Distributor Rebuild?

[6T5RUSH]

How do you measure acceptable play in an original distributor. Mine still has the 300 horse tag around it...#s are 1111076. I've got it out of the car (along with alternator, fan, fan shroud, radiator, carb, intake, heads and side pipes). I'm in the middle of swapping the LT1 cam and lifters for my hydraulic set up.

When the distributor was in the car, she ran fine. I've switched to Pertronix so it has the lobe sensor.

When you hold the distributor by the plate and grab the bottom of the shaft, there appears to be 1/16" or more of play up/down. What is acceptable? Is there a special tool to use to measure wear? What else should I be looking at?

Appreciate any responses. Now is the time to address all this. Already had my radiator flushed out and pressure tested.

Thanks again.

 

[magicv8]

That's acceptable. Feeler guages measure the gap. shim at the drive gear if you want it tighter for the pertronix, but don't take out more than half the gap, and don't reinstall the drive gear backward on the shaft - it only goes on correctly one way (odd number of teeth) - but you can install it reversed.

 

[studiog]

As long as you are checking your distributor for up and down play you might also want to check it for side to side wobble. Without getting out a dial indicator just see if there is any noticeable play side to side. This is not as critical with breakerless ignition as it would be with points. It would also show up with a dwell meter if you couldn't hold a steady reading.

 

[allcoupedup]

Jim,
I just went through this as well. The main wear components in a distributor (aside from the points of course) are the upper and lower bearings. This occurs due to the substantial load of the oil pump (cam drives the distributor, distributor drives the oil pump). The mesh between the cam gear and the distributor hear pushes it sideways.

Excessive wear shows as spark scatter at higher RPM's. The shadetree method is to put the distributor in a vice and wiggle it side to side. The best way to measure it is to use a SUN machine and check for drift and misfires on all 8 cylinders and use a dial gauge to check side to side play.

As studiog mentioned this is less critical without points but should not me ignored if it is excessive.

BTW - my LT1 swap has creeped into a complete rebuild. My block, heads, and crank are at the machine shop now. Got a friggin radiator from Mr. Dewitt too! I might get some aftermarket heads and a M20 to make up for my sluggish 3.36 rear end. I worked with Plasticman from the CF and ran some simulations - a 3.36:1 and the LT1 cam may make for some sluggish starts.

Be sure to check your cross gear end play - if it is excessive you'll eat mainshafts and cross gears and at ~$100/set they aren't cheap. Many of these old housings need a bronze button or hardened steel set screw to get proper cross gear end play. Let me know if you need more info. The cross-gear is MUCH harder than the cast iron housing and the mesh of the gears causes the gear to bore into the housing.

good luck
Brian

 

[6T5RUSH]

Thanks guys!

Magicv8, that's good news. I noticed it just clicks up and down within that 1/16". I think I'll leave well enough alone.

Studiog: I didn't notice any side to side play but I'll check for that, thanks!!

Hey Allcoupedup, How's the hydraulic to solid swap goin'? Sounds like the domino effect is at work for you. As Rosanna Dana says "If it isn't one thing, it's another!!" Sounds like you are on your way to a brand new car! So where are you on your project?

You might be interested to know that I shaved .6 of a second off my 1/4 mile time just swapping out my 3.36:1 open to a 3.70:1 posi. My benchmark of performance before my swap from hydraulics to solids is 14.2 @ 98 mph. Over time I've done the following to my 300 horse 327: Swapped out for the Correct Holley 600 cfm, vacuum secondary, mothballing my Carter AFB, correct 350/365 aluminum intake from the cast iron 300 horse version. Did change the cam to Speed Pro's hydraulic CS186R which has a 230/230 480 lift but with 1.6 Crane Gold Roller Rockers the lift ended up @ 512. Running factory rams horns and sidepipes, she ran sweet. The cam was rated from 3000 r's to 6. I am really looking forward to the seat of the pants feel going to this LT1 w/solids. Everything the Duke says about this swap reads win/win. From different threads I've seen both here and at the CF site, there's value in smoothing out the exhaust manifolds as well as the factory "dents' in the side pipes as they curve down and out to the sides of the car. I've got my pipes off as well as the manifolds. Have you heard anyone who's done this and noted a measured change for the better? Keep me posted on your endeavor. Sorry I got a little winded here...getting excited about this swap.

Thanks again all!

Jim (6T5RUSH)

 

[67HEAVEN]

I love it when a plan comes together!

 

[allcoupedup]

Jim,
I am truly converting to a '65 SHP minus the 30-30 CAM. Everything will be SHP (or better) minus the date codes of course - and I can't find a good deal on an idler pulley! I haven't checked into the dee groove pulley thing either.

Here's what's new for me:
Heads (going to 2.02/1.94 or maybe aftermarket)
Intake 3844461
Holley 2818
400083 fuel pump (new from GM)
Rebuild Recurve distributor
LT1 CAM
6 QT oil pan + windage
New oil pump
Comp cams 1.52 roller tip rockers
Forged aluminum pistons
SCAT I beam 4340 rods
SHP air cleaner housing and tubes
SHP choke tube and thermostat housing
oh yeah and a new radiator
trying to trade the M21 for a M20
all new hoses

I've been buying these things for 6 months now and have kept under the wife's radar screen (see boiling water and frog metaphor here) but DAMN this stufff gets expensive.

I'm glad I tore this thing down because someone had done a "taxi" rebuild - bearing/ring job + knurled valve guides. Once this is done I will NOT be worried about throwing a rod every time I rev it up to 6500. I still had the original pistons, nylond faced cam gear,freeze plugs, pistons,.... everything. AS the wise say --- bottom end gives reliability and build the top for HP!!

Good Luck. I hope you beat me to it!
Brian

 

[6T5RUSH]

Hey 67HEAVEN, nuthin' money can't fix!!

allcoupedup, you're doing it right. Don't know if Tracy Performance (586-772-8901) can sell you one at a price you can live with, but try him out for that idler pulley. Here's their site:

http://www.tracyperf.com/

Keep me posted.

Regards,