Building a 292 to run 65 to 80 mph all day long


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By junkyardjeff - 14 Years Ago
The builder of the 351-w thats presently in my 55 installed a cam that makes the motor run the most efficient at 80 to 85 mph so what do I need to do to the 292 where its most efficient at 65 to 80 with 3.00 gears,today I went to a show about 75 miles from home at that speed and it used less gas then it did last year at slower speeds. Its presently has 2.79 gears and will be installing 3.00 gears so I can get the peak efficiency of the present motor down to a little slower speed with the motor spinning a little faster and since I plan on staying with a 3 speed automatic I want to build the 292 to those gears,the 292 I have is a 62 and I have been wanting to find a set of heads with the larger valves but do I really need them since I am not building a high performance motor but a highway cruiser with the most torque down low on the rpm range. Another thing I need to know can a y block handle being be driven all day at 65 to 80 like the late model motors since I plan on taking it to Florida many times and I drive straight through.
By Ted - 14 Years Ago

There’s no problem on the Y’s durability to sustain high speeds for a long period of time.  The basic design is solid with the oiling system actually being originally designed on the side of being ‘overkill’.  As an FYI, the Y’s use the same oil pump capacity as the FE’s but the FE's end up being marginal in their oil supply with just a little bit of wear on their internals.  Modern oils of the correct viscosity and the use of hardened seats in the heads so that unleaded fuel can be used would be at the top of the list though in making sure the Y goes a lot of miles in any kind of driving.  For a lot of high speed highway driving, camming should concentrate on having good torque in the 2200-2800 rpm range so that the engine is perky going down the road.

By charliemccraney - 14 Years Ago
The large valve heads will very likely help because of the increased compression and the bigger valves probably won't hurt.
By junkyardjeff - 14 Years Ago
I always heard that motors with smaller valves made more low end torque then ones with larger valves,since I am much more familiar with the windsor series motors and the heads are a little restrictive on the exhaust side and needs a cam with more duration on the exhaust side is that the same with the Y heads.
By charliemccraney - 14 Years Ago
That could be true when considering valve size alone, but you have other factors to consider.  A bigger cam, and what else?  The compression bump of Gs or 113s will negate any detriment the larger valves may present.  Don't forget that the large valve heads worked great on 57-59 trucks.