Dino Engine Failure

Check ignition timing.

 

Check cam timing aswell.

 

Ditto. May have jumped time (Cam).

 

I would slow down a bit (pun intended). First, for compression to be low in all cylinders first speaks to measuring-device error. I would double check the compression readings with another gauge. Second, compression of 100 psi would not cause the engine to quit, nor would it prevent the engine from starting. Loss of power, maybe, with barely noticeable result on the street...yes. But complete failure to start or run unlikely. Third, what was the conditions of the sparkplugs? If rings are invoked as the cause, we should see oil-wet plugs.

Finally, for a cam to slip a notch on the chain is difficult in the Dino. Symptoms would be popping and rough running.

With the exception of your observation concerning spark, the symptoms sound more like a CD ignition failure, capacitor short, or points failure. For all cylinders to quit while fuel is abundant speaks to spark.

Let us know, but before tearing it down I would do more diagnostics and give a lot more thought to the issue. A quality rebuild 20,000 miles ago is not consistent with ring issues today.

Jim S.

 

Low compression may or may not be related. Unless you checked it recently don't assume it suddenly changed.

Change in cam timing would influence compression numbers but with 2 timing chains I would not expect it to affect all cylinders.

Look at the easy things first. If the distributor hold-down came loose timing could drift until it would no longer run. It is also possible that your advance mechanism failed (broken springs) this would leave the timing hopelessly advanced and it would probably not start or idle.

 

ghenne - so far you are doing everything correctly. Timing is not top of my list because if it were so far off that the car would not start, you would likely have popping and/or backfiring.

Could you have water in the gas @@!!!!!!!

Jim S.

 

If the cylinders are scored then the rings and pistons will be too as they did the scoring. Who rebuilt your engine the last time?

 

Obviously you need to fix this problem but it doesn't look like it suddenly happened.

100 psig is plenty to get an engine running.

The bottom line, this isn't why it quit running.



I stand by my initial diagnosis.

Your ignition timing was off.

 

If you were running it hard all day and had a combination of bad gas and overly advanced timing you didn't do the engine any favors. With all the chain and valve noise on a Dino you probably did not hear detonation which likely broke away the compression ring land. The reason it stalled out and did not re-start is because you just ran out of compression. When a cold comp test says 100PSI, a hot engine will show much lower comp.

 

Who previously did the work?

 

To even consider that someone who overhauled something 15 years and 20,000 miles ago is to blame is stunningly ludicrous. Thats half the reason I stopped fixing cars for anyone, they always think your to blame for everything no matter how long ago you fixed it even if it was unrealated. What kind of oil was ran in it the last 15 years, what kind of fuel, what grade, who set the points and ignition timing last, whos been driving it, was the aircleaner on correctly, did it have the correct spark plugs, was it overheated, was it lugged, was it over revved, did someone sabotage it. These are all honest and realistic questions, and I am sure with some time I could think of even more. But to go that far and run that good, and then suddenly lose power, speaks of something that effected all 6 cylinders equally, and not to long before you had trouble. Perhaps the last fuel stop you got the wrong grade of fuel, or it was contaminated. When your running hard in the upper rpms, things can happen remarkably fast. The heat can go from simply intense, to ferrocious, especially if you have the wrong fuel. I would probably rule out ignition, with split ignition it would be virtually impossible for both to be off together unless it was put together that way. And having chain driven camshafts, its just as impossible to jump time, and totally impossible both cams would jump the same equal amount. I think it points at fuel.

How fast can they go to hell? A kid accidently put jet fuel in a turbocharged piston airplane. With the fuel lines and colator all full of avgas, it started and taxied normally. Run up at the end of the runway was apparently satisfactory, and they recieved clearance. Witnesses said it seemed to take off fine. But the second it was off the ground it lost power on both engines, barely reached 50 feet of altitude, sank back to earth, and Mom Dad and thier two young kids bought the farm. When the FAA boys tore the engine's apart, they found all 12 pistons holed through the tops, melted. Figured it all happened in under 15 seconds. They probably were beginning to burn jet fuel just before it left the ground, and they began to melt immediately. It was something like 75 jet:25 avgas fuel mix, so it had a good dose.

How far back did you get fuel, what station, what grade, what pump? You may be able to make a claim if it is contaminated. It wouldnt have to be off very far to wreck your motor when your running like that that long and that fast. Of course we all know the Ferrari speedo is so innacurate, you really were doing the actual speed limit, RIGHT????? wink wink nod nod get the picture??? A small amount of diesel mistakenly added to thier tanks could screw it up real good. Whats the top of the pistons, spark plugs and combustion chambers look like? Post more pics.

