I've asked this question on a couple of other threads but didn't get much in the way of answers...we have a pretty "loose" 283 with a Petronix ignition and we're having trouble with AirCare idle CO. Plugs are Autolite 86's gapped at .035" (rough equiv. to AC R45's or R45S's I think). Does anyone have any other plug recommendations to make this thing burn a little cleaner - and a gap reommendation? One of my buddies said to gap them at .060" with electr. ign. but I think that's a bit much. Then a few of you here said about .045". Any thoughts anybody on both plug make and gap?
pertronix ignition will give you a longer dwell time, allowing the coil to charge longer(greater voltage). This allows you to increase the gap. Go with .045 and drive for a week or two and then check plugs, should be tan coloured. Then try .060 for the same time and check plugs, if they are dark fuel is not being burnt. If tan and drivability is good leave at .060.
i run a pertronix with my 350 sbc gap is .045 as I run it hard.
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pontiax- (canadian pontiac X frame)1964 Parisienne 2dr. Hardtop ,lagoon aqua metallic (Q) ,421 cid Dart Industries block and heads. 550 hp. 575 ft lb of torque.
...thanx a lot Pete. As I said, I doubt our rings are sealing that well so we get a bit of blow-by...we're getting quite a bit of carbon coming out of the pipes. I'll start off with .045". Would you rec. staying with the Autolites or maybe changing brands? To be honest, these plugs would be lucky to have 2000 miles on them, so they're not worn out by any means...just black...
Hey Neil, some good advice here. With my MSD and AC44 plugs set at 42 gap the engine runs excellent. Hotter plugs will help eliminate the carbon build-up also. Brian
...thx guys...hey Brian!!..how's that great big red 300-horse 4-gear CS runnin'?? Damn I wish we had a 4-spd..a helluva lot more fun than a 2-spd 'Glide...top-down weather is here though....parked 'er on Robson St. (our Yonge St.) last weekend at fulll slam and went for a stroll in the sun...when I came back I had to push my way thru the crowd around 'er!!...some fun conversations...think we'll head out to the big Maple Ridge A & W cruise night this Thursday...they have one every Thurs. out there, lots of great iron...keep in touch...
Instead of fighting with emissions every year, why not do an engine swap? It costs less than rebuilding your old dog, as decent 283's can be had for peanuts. I think I paid $400 for mine. A perfectly running 283 is always being yanked for to make way for the 327-350-383 upgrade. I've even seen 327's available for less than a grand. Just bolt on your goodies and go.
I have heard in Ontario people are adding some Methel Hydrate to the fuel, 4 litres per 20 litres of gasoline. Cost about $7 you find it in Candaian Tire Paint section and leaning out the mixture. These two tune ups can turn a fail to a pass .
Beat me to it again Ray, was just going to say that & there you are!!! Know a few people that did that when they actually tested the T-pipe & it works!! This new OBDII test it won't work!!!!Here in ont. anyways. Pete
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Some times I wake up GRUMPY, but today I let her sleep in !!!!!!!!BLACKSTOCK Ont.
...thanks guys...yeah, I already had the m/h tip in mind but wasn't going to add quite that much. If you guys think the 4/20 mix is safe we'll do that. Also told to spray a little water down the carb at high idle to get some steam working in the cylinders to clean them out. Also possibly some upper cylinder cleaner. Years ago a guy even told me to very slowly pour a can of STP down the carb at high idle, but never tried it.
Going to clean the plugs, open up the gap to .45", do a 4/20 mix of MH, take 'er for a highway run and then run it thru AirCare. And to you guys who recommended a rebuild or another engine...it's in the works but we just don't know which way we're gojng yet...maybe a 350 crate engine. But my son also sponsors the Nasty Fish drag race team out here and they may rebuild the original engine for him in the off-season next winter for just the cost of the parts.
Get rid of the Autolites (FRAM) and put in some AC Delcos
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Prince Edward Island
'64 Parisienne CS "barn find" - last on the road in '86 ... Owner Protection Plan booklet, original paint, original near-mint aqua interior, original aqua GM floor mats, original 283, factory posi, and original rust.
Get rid of the Autolites (FRAM) and put in some AC Delcos
NGK definately makes spark plugs for AC Delco. (NGK is made in JAPAN )
As a matter of fact, most anything that's AC Delco brand is made by the same manufacturers that make the majority of aftermarket replacement parts. Eg. - Gates makes their belts, and Raybestos makes their brakes.
If you think you are buying an O.E. part because it's in an AC Delco box, you're way off.
...set the current Autolites to .0045 gap and the car ran a lot better...we took it over to my son's wedding on Vancouver Island and she ran like a charm...will now pull plugs to check for colour...thanks for everyone's advice..!
Lefty, I would definitely take them up to at least .040". That Pertronix unit puts out a lot more energy than your old points system...that was what our problem was. That stronger spark wasn't being allowed to develop over a wider gap, so we weren't getting a complete burn. Hurts both mileage and emissions. I imagine you'll find the same thing...
