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Thanks for that. Yes you are correct the whole purpose of the 5.3 is that its disposable. I chose that direction as I don't have a fat wallet for rebuilding big blocks or buying new ct525 crate motors, just didn't bet on changing them like the rubbish bag!
I'm not much of a wheeler dealer kind of guy. But, the thought has crossed my mind that, if/when my engine gives up the ghost, I could probably sell off the bits and peaces I wouldn't use from a replacement engine and make up most (if not all) of the costs for the replacement. Intake and exhaust manifolds, heads, rockers, pushrods, lifters, any pistons/rods that are good from the failed engine... crank, throttle body, injectors, sensors, any connectors... pieced and parted out, dollars might add up quick. I'm not entirely sure it would be worth all the effort in the end. However, it could certainly take some of the financial sting away. I too have little to no room in my budget for short lived engines or the stamina to maintain enthusiasm while being repeatedly let down and disappointed.
Originally Posted by Huffa
Anyhow, yesterday I did order a set of Johnson high lift lifters from ebay, thought they looked a good bet, made is usa, $100us,hopefully no one tells me otherwise. The chap who supplied me the engine has kindly offered to measure it up and fit new cam bearings if possible so will get it back to him and see what's the story
I know nothing of those lifters and don't recall hearing of the brand. Suppose that could be good or bad. Personally would have gone with the known part with good reputation for about the same price.
If I was thrashing to meet a specific deadline and was willing to live with any resultant consequences, I'd absolutely do what I could to get all the shmoo out of the lifter bores, dimple the cam bore, Loctite a bearing in, run a brush through the oil galleys, cross my fingers, and give it a go. Otherwise, personally, if for nothing more than my own peace of mind, I'd start with a fresh donor.
The bowtie lifters "used" to be the GM Performance lifters with ceramic check ball. When I was testing them, they were black oxide. So I don't know for sure what you have there.
I see this type of issue frequently. Typically in an open loop cooling system marine engine, you want a little more lifter to bore clearance (.002-.0025). Especially aluminum blocks running in cold fresh water lakes.
...I see this type of issue frequently. Typically in an open loop cooling system marine engine, you want a little more lifter to bore clearance (.002-.0025). Especially aluminum blocks running in cold fresh water lakes.
The logic behind your statement is sound. However, I don't think is has as much bearing on reality as you think. Not to imply that I'm any sort of authority in the matter, but even beyond my personal first hand experience, I spend much of my time in performance boating forums and I have NEVER heard of or seen a lifter look like that. Other than flat tappets not getting broken in correctly or roller failures, lifter failures of any other sort are pretty darn rare in my experience.
It looks, to me, like a relatively malleable metal was smeared on those lifters. Most likely material from the spun bearing, drug up into the bores in the recess of the lifter axle. It's not present on the loaded sides of the lifter, where damage would most likely occur if there were a clearance issue. Also, there's an absence of any heat indicators in the metal color.
It's just my two cents that I wouldn't worry about the lifter clearance personally. Not in this case anyway.
Thanks for all the input. Since the guy is willing to have a go a repairing the block I will roll with that for now, it may not even be repairable. The Johnson lifters that I metioned earlier are a reputable name down here, surprised they are not a known brand to many, hopefully be ok
So after the engine had new rings/bearings and LS6 cam installed I have had it going. Whats the storey with too much oil being pumped up to heads and not getting away quick enough? At tuning at 8psi, 5600rpm it blew some oil out the rear rocker cover breather stack which is about 250mm high, the engine dosent fume excessively. I had to pull the engine out again to repair a crack in the sump and upon draining the oil it was metallic. Thinking it has or was spinning a cam bearing again the engine builder stripped it to find cam bearings perfect, but other bearings showing a slight sign of maybe been run low on oil. It has a melling HV oil pump which was fitted after the first engine had a falling oil pressure problem. Just before the first engine chernobyled it blew oil out breathers and all over the back of the boat. I thought it was just from poor rings and boost making too much blow by, but now I am wondering is it purely pumping top of heads with too much oil and starving the sump. Its worth mentioning that at tuning with this engine the oil that came out breather was only coming out the breather at the rear of the rocker cover, not the front breather on opposing cover. I have had the rear breather stack changed to the front, but this obviously is not going to cure my problems if oil is accumulating in the heads and starving the sump. Thoughts please
Hey Huffa, good to hear from ya. It's pretty standard to not use any rear breather ports on a performance boat. I've experienced the same on other engine combinations. Even with extended stands and baffling options, I'd have to clean up a light coat of oil off of everything on that side of the engine. Inside the boat... everywhere. Kind of a PITA. Most resolve the issue by venting from the front of the valve cover into one or two catch cans.
