Members engines who have blown

[enigma]

To put a stop to rumours and misinformation I am starting this thread for people to expand upon their experiences of VR4 engine failure and the probable causes. I will also include some of the pioneers in terms of engine performance on standard internals to show that the VR4 is anything but weak.

Below are a list of people that have suffered engine failure with a brief description of the circumstances.

If any of you would like to add anything please feel free.

Me - Engine failure x 2 due to broken piston ring lands.
Engine 1 broke 3 ring lands but continued running for 30,000 miles after the first instance. I finally pulled the engine and replaced it only to find that it would have run another 30,000 miles had I spotted that a rocker had fallen off.
Engine 2 broke a single ring land and continued to break up leaving bits of piston ring in the inlet manifold. 4 rockers were displaced on the rear bank.

PJJohnson - Engine failure due to broken ring lands. Suspected to be from long term high boost running.

RichieElliot - Engine failure due to incorrectly fitted boost controller and very large amounts of boost. I personally stripped this engine with the help of Derek and we found one broken piston and rod. It is likely that the piston broke, wedged in the bore and caused the failure of the rod. The offending piston required a very big hammer to remove it from the block.

Zentac - Engine failure due to high boost and nitrous use. Thought to be running in the region of 475BHP @1.3Bar on a large single turbo. Again it is likely that the piston broke wedged in the bore and snapped the rod.

Braindg - Undetermined engine failure. This was undermined at the time but I now highly suspect that a piston broke and displaced 1 or more exhaust rockers. The engine would run without the inlet manifold connected, but when it was attached it would not run. Why? Because the exhaust valves were not expelling the exhaust gasses they were exiting through the inlet valves and in to the inlet manifold effectively choking the rest of the engine.

Zedy1 - Broken PS/Cam belts on a high BHP nitrous engine

SGHOM - Undetermined engine problems - intermittent

valmes - Undetermined engine failure due to oil contamination

Conaboy - Undetermined engine failure

White Lightning - Undetermined engine failure

From the above list the following high BHP figures should be noted

Me - Engine 1 in the region of 330BHP with an additional 100BHP of nitrous
Engine 2 in the region of 350BHP with an additonal 130BHP of nitrous
Engine 3 in frankenlegnum 280BHP with an additional 200BHP of nitrous (no failure)

PJJohnson - Undetermined power, but likely to be in excess of 350BHP

RichieElliot - Undetermined power, but due to high boost likely to be well over 350BHP instantaneously

Zentac - Undetermined power but unlikely to be much less that 400BHP plus 50BHP of nitrous

Braindg - Undetermined power, but due to a boost related failure unlikely to be less than ~330BHP instantaneously

Zedy1 - Undetermined power, but 1/4 mile results suggest in the region of 350BHP with an additional 75BHP of nitrous.

SGHOM - at least 330BHP with an additional 100BHP of nitrous

valmes - undetermined power, but with replacement engine is unlikely to be making less than 425BHP

Conaboy - undetermined power but due to boost levels ~1.2Bar is unlikely to be less than 330BHP

White Lightning - undetermined power

In summary, there do not appear to be any failures that are attributable to 'weak rods' and the rods that have broken have done so due to another failure. Any talk of the VR4 engine being weak are unfounded as there are members listed above that have pushed the standard internals right to the limit and way beyond what is considered possible by so called experts. For everyday driving sensible mods can see safe running at levels of up to 350BHP and beyond. This is far beyond the level that 90% of the community are running. This is not to say there is no possibility of engine failure at these levels as it depends very much on the individual engine, how it was tuned, and how it is driven.

Please feel free to add more information about the engine failures above and add to the list as appropriate.

[enigma]

To add to my experiences here are more details about my failures

Engine 1 first let go when the boost was upped to about 1bar with peaks of around 1.3 iirc. The symptoms were rattly running for several minutes and the destruction of the spark plugs in the offending cylinder. Replacing the spark plugs once the bits of piston had worked through the valves cured the problem.

