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carby setup on a 202

I am having trouble tuning up a 202 blue motor.It has a 350 holly (58 jets & a 6.0 power valve)cain manafold,extractors & a mild cam.
when I set the timing to about 4 to 6 tdc the car will run fine around town in light through to heavy acceleration but on the highway sitting on a 100 kph the motor will start pinging going up a hill under moderate power.When I retard the timing back to about 0 to 2 tdc the pinging on the highway stops but the engine will lose power and stall when in town.I have tryed 59 jets,adjusted the fuel mixture and tryed another distributor all to no avail. Does anyone have any suggestions?
Also I was thinking of getting rid of the 350 holly and trying twin strombergs on a cain manafold or a webber of a xe/xf falcon but am unsure how eather of theses setups will perform in power and economy.

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try using higher octane fuel or switch to unleaded as i had the same problem

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HI I WOULD TRY LARGER JETS SIZE 64 IS ABOUT RIGHT FOR YOUR 202,THE POWER VALVE 6.5 IS ALSO TO SMALL YOU NEED A 8.5 WHICH I THINK IS STOCK SIZE FOR A 350 HOLLEY.THIS SHOULD STOP YOUR PINGING DUE TO THE VERY LEAN MIXTURE YOU ARE RUNNING.THIS IS ABOUT STANDAD JETTING FOR A 350 HOLLEY ON A HOLDEN STRAIGHT 6 DAMO

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i adree with Damo, but the 64 jets may be to big, maybe 62 would work better and a 7.5 power valve may be better, not sure, either way theres a few ways to can check, if you are cruizing (i.e. when the problem appears) have the timing where you set it for town driving, put your foot to the floor, the car will accelerate, then if you slowly back off, before the car comes back to cruzing, if it actually accelerates better than when your foot is to the floor that means its lean. On the other hand if you plant it and the car bogs down a bit then goes that means its too rich. Also once you sort the mixture out, the best way to do the timing by ear is to advance it till it pings then just back it off slightly so it stops pinging.

Hope that info helps you out some.

Sammy.

Sammy's Website

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I think maybe around the 7 degree btdc mark. The trouble I have had once before was due to a retarded timing...

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The power valve is either on or off, the fuel flow rate doesn't change between valves. The number on the vlves is a vucuum referance number,ie, 8.5 valve will open when the manifold vacuum drops to 8.5 inches of mercury,(when you accelerate hard, and then will close at 8.5 inches of mercury as the manifold vacuum increases). 6.5 will open later, 9.5 will open earlier. Basic rule of thumb, divde the manifold vacuum at idle by 2 and add 0.5. How old is the engine? It may have excessive carbon build up on the pistons? Try a 1 step colder spark plug? Make sure the vacuum advance is correctly connected, not direct to maniflod. Engine running to hot,make sure the guage is reading correctly? Cam correctly timmed? Take it to a mechanic give him an excuse to have a few beers!!

Pete

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pete your right all power valves do flow the same rate,but they do have a great effect on mixture strenth,but only at part throttle ,rich and lean,ie to low a power valve and climing a hill with pedal down under load you will get flat spots ,surging ect lean mixture . under load the power valve will close when the manfold preasure reachers that of the power 6.5 8.5 ect , ie cruse mode,thats when the main jets fully take over again.58 or even 59 main jets are way to lean for a 202 as is the 6.5 power valve opens to late and closes to early helping to add to the already lean miture caused by 58 mains,even changing to 59 mains will make no difference. you have to go up 2 sizes at a time to make a noticible difference.a simple thing to do is richen up the mixture only cost a few bucks and see what happans cheaper than a mechanic, and as sammy said regarding timing by ear ,an old racers saying is crank it up a bit and when it starts talking to ya,back it off a bit damo

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i run a holley on my modified black motor(mild cam extractors,balanced,lightened flywheel,ported head ,polished valves...blah blah)and had huge problems getting it to run right eventually I gave up and had it dynoed the results showed the best combination for this motor was 64 mains 6.5 power valve 25 pump jets with a green pump cam and the idle mix slightly rich for round town running I also run 10 deg tdc to allow for the cam hope this helps Aiden

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