While cruising at 80 mph, which is 3500 rpm, my A/F varies between 12.8 and 13.5 A short blast to WOT shows 11.0 ( too much traffic to hold WOT safely) Im thinking it could be a tad leaner. But it runs flawlessly, smooth, I don't wanna mess it up, plus Im not hearing any detonation, Im afraid if I lean it out, detonation will set in. I know I've said this before, but those Johnson roller lifters are the cats ass, I NEVER hear 'em, even after sitting for 4 or more weeks, fire it up, immediately quiet, and they stay that way Should I tinker with jetting till its broke, or leave it be?
Look at the plugs and I would run the plug I use the YR 5 NGK this is not an extended tip plug looks like the original plug from the 70 350. Plug runs clean on the motor I use this because of the nitrous but works well on the motor. You are at 11.1 on comp so don't lean too much better to be over than under on the fuel. Did Michaels put your bottom end together or did you do it been thinking I need to get the bottom rebuilt. I think you should get a nitrous kit and run a 100 shot and you will kick my 11.81 @ 114mph time off the map. Think about this Demko, if you run the same 125 shot like I did in the beginning I knocked off almost 2 seconds then, I was running 13.50's at the time and got to that 11.81 and I spun the tires 5 feet off the line then. you should be able to click off a 10.99 think about that for a moment, shifting at 6500 and it is at 5 grand after the shift and you are pulling like a Big Boy Freight train plus it will scare the **** out of you. lol lol I think this is possible and I think you can do this. So take yer arse to Summit drop by my house on the way back and take rt 14 to 480 to go home. Git er Done as Larry the Cable Guy would say. lol
I assembled the engine. That’s sorta what I was thinking with 11 to 1 comp. a tad rich is better I believe I’m running the YR5’s Good idea on pulling ‘em for a look, give me something to tinker with and it won’t break anything I have a new set of NGK plugs on the bench, I’m still running the same NGK’s from my old build. I’m still gonna try beating you N/A AND with 3.42’s
Yeah, Yeah, Yeah, I hear ya lol Yes YR5 NGK just double checked that on what I use. Good plug. Here is the plug site I have saved look at that for more info www.dragstuff.com/techarticles/how-to-read-plugs.html
Richer is better than leaner. With my big block, I started out with 14.0 for cruise and 12.0 for wot. I've been leaning it out a little at a time so now cruise is 14.6 and wot is 12.9. Just by seat of the pants feel, the engine likes it. I am a little concerned about detonation because my car is too loud to hear if it's pinging. Do you know if anybody makes an aftermarket kit for installing a knock sensor?
I was thinking too about a knock sensor, I have a Casper’s knock sensor on my GN but that goes thru the engines computer, yeah my car is too loud to hear a slight rattle or death knock on the highway. I checked plugs 1 3 5 7 all look the same. Checked compression just for fun with my over priced Snap On gauge, all 4 were the same 185 190 lbs. I’m calling everything good, before I break something LOL. Now I’m bored, maybe I’ll clean the Tahoe
Those look like UR-4 plugs, not YR plugs. YR plugs are recessed nose. UR are projected nose. Unless you have any extended WOT, I wouldn't worry too much about detonation. The track is where you'll want some race gas in there like you did in Youngstown.
That’s because they are racing type plugs. The projected nose plugs are better for the street. Interesting article, https://www.dragzine.com/tech-stori...ark-plug-debate-separating-fact-from-opinion/