 

ghenne: This looks like a really bad ring job and improper piston to bore fit, (likely someone slapped on new rings on old pistons and never rebored the cylinders or fitted the needed oversized pistons. it would have run for a bit more before you would have noticed the loss of compresssion, highly inlikely to be the cause of the shutdown. You asked: "Why didn't I blow any smoke or burn any oil? How could the engine have been running so strongly?" Because the rings were new with lots of "spring" as that dissapates it enables the wobble on top of the stroke and made the marks you see. Again no connection to its failure to start. With this I would not trust anyother part of the motor, likey there are other such "shortcuts" lying hidden within, you ought ot take it and anything else that was claimed to be rebuilt apart to the last bolt. So sorry, M

 

Can't chase the old mechanic, 15 yrs is a long time, and certainly even if the work was shoddy, it's just a part of the car's history now. No telling what other contributing factors may have been involved.

I agree with Michael, I'd have the engine torn down and examined carefully, you're gonna be doing a fair amount of work anyway, why not be sure that the car will go well from now on. Valves, guides, seats, the cams, carbs, the whole shooting match.

I did the same thing with my car 5 yrs ago. Started out just trying to get it to run, ending up really fixing the motor right, and have not regretted a minute, or a dollar of it.

Superformance has some nice high compression pistons that worked wonders with my car, and can sell you every part you need, at somewhat reasonable prices. Althoughthe dollar/Euro exchange rate is pretty awful right now. Parts are probably twice as expensive now.

Do it right, won't have to worry about it again. Can't really cry over spilled milk.

 

Its cold comfort, but remember 15 years ago was near rock bottom for these cars after the mad run up of the 80s. Owners saw their "investment" plumet and any repair bills seemed like throwing good money down a rat hole, so "right" made little sense. My 330GT was taken off the market in 1989 at $250,000 because the owner wanted more money, he held it through the drop. In 1993 he bailed out and sold it for $35,000. In those days I only followed the 12 nad 4 cylinder cars, others here may have the 1990 high median prices and the '93 bottom out numbers for the 6s.

 

Yeah, they are JE pistons from California. Are they exclusive to Superperformance? If not JE, try Wiseco the much larger sister company who actually produces the forgings.

 

Im thinking were only getting part of the story here. While the liners certainly look honed, and not so great, it does not look 15 years old or 20K miles. I could be wrong, but what it looks like to me, in that one single picture, is that someone sanded off debris in the cylinder after they got the head off and it "looks" like hone marks. Those diagonal scratches look very fresh and even seem to go through the vertical lines. Did your mechanic wipe it out to get a better look? Why did he pull the heads and not try to run it??? Why does it look like there is white particles on the cylinder, is it getting debris blown into it?

Tim brought to my attention these have a single distributor. The fact it had 100 psi compression it should have ran. In fact I wouldnt have pulled it apart until I ran it and found out why it quit. 100 just isnt that big a deal with an engine thats not using oil or smoking. I got a friends old Buick running once that was mostly 90 and under, half were under 80. It fired right up. There just is no reason this engine shouldnt have ran. The fact it started missing and then died could point to an ignition fault. Perhaps the distributor loosened up and rotated and burned up the engine before it died.

They say a picture is worth a thousand words. This one isnt, and its not telling us much. Post more pics so we can help figure it out.

 

Apologies, I didn't think of the time in those terms; 20,000 Miles in 15 years.
I've put over 13,000 KMs on my Euro Dino in less than 2 years.

Again, apologies for being out of line.

 

A compression test of 100psi and not running is the perfect example of how a comp test isnt a good way to check an engine condition by itself. In this case a running comp test to check one bad cylinder couldnt be used but if it had 1 or 2 dead holes that read 100psi a running comp test would reveal that they put out about 30psi, not the 100 you thought. Try it sometime. The leak-down test is the real way and the results wouldnt agree with the comp test in this case. The engine is baffed, never trust a compression test even on a PPI, too many variables.

 

I dunno.

I was told they also work for some Harleys, although that may be BS.

DM

 

All a compression test can tell you is if its basically good, and then only by seeing equal and high results. As a diagnostic tool its total crap. As a PPI tool I would trust it simply as a go, no go gauge. If a car wont pass a compression test there is something major wrong with it, and whether its valves or rings makes no difference, its a junk motor. Why pay a mechanic $100 hour (assume your out of town looking at a car) to diagnose the problem for the owner? Screw that, he can pay to find out, not me. If it passes a compression test, then do a leakdown test if you are still interested.

We going to see any more pics of this motor???