I looked at the picture we took before starting the carb replacement and the distributor is sitting in the same position as it was before. So unless the gears in the distributor went bad (less likely because it's a new replacement part not too long ago) I would think maybe the gas like someone else suggested. I'll top it off with 91 and maybe a little octane booster and we'll see.
I get a little backfiring now with the timing back to what it was before the carb swap, does that mean it's running rich? I detonated my way over the gas station and got some 91 octane gas (it was arco so probably 89 octane). Drove it around and still hear what I think is detonation.
Still sounds like your distributer is 180 out. Do a plug out timing check, and see if the marks are off, or the dist. is out.
check the timing gear to be sure, roller cams take a steel gear or bronze/brass that can get eatin pretty quick
When you say the distributor is in the same position are you talking about the housing or that you installed the rotor into the same position that it was removed?
I said i wasn't going to get into this, But before you put the Blower on. You better get this problem ironed out. I see in the post on the 331 build you found true TDC. Was this marked on the balancer or just on the degree wheel? If it was marked on the balancer it should be no problem to figure out what has went wrong. If not it will need to be found (TDC) on the balancer. I have saw the cheaper line of balancers be off by more than 10 degrees. And if you are going to bolt a Blower pulley to the balancer, It would be wise to buy a top of the line balancer anyway. I have seen more than my share of cheaper balancers busted due to blowers than from anything else. But this problem needs fixing before the motor sees boost or i promise you wont be happy with the outcome. TIMING IS EVERYTHING ON A BLOWN MOTOR. That's why i recommend the best components for the firing, timing system. Ive saw to many try to " Get BY" with the wrong stuff and they usually was put out of the business of being Blown. P.S. either buy a blow Thur or put the carb in a box. Unless you have extensive knowledge of blow thru, or know someone who does it is better to buy than to lose a motor.
this was on mo's old stock motor. its not going to see the blower. the distrubtor seems to have over 40 degrees of mechanical advance and 18 degrees of vac advance. we will take it apart today and see if we can limimt the mechanical advance. we may just lock it out and use the programable msd he has for the timing curves. it will be good practice and learining for the blower motor.
thanks for the advice. I definitely don't want to blow this motor up quite yet. I think Bryant and I will make the mods and take it to a carb shop and have them inspect it. I trust Bryant's judgement, he's done his fair share of supercharger work. I'm VERY fortunate to have him guide me through all this.
gonna finally get down to it and figure out TDC . . . bryant taught me how to make my own piston stop, awesome!! Started out with a spark plug. I then hammered out the porcelain thing I then cut a bolt in half. Bryant had already figured out how much I needed to cut off so that took a lot of the trial and error out. We took the cut off plug and the cut off bolt over across the street to Bryant's friend who is a great welder to weld them up. We probably could have done it here but Bryant didn't want to ruin the threads since the plug still has to screw into the head. I messed up the threads a little so bryant had this awesome thread file thing. . . how awesome is this thing? It's all ready to go and I just need to do the whole TDC thing now.
Make sure your engine is on the compression stroke - never mind it won't matter if the distributor is left in place.
so I finally got a chance to check TDC with the engine on the car. Removed the spark plug in cylinder #1. Just for background, I've been getting detonation so want to know whether my timing marks on my harmonic balancer is correct. Here is the park plug: There is speckling there, mild but it's visible. I then took the spark plug we made with the extension to serve as a piston stop. I rotated the crank clockwise until the piston came to a stop and I marked that point where the timing pointer is. Here is what the spark plug looks like that we made. I then turn the engine the other way and marked the spot again. The midpoint between these 2 marks would be my TDC. And it actually was exactly correct. So my balancer hadn't slipped. So that means that our timing was correct. You can see the two white marks and the center falls right on the stamped TC mark. At 10 degree initial I revved up to 3000 and was at total 32 degrees. I made sure to remove and plug the ported vacuum line off the vacuum advance. At my cruise rpm which is usually 2200 my total mechanical advance was at 21 degrees. Now at 4000rpm I was at 36 degrees. So that was a little much so I dialed it down to 8 degrees and the total at 3K was 31 and 34 at 4K. So after test driving the car with the vacuum attached I had still detonation. With the vacuum removed the detonation started later (at 2500rpm). So I still don't know why I get detonation.
Would an air/fuel meter help to know if your engine is running lean when detonating? It's just a guess
