vh blue 202 on unleaded

[mza]

ive been running my car on unleaded for a while now and was wondering what the symptoms are of damaged valve seats (?). i just have this weird almost rattly noise that only used to occur when i put my foot down but its progressively gotten worse to the point its always making the noise now. havent noticed any performance loss though. any ideas?

 

[vkberlina]

Have a look at my post on a previous thread "pining motor"

Your car was never designed to run on regular unleaded, it will cause damage to the engine and eventually stuff it.
Either run it on a higher octane fuel EG Optimax or LRP

Scott

 

[mza]

will read that, thanks. and i should have mentioned sorry, i run it on bp ultimate, cos yeh i know i need the higher octane rating.

 

[deathsminion]

A friend of mine had a blue 202, ran it on half super lead replacement, half optimax, and that still ruined the engine.

 

[vkberlina]

ok a bit more info now required

has the car always pinked?
has it been getting worse?
Has the timing been altered?
Has the carbie been rebuilt before?


Ok here goes

If the car has pinked for ages and progressivly getting worse and nothing else has changed offs are the tops of your pistons & combustion chambers are coated with carbon. Short of stripping the engine down to fix it Below is an old trick.

Get a glass of water or a sport drink bottle witht he squirt cap & no dont drink it
Have the car running, & remove the aircleaner
bring the RPM up to & hold at 2500 RPM
Now tip a small amount of water down the throat of the carbie, you should here the engine struggle a little RPM should drop a bit below 1000rpm.
repeat the process untill about 400-600ml of water has been used
This proceedure will decoak the piston tops & combustion chambers.
NB Its better to start with a small amount of water and increase amounts untill you have it correct.
Give the engine a bit of a rev up after ever couple of gulps to clean the carbon & water particals out.
NB: Dont have anything behind the exhaust a fair bit of crap should come out.

The ignition timing may be way off or you may have a problem with the vacumn advance on the dizzy.
Vac advance first
How you check it is to place a hose on the vacumn line for the advance unit and suck on it, if you suck air the advance is no good which could cause the engine to suck air into the inlet manifold causing your problem, if so plug the engine side of the vacumn line, repco do sell New bosh vac advance units for about $120
Next set the timing, generally when I used to set the timing on my 202 I used to advance the timing untill the engine would knock under load then back it off until it stopped, else you could use a timing light

If the carbie has been rebuilt it could be the cause of the problem if it hasnt been set properly, or it may have never been correct. If so I can dig out my rochester tuning guide to check the setting off. Another problem but unlikely is the fuel strainer could have garbage in it, just undo the fuel line from the carb and have a look inside the carb if its clean no probs.

Please note if you dont feel confident performing any of the above take it to someone who is.
Cheers
Scott

 

[mza]

well i dont know if its pinking, firstly, ive never heard it so cant say if thats the noise or not, its been doing it under heavy load since i got it, even on lrp, and by heavy load, ill refer to the vacuum gauge as its auto and has no tacho. it used to only make the noise around 5-15 on the gauge, now its all the time, this is over about 9 months progressively. and yeh nothing else has really changed at all. ill get my mate to have a look and have a go at the tricks youve said, thanks.