jd420 pics

[Jim B]

Great news, something going right for you.

[dtoots1]

well no good words from Clevite as yet..

Can someone give me the part number for .030 mains ...jd part number??..book claims only that they did have....030, .020 and .010 sizes plus an odd size tho cant remember that one.
Edit 6/29/24..that last odd size is .033

did find out clevite shows...same diameter mains for 2014 thru 2018 silverado 1500, but no dimensions to compare versus what measures from the caps

[dtoots1]

WELL the saga continues...got used standard mains from GaspumpSam in British Columbia and to my TECH mechanic..says he can fit crank and mains..maybe will have them in time for XMASS???
As info took 13 days to get mail from here to B.C....wonder if pony expressed??? bearings from there to here took 3 days less?

Enjoy!

[Jim B]

Well, it is progress.

Have a Happy Thanksgiving.

Jim

[dtoots1]

YES..Happy Thanksgiving to ALL!

[dtoots1]

OK All you guys..Here is where we are at with this old girl now..My cylinders were bored out to 4.26 so we new need pistons and rings that are .045 oversize..the 3 compression rings are 3/32 thick each and the oil ring 1/4 in...normal bore is 4.25 standard

Also the question is..what ring end gap can we run without issues (compression loss, oil)...if is ok to have a little more gap and no big issues should be able to run it.. with the new rings we have?..just the gaps a little wider than specs.

Would the compression rings hold it?

[Lavoy]

4.250 standard bore + .045 ovebore is 4.295. Something is off.
Lavoy

[dtoots1]

Found other info related...
ring end gap is .049 with standard ring it should be .023..so would need .010 oversize rings..to get correct gap?

bored to 4.26

[Lavoy]

There are no .010 pistons, so you can't have a 4.260 bore, or at least if you do, there are no parts for that overbore.
.045 overbore is is 4.295. You said you need .045 piston, that will not fit in in a 4.260 bore.
There are no .010 over pistons, there are no .010 rings. If you are truly at 4.260, you will have to run standard pistons and rings and listen to the piston slap.
Lavoy

[dtoots1]

Ok thats a helpful answer!!

[dtoots1]

Hey GUYS,

Got my engine back..am looking at my old harness...on the ignition switch the heavy red wire going to the starter post has a rectangular open box with some type of plastic poured into it...think may be resistor of some sort?? what is it and do i need in this? it was anchored to the console inside. 2 small bolts and nuts..
goes from witch to box and from box to starter

[Stan Disbrow]

Hi,

Is this one converted to 12v? If so, then a dropping resistor for the ignition comes to mind.

Stan

[dtoots1]

Nope Stan..it is still 6volt and came with the blamed thing in line..so what would it be and do i need it?? sure dont want it screwing something up if aint in line like original.

i cannot remember for sure but it seems to me that the 6 volt,,machines,, did have a resister?

fuse and holder is in dash panel .the box mentioned was mounted in the dash panel originally when i removed panel as it was (panel) broken.

After checking this once again..it is the heaviest red wire in the harness and appears to be a forked clip connector..like would slip in a sleeve connector on the voltage regulator or generator maybe..been too dang long since was apart..

[Stan Disbrow]

Hi,

Some 420 production used a resistor to dim the rear work light to make it a red tail light. These had multi piece rear lights rather than a sealed beam.

Others had a sealed beam with a circle cut out of the reflector plating which was coated with red to allow a second small bulb to be the red tail light.

So, the first kind had a resistor near to the ILBD switch to make the Dim setting work. The second kind didn't have a resistor as the Dim position fed a second wire to the rear work light.

And, these things have a funny habit of being changed over the decades. So, you might have a sealed bean rear light now which isn't original. And, so the resistor might be left behind. And, the resistor might not still work as the current pulled my the filament of a sealed beam is too great and they open up.

The fat red wire from the starter terminal is the feed line from the battery to the ILBD switch.

Stan

[dtoots1]

Stan,,

that fat line is the one with the open top metal box with plastic like stuff poured into it with one end from starter and other to ign switch..and it did have a broken fuse holder in the dash panel twist cap type..which i replaced...so wonder if i even need the other open box thingy..since NOONE so far knows what it is..tho it does look kinda original since has holes in dash for mounting..mounts to front..engine side..on right lower of dash..

oh and by the way...no lights atall on blamed thing anyhow...as yet

and isnt there a small resistor built into the ILBD switch?