Engine cylinder "Hatch marks"

[Walter P]

A strange situation on my port engine has come to my attention. My Hatt has a pair of 6-92 TA's of unknown HP. The standard 6-92's were listed in the factory brochure as having 435 HP ea. On the spec page of my Hatteras owners manual it lists my engines as "Special High Performance" models so my guess is as good as anyones as to HP.

The curious thing however is not the HP but the fact that these engines have less than 400 hours on them. The port engine was actually replaced less than a year before I bought the boat with a Reliabuilt long block assembly. The original as I was told had spun a bearing and messed up the block. About mid season last summer, I noticed that I was not getting the rated RPM. It was down about 100 - 150 R's. By the end of the season it was down about 250 R's. At the end of the season we made a run up the Hudson to Kingston from NJ (a little over 100 miles). We averaged about 17 K and the engines ran well at about 1950 RPMs. Upon our return I checked the transom for soot and sure enough there was a slight coating which was washed off quickly.

After thinking about it I decided to have the blower removed and the aftercooler etc cleaned. Well it's a good thing because after looking at the mess in there it was hard to understand how the engine ran at all. The blower is out for rebuilding... The bearings and seal were really in bad shape.

My real concern is that an inspection of the cylinder wall revealed that there were NO cross hatching left at all. WOW after barely 400 hrs. Is this possible? The conpression was good and the engine does not burn any lube oil so I'm kind of confused.. Any thoughts and/or recommendations?

Walt

 

[67hat34c]

have to wonder if they were ever there. is there a wear ridge in the sleeve? if not then suspect it was never honed properly.

 

[Pascal]

Hi Walter

it's my understanding that the cross hatching is a good wear indicator. if you dont' have any left, it sounds like that engine was not properly rebuilt, if at all.

i'm no expert... we'll see what the residents DD gurus have to say

 

[REBrueckner]

I'd call Hatteras and see what information they can provide on your engine HP...worst that can happen is that you waste a few minutes....

And perhaps there is a serial number or other identifier you can use to determine if the long block exchange was actually made...someone here likely knows how to identify an original block from a replacement..

 

[REBrueckner]

I forgot to comment that you say your "engines have less than 400 hours on them"....could you explain? Both engines? Original or time since some significant work was supposedly done? have you compared cross hatch visibility on the liners between the two engines...and the result?? Who did the replacement of the long block...There should be detailed records..if not see if you can call whoever did the work and ask them to confirm what was done...imply you need some work so they'll feel like helping.


Also, it could be worthwile knowing likely causes for blower and aftercooler "mess"...is that after only 400 hours or some other running time?? Maybe someone here can offer suggestions.

Also, your drop in RPM and even stern soot could be the result of fouling on the shafts/propeller...Are they clean and free of growth??? even a length of rope....Could you tell if the stern soot was from one engine or both?? Any vibration...which usually accompanies fouling....

All of the above are potential clues about what happened and what's happening...good luck,
post your findings for better analysis here.

 

[Genesis]

Sounds to me like someone installed a "long block" that was in fact an old engine that had never been torn down.

It got a "rebuild" consisting of several cans of paint.

Wouldn't be the first time I've seen someone be "had" like that.

 

[Boss Lady]

Perhaps, you may come to understand my rather opinionated definitions about engine rebuilds.

If there is no cross hatch, then you probably have what Karl has described as a rattle can rebuild. The PO most likely found a "running" take out and bought for what a core is worth. Put it in and had the legitimate shop bills for the R&R of the engine and some dummy receipts for a reliabilt engine. If it were me, and you have the documents for the reliabilt engine, I would go see whose name the warranty is registered to, and don't be surprised that the name is not the same as the PO. You may have grounds for a lawsuit and criminal fraud.

 

[captddis]

Or, they replaced kits but never pulled the blower and aftercooler to clean the airboxes. With dirty airboxes and a fouled aftercooler the kits could easily been wiped out on 400 hr. It is a common occourence, especially with the low ball overhauls. You would be suprised at who does this kind of overhaul. I know of a 12V71 TI that was rebuilt and redone 2 more times before they cleaned the airboxes.

