I have a thread about setting the timing on the 350 SBC in my T Bucket. But what Hoop98 and I found today deserves it's own thread. So, Hoop arrives at my house this afternoon and we get started to tune my engine. Hoop had me crank her up and we did some preliminary checks. Result... 4* initial and NO ADVANCE what so ever. Hoop had me pull the cap of my distributer and this is ONE of the things that greeted me, The cap had a hole melted through it! Hoop asked if I had plans to start walking. We also found I was missing a spring and had VERY little movement of the center plates. After I recovered from the embarr***ment of obvious neglect, we sprayed some WD-40 and finally got good movement of the plates. Hoop had brought a curve kit and I replaced the springs. A quick trip to the auto parts store and I had a new cap and rotor. We ****oned everything up and all is good. 16* initial and 36* total advance. If I'm wrong, I'm sure Hoop will chime in. During a quick test drive, I immediately noticed the difference. Which brings me to the con of HEI. It's easy to get complacent and let it go. When I had a points car, I was always checking it out. Just part of having a points car. With HEI, a lot of us kinda let it go till it stops working or we feel something wrong. So, thanks, HOOP. I really appreciate you coming over and sweating in the mid day sun. I think it was 95*. Yikes, indeed.
Hey we were missing the key ingredient of shadetree mechanicing, shade! Was nice meeting you and glad we could tune up your T
After you left, I ran a couple errands. I got done quicker than usual. Thanks again and if you're ever this way or we get together, I owe you some BBQ. Power of the HAMB and 95*.
Actually, I've already started. When it cools down, I'm going to readjust my carb. Since I had it running with bad timing, I'm sure I can tweak a little better performance out of it.
complacent..... isn't it great..... Todays cars create even more complacency, as the computer will keep it runnin with a little yellow light lit for months.... that is until that emergency errand, and the laws of physics.... and the dreaded tire kick..... Glad its runnin great now!
Seen that happen lots with the white plastic rotors, never the black ones. Never seen a pink/red one....
It's actually red. Came out pink in the pic though. Back when I first built my car, I replaced the black factory cap and rotor to an after market. Mainly to color coordinate with the red and black I had painted my engine & ch***is. So, timewise, it was about 7 years old. The one I went with today is an Accel unit. Surprisingly, it was $5 cheaper than the standard black cap and rotor. About 2 months ago, I had some work done on the transmission and we had to take the cap off to tilt the engine back. Unfortunately, we didn't take it all the way off. I would have seen that **** and replaced it, but with my limited knowledge on distributors, that's probably all I would have done. Hoops offer to help was a gift and I'm grateful. He gave a very good explanation of how stuff works under there. That in itself was worth his time and effort.
It was a problem because people ignored them. As part of our annual "tune-up" we lubed the pivots and checked mechanical and vacuum advance. We also cleaned battery connections, adjusted the belts, checked the starting and charging system. This was in the 70 - 84 time frame. If it had points we did the same but cleaned and lubed the point cam. We also lubed the manifold heat valve, checked choke linkages, pull-offs and fast idle speed. I would ck the power valve on Q-jets for sticking. This was a lot different than throwing a set of plugs in it...
The black rotors were bad about burning a hole under the contact and shorting to the distributor shaft and leaving the car dead. First one was pretty hard to find, second one a lot easier. It was bad enough that Delco Remy went to a different plastic (white rotors) to remedy the situation. You would still find one burnt through once in a while, but not near as bad as the black rotors.
Usually when a white rotor burned thru you would wind a plug wire not snapped on. Number 6 on the new (78) Regal-Century was hard to get to. Usually it would burn thru at the plug wire tower to a coil screw. If one of the came in running on 5 you could bet it was 6 that was dead. New wire and cap you were back to a full 105 horses. HEI's had enough voltage that if you put an open somewhere, left a wire off etc.., It was going to burn through somewhere.....
So next up Fred, go get a NAPA Echlin VC1838 Vacuum Advance. Just 2 screws easy to change out. When you take the screws out you have to tilt and turn it to disengage the rod. reset the initial to 16 and that will add 14 at cruise, 16 Base, 20 Mechanical and 14 Vacuum, that will be sweet....
Whole heartedly agree! Tune ups were recommended every 10 K when I started out. Maintenance has become a 4 letter word.
I was really embarr***ed when I popped the cap and saw that rotor AND cap. I usually take great care of my cars and do regular maintenance, but putting so much faith in the HEI bit me in the ***. On previous HEI cars, I've gone YEARS without even popping the cap. But that's what they do, they lull you into a state of comfort. On my points cars, we used to check and replace them every 3 months. So, now checking or even replacing the cap and rotor is on my yearly check list.
I think I'll be in Jackson, TN next week I didn't do anything special, and Fred did all the work. After 30 plus years it's common for the advance mechanism to be gummed up. It would be best to pull the distributor and thoroughly clean it, but not in 97 degree sun. If you have a distributor with mechanical advance, pull the cap and twist the rotor in the direction of rotation, it should move 10 - 18 degrees in that direction and snap back freely. If not investigate and free up. While you need a dyno or some road testing to get the last bit of power/economy, we know the typical SBC to get you very close. A stock HEI has 20-22 degrees of advance but it usually comes in pretty late. To check for 36 degrees we need a marked damper, a timing tape applied to the damper, or a dial back timing light. If you find the advance comes in too high slip over to a parts store and buy a spring kit. Put lighter springs on until the advance is maxed at 2500 - 3500 RPM. Set the advance to 36 there and and whatever your initial is is fine. If you have a high compression engine and get starter kick back you will need to add advance in the distributor. Here is a good guide. http://www.pontiacstreetperformance.com/psp/distcurve.html Once you have the total you need to setup vacuum advance, you want a unit that allows max advance at about 2 inches less than your idle vacuum. Oh and for SBC with these kind of advance numbers run manifold vacuum to the vac adv, Advance will usually work out with 14 -18 degrees vacuum advance. The VC 1838 has 14 degrees crank advance at 10-12 inches of vacuum so it works with Fred's 16 initial to give us 30 degrees at idle. If you get an adjustable vacuum advance you can use a mytivac and adjust it to 2 inches below idle vacuum to start. If you use an adjustable vacuum advance be sure to get an advance limiter plate. You can set the limiter to achieve 24 - 32 degrees advance at idle. If you are 12 initial, 16 would put you at 28. If you get sustained ping at part throttle run less vacuum advance, if you get transient ping on tip in and upshifts go to a higher vacuum. Simple eh?
hei issues like yours are common due to low quality parts in the market place. If red is cheaper than black they are black if that increases profit.
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