Ignition system update

[ralley]

Last weekend I finally finished the upgrade of the ignition system in our 1991 350. The 454 runs, at idle, GREAT!! It idles smoother, accelerates better, and the timing controls appear to work well.

I installed a MSD igniion system with a timing control--the basic stuff, nothing fancy. This weekend I will re-time the 454 so that, as suggested, the TDC timing is set so that the timing advance and timing retard can each be set a maximum of 7.5 degrees. For flatlanding and downhill, the timing gets advanced; for climbing, the timing gets retarded, or so the theory goes.

What I have no guidance on is: How Much retard or advance? Clearly this is related to engine condition--but listening to engine detonation (pinging) is a hit or miss proposition without adequate experience, particularly if the pinging is coming from under a well insulated doghouse.

Any guidance from folks who have done this before?? Can the vacuum gage be used as an indicator??

Best to all,

Rob

[scottanlily]

Hello ralley,

You have installed a fantastic setup ,I have installed quite a few MSD ignitions including the billet and pro billet distributors,.anyway ,The timing control on my travelall is setup like this : Engine off ,then set your dial on the controller to the middle of the range ,its 0 to15 ,put it at 11 ,Your engine should be fully warmed up choke open base idle,set the timing to 6or8 degrees whatever your factory specs are using the distributor .This allows you to turn the knob down to 0 or whatever below 11 on the controller for retarding the timing as needed .The good part is that at higher elevations say denver or aspen you can turn the knob on the controller forward up to 15 max to get more advance as needed ,higher elevation you can increase the base timing to get more power ,works fantastic !You can just turn it back if it pings ,in the desert ,arizona ,hot ,pinging, turn the knob down to anything under number 11 that stops the ping as needed.So while its for controlling timing ,retarding it ,you can also advance it too!! The best control available .I have used it in both types of elevations high and low ,works great !!The timing control is retard for uphill when pinging occurs ,higher elevations as I said you can advance it for power also .You dont need to advance it for downhill but you can gain better mileage if advanced ,on the flatlands with poor fuel quality it may ping at the stock setting number 11 so you may back it down to number 8 that maybe enough.It is trial and error but easy to do, you know that when you have it at 11 thats stock timing so if your not sure ,put back to number 11 and see what she does .And yes youll have to denote the pining sound by your ear.the vacuum gauge does not help ,but it works great at fuel consumption if you keep the needle at 20" of vacuum on the gauge as much as possible.My travelall is setup just this way ,If I am towing my tradewind on the flats and i get some ping at setting 11 Ill backit off to 7 or 8 about 3 ,degrees, no ping !You could crack the doghouse on initial tests to better hear the ping .You can PM me if you have more questions as I use MSD products alot .I also run the MSD 6A control and the wires ,the distributor has all the MSD (FORD DURASPARK) pickup piece used in all MSD pro billet distributors as well.

You,ll be happy with it

Scott

[swebster]

I'm interested in hearing more about your results with the MSD system. I've replaced my iginition back to stock, but have been considering an upgrade for some time. It's that wobbly idle that makes me wonder what's happening at speed.

It is really hard to hear knock at speed (55 - 60 mph) through the doghouse. While you're adding MSD components have you looked into this knock alert from MSD?

http://www.jegs.com/webapp/wcs/store...tegoryId=17967

[ralley]

No, I hadn't seen the knock alert--thanks. I will re-time over the weekend and run for a few miles before I decide if my hearing has become as bad as I think it is!! (or $139.00 worth, anyway)

The one thing I noticed immediately is the starting. The engine usually had to turn over for a second or two before it started. After adding the ign and timing stuff, it starts immediately, with no appreciable cranking. The stock coil may be a bit weak--it's been on top of that engine for a long time, and I have left it in place. The new coil and wiring is configured so that if the MSD stuff fails on the road, I can restore the original configuration and get on with it.

[overlander63]

I know y'all are aware of this, but I will post it again for the benefit of other folks that may find this thread as apart of a search.
Without getting too technical, when the spark plug sparks, the flame front, or wave of burning fuel travels at 55 mph across the inside of your cylinder. When you hear your engine ping, it is because the fl;ame front has gone supersonic. A little sonic boom inside your engine. If you have ever had one over your house, you know how it rattle the windows, and maybe can break something fragile. It will do the same inside your engine--Uhh, hopefully it won't break any dishes in there, but it can cause problems like damaged pistons, destroyed spark plug ends, etc.
It is important to keep your engine from pinging, so do your best to set your timing so you can just hear a small pinging, and then back the timing off a degree or two.
This concludes our public service message, and thank you for flying Airstream Forums.

[ralley]

Yeah--that's why I asked the question. Somewhere I have seen a photo of a completely missing piston because of a detonation problem.......Thanks for the reminder for us all.

Best,

R

[ralley]

OK, GIRLS: We now have adjustable timing, and it was a female canine to do.
The following problems exist in the 350 timing.
1. There are two set of timing marks bolted to the block.
2. The set on the bottom of the engine (4 oclock, viewed from the front) is worthless--there are no corresponding timing marks on the flywheel.
3. The set of timing marks bolted to the block at about 1 oclock is used to time the engine, but THE TIMING MARKS CANNOT BE SEEN FROM ANY ANGLE INSIDE THE VEHICLE. Either the belts or the bracket for the fan always put the timing marks in shadow, and there is no place that you can place a mirror to make the timing marks visible.
4. What can be seen is the sight hole in the timing bracket, the center of which is TDC.
5. Using a mirror, you can determine that the diameter of the sight hole is 4 degrees.
6. I adjusted the timing to be 1 diameter of the sight hole beyond TDC, giving the 4 degrees BTDC required.
5. It is very useful to have a remote starting switch in this process. Unfortunately, the placement of the starting switch post on the solenoid makes the attachment of the remote switch wires very difficult (one of those Red Cross jobs--requires blood donation because of the proximity of the sheet metal shielding for the solenoid). The ground bolt on the starter is also in the way, making for very difficult attachment.