 

[Boss Lady]

I would not be surprised at who does these kind of overhauls. My experience is "most" overhauls are really "repair" jobs, being sold as an overhaul. I will not get on my soapbox again.

You get what you pay for. (when it comes to marine engines, you only get what you pay for if you know what you are doing). If you don't then find somebody who does, or else prepared to get screwed.

 

[krush]

Or, they replaced kits but never pulled the blower and aftercooler to clean the airboxes. With dirty airboxes and a fouled aftercooler the kits could easily been wiped out on 400 hr. It is a common occourence, especially with the low ball overhauls. You would be suprised at who does this kind of overhaul. I know of a 12V71 TI that was rebuilt and redone 2 more times before they cleaned the airboxes.

I was going to say the same thing, but you beat me to it. Somebody that works on these things for his livelyhood told me that the crap in the airbox is just sandpaper--missing the paper.

Does the motor pass the "Genesis 30 second compression test"?

 

[captddis]

I was going to say the same thing, but you beat me to it. Somebody that works on these things for his livelyhood told me that the crap in the airbox is just sandpaper--missing the paper.

Does the motor pass the "Genesis 30 second compression test"?

Oil + soot = grinding compound and on a 71 throw in metal filings from the honing. yuk!

 

[Genesis]

Irrespective of that a "longblock" motor should be able to have the airbox LICKED before it is fired up with nothing other than the nasty taste of oil coming off on your tongue.

If you were given a receipt claiming that a longblock engine was installed then you have a situation where you were defrauded and the money involved is not trivial. We're talking in the tens of boat-bucks.

A "longblock" is not an overhaul, its either a crate motor or one shop-built on a stand to crate (or better) standards.

 

[captddis]

If it was a factory longblock, there will be a plate on the right rear of the engine with a ser# starting with LB------- and it will say if the crank is std or US and bore size.

Karl- I'll leave the airbox licking to you.

 

[Walter P]

All...

Thanks for all the responses, First of all, I to suspected that someone had to be playing a funny game here so I checked the serial # on the "new" engine and called J & T to follow the trail. They confirmed that it was a new long block assy and was in fact shipped to the yard that did the switch out. No way would they assume any responsibility for early wear or anything else since a few years had passed since then and there was no way to prove the run time. The previous owner while not the most experienced boat owner around was/is not a thief. In fact he was being taken advantage of by the yard for quite a while it seems. They charged him close to 30 K for the engine switch out, followed shortly thereafter by the installation of a brand new 15 KW Westerbeake gen set for 27 K. I have all the repair receipts for all the work that had been done during the few years of ownership by the PO and in my opinion they really had been screwing him for some time.

I wish there was something I could do to expose this shady operator. When I bought the boat, it was on the hard at their yard in So. Jersey. One Saturday morning when I was preparing to get the boat ready for the launch and trip to Sandy Hook, I needed to have the fuel cleaned and new batteries installed along with a few other things that I didn't have the time to do since the boat was not in the best of shape. (I wore rose colored glasses when I bought her). I got what I thought was a fantastic deal since the PO was so fed up with everything about boating and wanted out. Anyway the idiot had no idea as to how I felt about bigots and comenced to recite a long "joke" fest with a couple of his employees about the PO. The Gentleman happened to be Orthodox Jewish and was very observant. When I told them I didn't appreciate their attitude they seemed annoyed with me. When I told them that my ancestory on my fathers side was Jewish they did everything they could to get me out of there fast.

Since this forum is not the proper place to post the name etc of lousy people in the boating world, I will refrain from doing so. If anyone wants to PM me, we can talk about it.

Sorry for digressing but I'm still pretty ticked off about the incident. Please believe me when I say that the work was crap and while I believe they did install a new long block, I also believe that they installed some defective parts and I wouldn't put it past them to have installed the old aftercooler and blower. My mechanic told me that the aftercooler was so clogged that it was incredible that it ran at all. The blower was shot and the oil seals were all leaking profusely all over the aftercooler. He thinks that the soot came in from a broken exhaust clamp to the turbo. Mix that with an oil leak and you get gunk, also known as abrasive material.

