Initial timing troubles

[Mr.Mopar]

Now that I have gotten everything back together and running, When I start the 340 when its warm, it makes a pinging sound, like too much timing and the starter is dragging. I've only got 10 degrees initial, and 36 degrees total at 2500 rpm. I know this is an advanced timing problem but why at 10 degrees? Should I change the advance springs back to stock spec. or what. Now that I've got good compression,(should be 10:1) I've got other problems. How about fuel? Maybe the octane is too low now? Whaaaaaaat!!! Help!

[Hittman55]

I have a 360 engine with about 10.0:1 compression. Too run this much compression with todays gas, your advance timing will suffer! You say the starter is dragging when hot. This is for sure to much timing! You need to look at the distributer closer, like the mechanical advance built in, and the vacum advance. And make initail changes. I can only run about 30 to 33 deg advance with 93 octane! You can go a few jetts fatter in the carb, this will help your high compression. Try Backing your timing off a few degrees. This will help.

[Mr.Mopar]

Ya, I guess I gotta re-curve again. The low comp. I had before was o.k. with the faster curve. I will baseline at stock and try again. ARRRRRRG!

[440cj]

Hey alrighty then, it's "compare notes" time! No, really, on the way home tonight I finally hooked up the G-tech to see what the rebuilt 360 will show for rr hp. I know initial is around 12-13* and vacuum advance is backed out a lot. Just filled up with 92 octane this morn (Racetrack) and after fine-tuning the Demon Sizzler-rebuilt TQ on the street, dialing in 3600# for car/driver (I weigh 215# and '73 Dart Sport has A/C. ps. pb and 727) I let it rip...fell flat on her face after 1-2 shift, then picked up somewhat with eversoslight ping after 2-3 shift. Meter read 146 hp. . I turned around and made a 1/2 mile drive back, turned around and tried again. This time it ran all the way through but felt a little weak. Meter read 185 hp. One last time after a 4 mile drive to help flow some air over the engine (7:30 pm after a high of 82* here in Texas, have run 93 octane till today) and I set up for last run. Lotta pinging halfway through 2nd gear (3.23 sure-grip) and felt like it way nosing over right before 2-3 shift. Yaaaaaaaaaaaarggggggghhh! NO more Racetrack gas ever again. Today's fuel is about 1/3 the quality it was even 10 years ago IMO. Had a Datsun 240Z with a 350 Chebby in it show up at work today to show her ex-husband, and after she opened the hood the first thing I noticed was the fuel percolating in the glass fuel filter! It's not even summer yet! Oh well, will back my initial off to 8* tomorrow morn and do another G-tech trial, then post my results tomorrow eve. Guys, let me know what/how you solve your dilemmas as well, maybe our trial-and-error will save someone else a lot of headache, eh? Oh yeah, I'm running true 9.82:1 compression with KB quench dome Hypereutectic's, etc. 440cj

[Mr.Mopar]

Right on, good to hear from you, haven't gotten out yet because of a huge dump of snow here, but have the initial set at 13 and changed springs back to stockers and got 33 at 2500 rpm. Will keep you posted and please keep us posted. Thanks

[George G. Leverette]

Sounds like too much initial most of the books recommend 2 1\2 initial for the small blocks. I have a 340 with Hughes 470\504 and run abour 5 degrees initial and thats on the ragged edge, it pings at part throttle settings. Recommend the 2 1\2 BTDC at 750 RPM with the dist disconnected and the carb capped. I have agonized with vacumm guages connected timing lights, and friendly advice and found that the best method is to time the engine by sight and feel. after every thing looked and felt right, hooked the paraphenlia up and recorded the settings this really gets you close and adjustments can be made to your satisfaction.

[PapaBato]

440cj dont ever use racetrack gas. i got it once for my car out of convenience but it was pinging and ran pretty bad compared to exxon or other good gas.

[Mr.Mopar]

What..2 1/2 degrees, wouldn't even think of setting it that low. Thing would stumble and have no bottom end at all. I tried 10 degrees before the engine rebuild and had to set it up to 14/16 to get any performance out of it. Sorry, but I don't think that will do unless there is something I am missing.

[440cj]

Well, not to be a spoilsport but I did retard the initial to 5* and then reset the idle mix and curb idle, then waited till tonite to G-tech again since last night was "dodge the 3 tornadoes" night here in the Metroplex . Only did one run but earlier today filled up with 93 octane Texaco and pulled a 205 rr hp reading...felt ok. I really feel I'll have to install an electric fuel pump back at the gas tank like I did the '71 Charger to keep a good fuel supply to the high-output Carter mechanical (new also) since high heat seems to put a strain on todays fuel as well. Probably need a better and bigger (at least 1/2") spacer for the TQ on the stock dual-plane so I can get some carb signal back...hard to adjust idle mixture even with vacuum guage. Anyone know of a TQ or Quadrajet 4-hole carb spacer in the 1/2" to 1" range??? I sure do need one bad. Lemme know, and will keep updating as I go. One other question though...if you increase compression like I did from a guestimated 8.4 (rated, probably actually 8.2 or a little less ) but leave everything else basically stock except Hughes AL 2340 hydraulic and pocket-ported stock valve-size "587" heads and balancing rotating assy. to say a 9.82:1 or in you guys' case 10.0:1 cr, do you really need to adjust timing ahead at ALL? I can't see where it would benefit if your cam isn't bleeding off that much cylinder pressure in low to mid rpms...or maybe I'm stupid ... Let's hear some feedback on that can o' worms, eh? 440cj

[Mr.Mopar]

Maybe you're right George, I could be missing something, and I'll be the first to admit it. Just seems too low. I will try 5* and see how that works. May have to put the lighter spring back in to get the right total advance at the right rpm again. Trial and error time, hoping it all works out. You guys are dodging tornadoes and I'm still shoveling snow. Dammit when can I get out on the street!