Tachometer

Thanks guys I feel better about it now

You really need to learn the terms.

Rocker arms rock back and forth on top of the valves. Pushrods are the rods that push the rocker arms...not to be confused with connecting rods [often simply referred to as "rods"], which connect the pistons to the crankshaft.

As long as you're willing to learn, you find the guys on these forums are willing to help you leanr. And if you ask us something we don't know, we'll do our best to find the correct answer. And if there happens to be a difference of opinion on what the correct answer is, we'll try to give you the best answer we can anyway.

And here's how the lifters--also referred to as tappets--rotate:

The bottom of a new [non-roller] tappet is convex shaped, not quite hemispherical but tending toward hemispherical, and are highest in the center. The cam lobes are also tapered on the sides, and crowned in the center. With this relationship, it causes the tappet to rotate in the bore. This rotation helps minimize wear on the tappet face, which keeps the engine running longer between required tappet and camshaft replacements. If the bottom of the tappet was flat, and the cam lobe was flat, wear would be accelerated, and pretty soon you'd have a wide groove worn into the bottom of the tappet face.

Thanks Buzz, and while we're on the subject does the 1956 BD220 have hydraulic or solid lifters?

All the International sixes through 1968 used solid lifters. It wasn't until IH went to the AMC six in 1969 that they had hydraulic lifters in a six.

So then the question would be. Can the solid lifters be changed out to hydraulic lifters?

It depends on whether anyone makes a hydraulic lifter of the identical height and diameter.

No, I don't know the answer to that question.

To run hydraulic lifters, the lifter bore has to have a feeder hole from the oil galley to force feed the lifter with oil pressure, if it is lubed by splash oiling it will not support a hydraulic lifter. Food for thought.
Bill

I believe the cam "ramp profile" is different on hyd and mech lifters as well. (the portion of the cam at the begining end end of the "bump")

http://mgaguru.com/mgtech/ignition/ig104.htm

I dont agree with their logic or drawing. The high tension winding is not common with either the + or- of the coil but is grounded to the coil case. To do otherwise would put the high coil voltage thru both the points and condensor. Not to mention that the primary wire to the points would be carrying the high voltage, you would see it arcing to ground. Also in one paragraph he says the secondary is "ac" while talking about which way the spark jumps, which can only be influanced if the output is DC, and AC spark would jump both ways with the cycles. The output of a coil is DC but not a smooth or consistan e current but more of a "sawtooth pattern", as it ionized the air.
Spark can be either ac or dc but in a battery and coil it is dc. An ingniter for a home furnas is ac.
Some coils (like coil packs on modern cars or some motorcyle coils) have each end of the secondary connected to a plug, one fireing at TDC compression and one wasted spark at TDC exhaust on a mated cyl.

I know this goes back to page 3, but I finely found the Delco file that explains coils better then I can. It also shows "buzz coils" on the last page, and on those (buzz coils) the secondary IS connected to one of the primarys, which may be where the link that Buzz posted got that idea, Normal ign coils do not have the secondary connected to the primary
Humm, will not let me attach a PDF. Well I've got a good explanation if someone can figure how to post a PDF.