Because this work took much longer than I had planned, a test run will have to wait until next weekend.

If ever the fan and water pump housing have to come out, I plan to grind off about half an inch of the bracket so that the timing marks can be seen, making this process much easier.

[87MH]

Originally Posted by ralley

OK, GIRLS: We now have adjustable timing, and it was a female canine to do.
The following problems exist in the 350 timing.
1. There are two set of timing marks bolted to the block.
2. The set on the bottom of the engine (4 oclock, viewed from the front) is worthless--there are no corresponding timing marks on the flywheel.
....

Try timing off of the #5 cylinder for the 4 o'clock position -

The top timing marks are inaccessable on most MoHo's -

On the '87 345 (454 engine) using the lower timing indicator works if you time off of the #5 cylinder.

[ralley]

NOW YOU TELL ME!!!!!!!!!!!

Thanks!

Best,

Rob

[scottanlily]

Hello rally,

Once you get your base timing set ,youll be on your way.Light pining is no good ,what damages the pistons is detonation ,they are the same but not the same ,meaning that detonation is destuctive quickly ,you have 2 flame fronts burning scross the top of the piston colliding ,simular to pinging which has been described in the previouse post.Detonation is where hot carbon in the cylinder ignites the fuel as can skyrocketing chamber temperatures combined with poor fuels ignite the fuel prematurely ,then your normal spark occurrs causing the other flame front to begin across the top of the piston where they crash together ,goodbuy piston ,the ring lands take a huge pounding as well. I would definately install the MSD knock retard .the knock sensor threads in place of one of the block drain plugs above the oan rail on the side of the block.That MSD sensor is basically a GM knock sensor used on all computor controlled 350s 454s etc. to date.I went a little more technical to give a bit more detailed description .It is important to know that light pinging is never good ,but detonation kills quickly.

Scott

[ralley]

Originally Posted by scottanlily

Hello rally,

Once you get your base timing set ,youll be on your way.Light pining is no good ,what damages the pistons is detonation ,they are the same but not the same ,meaning that detonation is destuctive quickly ,you have 2 flame fronts burning scross the top of the piston colliding ,simular to pinging which has been described in the previouse post.Detonation is where hot carbon in the cylinder ignites the fuel as can skyrocketing chamber temperatures combined with poor fuels ignite the fuel prematurely ,then your normal spark occurrs causing the other flame front to begin across the top of the piston where they crash together ,goodbuy piston ,the ring lands take a huge pounding as well. I would definately install the MSD knock retard .the knock sensor threads in place of one of the block drain plugs above the oan rail on the side of the block.That MSD sensor is basically a GM knock sensor used on all computor controlled 350s 454s etc. to date.I went a little more technical to give a bit more detailed description .It is important to know that light pinging is never good ,but detonation kills quickly.

Scott

Thanks very much for the recommendation. The timing is set, and is OK--I just won't be able to test until Saturday.

I have no clue when the PO last changed the antifreeze and blew out the cooling system. Sounds like a good time to do this work--and I can install a knock sensor at the same time.

I hope to spend some time driving the 350 this weekend just to see how the timing control and ignition works. I'll let folks know what I think after about 25 miles of hills.

Best,

Rob

[ralley]

Originally Posted by ralley

Thanks very much for the recommendation. The timing is set, and is OK--I just won't be able to test until Saturday.

I have no clue when the PO last changed the antifreeze and blew out the cooling system. Sounds like a good time to do this work--and I can install a knock sensor at the same time.

I hope to spend some time driving the 350 this weekend just to see how the timing control and ignition works. I'll let folks know what I think after about 25 miles of hills.

Best,

Rob

I put 26-28 miles of gentle hills on the Zeppelin yesterday. I think I have a bit more power-say, 10% or so-and the vacuum gage seems happier, staying off the bottom peg a bit more. (This is good, because the cruise control appears to be a vacuum system, so it cuts out without adequate vacuum!!)

I mounted the rheaostat which is the timing control to the right of the heater control and just below the dash radio, easily within reach, and without much parallax error from the driver's seat. I set the timing, which is 4 deg BTDC at 9 on the rheaostat (which runs 0-15) so there is plenty of advance or retard.

I wired in the new coil, and left the old one in place. I wired in some bullet connectors which will allow the entire new system to be bypassed and returned to the status quo ante electronic if necessary.

So far, I'm satisfied that Zeppelin starts better, runs better, and has a bit more power. I am not sure how I would quantify the differences, and justify the expense in time and materials. Fuel economy (surely an oxymoron in a vehicle weighing 17000 lbs) remains to be seen.

Best,

Rob

[scottanlily]

hey rally, I believe you have ,runs better,starts better,control the the ping if needed. your reward will be that you now have control at your finger tips to adjust your coach as you drive ,hear the ping,you back down the timing ,so on and so forth. Need more power advance it.its all good!

Scott

[ralley]

I installed the knock sensor today. It works. Engine doesn't knock, anyway!!

Thanks to all for the sound, sage advice...........

Rob