Low Engine Power, White Smoke

fpc310
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Low Engine Power, White Smoke

Postby fpc310 » Wed Jun 17, 2020 4:19 pm

First, I will say me and these 318's have come a long way together. I feel like I am SO CLOSE to getting them running perfectly. There was a time that I couldn't keep them running at low RPM. I did the following upgrades and they have idled wonderfully since:

Installed Performance Distributors DUI ignition system & wires
New Plugs gapped to 0.50 (per DUI recommendations)
Timing to 6 deg BTDC (*** I think...)
Edelbrock 1409 carbs (new)
New Fuel lines from the tank to the pumps
New fuel pumps too.
Installed the correct temp thermostats
Checked compression w/ good results. (First time for this - probably did it incorrectly, but I did it)

Still, however, I have more issues... Mostly with low power & white smoke.

The port engine wont run past 3000 rpm. I can give it more throttle, but no more power. It hits a hard wall.
There is white smoke that dissipates pretty quickly from the port side only.
The exhaust odors are apparent from the flybridge... possibly rich?
The port engine takes a couple of tries to start / keep running from a cold start.
RPM's remain steady, engines sound good (No missing from what I can hear), fuel is good, idle is perfect, no oil consumption, oil is clean, running temp is 140 or less.

Things I haven't done yet (or could've done wrong):

I haven't made any adjustments to the edelbrock carb. It is just as it is out of the box (except PCV vacuum mod). It could be rich, could be lean. Not sure how to dial that in yet.
I'm not 100% confident my actual timing is 6 degrees before, or 6 degrees after. Evidently this is easy to mess up when timing from the flyweel markings.

What am I missing?
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio

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Busia
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Re: Low Engine Power, White Smoke

Postby Busia » Thu Jun 18, 2020 2:23 am

You HAVE to adjust the carb. And set the timing. I would use a vacuum gauge to get maximum vacuum.
BUSIA
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW

fpc310
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Re: Low Engine Power, White Smoke

Postby fpc310 » Thu Jun 18, 2020 12:35 pm

Got it. I’ll get a gauge and try that. I did verify that I am timing from the correct marking on the fly wheel. I will use vacuum to adjust the carb and timing further. Is there a best place to hook up a gauge? I’m assuming this must be done directly from the manifold and not from a port on the carburetor itself.

Thanks for the tip.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio

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Busia
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Re: Low Engine Power, White Smoke

Postby Busia » Thu Jun 18, 2020 12:57 pm

Not familiar with your carb, but see what you have and try it. If you have PCV you can unhook it and put the gauge there. Gauge is about $20 at NAPA.
BUSIA
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW

Fastjeff
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Location: Rock Halll, MD
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Re: Low Engine Power, White Smoke

Postby Fastjeff » Thu Jun 18, 2020 1:28 pm

Hold it! You can not use the PCV hose for your vacuum source when adjusting the idle mixture screws, or you're adjustments will end up way too rich.

Every marine engine needs a PVC system due to the moisture experienced in the marine life. That said, you need to find another vacuum source to attach the vac gage for idle adjustment. I used the choke pull off on my carbs.

Jeff

PS: Have you considered running a compression test on that motor?
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

fpc310
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Re: Low Engine Power, White Smoke

Postby fpc310 » Thu Jun 18, 2020 8:14 pm

Hey Jeff,

I did do a compression test. I don’t have the exact numbers on me, but all cylinders were within the Chrysler specs in the original manual (100-120 I believe)

I’ll test vacuum from a choke pull off port. What’s a respectable vacuum goal for carb adjustments? Do I adjust timing then carb? Or vice versa?

Thanks
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio

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Busia
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Re: Low Engine Power, White Smoke

Postby Busia » Fri Jun 19, 2020 5:01 am

Fastjeff wrote:Hold it! You can not use the PCV hose for your vacuum source when adjusting the idle mixture screws, or you're adjustments will end up way too rich.

Yes, I was aware of that. I have a different engine and different carb. (Chev 350 with a Holley carb) On mine , I am able to disconnect the PCV hose from the carb and use that port to measure the vacuum. Have to be quick if the engine is running but it seems to work.
BUSIA
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW

Fastjeff
Site Admin
Posts: 1303
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD
Contact:

Re: Low Engine Power, White Smoke

Postby Fastjeff » Fri Jun 19, 2020 7:01 am

..."On mine , I am able to disconnect the PCV hose from the carb and use that port to measure the vacuum. "

AH, but your idle adjustment will be wrong soon as you hook that hose back up. (The PCV system is a controlled vacuum leak.)

..."What’s a respectable vacuum goal for carb adjustments? "

All you can get! Seriously. The actual number doesn't really count.

Good luck!

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

fpc310
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Re: Low Engine Power, White Smoke

Postby fpc310 » Fri Jun 19, 2020 7:39 am

Thanks Jeff!
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio

pbaker32s
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Re: Low Engine Power, White Smoke

Postby pbaker32s » Sun Jun 21, 2020 8:38 am

Sounds like possibly a leaky head gasket. Maybe get a bore scope from harbor freight and have a look see