We went our for a late fall cruise this afternoon in our '67 Commander 31 with 327F's (900 hrs). The boat was running great at 3100 rpm's / 22.6 mpg. for a mile or two when I noticed the port engine rpm's dropping. Within another 1/4 mile or so it was loosing power and oil pressure dramatically! I also thought I heard a couple of "backfire" type noises, but they seemed to be coming from the FRONT of the engine room area (like just forward of my feet at the helm).

I shut it down immediately and we limped back in on the starboard engine. The engine never overheated (160 max) and when I checked, the oil level was only down 1/2 qt. or so.

I anxiously invite any "arm-chair quarter back" speculation before I call the yard in the morning. Thanks!!

Views: 334

Reply to This

Replies to This Discussion

Honestly sounds like it’s possibly terminal. Definitely need more investigation, but the few times I’ve experienced a lose of both power and oil pressure death was shortly to follow. 

Does the engine still turn over? 

Yup, it runs. I restarted it after I checked the oil level while we were still out there. It ran but didn't want to rev in neutral. I tried it once very briefly and shut it down again. That's when we limped back in on one engine.

Mike H said:

Honestly sounds like it’s possibly terminal. Definitely need more investigation, but the few times I’ve experienced a lose of both power and oil pressure death was shortly to follow. 

Does the engine still turn over? 

I lost the stb engine, 327F with ~1200 hours on a test run.  I came home for a weekend ran to the harbor did a quick tune-up of the port engine that was having problems, all seemed good.  Went out to the channel to make sure it would run WO, all was good, hard right back to  harbor stb bogged thought it was due to the turn, it continued to bog, throttled back and checked gauges in time to see 0 oil pressure and as I reached for the key the engine locked.  All the oil was out of the engine.  Turns out, and this has been relayed many times, the cross over of the intake manifold burned through allowing the exhaust to pressurize the pan and blow out the oil.  I think you were fortunate and got it stopped in time.  Check compression, pull the intake and if your lucky all will be good with a replacement intake.

Good luck, Tim

Does it have oil pressure when you restart it? 

Greg Beardmore said:

Yup, it runs. I restarted it after I checked the oil level while we were still out there. It ran but didn't want to rev in neutral. I tried it once very briefly and shut it down again. That's when we limped back in on one engine.

Mike H said:

Honestly sounds like it’s possibly terminal. Definitely need more investigation, but the few times I’ve experienced a lose of both power and oil pressure death was shortly to follow. 

Does the engine still turn over? 

Hi Mike, on the restart after I checked the oil level, I really don't know... The needle might have come up to maybe 10 psi. I rev'd it once and when it didn't respond I turned the key off immediately! I"m 99% sure the engine didn't seize.

I agree with Tim. I think it's a good chance you have a partially blocked riser and the intake manifold exhaust crossover burned through which allows hot exhaust to pressurize the crankcase. Here's a couple of things to check -- Pull the distributor cap and see if it has crankcase moisture inside. If so, dry it out with a dry rag or something similar. Next, fire the engine and take the oil fill cap off. Hold your hand just over the oil fill hole and see if you can feel blowby. If both conditions are present, you may be in luck and your 327 will live to propel the boat again with a new intake manifold. The only thing not explained by this manifold problem is the dropping oil pressure. ?? 

I hope Dick and Tim are right --  however if the loss of oil pressure due to supply side problem such as clogged/broken pickup or some other clogged passage it could be the loss of power due to over heating of crank bearings . I have seen that with the subsequent cooling after quick shutdown that allowed a brief engine restart. This could happen right before the crank fuses itself to the bearings and ''spins'' one of them. I guess a oil pump problem could cause same issue, but seems that problem would have presented itself more slowly and noticed way before

Thanks for all the comments guys! Lots of food for thought.

Al, it did happen somewhat slowly. The oil pressure did drop rather gradually over the course of maybe 1/2 mile before I shut down the first time. I'll probably try Dick's instructions later this week along with a compression check (assuming it still cranks).

You can send an oil sample off to Black Stone Laboratories too. That should tell you if there’s significant internal bearing damage. It’s only $28 and they’re pretty fast.  

Greg Beardmore said:

Thanks for all the comments guys! Lots of food for thought.

Al, it did happen somewhat slowly. The oil pressure did drop rather gradually over the course of maybe 1/2 mile before I shut down the first time. I'll probably try Dick's instructions later this week along with a compression check (assuming it still cranks).

WEEKEND UPDATE: I tried all the above suggestions in order.
1. Compression Check: Good
2. Distributor Cap: Dry
3. Oil Cap off: No blow-by felt

With that, I started the engine and let it warm up. It idles rather unevenly, with lower than normal RPM's (500 or so) but there's good oil pressure at idle. It seems to rev OK in neutral, so I figure let's see how she runs... We leave the slip and head up river on a very calm day.

The engine runs a bit rough but rather normally at idle and up to about 1500 RPM's. But if I try to accelerate any more to get up on plane, there's really no power & I immediately hear a series of loud pops or bangs beneath my feet in the engine room. It's almost like a back-fire sound I suppose, but it's coming from directly beneath me and NOT in back at the exhaust pipes.

So we head back to the slip at idle without issue. Still good oil pressure and not overheating. I'll call the yard in the morning and relay all this. They'll take her for a similar test spin before pulling her for the season later this week. Any thoughts about all this, for when I call the yard in the morning? 

Thanks!

You don't have Pertronix in your distriburtors do you?  If not have you checked the point gap and timing?

Might be as simple as a plugged fuel filter, I would also be suspect of the ignition. 

Reply to Discussion

RSS

Club News

Styled In Fiberglass

For your reading pleasure, the latest issue of the Chris-Craft Commander Club's newsletter, Styled In Fiberglass, along with past issues, can you accessed through the link below.

Styled In Fiberglass Issues

________________________________________

The 2018 Chris-Craft Commander Club National Rendezvous is in the books and it was a great time!!

City of Mentor, Ohio

The city of Mentor, Ohio and the Lawnfield Inn & Suites were wonderful hosts.  A special Thanks to Rob Kneen, the local member sponsor, and Char Pike for the hours of hard work put in organizing and coordinating an amazing weekend. 

The Rendezvous Photo Albums can be accessed through the links below, as well as, under Library, Photo Albums.  We will continue to add links to other albums as they become available. Also below, you will find links to a couple articles written for the local newspaper.

Photo Album 1                 Photo Album 2  

Photo Album 3

Articles:

Chris-Craft Commander Club Celebrates Anniversary in Mentor

Chris-Craft Commander connoisseurs congregate at Mentor Lagoons Marina

_________________________________________

 

© 2018   Created by CCCC Webmaster.   Powered by

Badges  |  Report an Issue  |  Terms of Service