When you say .9 Volt across the top of the coil are you measuring between the two coil terminals? To get the voltage at the coil you would measure from the coil + to battery ground.
Yup, that's what I did. .9 volts. Perhaps that diode is the culprit, or I've got something elsewhere causing problems. Could be why the plugs look like I'm running rich if they aren't getting the juice they need. Sent from my Pixel 3 using The H.A.M.B. mobile app
Even if it's coming from the box, shouldn't I see 12 ish volts on the positive side? Sent from my Pixel 3 using The H.A.M.B. mobile app
Throw that Edelbrock as far as you can and replace it with a Holley. If you have a manual trans and decent rear gears that air gap isn't your problem……………………….
do not know what a billet build truly is - but, factory 355/zz4 comes with distributor and does not have vacuum line run to it.
Good write-up about vacuum advance... except it yet again states that the use of "ported" advance came about because of emissions concerns; when in fact ported vacuum for the advance mechanism WAS used on most vehicles up until emission controls came along. Sure would like to know how that story got started... must be a Chevy thing. Just try both ported and manifold advance and see which one gives you the best results. I'm going through that on my Cad right now; we'll see which way works on this engine.
"...the spark plugs are a little black..." Harris, I think you answered your own question. The spark plugs are fouled. At some point you were running quite rich. You may have fixed that. But the plugs still need to be changed out. I've done the same thing. Wondering what it could be after I fixed the carburetor and everything else is new. Give her a try. Sent from my VS835 using The H.A.M.B. mobile app
But if the carb is still running rich, you might wanna fix that before you foul out another set of plugs. Sent from my VS835 using The H.A.M.B. mobile app
I can't say for sure, but I think the 6al box will put more than 12 volts to the coil. Is the coil correct for the msd?
If the spark plugs are fouled, I'd be tempted to throw a new set in there and start the engine. If it runs good, shut it right down. And then you'd know the cause and you can fix it. Sent from my VS835 using The H.A.M.B. mobile app
Did you get this paperwork with the carb ? https://www.edelbrock.com/pub/media/wysiwyg/documents/carb-owners-manual.pdf It’s quite useful to help you with tunning their carb. Well worth the reading. Tuning is a dance just like any other dance, you repeat a series of steps over and over. Then start over and see if the changes gets better or worse. Some of it is like the eye glass exam, what’s better 1 or 2 click click, 1 or 2 click click on and on. It’s the same but takes a lot longer. There’s a complete process to reading plugs and when done correctly leads to tuning changes of the right circuit And in the right direction. Usually go thru a few sets of plugs
Just did. Hesitation/ pause was longer. The popping never came. Sent from my Pixel 3 using The H.A.M.B. mobile app
Yeah, I've read it a bunch. I haven't done the wot people since it's a brand new motor and want it to break in a bit. That being said, I've followed the guide to no avail. Perhaps I'm inexperienced enough to put the right word with the right troubleshooting box. I've tried so many I'm to the point of confusing myself if what differences the the changes have made. Sent from my Pixel 3 using The H.A.M.B. mobile app
Talked to msd, basically he said I'm not going to be able to read it there and if it was running, it's getting voltage. Not very helpful, but he did tell me to get the diode off the would be r terminal. Sent from my Pixel 3 using The H.A.M.B. mobile app
Well then, you said it was fine at mid throttle range and since you want to keep it easy just keep your foot out of it. Get it good enough to get some miles on it and come back to it. You really don’t have a choice. So when you come back to it, you’ll have had a chance to study that paperwork from the beginning a few times. The theory of operation is pretty important to get the right circuit changed based off the plug reading. just start tuning from scratch and keep meticulous notes about what it’s doing what you changed and what happened. Honestly the engine will change its required adjustment to keep you both happy after some breakin time anyway. Without a photographic memory we need notes. Spend a few mins keeping track and things will be easier
Something you said above bothers me a little. "...and wanted to break in a bit." The people you bought this engine from, did they already run the engine and break in the camshaft for you? Or, on your first fire up did you high idle the engine (1500/2500 rpms) for 20 to 30 minutes to break in the camshaft? New cams don't like to idle around until the cam lobes and lifters get to know each other, i.e. breaking in the cam. Hope you don't have a bigger problem now. -Dave
Damn, a lot to digest there, but an awesome resource. Thank you. I guess it's off to getting new plugs and trying one circuit at a time. Sent from my Pixel 3 using The H.A.M.B. mobile app
Am going to throw another wrench In the mix. On MSD’s there is no voltage to the coil until the distributor is rotating. Here’s another possible issue. Rotor phasing issues.
Yes they ran it on the Dyno. It is also a hydraulic roller lifter so I shouldn't have to worry to much about mating the lifters. I only say that again as blueprint reccomends taking 500 miles to break it in. That being run at different rpm and loads, avoiding long wot runs. Sent from my Pixel 3 using The H.A.M.B. mobile app
The Jalopy Journal
