I know there are a gazillion threads on this and yes, I have read them. Perhaps I should read them again. Pulled the #1 spark plug, bumped the motor till air came out of the hole. Moved the balancer to that the white marking/grove was a 0*TDC. Put the distributor in with the rotor pointed to the #1 wire on the cap. Clamped everything down, capped the vacuum advance, put the plug back in and started it up. Car idles rough. The mark I made at the 30* mark was a TDC with the timing light. Adjusted the timing light so that the white mark was at TDC and it was up to 40* advanced. I have no idea what's going on. I tried to move the rotor around counterclockwise then it died. Shouldn't the white mark be at 0* TDC with 0* advance on the timing gun?
Well, it runs so that is good. When you move the advance dial, you visually move the balancer mark until it lines up with the zero on the timing tab, and then you read your timing off the dial. Sounds like it was running very advanced. What confuses me is that you are talking about a 30* mark and a white mark. I hope you aren't confusing the two. With a dial back timing light, there is no need for a 30* mark, you don't need it. To adjust the timing, you move the distributor body, but you wrote rotor, so I assume that is what you meant. If after you have warmed up the engine, it won't idle with less timing, something else is wrong. I think you should tell us as much as possible about the engine, cam, ignition, carburetor?
Whoops - sorry about that, let me back up a bit. 70 GS 350. TA 284 cam, stock 750 cfm carb, hei ignition. 0 miles, but I did break the cam in. Yes, I moved the whole distributor, not just the rotor (Sorry) The 30* mark i added (sharpie mark) so I can see where the advance comes in. I'm not timing the car to that mark, just planning for down the road. I know the difference between the two and that is why I started this thread. The white mark is at the groove in the balancer and that was at 0* TDC when I started. Start the car up and when it aim the timing light, the 30* mark (sharpie mark) is at 0* TDC which it shouldn't be, right? When I adjust the distributor, eventually it dies when I try to retard it, or maybe I'M the retard. Anyway - it's messed up. Is the distributor off a tooth or two? I'm in over my head with this, and want a professional to figure this out. The more I mess with it, the more I'm afraid I'll screw it up and damage something.
If the 30* mark is at the 0 on the timing tab, it means your timing is at 30*. Guys always talk about a distributor being a tooth off, but if you can move the distributor enough to adjust the timing, the distributor is in correctly. I would try increasing the idle speed, and then see if you can retard the timing. In a lot of cases, when you install a cam, you'll need to get the Q-jet modified to idle correctly. Put a vacuum gauge on the engine, and make sure you have good vacuum. It should pull about 13-15" of vacuum fully warmed up. Ideally, you should aim to idle at about 12* BTDC, but that may not be possible with the HEI you are using. HEI's frequently have a lot of mechanical advance built into them, and you will have to see where your initial timing ends up after setting the total advance.
I didn't mess with the carb at all, although I'm was under the assumption it was rebuilt to handle the cam when the whole motor was built. It's been so long now. It runs better the more I rotate it counter clockwise but the #2 plug wire is stretched as far as it could go, that why I thought moving the distributor might help that problem. I'll continue to mess with it. Thanks for your patience. BH
CCW advances the timing even more. Considering that it is already at 30*, and the mechanical advance hasn't all come in, I'd say something else is wrong. Don't attempt to drive it like this as it will almost certainly be over advancing at higher RPM. If you get on it, you risk damage from detonation. Sometimes engines with a vacuum leak into the valley will want a lot of advance to idle. A vacuum leak into the valley can result from an incorrect fit between the intake and heads. That can happen from milling the heads and/or block excessively. That is why I suggested getting a vacuum reading on it.
There's no front clip on it, so I'm not driving it anytime soon. As far as point #2 is concerned, please say it isn't so. I'll get a reading on it. Just checked - over 20" of vacuum. I hope that's a good thing!!
It's pulling 22" of vacuum warmed up. Seems to idle nice. It's still on jackstands so I haven't even tried putting it in gear. I'm going to put it back on the ground tomorrow. Still 30* advanced and I'm still confused. Distributor issues? I feel like there's something very basic that I'm missing or doing wrong. I read the power timing thread and trying to follow that to the tee. BH
I don't understand. A stock engine should pull 20" at idle in Park. You have more than that? I thought this engine had a cam (284?). It should make less vacuum. Was the cam degreed in?
I don't understand either - Stage 1 Automotive did all the engine work along with Gessler. Cam was broken in, anything internal was done by Rob, not me. If I can't figure out timing can you imagine me doing a rebuild? What a mess. I'll figure it out eventually - I appreciate your help Larry! BH
This is probably a dumb question but I am going to ask it anyway. Are you sure your plug wires are installed in the proper locations and the firing order is correct> The amount o advance you are talking about seems to me to be possibly caused by incorrect firing order, especially if the #2 plug wire is stretched as far as you say.
Timing is timing. If you are measuring 30* of timing with your light, that is what it is, unless the light is off. Try another light. If you went to adjust the timing and as you turned the distributor, you ran out of travel, then the distributor would be in wrong, but as long as you have the ability to move the distributor and adjust the timing to what you want, it is in right. The only time I have seen an engine run that advanced is one of 2 things. First was an internal vacuum leak, the other was reversed polarity on an MSD magnetic pick up. If the firing order was incorrect, it wouldn't make a steady vacuum of 22".
I'm an idiot - #5 and #7 plug wires were reversed. Fixing that helped somewhat, I think I'm close to the 12* advance timing range at idle. I'm gonna leave it alone at this point. Not even close to being driven right now, but it runs nice and smooth with 20" of vacuum. I actually rotated the distributor and then moved all the plug wires over one spot counter clockwise, now the rotor and wires fit underneath the air cleaner and it still is in the 12* range with room to adjust. When I get ready to drive it I'll have to get someone over to take a closer look at it. I feel like I'm close and it has a nice idle to it. I'm happy with the way it sounds. Now...why no power steering? Yes, there's fluid in it. Air lock? BH
Larry- you're right once again. Since the carb was rebuilt I didn;t really mess with the idle screws, but in adjusting it I was able to raise the idle and backed down the timing. I can now set it wherever I want it at idle, it's right about 12.5* and it idles at about 600 and drops 50 when it get put into gear. I also moved all the wires over one spot on the rotor so the air cleaner can now fit on it. I haven't checked the total timing but I'm aiming for 32-34* total. Is that about right? Off to replace power steering pump. BH
Yes, 32-34*. Just make sure that you disconnect the vacuum advance, and that you are seeing all the mechanical advance in. That requires light springs so you don't need to rev it to the moon. Biggest mistake people make is assuming all the advance is in before it is. Stock springs will not let that happen until 4000 RPM or more. Use the lightest springs you can find just to set the total advance, then switch back to springs that get it all in around 2500 RPM or so.
Got it - thanks for the advice. I think I may get this thing on the road before July 4th if my fenders come back, just renewed the tags and insurance. BH
