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Can a new engine recover from fuel wash?

Started by _Viper_ , Oct 06 2013 09:40 PM

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29 replies to this topic

#1 _Viper_

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Posted 06 October 2013 - 09:40 PM

Hey guys, my friend had a engine built (4cyl petrol turbo) and we fired it up for the first time... ran really rough... had it "running" for about a minute or so while trying to adjust the ecu (which had a blank tune and the reason why I thought it was running rough) Not having any luck so shut it down to check over everything...

Then I noticed a bit of a puddle at the exhaust... fuel...

Pulled the plugs and 1, 3 and 4 were a little sooty and number 2 clean as a whistle and wet.

Cranked her over with the plugs out and yep heaps of fuel squirting out of #2

Removed the injectors and #2 injector I could blow straight through! Asked where he got the injectors.... Ebay. :(

He had another set of injectors, threw them in... dropped the oil just incase, cranked it over with no plugs to try get as much of the fuel out, also blew inside the chamber through the plug hole with a blow gun.

Fired it up, ran heaps better... Did about a hour or so of tuning and is running quite well but thought I would do a compression test.

#1, #3, #4 all on 150-160psi #2 is on 120psi :(

Is it possible that with all that liquid fuel in there it has blown a headgasket around #2? (altho there is no sign of oil in the water or water in the oil)

Or would the fuel wash just damaged the rings?

Since the rings are still "bedding in" is it possible that #2 will come good with abit more running? or will it only get worse and we would be better to pull it down and hone/re-ring..

Or will it do no extra damage then whats already done and should just see if it comes good but if not then re-hone?

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#2 S pack

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Posted 06 October 2013 - 10:32 PM

Did you do a wet comp test with a squirt of oil in the cylinders to see if the pressure readings increased?

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#3 _Viper_

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Posted 06 October 2013 - 11:35 PM

Nah I didnt but I guess that will tell us if its rings or gasket hey... will do

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#4 _Ned Loh_

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Posted 07 October 2013 - 07:21 AM

After an hour under load tuning, the rings are bedded. Bent conrod?

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#5 _oldjohnno_

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Posted 07 October 2013 - 08:08 AM

I'd be inclined to borrow or buy a boroscope (you can get them cheap from the hardware shop) and have a squizz through the plug hole and/or a port. If the wall looks ok I'd replace the injector(s) and run it for another half hour then recheck the compression. The results of the test would determine whether it stays buttoned up or gets fresh rings.

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#6 _Viper_

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Posted 07 October 2013 - 07:21 PM

Engine is running decent atm so dont think bent conrod, plus they are forged rods/pistons... (do you suggest this as it may have hydraulic locked with the liquid fuel? There was never any big thuds or bangs etc just ran rough, just like 1 cylinder wasnt firing)

I did the oil down the plug hole trick and the compression didnt change at all, which leads me to think possible head gasket? altho no signs of oil in the coolant or vice versa still...

We are thinking of pulling the head, checking the head gasket and will also give us a good look at the bores and go from there... If there is no scuffing but we also do not find any obvious head gasket damage.. then what else could it be? Will do our best to look for a broken ring from above.... can the rings get damaged but not damage the bores? A bent conrod would be obvious would it not? Fuel in the bore cannot effect valve sealing right?

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#7 _oldjohnno_

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Posted 07 October 2013 - 09:00 PM

Pretty sure that hole will need a hone and rings.

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#8 S pack

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Posted 08 October 2013 - 12:28 AM

My understanding of a wet compression test is:- the addition of oil in the cylinder will increase the pressure reading if the compression rings are the problem, if there is no change in the pressure reading this usually indicates a blown head gasket or a valve that isn't sealing properly.

I'm sure these test procedures are not infallible but they are usually a good indicator.

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#9 _Viper_

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Posted 08 October 2013 - 12:56 AM

Ditto, but johnno knows his stuff, how come you are pretty sure it needs hone n rings tho if the oil didn't change the reading?

might buy a leak down tester tomorow actually and that may help to give us a clearer answer.

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#10 S pack

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Posted 08 October 2013 - 01:01 AM

Clint, when you did the oil test did you put in a good squirt and then crank the engine over a few times to get the oil in around the rings before you did the test?

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#11 _Ned Loh_

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Posted 09 October 2013 - 12:38 PM

do you suggest this as it may have hydraulic locked with the liquid fuel?

yes, that was my free of charge wild internet guess. I didn't think that "a minute" of running would be enough really screw the ring seal.

If it's a decent dollar motor stump up for a few gaskets and pull the head for a look. it's only a couple of hours work. If it's a cheapie give it death and see what happens*.

Regardless, I'm curious, please post up what the outcome is.

*all care, no responsibility

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#12 _Viper_

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Posted 13 October 2013 - 06:17 PM

Ok well the plot thickens!