Another piece of piston released itself during a dyno run at Well Lane turbo centre. Whilst on the rollers I produced 275BHP at 75% throttle and on 5 cylinders. Again after a period of rattly spanners the plug was replaced and I carried on my way.

Twice during Trax 2004 bits of piston removed themself from my engine and exited through the exhaust. I have video footage of me increasing the boost along the start finish straight and evidence of the failure during exit of the first corner. I fixed the engine after the morning session and went out again to do the same thing in the afternoon. After much rattly spanners, some help from members and some swearing from the wife the car limed away from the circuit, by the time we hit the main road it was running sweet again.

Another 3 or 4 instances were recorded during day to day driving to and from work with the same syptoms and cure.

The final nail came a couple of days after running a 12.7 1/4 mile utilising ~80BHP of nitrous. Same symptoms but this time it was not hunky dory after replacing the plugs. I drove with it on 5 and very lumpy for a couple of months and several thousand miles. Turned out that when I removed the engine one of the rockers had fallen off due to a valve being jammed open by a bit of piston during a revolution. Had I fixed the rocker I would have been back on a 6 cylinder engine albeit with 3 very broken pistons.

My 2nd engine went a few weeks ago during a very hard nitrous launch at Santa Pod. The engine was recorded at in excess of 330BHP at WRC BEFORE I fitted the MAP ECU and further tweaked the fuelling. I was also running 130BHP of nitrous which would put me very close to 500BHP. I launched at about 3000RPM and at around 5300rpm it all went wrong. I completed the 1/4 mile and was only just beaten by the 106 Rallye in the next lane despite coasting most of the way as I knew what had happened. After much cursing I drove 70 miles home. I then continued to drive a further 40 miles to work and back before stripping the inlet off and replacing the plugs. After starting the car it was apparent all was not well so I stripped the rockers off to find 4 rockers from the back bank had come off. I refitted these and restarted the engine. The next morning upon starting the car there was the familiar death rattle as more piston broke off. This time a stripdown revealed bits of ring in the inlem manifold which spelt game over for the engine.

So at no point has there been a rod failure, but I have broken 4 pistons................

[Funkstar]

Nice post Dave. Could be a lot of help to determine and deterring future problems.:2thumbsup

[The Vee]

Post mortem will be carried out on White Lightning's old engine asap. As far as I'm aware it was standard power and suspect oil starvation problems causing bottom end shells to wear out. Will post more when I can confirm.

[White Lightning]

Post mortem will be carried out on White Lightning's old engine asap. As far as I'm aware it was standard power and suspect oil starvation problems causing bottom end shells to wear out. Will post more when I can confirm.

Yep, standard power on mine. 260bhp with just an aftermarket exhaust (cat back).

[bradc]

The piston ring lands are the little parts taken out of the piston around it's circumference to fit the rings in aren't they? Why are they failing so often? Would forged pistons help that, or does it have something to do with the design of the rings themselves?

[enigma]

The ring land is the part of the piston above the ring (or between them) Shown as A in the pic below. They are failing because it is a weak area! It is quite small given the job it has to do and because the pistons are cast the increased cylinder pressures with higher performance engines cause them to break up.

[bradc]

Thanks Dave :) Do you have a link to the site where that pic is so I can see what all the rest is?

[enigma]

Thanks Dave :) Do you have a link to the site where that pic is so I can see what all the rest is?

Sorry.............did it at the in laws.

[conaboy]

Nice write up:2thumbsup

My engine was never inspected, Mo picked my car up and replaced it but.....

I asked him to install my Apexi SAFC while he had the car, after it was installed he noticed the throttle postition never went above 75%, even when it was fully open. He took the TPS and checked, cleaned and reinstalled it. Problem solved.

Guessing this may have been the problem. Possibly caused the engine to run lean resutling in terminal engine damage.

[BraindG]

Mine as caused by incorrect installation of cam belt, turn engine.. clatter clatter.. dead.

