shaped as were the intake ports. Photo on far right shows spark plug thread insert.
On the upper end, above is a 2L fuel injected Fiat Spider head destined for the "wild" engine show on the engine services page. Final CR at 10.25:1. Chambers have been fully developed. Large intake and exhaust valves. Seats enlarged for valves and ports shaped below valves.
All the best head work will not result in peak performance unless it is all dialed in properly. Photos above show a 2L head built up with Pitatore 40/80 cams and Miller's Mule adjustable cam gears. In the middle shows intake valve at full lift. To the right, exhaust valve at full lift. It is critical to mark the cams for full lift, and the correct position for timing with crankshaft at TDC. Degree wheel used to find exact point of peak lift and position for correct timing with engine.
Above is a head for customer David Corder. 2L head destined for a high performance street and occasional autocross Spider. Intake and exhaust ports gasket matched and shaped. Large valves and Crane Cams valve springs. Photo to the right shows index marks for cam timing.
Customer's 1608cc head and matched/ported 1800 style intake manifold. To the right is a lovely shot of the above head in TJ's beautiful Spider.
Above, Manifold matching an 1800
I haven't forgotten you SOHC guys either. I also offer rebuild services for single overhead cam heads as used on Fiat 128, X1/9 and Yugos.