318 ignition system

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JohnO
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Re: 318 ignition system

Postby JohnO » Mon Jul 08, 2019 5:40 am

Thanks for the update. Much appreciated.

fpc310
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Re: 318 ignition system

Postby fpc310 » Tue Jul 09, 2019 12:53 pm

I have the DUI setup. They say they are certified for marine use and they are ignition protected. I’ve had them on for a few months and they seem to have solved my issues. They are bigger and I had to remove the oil pressure “engine out alarm” sensor. I’ll have to find and elbow and add it back sometime or find another way to detect an engine out. Although I haven’t had it under load much with the weather this season, I have brought it up to temp many times and shut it down. It starts back up fine and will idle with no trouble. So far so good. My only complaint was the wire lengths. They worked, but man there was no margin for error.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio

fpc310
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Re: 318 ignition system

Postby fpc310 » Sun Jul 14, 2019 6:45 pm

OK, I took the boat out for the first time with the new performance distributors DUI on both 318’s. They definitely run smooth, but the port engine seems to max out on rpm’s at 2800 at full throttle. I was hoping for an opinion on whether this is likely a timing issue, Or possibly a fuel flow issue. Everything runs fine at title and it runs perfectly fine. It just MAX is out and won’t go above 2800. I appreciate any comments on that.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio

jralbert
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Re: 318 ignition system

Postby jralbert » Sun Jul 14, 2019 9:24 pm

fpc310 wrote: max out on rpm’s at 2800 at full throttle. I was hoping for an opinion on whether this is likely a timing issue, Or possibly a fuel flow issue.
I go with the fuel flow issue and at the risk of sounding like Johnny One Note, check the little secondary filters at the mouth of the carb (if your carb uses them). Those dollar-fifty little buggers were always the culprit when I had the same symptoms. (do your engines cough and stutter when you try to push above the max?)
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

fpc310
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Re: 318 ignition system

Postby fpc310 » Sun Jul 14, 2019 9:30 pm

It’s a brand new 1409 on it with all new filters in between. No coughing, no sputtering... it just stops at 2800 and any other movement from there with the throttle does nothing at all. Out of gear it’s a different story. It goes all the way up to 4000 with no problem at all. Sounds good too! This is just a problem while under load.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio

Fastjeff
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Re: 318 ignition system

Postby Fastjeff » Mon Jul 15, 2019 7:08 am

Are you sure the secondaries are opening? If the choke is not opening fully it prevents the secondary barrels from opening.

With the motor fully warmed up, shut it down, pull the flame arrestor and see if the secondaries open at full throttle. If not that's the problem. Readjustment of the linkage will correct that.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

fpc310
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Re: 318 ignition system

Postby fpc310 » Mon Jul 15, 2019 9:46 am

The secondaries open, the electric choke opens normally and fully. I’m wondering if a 318 has enough vacuum to overcome the counter weights? The new carb is an edelbrock 1409 600cfm. This replaced the carter AFB, which was less CFM I believe.... and I successfully turned an ignition thread into a fuel system topic. My apologies on that.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio

jralbert
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Re: 318 ignition system

Postby jralbert » Mon Jul 15, 2019 11:30 am

(yeah, you did do a quick course change :))
If you suspect vacuum as an issue would it be correct to wonder why it's a problem in one engine only and the other is fine?
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

fpc310
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Posts: 18
Joined: Wed Sep 05, 2018 5:39 pm

Re: 318 ignition system

Postby fpc310 » Mon Jul 15, 2019 2:53 pm

jralbert wrote:(yeah, you did do a quick course change :))
If you suspect vacuum as an issue would it be correct to wonder why it's a problem in one engine only and the other is fine?


Yes. It is curious. I’m going to just run the hell out of it but yeah, circling back to ignition, no more stalling with the performance distributors setup. Very impressive.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio

Fastjeff
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Re: 318 ignition system

Postby Fastjeff » Mon Jul 15, 2019 6:13 pm

Could you have someone eyeball down the carb as you open the throttle ands see if the secondaries open?

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington