318 ignition system

Things that are of general interest.
EWRice
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Joined: Thu Feb 04, 2016 12:37 pm

Re: 318 ignition system

Post by EWRice »

I assume by your comments that your new distributor has the vacuum advance. If so, did you set the timing with the vacuum hooked up or disconnected? I would disconnect the vacuum advance and plug it off permanently. There is no benefit to it in a marine/industrial application, and sometimes it can cause issues at light throttle/heavy load situations. If the timing was set with vacuum hooked up at idle, then it will be retarded 20-30 degrees by 50% throttle.

Also as Jeff said, make sure the secondary throttle plates, not the air valve, is opening.
Muskegon Lake
1972 32' Express flybridge
"AL13"
Twin 318s
On board air & prime 920
1963 Thompson Super Sea Lancer
Graymarine 327
1961 Alumacraft 12'
'55 10hp Johnson
fpc310
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Re: 318 ignition system

Post by fpc310 »

No, no vacuum advance. It’s the marine version. On the carb, the secondaries open at WOT, but I was curious if there was enough air flow to overcome the counterweights on the secondary air flap. Edelbrock says it shouldn’t be a problem. I’m leaning more towards the timing being too retarded. The initial timing spec for the distributor says 12 deg BTDC for the 318. I have it at 6 per the Chrysler book. I’m not sure if the timing is too far advanced too early. I may need a real mechanic to help me determine that.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio
EWRice
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Re: 318 ignition system

Post by EWRice »

Did you use the correct 6 deg. mark for the direction of engine rotation? This has bit me a few times over the years.
Muskegon Lake
1972 32' Express flybridge
"AL13"
Twin 318s
On board air & prime 920
1963 Thompson Super Sea Lancer
Graymarine 327
1961 Alumacraft 12'
'55 10hp Johnson
Fastjeff
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Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: 318 ignition system

Post by Fastjeff »

If you are using the flywheel end for timing (recommended) the center of the arrow is TDC. The required advance is on either side of the arrow, one side for normal and the other for reverse rotation.

One problem I've seen is that the spark advance mechanism does not return to the idle position do to sticking. If this is the case, timing it will produce a retarded condition. To avoid that I regularly apply the infamous "Fastjeff Shuffle": with the cap off, flip the rotor at least a hundred (seriously) times to loosen it up. (Put some music on to listen to as you flip away.) A drop or two of oil on the felt under the rotor should be applied first.

Then time it.

Good luck!

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
barkleydave
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Posts: 410
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Location: Kentucky

Re: 318 ignition system

Post by barkleydave »

Why fight with obsolete ignitions. Been running the Pertronix test for 6 seasons absolutely NO ISSUES. i did have to replace one cap.
The testing is completed so no more free stuff... oh well :(
1987 Marinette 29 FB Sedan
Retired Boat Accident UL and USCG trained investigator
Retired USCG Captain
JohnO
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Posts: 15
Joined: Sun Jul 23, 2017 10:55 am

Re: 318 ignition system

Post by JohnO »

Jason (or Carl) I could use the same help, I searched for the solution but couldn't, find it. I jumped the ignition wire from the ballast, 12V at the coil but still doesn't work. Lost my sniffer too so I'm assuming that wasn't the solution. Put red distributor, and jumped ignition wire to Positive coil, put black distributor and left existing black wire (I think this is going to tach) on negative side.

John O.

>>>The only problem I had , and thanks to Carl for the suggestion, which Carl if you're >>>reading this I'm still going to get by one of these days. But the issue was I had to by pass >>>the entire original ignition system. Mine was equipped with a dual ballist resister. I >>>initially just bypassed those by making a jumper wire and plugged it in place of the >>>ballast.Going through the ignition control box only gave me one spark when I engaged the >>>key and one when I shut off. By bypassing the entire system it was flawlessly.
John

1984 28' Sedan Flybridge
Father original Captain
Spudweasel
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Posts: 11
Joined: Fri Jul 21, 2017 7:16 am

Re: 318 ignition system

Post by Spudweasel »

John, sorry buddy just saw your post. Ok so here is what I did depending on what typ of ballast you have you will with have to use one or two jumper wires this will supply the full 12 volts to the system. Then just change swap out your coil and obviously red wire from dist to pos side of coil black to neg. I then disconnected the wiring harness from the original ignition control box. Now mind you this is all from memory and it's been a day or two. Simple explanation is treat it as if it doesn't have any type of ignition system at all and you're just dropping a distributor in. If I can figure out the pm feature here I'll send you my number. I'll be at the boat sometime tomorrow and I'll double check what I've done and maybe be able to walk you through it better.
Jason
1976 32' FB sedan twin 318 closed cooling
"Minor Adventure"
Harrison Bay
jralbert
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Re: 318 ignition system

Post by jralbert »

"... If I can figure out the pm feature here I'll send you my number...."
top of the page, click on private messages...then, on the page that comes up click on "compose" on the left side
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD
Spudweasel
Member
Posts: 11
Joined: Fri Jul 21, 2017 7:16 am

Re: 318 ignition system

Post by Spudweasel »

Haha thanks Joel got it figured out. I got my number sent to John.
Jason
1976 32' FB sedan twin 318 closed cooling
"Minor Adventure"
Harrison Bay
JohnO
Member
Posts: 15
Joined: Sun Jul 23, 2017 10:55 am

Re: 318 ignition system

Post by JohnO »

I'm back! Jason helped me out with the installation of my pertronix distributors. His advice was right on because I have a starboard engine running right on. Now back to the port. I get to right around 1500 under load and the engine dies. Sometimes with back fire through the carbs. I have been chasing fuel issues with no solution (other thread). Port side was my first install and I did a dumb thing misinterpreting some one else's advice. I turned the gear where the shaft goes into the key slot to match the old rotor position. Long story but I ended up getting back to basics to get everything running again. This is what I did, removed #1 plug, finger over hole, got a compression pressure, rotated to TDC off the damper (used this instead of flywheel because it was 2 degrees different), set timing at 500 rpm to 5 degrees BTDC. Runs great through 3000 out of gear. Put in forward and it gets to 1500, continue with throttle, no faster, starts to decrease power or backfires, or dies. Had two different people tell me to time by hearing. From about 1200, not under load, moved cap to best RPM, dropped to around 900, did same, dropped to 700 did same, dropped close to 500 did same. Runs good, and runs good al the way through 2000 under load. Put timing light to it, mark is way over BTDC, and reading about 36 BTDC. One guy told me it doesn't matter it runs, another told me if it was 36 degrees out he would be shocked it would start. I want to get this right! I was told it could be me turning that gear and to point the slot right at #1. Removed distributor, and was one click off, I rotated it so the key slot was pointing right at #1, (1984 LM 318, from aft side of the engine looking forward, cylinder left side front by pulleys), timed it by RPM, runs good, but timing reads around 36 BTDC, set it back to 5 deg, same problem at 1500. Someone suggested going from silver springs to gold. Because it doesn't advance until 2000 then it jumps to 20 BTDC. They said it should advance gradually up to 2000. STB does same thing but it seems to run OK.
John

1984 28' Sedan Flybridge
Father original Captain
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