The mystery is that the compression seem to spec and it doesn't use engine oil between oil changes. It also passes the Genesis 30 second test with flying colors. Even after not starting the engines for 2 or 3 weeks they light right off with a touch of the starter.

The starboard engine was majored by a DD dealer in Montreal about 6 months before and that engine has no issues at all. I will have that engines' hatch marks checked this weekend, but I'll bet they are OK.

Is is just dumb luck that although the hatch marks are gone and the engine seems to have good compression a fluke or am I kidding myself and should either rebuild or replace. At this point replacement with a couple of new engines would probably not cost much more than rebuilding at todays' prices. Advice - suggestions please.....

Walt

 

[captddis]

If the engine had an exhaust leak and a plugged aftercooler, then there is the answer to the worn kits. As far as what to do, If the engine runs fine after the aftercooler cleaning keep on running it. Gradually it will deteroriate but may be years. You may want to do a airbox inspection and check for broken rings, although if it starts clean you are probably ok. I have a customer who had a massive exhaust leak in 1994. The exhaust elbow came off, and he pulled the imploded airsep off and ran in. The engines are still running and don't use oil, however they smoke the marina out on start up even with block heaters on. Good luck

 

[Genesis]

Ok, given that you've traced the block you've gotten a lesson in what exhaust leaks do.

Clean the aftercooler and replace or fix the blower (probably easier to swap it for a reman; look carefully at labor time required to overhaul .vs. swap)

If it lights off ok on my "30 second test" then I'd check the rings to insure you don't have any broken ones (can be done through the airbox covers) and run it. I would NOT tear it down even with blown crosshatching assuming cold-start performance is ok, because even though you're near wear limits (or perhaps beyond them on a "factory advisement" basis) if the engine is running ok and the rings are intact there's no particular reason to tear the engine down.

 

[Walter P]

Thank you Gentlemen for the good advice. If for any reason the engine shows me signs of problems again, I will swap them out for new Cummins 450's. In the meantime I will instruct my mechanic to check out the rings.

Ain't it fun to have a boat?

Walt

 

[bobk]

Walt, good luck with the engines. Hope you get all the time in the water that you want.

Bob

 

[SKYCHENEY]

I have never heard of this, but this story got me wondering: Is there such a thing as a liner without cross hatches? Could this long block have been assembled with some odd liners of some sort? I only ask because Walt says that it runs well and has good compression. There just seem to be parts of this that don't add up. He uses no oil.

I thought cross hatching helped to retain oil film on the cylinder walls. If it is not present, doesn't that lead to increased wear? Maybe the mechanic who inspected these doesn't know what he is looking at or maybe he just wants to drum up some rebuild business. Just some thoughts.

 

[Walter P]

I seem to recall many years ago (about 50 plus years) when I was in my 20's my passion besides the ladies was fast cars. My recollection is that other than the very fine marks left after honing the cylinders there were no hatch marks as are on Detroits. However I can't believe that my engine is some sort of a hybrid. The proof will be soon when we commission the boat for the season.

Realistically, the engine will probably fail in the near future and as previously stated, my plan would be to replace them with new 450 hp Cummins. The cost difference between a "quality" rebuild and replacement with the Cummins is probably about $25,000. While I don't mean to imply that 25 K is peanuts but when you consider that everything will be new, including the gear, I believe it's a no brainer. Bonus benefits are better mileage and less weight as well as more room in the engine room. Damn, I think I'm talking myself into going for it sooner. Actually the weight loss may actually be a detriment as it will impact negatively on the designed metacentric height. Will need to investigate that possibility with a marine engineer/naval architect prior to proceeding.

Bob K.... I'm not really worried about not being able to use the boat during this summer because if the engine fails I can always mooch rides with you at the Baltimore YC...LOL......

Walt