I see the suppliers have choices here. I can get the small time gear for the crank shaft, made of steel for about $12.00 or another one, also of steel for about $65.00. Any info/input on these.
Is there a big difference in function or performance?
I like a bargain as well as anyone but I don't want to replace this any time soon due to a poor performing part either.
I replaced the large gear with a bronze gear and the small gear with the $65 based on advice from the forum. Bottom line I think is that if you use a soft large gear like nylon or fiber you can use the cheaper gear, but if you go with a metal large gear you better go with the $65 small gear. It is an interference fit and I had to warm it up in the oven first to get it to go on the crankshaft, still had to help it some with a small rawhide hammer. Did it while my wife was out of the house.
Good call Jeff. Thanks for the advice too.
I have rebuilt dozens of engines using the $16 steel crank gear and the $50 aluminum cam gear and have had no problems. Of course, all those engines were freshly re-babbitted and I have to say that how the gears mesh can be particularily dependent upon how good the babbitt job is. All the small (crankshaft) timing gears should be a press fit on the crank and should easily press on with a small shop press. Be aware that occasionally the front of a camshaft will be bent and this can cause some mesh problems.
There is a huge issue that seems to escape many peoples attention... If your car is equipped with a generator, it is VERY IMPORTANT to also replace your generator gear when you replace timing gears and it is also VERY IMPORTANT to check the generator shaft with a dial indicator to make sure it is not bent and has no runout. If your generator shaft is slightly bent, the generator gear is going to be "crashing" into the large timing gear every revolution of the generator until it "wears in". In the event of a worn or pitted generator gear, it will rapidly wear the large timing gear all the way around.
Adam's right. In my younger days, when short the cash to do it right, I used an aluminum camshaft gear with both and old crankshaft gear and generator pulled off a T in a junkyard (yes, there were a few lurking around yet in those days). After running this car for 20 years, I tore down the engine to "do it right". The aluminum gear looks like it would work well on my radial arm saw as a dado cutter.