Discussion in 'Ocean Yacht' started by Boomer, Nov 14, 2017.
That's works for me!
made me laugh, but seems about right!
AFTER she warms up a little !!
You guys are hilarious
Years of cruising on the boats we luv. Most of us have spent many nights wondering about our 71 issues.
I think I speak for a bunch of us; there is no sweater sound or more reliable block than a 71. Even if they smoke (some??).
To further reinforce the kind-ship here on YF, these Post owners continue to impress me.
I can not think of a finer group of boat fans. I'm glad they tolerate me.
I know it's an Ocean post but your experts here may push a different hulls.
Most all of the fine ole gals were push by Detroit's, that we all luv.
I can only wish more hardened Bertram fans would come together.
Post kids are cool,
When it takes more than a full can of ether to get her firing?
Next time you're bored, pull the air box covers and check the cylinder wall conditions. If they're not scored too bad you may just have stuck and/or broken rings which doesn't necessarily mean a full re-kitting is required. Tell tales are dark carbon streaks.
I could always repeat what a "head engineer" from the factory told me one time; "Compression doesn't really affect horsepower"
I know it sounds unbelievable but he actually said that to me standing in the cockpit of a boat with a pair of anemic 12V71's, when he did the Covington service manager standing there just did a face palm knowing the "mad German" (me) was about to erupt, and he was correct.
ZERO psi, then pull the head.
During the cold months block heaters help. When warm and the smoke blocks the sun and does not clear.
If your really worried about the end of time, Have a old DD tech pull the air box covers and look at the liners. If their scuffed and black smudges, then rebuild.
Hatch pattern is nice nut a smooth liner and piston rings still loose in the grooves are good signs.
The 485HP tune (671TIB), makes so much forced air while running, a lil low compression on start up is not a big deal. Just watch your smoke when warm.
Thank you...have some scoring but most of the hatch marks are still here
Light scoring fine as long as not from bad rings. If the rings were free, then go fishing and sleep well.
What do you mean the rings are free? Motors run good
He's referring to the piston rings.
You can access from the side inspection ports. If they're broken or seized your heading to failure. Ask me how i know.
During the air box inspection when the hatch marks were checked, a lil push against the piston rings to ensure their free and not stuck in the piston grove or broken.
If you had a real old school DD tech, this would have been checked and a bore scope pic looking up towards the exhaust valves.
Light scoring usually is not an issue. Grunge/Slobber from the air box is normal and mostly this culprit. These would be above the ports your looking thru.
Carbon/solids usually leave scores below the ports. These need to be checked on in a few of years.
Hopefully you did get pictures of these (labeled) and can compare one or two lungs in a few years.
Bottom line; your running well, don't touch them except to change (correct CF-2) oil.
Do have the boroscope pics for future comparision...also doing another oil analysis to make sure we solved the fuel dilution problem in the oil..was just over 8% for oil with approx 150 hrs. Deferred maintenance I know...will change every 100 hours?
Nice Boat.... Congrats...!!
Are swinging 3 or 4 blade props? Dimensions?
There is a man who drives around the country working on DD's to get old buses back on the road and turned into RV's. He is coming to teach me about the 671's on my boat. I will post info about that when he is here. He loves the engines and likes to make them run.