Although it has been around for a very prolonged time, the Ford Pinto engine is still a popular choice for lots of tuners. The Ford Pinto head was modelled on the Ford engine of 1970. The head design has evolved from the old carburation type to the new injection type on some classic cars. If you are destined to put carburation on these injected heads, some modification is needed.
Sorting selected used cylinder heads. The oil dirt and coke have to be removed from the cylinder heads. The bearings should be replaced and the status of threads need to be checked to. Waterways should be checked for cleanliness then pressure test to 70 P.S.I to make sure the heads are not cracked.The inlet port on the injection cylinder heads are a lot higher than the standard cylinder head because of the shape required to site the injectors on a road car, so its best to clean out the bottom of the port with a die grinder to allow a new alloy stuffer to blend in and locate without thin edges. The head will require to be drilled to accept two 1/4 UNC bolts. For added safety on the modified heads, the modified stuffers will be held in place by allen bolts. Also the valve guide holes will be re-drilled and tapped a further 0.2″ further into the cylinder head. All this work should enable the modified parts to fit the combustion chambers. You want to make sure all the ports are polished and balanced. The valves should be blended into the valve seats.
The exhaust ports are gas flowed out to relieve restriction around the valve guide area and the top front area of the port at the head face. A properly modified Pinto head could flow lots of air with bigger valves the standard 140 cfm can be raised to over 190cfm. The port on the inlet side would only need increasing if you intend to fit bigger valves. A great result can be gained by getting the short side bend correct. If the changes are wrongly made in this area can result in losses of power in the region of 20bhp. To achieve large gains from buying a cars For Sale with a Pinto engine you have to get the race heads prepared properly.
Expect to spend a large chunk of your money on the head of the pinto engine. The standard vales are 42mm inlet, 36mm exhaust. The standard exhaust valve is big enough and there is little point in fitting larger ones for road use. Considerably bigger inlet valves can be good, so budget on getting the head modified properly.Standard valves are 42mm inlet and 36mm exhaust. The standard exhaust valves are said to be good even for many race applications. However much larger inlet valves are considered great if you are building a full out and out race car.