I highly... VERY highly doubt, that excessive oil is collecting in the head, in turn starving the pan and oil pump. Not unless there's some sort of physical obstruction that isn't intended to be in the engine.
Without going back and reading everything, I forget... are you data logging oil pressure? Or just monitoring the gauge? Did you ever see anything suspicious?
Thanks mate, still no data logging,never seen anything suspicious, only run in a straight line so surge isn't an issue. This is my second block. First engine spun centre main and had a falling oil pressure issue when been thrashed for more than a couple minutes, so ditched that engine got another, only got up to 4000rpm on tuning and it spun a cam bearing and jammed 2 lifters in there bores driving valves into piston, that block was repaired and what im currently running bit ditched the high lift compcam for the LS6 cam
Bummer on another issue. Do you need HV? Oil pressure at turbo dropping off compared to engine? Is HV creating a potential for frothing oil due to excessive return volume? Unable to keep oil around pickup - oil is bouncing above pickup, oil shifting away from pickup, etc? Datalog oil pressure and level. Add oil accumulator (cheap insurance) to keep system charged unless root cause problem identified and resolved. Just some thoughts.
How many oil changes were on this rendition? Was this the oil that this engine was originally started on? How many hours of operation?
The amount of metallic in the oil... a considerable amount or just enough to raise suspicion? Somewhere in between? Did he/you cut the filter open? If so, would you please post a picture of it.
What bearings were showing slight signs of wear? Main? Rod? Was it just one or two, or the whole set? Were those particular bearings also new or were they reused from the last engine? Could you post a pic of the bearing wear?
And just to verify, you never saw/witnessed a dip in oil pressure. Correct?
As soon as I let the bung go I was alarmed at the colour of the oil, but also knew that there was a lot of assembly lube used. The bung had fur on it. I took the sump off and the oil left in there had a slight bit concerning metalic look, I waved a magnet over the oil sitting on the cast alloy part of sump and it was all drawing towards the magnet. I pulled a couple of big end bearings, nothing real bad other than some scratching from contamination but they weren't great considering its only done less than two hours running, it had all new bearings fitted, no I have never seen a fluctuation in pressure, but I only run an autometer mechanical gaugeHere's magnet after been swirled around in oil drained from sump into jug, not swirled in bottom of sump Big end bearingHere's the bung, it actually had a bit more than this on it
That's not bearing material on the oil plug. Check every component very carefully and try to identify where it came from. Everything. Both, the cupped and valve end of each rocker. Any shims under the valve springs, push rods, timing chain/gears, all the journals on the crank, absolutely every possible place ferrous material might come from.
If there's no obvious wear on any of the parts, it may be that it's from previous mishaps and something didn't get sufficiently cleaned or flushed out. At this point, the block needs a thorough cleaning of all the oil passages with a brush, oil pump disassembled and cleaned, oil cooler and all connecting hoses completely flushed and/or replaced if there's any doubt about them being completely free of contaminants, and anything else that might be hiding some glitter.
If there's no damage to the hard parts, you got off lucky. A complete douche and new bearings should set you straight.
Be thorough in cleaning everything... Depress the lifter plungers in solvent... everything you can do to get any contaminants out of their little hiding places. Disassemble and clean the turbos, turbo oil supply and drain hoses... Anything that comes in contact with oil.
If you do find where the shavings came from, let us know what you found.
