Ooops sucked paper towel (Bounty) into Perkins 6.354 air intake

[Cadence]

Originally Posted by CareKnot

I know I am a little late to the party. However, having read the entire thread I would have suggested a compression check if there were any concern about the valves. Sure as heck beats pulling a head.

I think just running the engine will make everything as good as gold. JMHO

How did your boat work out?

[CareKnot]

In the end, fine. But boy do I have some stories to tell!

[thruska]

Originally Posted by jimbunyard

The 4-71 has an advantage (as do all 2 cycle Detroits), a 'macerator' (gear driver roots blower) before the intake ports on the cylinders. A runaway engine probably just used the extra carbon to runaway more until the plywood cutoff the air. Many Detroits had an emergency shutdown, which consisted of a close-fitting, spring loaded steel plate situated in a housing above the suction side of the blower to physically cutoff the air supply in the event of a runaway. Operators were cautioned to be sure they needed to use it though, cuz you ran the very real risk of sucking all the seals out of the motor if you did...better than blowing a rod through the block though...

From the mid fifties to early 80s we used 471 detroits as drive units on Daffin hammermills. They had oil bath air cleaners. The name screamin' jimmies had new meaning after you'd hear a runaway ! I recall one time while my dad was stuffing his cap in the oil bath after knocking the cap off it. He motioned to run away as others were coming out of the office to see what the unusual noise was about ! Those hammermills ground up damn near anything... two by fours, frozen pigs, glass bottles. The root blowers were also used to vacuum grains and blow the ground up grains or whatever, into bulk tanks.
Those 71 series are work horses ! They ran a lot of carnival rides back in the day as I recall.

[Dockhead]

Originally Posted by CareKnot

I know I am a little late to the party. However, having read the entire thread I would have suggested a compression check if there were any concern about the valves. Sure as heck beats pulling a head.

Yes, I think he still should do it. You can have a problem with a valve and not notice it at first on a big six cylinder like that one.

Only, we don't normally do compression tests on big diesels -- almost as much trouble as pulling the head. It's not like doing it on a gasoline engine. Rather, we crack each injector pipe in turn to make sure that each cylinder is pulling its weight. The RPM drop should be precisely equal for each cylinder.

The OP should do this to be sure that the valves are all seating. If there's a problem, it will probably not be too late to fix it before burning a valve.

[Jim Cate]

Ya know, I find it very hard to believe that some remnant of a paper towel could survive in any state that would keep a valve from seating. This whole worry wart scene is so typical of CF folks seeing the worst possible outcome of any scenario and then assuming that it has been even worse!

Gas flow velocity across valve seats is pretty high, temperatures are pretty high, seat pressures are pretty high and paper towels are pretty soft and fluffy (just read the ads). In the OP's place, I'd put this worry behind meteor strike, possibly just ahead of zombie uprisings.

Only an opinion, but then no one else has anything more substantive to offer!

Jim

[jimbunyard]

Originally Posted by Jim Cate

Ya know, I find it very hard to believe that some remnant of a paper towel could survive in any state that would keep a valve from seating. This whole worry wart scene is so typical of CF folks seeing the worst possible outcome of any scenario and then assuming that it has been even worse!

Gas flow velocity across valve seats is pretty high, temperatures are pretty high, seat pressures are pretty high and paper towels are pretty soft and fluffy (just read the ads). In the OP's place, I'd put this worry behind meteor strike, possibly just ahead of zombie uprisings.

Only an opinion, but then no one else has anything more substantive to offer!

Jim

Not only that, valves have rotators, any residual speck of paper not blown (sucked?) away by the rather intense air flow within the intake/exhaust tract has long been ground into oblivion by the extreme pressure induced by the valve spring and the rotary motion of the valve against the seat...

[Dockhead]

Originally Posted by Jim Cate

Ya know, I find it very hard to believe that some remnant of a paper towel could survive in any state that would keep a valve from seating. This whole worry wart scene is so typical of CF folks seeing the worst possible outcome of any scenario and then assuming that it has been even worse!

Gas flow velocity across valve seats is pretty high, temperatures are pretty high, seat pressures are pretty high and paper towels are pretty soft and fluffy (just read the ads). In the OP's place, I'd put this worry behind meteor strike, possibly just ahead of zombie uprisings.

Only an opinion, but then no one else has anything more substantive to offer!

