Engine designs that have problems 22

[enginesrus]

Since the one thread I started, is headed way off topic, reason for this.
Engine designs that have problems or have had them.
I'll start with the 3 valve Triton.
This guy explains. Has data from others that deal with the same problems.

https://www.youtube.com/watch?v=xcN_WcGr4BU

 

[TugboatEng]

You bought a car that was designed to be cheap and in the world of nearly $200 an hour labor any repair must be fast or you'll exceed the cost of the car. Thankfully Honda had complete engines available so you didn't have to waste all of that money on labor.

But the real problem is the cost of labor and the auto manufacturers have nothing to do with that. I have a block I need decked for a new head gasket and there is a months long lead time to get it under the mill.

 

[GregLocock]

In context a new short engine costs a car company about $2000, it would be easy to spend that on tearing an engine down, regrinding the bore, and replacing the piston and ring. The days of the UKP 25 cylinder head rebuild are long dead.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[SnTMan]

Hagerty Media: "Bronco engine investigated for “catastrophic” failure".

Stay tuned, I guess

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[SwinnyGG]

This is relatively old news to those of us with orders placed.

It's been traced to a bad batch of valves which have been suffering stem failures. There's more failures so far than they are reporting there - last I was on the forum a couple of days ago, I believe the failure count was in the low 50s.

 

[BrianPetersen]

The 2.7 EcoBoost in the Bronco is the same one that's in the F150, isn't it? If not, what's different? If it is, doesn't the issue also affect F150?

 

[SwinnyGG]

I believe the are substantially the same. There are some accessory plumbing differences (Bronco engine bay is significantly smaller). Both engines are produced at the Lima engine plant - but I believe they are different enough to run on different lines, which would explain a batch of flawed valves making it onto one platform and not the other.

 

[enginesrus]

Problems with valve stems? Gosh even in the war days with very poor grade of materials Germany could make decent valve stems. So the question is who is the real valve manufacture of these costly broken valves?
All of this having parts sub contracted from out of country, ends up costing us. Manufacturing needs to be 100% in house, so tight controls are kept on processes. Huge engineering failure.

 

[SwinnyGG]

How exactly do you know that German valves made during WWII were 'decent'?

And what exactly makes a 'decent' valve?

Who is the 'us' you think this particular failure is costing? Do you own a Bronco or have one on order?

Do you know who supplies the valves in question?

Do you know where they are manufactured?

Do you actually know anything about this problem, or are you just happy to claim the sky is falling?

 

[kjoiner]

Speaking of timing chains, how about the one on the Ford 427 SOHC. I read somewhere it is around 6 feet long.

 

[Lou Scannon]

You have a criticism of that design, considering its purpose?

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[kjoiner]

Hi Lou,

I don't have any criticism of the design. It's amazing for a relatively short term development in the 60's. Timing chains came up and I thought the Cammer was interesting because of the length of the timing chain and its arrangement. The main problem with it was the NASCAR banned it in the fashion it banned the Boss 429.

Kyle

 

[Lou Scannon]

The Cammer was never sold in a production passenger car, so it did not qualify for Nascar homologation.
The Boss 429 was allowed to qualify for Nascar homologation, I assume by negotiations between Ford and Nascar, with the intent of providing worthy competition to Chrysler's mighty Hemi, which had been dominating the high speed tracks since 1966. (There's a lot more to the story, which you probably know, so I will leave it at that, so as not to hijack this thread more than necessary.)

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[JayMaechtlen]

Mazda rotaries - we had an RX3, a 1973 or '74?
Ran great, not super powerful but pretty peppy. Wouldn't quite do 80 mph over the top of Cajon Pass.
(picked up one of my brothers at LAX, accidentally drove most of the way home in 2nd gear before I noticed. Yes we were on the freeway)
At 80k miles its o-rings failed, allowing coolant into the chambers.
The family kind of sat and procrastinated, eventually I took its motor and another one wit the same problem apart.
It had sat around rusting for a while, so I had a devil of a time getting enough of the apex seals out intact.
But By mixing and matching, I got that sucker back together (new face seals and o-rings, refaced end and middle cases) and it ran fine.It ran for many years after that, until if got crashed again (sister got rear ended, I think) and she retired it in favor of a Torino.
(yeah, that must have been a shock to the driving perceptions)
So I consider the rotary to be a very decent motor.


Jay Maechtlen

http://www.laserpubs.com/techcomm

 

[TugboatEng]

The RX up to 7 were fine because they were competing against a lot of lazy development. The RX8 proved the rotary engine is a novelty in today's world.

 

[enginesrus]

This section is called "Engineering Failures and Disasters" I've posted mostly Engineering Failures. And an engineering failure as related to Engines is the failure of the engineering department to properly design said engine or parts. In some cases rather than improve a bad design it is made similar but worse. Can anyone think of any examples? The "Disaster" part is when many people are financially stuck with the results of the bad design, or life is lost because of it.
And all joking aside, some cases of magnesium fires in the piston airliners during rain events was catastrophic, there is information out there about it.

 

[Alistair_Heaton]

not car engines but saw a 2 stroke opposing piston diesel engine self destruct which thankfully never killed anyone but a couple were in hospital for a while.

It was a tank engine and one of the fuel pipes fractured when the power pack was being replaced.

This was on the return line.

So it ran fine but filled up the engine bay.

When the engine turned off it started sucking fuel back through the return line and self feeding the engine. The revs went through the roof and quite quickly engine block failed above 10000 rpm. The gun barrel was over the engine bay for test driving and it blew the turret off and sprayed hot metal upwards and ignited the fuel left in the engine bay.

One broken leg off the turret and 1 nasty life altering burn resulted.

The fix was to put a nonreturn valve hard after the metering setup. Previously it was the other side of the fuel decouple in the engine bay. To change a power pack you had to decouple I think it was 2 fuel lines, 4 hydraulic and 3 electrical connections you could do it and swap the pack in under 30 mins.

 

[TugboatEng]

Never cared or the pressure-timed injection on the old Cummins engines. Unit injectors in the head, injection quantity was directly proportional to supply pressure, normally controlled by the governor. I think you can imagine what happens when a return line valve is closed and places back pressure on the system.

 

[enginesrus]

What gets me is when a problem exists with a certain brand engine in X series, and is known to happen for some years, no improvements are made or even attempted. Why?
What usually happens is the company's reputation starts to slowly go down the sewer.

 

[Alistair_Heaton]

Money...

 

[CWB1]

"Known problems" are usually grossly overrated. Several of the issues mentioned above are great examples - "known problems" that only affect a tiny percentage of total production or cost relatively little to fix, and are only really 'known problems" bc ignorant old men need something to gripe about besides the weather and youth.

"Reputation" is worse in that its often contrary to fact. Many studies of dual-branded vehicles have shown vastly different opinions of vehicles differing only in the badges. Its unfortunate, but preconceived notions and popular advertising shape reputations more than quality, and the general public largely cannot differentiate between paid advertising and hobbyist/entertainment rags/sites/awards.