Are the stock ones sealed at the back then ? Otherwise they’d suffer the same. I’ll open mine up when I get back, it’s been a few years now since I was inside.Originally Posted by spfautsch
Mitch
Are the stock ones sealed at the back then ? Otherwise they’d suffer the same. I’ll open mine up when I get back, it’s been a few years now since I was inside.
Mitch
'95 Z28 M6 -Just the odd mod.
'80 350 A3 C3 Corvette - recent addition.
The bearing grease seals are what make them "airtight". Obviously this is less than optimal, but the distributor really doesn't need to hold much of a vacuum. The amount of air the check valves allow the intake to pull through it is fairly small. But if the inlet hose clogs or gets pinched it could put the opti under full intake vacuum and I would imagine that could cause problems.
Last edited by spfautsch; 02-14-2018 at 12:59 AM.
The restrictive nature of the vacuum check valves should limit the vacuum enough to pose no threat to any bearing, I think. But the metal shielding is a bit less waterproof, I'd say. Condensation may pose a threat to a metal shielded bearing. I suppose I will have to look a bit harder. Will probably be derailed by Valentine's Day, though. Such an inconvenient holiday.
Still drafting up a degree wheel in CAD, despite a toddler bumping my elbow at every opportunity. I noticed the slightly abnormal shape of the wheel, but I do wonder if it was pressed up flat against the scanner with a weighted object. Still, it is very useful for indexing the design properly. Thanks again. I have not superimposed one onto another yet to check for differences. And yes, I will take any scan I can get! I believe these are made by heavy chemical etching, not laser cut, as some may believe. Kind of like when etching a PC board, but with stainless steel as the material.
The restrictive nature of the vacuum check valves should limit the vacuum enough to pose no threat to any bearing, I think. But the metal shielding is a bit less waterproof, I'd say. Condensation may pose a threat to a metal shielded bearing. I suppose I will have to look a bit harder. Will probably be derailed by Valentine's Day, though. Such an inconvenient holiday.
Still drafting up a degree wheel in CAD, despite a toddler bumping my elbow at every opportunity. I noticed the slightly abnormal shape of the wheel, but I do wonder if it was pressed up flat against the scanner with a weighted object. Still, it is very useful for indexing the design properly. Thanks again. I have not superimposed one onto another yet to check for differences. And yes, I will take any scan I can get! I believe these are made by heavy chemical etching, not laser cut, as some may believe. Kind of like when etching a PC board, but with stainless steel as the material.
Distributor body, hub and shaft. Note, the rust came out of the water pump coupler when I was blowing the engine off with compressed air, it wasn't inside the opti. I guess I didn't use enough grease when I installed the coupler.
Base diameter of the outer race
Overall diameter of the outer race
Depth of the shoulder
Demonstrating how the mounting ring rests on shoulder when installed
I may not need a bearing as bad as I originally thought, but hopefully these might enable someone to find a reasonably well suited replacement.
After I finished taking these I did some experimentation with what I initially reported was a "garbage" remanned distributor base. The optical sensor may be a Mitsubishi - I still have reservations about using it in the car when I have an AIP sensor that is known to work in-situ. But one of the things I tried was spinning it with a drill with the controller in normal mode to see if sequencing worked. Though sequencing wasn't perfect, the impedances may be wrong because it's not also connected to the PCM as it was in the car. Out of curiosity I tried my known good AIP sensor in the other base, and it also exhibited similar sequence issues. More importantly, after spinning for 20-30 seconds at ~1000 rpm the bearing stopped making such a ridiculous racket. I'm thinking the grease just wasn't distributed through the bearing. Because there's no evidence the shaft was marked or keyed for index before disassembly, I'm starting to wonder if this might be a new old stock Delphi base. Thinking this one's a keeper after all. Just when I was starting to feel like I'd never catch a break!
Last edited by spfautsch; 02-14-2018 at 06:47 AM.
Double roller timing set dropped another degree off the skew (#6 is coming in at +7, #1 at +9). I'm relatively sure the issue I was measuring initially is a case of tolerance stacking. I'm going to pull the cam out and make sure the front bearing and journal look good, but the only other explanation is that the shoulder on the cam that fits into the cam gear is also offset a few thousandths. +/- 1 degree is acceptable to me - I'll center my opti wheel at zero on one of the in-between cylinders and be happy.
I eliminated the opti as the sole source of the problem by measuring cam ICL on both #1 and #6, and there was a similar skew.
I still have to measure cam advance at least one more time since I went too optimistic picking the advance keyway on the initial assembly. Then dump the oil, oil pan, pull the headers so I can invert the engine and clean the mating surfaces comfortably, etc.
I went with a Cloyes 9-3545x9 set that was almost a third of what the single roller set with water pump drive I bought last year cost ($220). I didn't hear anything to lead me to believe the chain was hitting the timing cover, but will report back if clearancing of the cover is needed - I slathered a few globs of grease on the chain before the last mock-up assembly.
Since the double roller timing set cut about a pound of weight from the rotating mass, I ripped off the "might as well" band-aid and ordered an electric water pump and a freeze plug to close off the water pump drive hole. It's only money, right? Will run it off the recently deleted air injection pump relay.
Last edited by spfautsch; 02-16-2018 at 06:30 AM.
Wanted to drop a little more information and an update.
First, I discovered that the Delphi distributor base uses a slightly different bearing. 6003LU - as a standard order part # it has roughly the same outer diameter as the Delco bearing, but with an overall larger race that looks like could be chucked up in a lathe and cut to fit the application. Also it only has a step on one side of the race, for the retainer. Unfortunately this retainer has a larger ID than the Delco design, so you'd need to source a different retainer and bore / ream the step out of the bottom of the Delco bearing bore to use this bearing in the Delco. The Delphi base has slightly different dimensions, presumably to enable them to use this particular standard order bearing and cut it to fit thereby eliminating a special order item. Whatever the case, this bearing appears to be readily available. Also, the OE optical pickup can be made to fit the Delphi base by simply shimming it up with a couple washers. Long story short, the Delphi base is probably more rebuildable then the Delco-Remy. One thing I would want to change to the design is to make the thin retaining ring spring hardened in a shape that puts constant tension on the outer race to keep it seated, as I discovered it bends easily.
When I got to degreeing in my cam and checking timing yesterday I was shocked to find only 1 degree total skew. Evidently there is enough slop in the fit between the cam and timing gear to allow for this. So where I was at +/- 1 degree I'm now at +/- 0.5 degree. I realize this is probably irrelevant to most of you, but I found it interesting that tolerance stacking could cause 4 degrees of skew.
Last edited by spfautsch; 02-20-2018 at 12:04 AM.
Still taking too long to draft up an optispark wheel, due to my laptop dieing randomly during drafting. Time for a new laptop and a qualude for the toddler. Unfortunately, it is not the same old cpu fan scenario that is typical. Perhaps I should buy a toughbook.
Tech moves so fast and can be so inexpensive I don't see much value in buying an extremely expensive piece that will last "forever" and continuing to use it well past it's point of (designed) obsolescence due the fallacy of sunk cost. I tend to buy something nice (by my extremely low standards) on clearance every 3-5 years and consider it more or less disposable. When my current rig dies (an inspiron 13 3-in-1) I'll move the ssd and memory from my old one to my new one and never miss a beat. But then I don't run windows.
I'm not making much progress here either. I did spend some time working on the coil harness over the weekend. That was before I discovered I have a valve stem and possibly a guide, seat that are trashed. I haven't worked up the courage to pull the head yet and assess the damage fully.
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