Jim

Yes, that's sounds plausible. I would file that in the "hope for the best" folder.

And I would still do the cylinder balance test

[malbert73]

Originally Posted by Dockhead

Yes, that's sounds plausible. I would file that in the "hope for the best" folder.

And I would still do the cylinder balance test

What's the cylinder balance test?

[Dockhead]

Originally Posted by malbert73

What's the cylinder balance test?

Important test procedure for diesel engines.

Crack each injection line in turn, and measure RPM drop. Any cylinder showing less RPM drop than the others, is not pulling its weight. Meaning it either has less compression or wrong valve timing or adjustment or not getting fuel.

If every cylinder shows same RPM drop, then every cylinder is working equally.

Largely replaces the need for a compression test on a diesel engine. If a diesel starts well, and passes a cylinder balance test, then you can be pretty sure that everything is ok with compression.

[malbert73]

Originally Posted by Dockhead

Important test procedure for diesel engines.

Crack each injection line in turn, and measure RPM drop. Any cylinder showing less RPM drop than the others, is not pulling its weight. Meaning it either has less compression or wrong valve timing or adjustment or not getting fuel.

If every cylinder shows same RPM drop, then every cylinder is working equally.

Largely replaces the need for a compression test on a diesel engine. If a diesel starts well, and passes a cylinder balance test, then you can be pretty sure that everything is ok with compression.

Awesome. I was going to do compression test and this sounds like a much better test. Do you just pick a fast idle or moderate RPM?


Sent from my iPhone using Cruisers Sailing Forum

[estarzinger]

Originally Posted by Jim Cate

This whole worry wart scene is so typical of CF folks seeing the worst possible outcome of any scenario and then assuming that it has been even worse!

Jim, were you not read into the plan code name "Complexity"? The old timers all agreed to participate in a conspiracy to make everything sound as complex and difficult and dangerous as possible. The objective is to scare people off so the anchorages are less crowded.

The slogan for the group is "need $10m, a rocket science degree, and you will still die" . . . can use it to answer pretty much any question asked

[Cadence]

Originally Posted by Jim Cate

Ya know, I find it very hard to believe that some remnant of a paper towel could survive in any state that would keep a valve from seating. This whole worry wart scene is so typical of CF folks seeing the worst possible outcome of any scenario and then assuming that it has been even worse!

Gas flow velocity across valve seats is pretty high, temperatures are pretty high, seat pressures are pretty high and paper towels are pretty soft and fluffy (just read the ads). In the OP's place, I'd put this worry behind meteor strike, possibly just ahead of zombie uprisings.

Only an opinion, but then no one else has anything more substantive to offer!

Jim

Well put.

[HopCar]

Originally Posted by Jim Cate

Ya know, I find it very hard to believe that some remnant of a paper towel could survive in any state that would keep a valve from seating. This whole worry wart scene is so typical of CF folks seeing the worst possible outcome of any scenario and then assuming that it has been even worse!

Gas flow velocity across valve seats is pretty high, temperatures are pretty high, seat pressures are pretty high and paper towels are pretty soft and fluffy (just read the ads). In the OP's place, I'd put this worry behind meteor strike, possibly just ahead of zombie uprisings.

Only an opinion, but then no one else has anything more substantive to offer!

Jim

Jim, I would agree with you if it was a lesser paper towel. But you need to take into account that it was a Bounty paper towel.

[Cadence]

Originally Posted by HopCar

Jim, I would agree with you if it was a lesser paper towel. But you need to take into account that it was a Bounty paper towel.

It could have been worse and have been a highly touted toilet paper.

[ValiantV]

Originally Posted by Dockhead

Important test procedure for diesel engines.

Crack each injection line in turn, and measure RPM drop. Any cylinder showing less RPM drop than the others, is not pulling its weight. Meaning it either has less compression or wrong valve timing or adjustment or not getting fuel.

If every cylinder shows same RPM drop, then every cylinder is working equally.

Largely replaces the need for a compression test on a diesel engine. If a diesel starts well, and passes a cylinder balance test, then you can be pretty sure that everything is ok with compression.

Back in the day, a "power balance" test was also something a conscientious and well-equipped auto mechanic would perform on gasoline engines.

I think since the days of computers running the show on gas engines, it's just a fond memory now.

Nice to know it's still useful on diesels, and, only takes a wrench an a tach to perform. No $50,000 Sun engine analyzer.