We used a boroscope down the suspect cylinder and found vertical score marks... so decided to do a re-ring. Engine was removed (I bought a leak down tester and was planning to test the motor but the owner removed the head before I got there, Doh should have told him) Anyways confusingly we found pretty much identical scuff marks on all 4 cylinders

#2

#4

Matching scuff marks on the pistons

Now im confused why #2 was down on compression when all bores were stuff... Can the fuel wash cause the rings to be damaged and not the bores? (none of the rings were actually broken, could not see any obvious signs of damage to #2's rings) I should mention these are forged pistons but side clearance is in the correct range AFAIK 3-3.5thou

The head gasket did not come apart cleanly so couldn't have a definitive look but was no obvious signs it had blown. (wish i got a chance to use the leak down tester)

Anyway we wanted to go ahead with the re-ring but after removing the big end caps it would seem that the compression issues may not have been the motors biggest worry...

Matching wear on the cranks big ends

You can see the small particles imbedded in the bearings (lucky we pulled the motor apart huh!) that was after only about an hour or so of running... Correct me if im wrong here but this could only be caused by 3 things? either the builder was not very clean when he built the motor (altho its from a very reputable builder that runs 8 seconds with similar motors, but hey anythings possible. The motor had been in storage for 2 years since it was built with no head or timing cover on it... so possibly it was not stored very well and all sorts of crap made its way into the oil gallery's or 3 something is wearing inside the motor and releasing particles... But if this was the case... say the timing chain was wearing alloy from the timing cover wouldn't these particles just fall into the sump, the oil pump pick them up but the oil filter uh filter them out before making their way into the gallery's?

So I went looking and found these marks on the timing cover (2 marks from the timing chain near the center)

Thought maybe thats the cause but after talking to the owner he says those marks were already there...

Anyway to me it looks like it would take alot of particles to cause this in such a short time???

There was still some marks on the main bearings but nowhere near as much as on the big ends... does this tell you anything in particular? I looked down the cross drilled passages of the crank and could see a few particles inside... I told the owner to have the oil filter cut open just to have a looksie.

Pretty sure this is inconsequential but I found this in the sump:

I knew I had seen it before, took me a Minute but its off the timing chain tensioner, its a little tang that sticks out the side and its there so when you release the tension you can push it right back and this tab locks it in the open position, the owner probly snapped it off while sticking the screwdriver down the timing cover as I know this is pretty fidly... it made its way down to the sump where I dont think it would have caused any issues after that.

So just wondering what everyones thoughts are... atm Im leaning towards bad storage and the engine getting filled with crap in that time? But why the score marks on all the bores and not just #2, its a multipoint injected engine so unless the fuel was making its way back up the runners and into the other cylinders also... is that possible? but why only #2 down on comp... still possible head gasket I suppose?

looks like the big ends will need to be re-grinded... hopefully get away with a linish on the mains. Will make sure I give all the oil passages a REALLY good clean out.

I would like him to have the deck faced lightly as its got a few rust stains from the long storage but money is a issue, would have to remove the o-rings and Im not sure if they would need to be cut again as the grooves wont be as deep anymore?

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#13 _Viper_

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Posted 13 October 2013 - 06:24 PM

Oh forgot to mention the oil reliefs at the end of the crossdrillings in the crank look like they were down abit rough and their was burrs sticking out the edge of most of them, surely this isnt good?

And when I removed the big ends, the bearings had bugger all crush/spring to them and most pretty much just fell out... any idea what can cause that? (besides poor machining)

Last but not least I noticed a couple of the bearings had small dots where the alloy was completely gone down to the copper... what would cause this? Can see it just above the middle oil groove near top left corner.

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#14 _Bomber Watson_

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Posted 13 October 2013 - 06:29 PM

Looks like a 200,000km bottom end to me....Sure the engine builder actually touched it?

I can already see a slight lip at the top of the bores, correct me if im wrong though as pictures dont tell everything. I cant see any way that you could get a lip at the top of the bore after an hour.

Cheers.

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#15 _Viper_

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Posted 13 October 2013 - 06:58 PM

Nah no lip at the top of the bores, must just be the pic... I know the engine builder (by Know i mean ive had him on my facebook for a number of years and we chat often and has given me plenty of advice in the past), he has pumped out multiple 8-10 second gemini's and a few guys over here run his motors with success, Engine is filled with good gear, the hone marks on the bores are still very prevalent...

Not really doubting the engine builder, more likely particles made it into the engine after it left him... unless he happened to have a bag full of 80-grit he unknowingly spilt into the engine

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#16 _Bomber Watson_

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Posted 13 October 2013 - 07:04 PM

Cool as. I've pulled apart million km old holden sixes with 20mm of sludge in the sump and rocker cover that have had less wear on the skirts/bores than that....And the bearings have looked better. Is all.

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#17 TerrA LX

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Posted 13 October 2013 - 07:16 PM

I think even the best engine builders have been guilty of banging a motor together when the owner keeps his hands firmly in his pockets.

I'm with bomber on this one, looks more like a re ringer than a rebuilt motor.

Draw into a motor which you have no real gauge of what was actually done to it and then having to pick up the pieces, I feel your pain.

I would be double checking every clearance and measurement and making the necessary rectification work.

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#18 _oldjohnno_

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Posted 13 October 2013 - 07:20 PM

Are their scuff marks on both sides of the pistons/walls or only one?

