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Timing plugs?

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C

Crisis

Jedi Hopeful
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I know we've been over it before, but I hope you will indulge me a few stupid questions about timing. I have a 73 TR6 with a retard vac on the dizzy routed to the valve on the upper hose, then to a port on the bottom of the rear carb.
1)I want to plug both the port on the retard and the carb. Can I do that? If I can do without that small long hose and valve on upper hose, I would like to.
2)What do I plug it with?
3)Then do I still set it at 12BTDC-adjust carbs-12BTDC etc.(tune).
Thanks.
 
Well there's no point plugging of the distributor retard unit since it only receives the vacuum; just leave it open.

Plug off the small nipple under the rear carb, there should be a 90degree rubber elbow that the hose plugs into, you can just put a small screw into the elbow to seal after removing the hose; then you can take off the hose from carb to retard.

As a matter of interest, why are you removing the vacuum to the retard? I don't think it does any harm (though I don't think it does any good either)

I'm not really sure what you should set the advance to without the retard unit attached; I know when I pull the hose off mine at idle the timing jumps quite a bit more advanced on the timing light
 
Graham, to be honest I'm not sure why I want to take it off. I just thought I'd like to clean up the engine bay by removing a few things that are not necessary for everyday driving. In addition, I'm not sure the valve on my upper rad hose is working; and I have the one piece hose as a spare. Thought I'd just use it instead of the questionable hose/valve setup.
I thought I read here somewhere that the car would operate just fine without the retard hook-up? As my car is not running very well I thought I'd go through the tune-up sequence; valve adjustment,timing, carbs etc. to get things back in order and thought it would be a good time to take that valve/retard out of the equation. Any of your thoughts are appreciated.
 
My understanding of the retard system is that it only affects things on decelleration or over-run conditions and is strictly there to improve the emissions and it's efficiency at doing that is debatable.
I beleive you are correct that the car will run just fine without it.
That valve in the rad hose is supposed to stop the retard working when the engine is cold (I think), on my car the vacuum is applied to the retard all the time, ie the valve doesn't seem to work but the car runs fine anyway.
I left mine in place because I like to keep things "looking" as stock as possible, although I've got increased compression and a hotter cam neither of which are visible.
 
Any auto parts store should have a suitable vacuum cap for the fitting under the carb. Sorry I don't recall the size offhand, but they'll have an assortment that covers it. As noted, no reason to plug the retard line on the dizzy (tho it won't hurt anything).

I dislike the retard, because it increases fuel consumption at idle as well as the tendency to overheat. However, you may have some trouble getting the idle rpm down where it belongs without the retard. If so, check the linkage to the float bowl vent valves as it may be holding the throttles open. On my Stag, I was able to bend that linkage a bit, so I could still adjust the vent valve as it should be (closed at idle).

I would suggest starting at the book value of 10 BTDC for timing without the retard. Once everything else is set up and the engine is running well, you can try a bit more initial advance and see how it goes. 12-14 might get you just a bit more power, and just a bit more fuel mileage; at the risk of breaking a piston or ring if it starts knocking and you don't hear it. But it should run fine at 10 BTDC. And yes, you keep that setting when making other adjustments.

While you are setting the timing, also look for spark scatter (mark jumps around under the light), and that the timing advances smoothly as you rev the engine up to 3500 rpm or so. If it jumps around or doesn't move, you have distributor problems (worn shaft, worn or stuck advance mechanism, etc.)
 
AltaKnight said:
That valve in the rad hose is supposed to stop the retard working when the engine is cold (I think),
Click to expand...
Other way 'round; it's supposed to stop the retard when the engine is starting to overheat; thereby raising idle rpm and hopefully cooling it back down.
 
TR3driver said:
AltaKnight said:
That valve in the rad hose is supposed to stop the retard working when the engine is cold (I think),
Click to expand...
Other way 'round; it's supposed to stop the retard when the engine is starting to overheat; thereby raising idle rpm and hopefully cooling it back down.
Click to expand...
That might explain why mine doesn't seem to do anything; I've never got into an overheat mode in my car.
 
AltaKnight said:
I've never got into an overheat mode in my car.
Click to expand...
There ARE certain advantages to living up North !
:driving:
 
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