Re: Replacing a dizzy, am I trying to make this too simple?
What ever u do... Set the engine to TDC as Fred says, remove the key from the ign and hide it in a dark place.
No u cant simply pull the old out and put the new in.
1/ often the slot bit in the top of the oil pump down inside the engine twists slightly and may need realigning to get #1 to the front a VA pionting in the right direction...look at the bottom of the new dizzy and u will see where ot goes in the bottom of the shaft.
2/ The new dizzy will be sligtly different configuration in side because of a different VA with a different length arm that sets the intial timing in a different place.
3/The amount of degrees in the counterweight part of the new dizzy will be VERY diffrent, as will the weight of the springs that determine the rate of advance against rpms
4/The VA will also have very different configuration, not just the number of degrees in it but the amount of Vaccuum required for it to start to advance and the piont at which it finishes... this will also require re configuring...this also refers back to 1/
If one refers to the AC/Delco electrical service manual there are literally 1000s of dizzies, all different specs, then combine those with 100s of VA specs...each combo for different vechiles of different weights, different rear axle/ gear box combos, different wheel diameters , different engine power and sizes , and different end use of the vechilce.
Therefore it is impossble (and uneconomical to produce) to simply buy a 'matching' dizzy out of the box and drop in.
If your orginal dizzy has been dialed into to your engine , to take account of any rebuils, rebores etc, the very different fuels we now use....
Simply take a bit of graph paper and a timing light and re graph what is in the current dizzy, and note the VA specs...then reproce those onece back in the car by filling off counter weight tails, changinf springs and adjusting the VA and setting the intial timing position.
IF it has never been dialed in , then to do so u will have to make sure that there are no vaccuum leaks, establish that the carb is dialed in with O2 sensors , data loggers under load, cruise and idle...THEN establish yout tuning pionts in the timing. intial , idle, total, and amount of VA.
It also very highly recommended that all new HT leads, spark plugs shuld be installed so get correct readings.
9/16 ring spanner
O2 sensor and data logger
hand vaccuum pump
tape for the Harmonic balancer to extend the timing marks out to 40 degs
Graph paper and pen.
We look at out lumps of cast iron and very rarely appreciate the presion settings and engineering that goes in to them....machining down to fractions of 1/1000"
Carb jets and setting even smaller
Timing to hit the max piont of explosion at the correct piont at a given load and rpms in a narrow 'window ' of 12 to 18 degs ATDC +/- 1 deg or less.
Funny how we spend hrs getting panels lined up down to small fractions of an inch to look good, and so many dont give a damn after spending so much money and time of having the engine run as well...
I dont want to put u off....we have talked , many times, in old posts , members who have never done stuff before, suspenstion , brakes, panels, welding.....and dialing in engines...this is what this communty is about.