The Stovebolt Site Forums The Shop Area Engine Shop '68 L6 Distributor gripes

A couple of things: the distr that's on the truck now has a loose breaker plate, with too much horizontal and vertical slop, and the vacuum advance diaphragm doesn't seem to move. Truck won't seem to accelerate. Tuned up with new plugs, points, condenser, wires, cap, new ballast resistor, fresh starter/coil/dash leads, new gas filters and fuel pump, but it still won't exceed 45 mph. Another distributor I had in storage has a tight breaker plate but a dirt-clogged vac adv and a fried coil/bkr lead. Also the roll pin holding the cam/drive gear is wobbly. I have a new vac adv, lead and roll pin. Before I install them I want to know if the gizmo is still any good.
Is there a way - like a micrometer or caliper - to find tolerances for the breaker cam lobe dimension? The enertia weight springs looked good when I spun it on the chuck of my 18vdc DeWalt, but I thought I noticed a wild wobble. If this is the one I pulled 15-odd years ago because the cam lobes were worn [and not helping dwell] then it won't be much use except as a core, but I didn't want to go the checkerzone route since their cores have been beat to hell before they rebuild them in [China, Maylaysia, Mexico, Haiti] pick one.
It's a'68 292 in a C/10 pickup w/390 4bbl Holley. It was bored out .030 when it was rebuilt in '77.
Maybe I can cannibalize the two units into one useable distributor? Can the breaker plate be installed _in situ_ w/o pulling the whole candlestick?

Yes, you can. However, I would also replace the advance springs, and also pull the shaft to clean and lube. Don't about the lobe tolerances, though.

Thanks, Fred.
Is white lithium a good lube for this application? And you say don't [worry] about the cam lobe tolerences?

Before I say put everything back in storage and find a HEI from a later model L6, could you explain "new ballast resistor". Your '68 originaly had a ballast "resistor wire" that went from the distributor to the firewall/bulkhead connector. Did you or someone add a ballast to the original or just replace it.
The HEI will eliminate all your concerns and be close to maintenance free.

I neglected to mention I've got a Mallory Voltmaster II coil mounted to the block (instead of the stock coil). This unit requires a Mallory p/n 700 ceramic resistor in series with the yellow lead from the solenoid to the coil (+) positive terminal. The old one was flaking apart in the back after only 25-odd years and, although continuity rang good, I was unsure of nominal resistance values, so I decided to R&R it.
Meanwhile I noticed the vac adv can was bashed and wouldn't actuate, so I replaced it. Still no power at speed.
Thinking maybe the harmonic balancer had "walked" or spun so timing marks were off considerably -- I pulled the dampener. It looked OK as far as the timing mark being within 4 or 5 degrees of the timing mark on a known good '67 balancer with the woodruff keys lined up [one on top of the other]. I went down to the car wash and blasted an unknown amout of "gak" off the part. Cleaned up -- I saw the inertia ring was not flush with the front of the mounting center but pushed aft maybe 1/4". I'm going to show it to some machinists later.
The big bite is the timing gear cover has a rip in it from the crank gear inside and the harmonic balancer in front - with road dirt -attracted -abrasives building up on the back of the inertia ring - it wore a 3" by 1/2" tear in the sheet metal for oil from the timing gear oil director to leak out from. I think I found my high speed oil loss. The saved donor timing cover from the '67 block had the identical rip! Today I'm on a sheet metal hunt at the junkers.

Dagnabbit kumpewter wuz spost ta sey "I don't know about the lobe tolerances". After looking in my manuals, the only recommended way to check the dist. cam lobe wear is with an osciliscope. Another way would be to set up dial indicators and compare to a new one. You need a good measure on both lift and duration.

Recommended lube is cam & bearing grease, your white lithium should be thin enough for this.

Have you priced rebuilds? Last one I bought for a 235 was only $25. Parts guy wasn't to happy with my core. I had disassembled it to check the shaft which was severely scored, so I just chucked all the pieces in a ziplock. Had to assure him that all the pieces were there!

Well I scored a front timing gear cover at "Action" wreckers today. $20! It came off a 250, so the timing comb is at 1 O' Clock instead of 4 O' Clock on a '68 292. Big deal -- I'll cut off the 250 tab with a grinder and cut out the timing indicator index from the scrap '67 292 plate and I can JB weld it on at 4 O'Clock or get sombody to braze it or save one of the donor bolt holes and use that to mount it on.
Cool guy at the wreckers, he showed me snaps of his Orange '57 Chevy Sedan Delivery with 261 L6 and dual rochester monojets on Fenton dual carb intake and Fenton headers.
He also said he had a early '70s 6 cyl HEI w/ext coil for $60.
I also have a new -in -box Accel Blueprint point type distributor I was hoarding for my soon-to-be-newly rebuilt engine. The one I haven't got to the machinist's yet. I know I could get an "ultra/energy" lifetime warrantied stock rebuild of a stock candlestick for under $40 bucks down at the corner checker/zone, but I wanted to rebuild the Delco Remy unit that I [think] came from the factory with my OEM block. At least I know where it's been.
Has anyone else seen the external ignition condensors in Santucci's book. The ones about 1" in diameter and 3" long? They hang off the distributor's side opposite the vacuum can. They must kick a$$. Where can I get one?