[enigma]

Mine as caused by incorrect installation of cam belt, turn engine.. clatter clatter.. dead. Yep, but I think it may not hav been as dead as you think..............

[Kieran]

Mine as caused by incorrect installation of cam belt, turn engine.. clatter clatter.. dead.

So it wasn't a piston related failure as originally suspected? Did Mo ever get to the bottom of what was wrong with that engine?:inquisiti

[BraindG]

So it wasn't a piston related failure as originally suspected? Did Mo ever get to the bottom of what was wrong with that engine?:inquisiti
nope its still at his as far as i know..

and dave yeah, if the back head was reworked it would prolly have/would work again, but not alot of us knew much about vr4's in those days, not like now.

[Eurospec]

Honestly speaking i've not encountered a blown up VR4 yet, but i've seen blown up scoobs, evos, fto's, ZX 300's and GTO's.

What i notice is two main forms of failure:-

Top end blown. Normally the ringlands get blown out, smash themselves to bits and send metal all about the engine. Kills the valves, the head, the bore and the piston itself. Never seen a bent rod with this.

This is a typical failure in turbo cars that are boosting beyond the capability of the fuel system and detonate. It only takes a couple of occurences and it isnt like you can hear it. This is where datalogging is a real bonus in tuning. The knock sensor will pick up knock the human ear cant hear, even on the dyno with det cans. I could point to an example of a customers car which the logger showed a knock count of 28, but the dyno operator only heard one ping. In the VR4 with datalogging only just coming into the mainstream it would not surprise me to find some cars out there are knocking at the levels of boost they are running. I'm not saying thats a fact, just that its a suspicion of mine. Worth the investment in a logger to check anyway.

In NA and Turbo cars you see bottom end failures. Bent rods, straight big end bearing failure, big end failure at speed causing bent rods as the rod picks up on the crank. There is a theory that says if a car experiances low levels of knock for sustained periods that will increase the load on the big ends and whilst it isnt enough to detonate a piston, it is enough to repeadedly hammer the big end shells into submission. When a big end fails it is possible to bend a rod. Normally when a rod breaks or bends enough force is exherted to bugger everything in the bottom end, so its a bit chicken and egg to say which went first, the rod or the bearing.

Gut feel, the 6A12 engine from the FTO is primarily an NA engine, although it was available as a turbo in the early galant. When they developed the 6A13 i suspect they used a base 6A12 engine bored it and added a stroker crank, meaning the rods will be longer, and so designed for the turbo application. Its pure supposition on my part though and not to say that the rods arent the weak link.

As to whats the weakest link, i dunno and i think its very hard to prove unless people have got cars with a bent rod with no big end damage and where the car was known not to be detonating.

Cheers,

Ben.

[valmes]

I just want to clear up something about my failed engine (the last one... was it a year ago?).

I spun the bearing... due to OIL CONTAMINATION (mechanics who assembled it back after I've been in a car accident, didn't clear out the oil pan from debris... we found parts of the head cover in the oil pan… that tells the story), aside from that - rods, pistons and rings were in good condition, despite the fact, that I pushed it past 1.3 bars occasionally... they still are in good condition, I kept the engine for future experiments.

PS: I just realized who Enigma is… ;)

[enigma]

I just want to clear up something about my failed engine (the last one... was it a year ago?).

I spun the bearing... due to OIL CONTAMINATION (mechanics who assembled it back after I've been in a car accident, didn't clear out the oil pan from debris... we found parts of the head cover in the oil pan… that tells the story), aside from that - rods, pistons and rings were in good condition, despite the fact, that I pushed it past 1.3 bars occasionally... they still are in good condition, I kept the engine for future experiments.

PS: I just realized who Enigma is… ;)

Thanks for that I will update as necessary :2thumbsup

[enigma]

Val, didn't you pop another engine by accident?

[valmes]

The very first one (like 3 years back when I got the car...) failed due to... lack of oil as such! :) Basically I killed it myself on purpose!

