1967 Rambler American AMC Short-Block Buildup - Don't Drive A Beemer, Build The . . .Ultimate AMC - CC/Rambler

The slugs use a 0.927-inch pin and 1/16-inch rings. With 0.250 pockets and a 0.175 dish, they yield around 11.0:1 compression with the 53cc chamber on the Indy heads.

With a deck height of 9.180, a stroke of 3.93, a 6-inch rod, and a 1.213 piston height, the pistons are 0.002 in the hole. The total quench is 0.042, and the compression ratio is 11.13:1. With a light car and a big cam, this should be on the edge of 91-octane use.

With this much power and drag racing in the plan, we had to address the oiling system. The stock oil path runs through a port in the pan rail on the cylinder block then into the oil pump, creating a restriction. The solution is bypassing the gallery with a plug and using a braided line to pick up oil directly from the sump.

The Milodon pan has a baffle for drag racing and provisions for a single- or dual-line pickup. The system doubles the available oil volume to the pump.

Another problem with the stock timing chain cover is the oil pressure relief valve assembly that was originally designed to bypass oil inside the pump to regulate pressure. These parts wear out, eventually causing pressure instability. The filter bypass would work when the pressure bypass was at capacity, and that was all the time, since both bypasses were barely adequate for the stock high-volume oil pump. The Bulltear oil pump cover eliminates the stock oil filter adapter and the filter bypass completely. The pressure bypass is on the plate and recirculates the oil in the pump using OEM replacement parts. The spring and the plunger are set for 70 psi, protecting the filter and the engine from contaminated oil.

Factory timing chain covers have a number of problems. They tend to spring leaks when the water pump cavitates and the oil pump gears eat the housing, causing the oil pressure to drop below 10 psi at idle. Since factory covers are getting hard to find, Bulltear Industries makes a nickel-plated cover that resists wear and fixes those problems.

The oil pump gears in the Bulltear timing chain cover are grooved. This helps relieve the binding pressure on the distributor and cam gear as they spin the oil pump so they'll last longer and cause less wear on the oil pump housing.

Another factory weakness is the stock oil filter adapter and its oil filter bypass assembly. Back when these engines were designed, oil filters had no internal bypass and could blow off when the engine was cold and oil pressure was high. The solution was the bypass that sent unfiltered oil back into the engine. Not good. Filters were also smaller and less efficient in terms of total flow. The Tri-Flow external filter/oil relocation plate eliminated the bypass entirely and picks up oil directly from the Milodon pan. It also allows you to use a single- or dual-Fram PH8A. If you don't have a Milodon pan, Bulltear offers the 626 plate to replace the oil filter adapter.

Professional Products offers two dampers for AMC engines. The one we used is SFI certified, so we can use it to drag race; the other is not. The dampers come with an assortment of counterweights for the 304, 360, and 401 engine. You'll need to switch to the four-bolt accessory pulleys to use these dampers.