924Board.org

[xpernet]

Hey Guys

Just replaced the Distributor cap, and this little metal thing (i dont know what do u call it) and all is great. But now, when we Start the car or get into high RPM, there is this "Kurr Kurr" sound coming from the engine. My dad says that these are the pistons.

Is this a serious problem? We live in the mountains, and dad is using the car as his daily driver. It was producing this sound all the way to home (up hill only, and highways)

How could it be resolved? I was thinking of an engine rebuild, since she needs one, but that should wait to the next month if so.

Thanx in Advance
_________________
1977 Porsche 924
Sunroof Delete
Megasquirt II EFI & EDIS
Carrera GTS / 944 Body

"If one does not fail at times, then one has not challenged himself." Ferdinand Porsche

[Helstrm]

I have never heard a Piston make a Kurr sound but any sounds that a piston makes is a bad thing.. However I doubt that the piston is making the sound.

I will yield the floor to the 924 guys because I don't have much knowledge of the early 924 engines. I have only worked on the 2.5 liter.


For the most part the pistons won't make additional noice unless the rod dearing is going bad or it is carving it's initials in the cylinder walls.

[xpernet]

I was abit hasty to post this problem. My dad jsut called, and he took her to a mechanic to buy some additive. The guy said, that sudden performance gain and octane change ( we accedentally filled her with 92 this morning) was causing the sound.

One mothball to the tank should pump up the octane

xpernet
_________________
1977 Porsche 924
Sunroof Delete
Megasquirt II EFI & EDIS
Carrera GTS / 944 Body

"If one does not fail at times, then one has not challenged himself." Ferdinand Porsche

[Helstrm]

If anything that would have cause spark knocking,.. (Detonation) But good luck with it.

[5150]

little metal thing - contact breaker (points) by any chance? Could be that the gap is slightly out, when I replace mine I usually have to fiddle on with them to get the gap just right otherwise the car sounds terrible...
_________________
Mars Red '78 Euro 924 n/a
http://www.cardomain.com/id/5150_uk

Graphite? Grey Metallic '85 (late model) 944 2.5

There are two kinds of pedestrians: the quick and the dead.

[Mike924]

Our engines won't like running on 92 octane (that's only just a bit more than water, isn't it? ). They were designed to run on 98 and they just about get by on the 95 piss that gets sold here (with a timing change).

Running on too low octane fuel will cause the engine to 'knock' (particularly uphill), which could be described as a 'kurr-kurr' sound.
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[Raceboy]

It depends on which measuring method is used to mark the octane value.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[timstar92404]

isn't the 924 suppose to run on "reg" gas ?

I think here reg should be 98 octane?
_________________
78 924 sold.
85.5 944

[timstar92404]

I don't know much but I would think if there is something wrong with your pistons and they are making noise the engine won't be running for too long.....
_________________
78 924 sold.
85.5 944

[Helstrm]

[Mike924]

It must be like Raceboy says and we must have a different scale of octane ratings from you guys.

Here in the UK, standard unleaded is 95 octane and some garages sell 97 'super' unleaded. On mainland Europe, you can also get 92 octane, which even some modern cars have trouble with.

(In the Seventies you used to be able to get 110 octane! That's when a number of performance cars e.g. E-type Jags, etc would specify a minimum octane level of 100.)
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[Helstrm]

No wonder you guys pay so much for gas... Selling you guys racefuel at the pumps...

93 is the highest you will find at the pumps around here.
_________________
87' 924s (944 Wide Body) Project
01' Suburban (To haul the kids around)
03' Eclipse GT (To keep the wife happy)

[Raceboy]

Our regular is 95, higher ones are 98 and 99 and you can get 102 (Neste Green Racing and ELF) too.
I use 98 daily, on a turbo I have used toluene to boost octane (much cheaper) like Formual 1 cars at 80's (they used almost pure toluene, octane 121), but pure toluene ignites very hard (on F1 cars they heated gas tanks).
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[xpernet]

from what i can see here, 95 (which is regular) seems to be like 92, and 98 (super) seems to be 95.

xpernet
_________________
1977 Porsche 924
Sunroof Delete
Megasquirt II EFI & EDIS
Carrera GTS / 944 Body

"If one does not fail at times, then one has not challenged himself." Ferdinand Porsche

[crazyinkc]

We use (RON+MON)/2 here in the US and I think Canada uses the same method. I am sure someone in Canada will know. The rest of the world uses RON. So the US (CLC) 87 octaine is 91 RON and 91 US (CLC) is 95 RON. RON is Research Octaine Number and MON is Motor Research Method. CLC is US Cost of Living Council. RON is ROZ in Germany. I am no expert on gasoline or octaine ratings, I just searched the internet and found some info from a few sites.