Long story short - I drove the car without oil for (that was 210km trip from my city to the drag racing event "close by" ;) ), I don't really recon now, exactly how many km non stop... but I think around ~150 km and at constant speeds in excess of 140-170 kph.... Engine just didn't want to die!!!

Finally it gave up and one piston was lost in the process and the connecting rod was bent... no it was sticking out of the block actually!!! Hell, the crank was bent! :) Fun times...

BTW, 1 piston and rod was sent to Marcel (he needed them as a sample to make forged pieces). 4 remaining rods and pistons after some work on them lived happily ever after in a Turbo Lada... somehow dimensions were similar. :)

So, I don't think this engine could be called "weak" by any means... ;)

[enigma]

I don't think this engine is weak by any means... ;)

This is kind of my point :scholar:

[Adam.Findlay]

So, I don't think this engine could be called "weak" by any means... ;)
Definatly not , I threw a conrod through the metal plate next to the sump pan it punched a 6inch hole in to the poor motor. My disaster occoured on the down rev approaching a hairpin on a racetrack, I was on the warmup lap folowing the pace car and a heard an almighty bang, (horrendus clouds of smoke in my rearvision mirror) and a conrod came flying across the tarmac. quite impressive but terrifying. I am yet to dismantle the ruined engine but as far as i can tell it had spun a big end and weakend the bottom end of the conrod, heat stress caused the weakining then it gave way after being up under load on the race track, until the heat became to much. (engine had been run at 1 bar for 2 weeks not excessive use) but at time of explosion the EBC was off and standard boost pressure was being used, oil was fine water was fine, i do suspect a bit of knock may have been to blame for the big end bearings demse.

The one good thing to come of the engine throwing a rod is i now have a set of heads to port and polish and grind bigger valves into, and if i am very lucky a block to add forged internals too. now money is the big issue :( !

But i know they are solid engines because when i went to buy a new engine the 2nd wreckers i rang had 5 yes FIVE in stock, so I managed to pick up a engine that had only done 30000kms for 500 NZD, and the guy who worked at the wreckers said thats the first 6a13tt that he has sold for a factory replacement, as neither he or any of his collegues has seen a 6a13tt throw a rod on standard boost, full of oil, full of coolant and properly maintained.


The guy who works at the wreckers is going to be putting a 6a13tt into a 6a11 lancer with a gsr drivetrain, he is a mate of mine after realising the same intrest in 6a13powerd cars :) , will upload photos when that is complete.

[foxdie]

Old thread alert! :D

Just read this, quite interesting.. What options do we have for strengthened internals by the way? And do they make a difference?

[Turbo_Steve]

Search for "forged" and you will find the answers you seek :D
There are a couple of options for forged internals, but it's going to leave your wallet cowering in the back of the wardrobe, and weeping blood, especially if you're having someone else do the build work.

Generally it seems that a decent sized turbo, sensible boost and good fuelling seems to be an effective way of preserving these engines: steering clear of det on cast pistons+rods is the main issue: they simply cannot take that kind of abuse: Most people chasing the 500bhp mark seem to gamble on it: Have the funds to build a fully forged lump handy, and push the standard one to see how it lasts. Generally, they seem to do okay.

[Madhav]

I really don't see the point of forged unless you are chasing huge power. Mine has run 260kw and will eventually see 280kw atw with a little more boost and a modified fuel rail and the engine internals are totally stock.

[kiteman]

I broke my engine while tracking last march. It had just completed a year of what I consider to be hard trackday driving ( 25 to 30 trackdays)
Have'nt stripped the engine yet to figure what gave up, but the general opinion is the oil pump.
Before it packed in I honestly believed the engine to be bomb-proof.

[chris g]

As someone who has posted in the past about this issue, I have never thought of our cars as having weak engines...

And with a number of 'blown' engines we are getting more info about the areas that can fail in everyday use or in more spirited use with std or modified engines..