Best of luck Huffa. I hope you don't find a smoking gun and it's a quick turnaround for you.
-Seth-
Oh, and so far, I'm not seeing evidence of low oil pressure. Evidence of junk in the oil, yes. Wouldn't be the first time one failure killed several engines.
Thanks for that. So to go back to my tune day, it blew some oil out the rear breather stack but not the front stack at all and another thing to mention is that both rocker cover gaskets have been leaking a bit even tho the gaskets look fine. Does this not add to the idea of excessive oil accumulation upstairs? Thinking about adding external drain backs to fully eliminate this, good idea? Cant hurt?
You could. Would't hurt anything. However, I don't think it will solve anything either. Again, oil out of the rear breather isn't uncommon in a performance boat and is usually solved by doing as you did, moving it to the front of the engine.
If it were holding that much oil, you would have seen it on the gauge. No doubt.
Ultimately, up to you. If you will feel better, do it. If you want my opinion, don't waste your time, it's not doing what you think it may be doing.
So I have been thinking what plenty have already told me to do and set up a dry sump arrangement on the 5.3. I know stuff all about them, can anyone offer advice on how many stage I need and where to get a good value LS kit from? Would I be correct in saying it should solve all my oil blowing and bearing scoring problems I have had?
I just worry about the angle the motor is on when the boat is trimmed up going hard out pulling 5500rpm or so, sump is a front hump and has to be as there is insufficient room at the back under the engine for a rear sump, although a mate runs a LS1 TT in a race boat with the same sump and never had an issue, duno why do most serious engines use dry sump? Must be good reasons
If you're not seeing a fluctuation in the oil pressure, it's not likely going to solve the problems you've had. Tons of boats out there running sustained RPM without issue.
I know you're fairly certain the first failure was an oil issue. Looking from the outside, I'm not entirely convinced it wasn't a simple thrust issue. If not from the jet pump coupling, could have been as simple as the bearing shell halves weren't seated properly or insufficient end play.
The second, spun cam bearing and bearing material gumming up and sticking the lifters in their bore... who knows? Could have been oil related. But, it does happen occasionally, even with sufficient oiling.
This last one has trash in the oil and damaged bearings, but no indication yet, of where the trash originated from. The damage we've seen is most likely from debris in the oil, but we haven't seen a part that was likely damaged by lack of oiling.
Personally, I'd just start with a fresh donor engine and eliminate the need to completely clean every nook and cranny of the one you have. The peace of mind, not having to worry if I got all of it out would be worth it to me personally.
Reassemble the combination you have, but this time set up your logging capabilities and log oil pressure from the stock location on the rear/top of the engine,. As the tuner is reviewing the logs he/you can also note any oil pressure concerns. Make a rip, review, make a rip, review...
At that point, if you're seeing funky stuff that you didn't notice before, sure... investigate a solution. Otherwise, you could be throwing time, money, resorces, and emotional stress at/for nothing, shooting in the dark per say.
To address the question presented, didn't one of the recent Corvettes have Dry Sump? I'd be curios what the costs are compared to aftermarket solutions. Guessing it would be easier to adapt, being as it's configuration and components would already be pretty much LS specific.
The one thing dry sumping your engine would cure, without question, is... your valve cover wouldn't leak oil anymore. However, that could be the only thing it solves.
Again, I'd verify through data logging that there is/isn't an oil pressure issue, before spending the time and substantial cash on oil system modifications. While you're at it, put a temp sensor in the pan too. Log oil temp and pressure.
BTW, what oil are you using? What oil pressure do you see cold/hot, idle/WOT? And, I thought you went with the Commodore oil pan, what pan do you have now?
And a last thought... The guy I mentioned before, with the TT LS jet drag boat... he used a stock oil pump and shimmed the relief spring to slightly increase the pressure. Commodore oil pan and hitting 7800 RPM occasionally. He said his oil pressure was rock solid, so that's the route I took on my build (not a jet & different pan). Mine should be on the water in the next 4-6 months. Just thought I'd share that.
12-13-2016, 02:07 PM