And has it been running under load? A common cause of sprung bearings is detonation/preignition. It's really hard to diagnose with photos but it looks to me like a combination of contamination, fuel dilution and possibly excess spark lead. All or any of these can make a fresh engine look decidedly old in a matter of minutes. Some close up photos of the bearings, walls and pistons (including top and underneath the crown) might help.

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#19 _Viper_

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Posted 13 October 2013 - 09:12 PM

Owner has taken the motor and bits to the machine shop now so I cannot take pics but Ill see if he can take a few for me

Scuffs marks are on both sides, It spent about an hour on the dyno with only a few short pulls under low boost, Ive got kmon knock ears and was no signs of detonation as well as the owner keeping his head in the engine bay keeping an ear out for any bad noises or leaks... it was very early in the tune so timing was locked at 20 degree's BTDC just so I could dial the fuel in, and I only got to 4500rpm

Tops of the crowns looked 100% brand new as well as the bottoms altho the exhaust valve looks like it has just kissed pistons #1 and #4 (come to think of it ill double check it wasnt piston #2 that had the valve kiss... maybe the valve is slightly bent and not sealing properly hence the comp drop) so clearances will be checked before it goes together (the owner bought the short block and fitted the head himself but never checked clearances properly... I turned the engine over by hand before it was ever cranked over but that was the best I could do without pulling it apart) Brand new Eagle Rods with ARP bolts... The crank would of had to be machined to suit these rods so new bearings would of been put in... Even if you were to re-ring a engine surely you would throw a new set of bearings in anyway they are cheap as... why wouldnt you... Money for the build wasnt a issue... he has a set price for his engine packages... its just now this is all unplanned cost for the owner so things are getting tighter.

if it was detonation doesnt it usually hammer the middle of the big end bearing on the piston side?

I zoomed in and cropped the few images I have, photobucket downsizes them automatically or maybe its the forum, but lets see how this goes.

Edited by Viper, 13 October 2013 - 09:13 PM.

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#20 _Viper_

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Posted 13 October 2013 - 09:15 PM

Oh and there was no signs of specs on the spark plugs, there were a nice tan color

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#21 TerrA LX

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Posted 13 October 2013 - 09:37 PM

Forgive me if I insult, but building a short motor to let it sit for 2yrs then slapping a head on it with some ebay injectors, sounds like a base budget build to me.

The last "rebuilt" long motor I looked at to ready for fit had 2 or 3 collets not seated correctly, a mushroomed lifter, a cam shaft not even fit for a re grind and one end cap was about 040 shorter than the others... bearings looked similar to your photos.
I have seen enough horror stories of "rebuilt" motors to know that anything you did not bolt together needs to be pulled apart.

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#22 _Viper_

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Posted 13 October 2013 - 11:45 PM

No offence taken... The owner has indeed skimped on a few key parts and made a few mistakes (ie letting it sit for 2 years and not keeping it properly sealed) but my point was that the engine builder himself would not have skimped as he sells these packages to run 10 seconds (and many do, depends on the size of turbo you fit and how well you setup the driveline (auto, stall, transbrake or manual etc)

But he has certainly learnt his lesson and that is Cheap parts cost you money in the end..... OR maybe if the injectors did not leak we would not have pulled the motor apart and found the fkd bearings... so maybe the injectors "saved" the motor... depending how you look at it haha..

Or if everything was done right for the get go and stored correctly with the right injectors it would of been right first time...

But as im still learning (and will never stop) I just like to find the root cause for things so I know in the future and hopefully stop them becoming issues before its too late..

IE ive learnt to query where the owner of a custom setup got his injectors from and to make sure a fuel pressure gauge is fitted, get the system up to operating pressure and watch the gauge for a while and make sure it holds pressure, if not then investigate....

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#23 TerrA LX

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Posted 14 October 2013 - 10:37 AM

We all live and learn.

Funny, I know he may have gotten away with it if the injectors were good to go but Wasn't the point of the tear down low comp on 2?
I don't think the injectors caused that, maybe the suspected bent valve.

Anyway I will go back to lurking and wait and see.

Keep up the good work.

Edited by TerrA LX, 14 October 2013 - 10:38 AM.

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#24 gtrboyy

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Posted 14 October 2013 - 11:46 PM

Normally I'd assume motor has been cooked or too tight clearance to score marks from the piston skirts like that.Looks bit suss if score marks were there when it got put together.

As for bearings etc looks like it had no oil for some time & was dry when turned over/started...metal on metal untill it got oil pressure.Might have been put together with just engine oil builder thinking it won't sit too long or would be sealed.

Sounds like a combination of errors made over time like engine not sealed properly,put together with oil not engine lube & sounds like head wasn't checked that had bent valve which showed up as cylinder problem.

Just unlucky thing to happen & learn from.

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#25 _Viper_

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Posted 15 October 2013 - 12:12 AM

Yea I'm now leaning towards the valve causing the low comp (once again wish it got to use the leak down tester)

when the motor was bought to me it indeed had no oil in it, id dare say it had none for the 2 years. I filled with oil and cranked the engine over with no plugs until it got oil pressure before it was fired up (oil pump in sump, no way of priming it externally)

but yes seems to be a combination of things, least we found the issues before the engine was a complete write-off