Re: performance tune up

by dynchel Mon Jul 28, 2014 4:19 pm

The old plugs were in before the MSD install, I believe they are (I haven't pulled them) at .060. It runs strong, but has a misfire above 3000 rpm's (under moderate acceleration)

by 77mali Mon Jul 28, 2014 6:28 pm

Do you have a timing light? You can do an autozone rental for one of those. The MSD box might be throwing your timing off by a few degrees. Double check you Dist alignment when you check timing. If it still has the same symptoms your timing gear may have been installed in an advanced or retarded state (4 degrees plus or minus). Also when doing initial timing cap off the dist & carb at the ports that are connected to each other.

by dynchel Mon Jul 28, 2014 6:38 pm

I do own a nice dial back timing light (even a distributer wrench) but I've played with the timing for best power output (with no detonation, or slow cranking)

by 77mali Mon Jul 28, 2014 6:57 pm

When I did my motor recently the carb was also an issue. In my case it was just not going to happen w/ the Qjet b/c the fast idle cam linkage is all messed up. With the Holley I was able to adjust curb idle to compensate for some slight back-fires that occurred when adjusting initial timing. I didn't put a light on it yet but that did the trick at idle & revving by hand to about 3500 rpm.

by dynchel Mon Jul 28, 2014 7:17 pm

Nice thing about Holley's, just about any carb problem can be adjusted out. The timing thing is a possibility though, I may have to hit my master tech buddy up to go through that (I've tried I don't think I'm smart enough to comprehend it 100%)

by 77mali Mon Jul 28, 2014 7:29 pm

Yes you are but having a buddy who's a pro is even better! You'll get it sorted that much faster & hopefully the first time out.

by bracketchev1221 Mon Jul 28, 2014 8:07 pm

Cam timing and ignition timing are unrelated. The timing chain indexes the cam to the crank. A timing light indexes the distributor to the crank. Advancing or retarding the cam changes the valve timing events to the relation of the piston at top dead center. Yes the distributor is driven by the cam. But you move the distributor body to re index the distributor trigger points to top dead center for the piston. The big issue with stock type distributors and timing changes is shaft end play. If the distributor shaft moves up and down, it rides up and down the teeth of the cam and that can cause ignition timing to bounce.

by dynchel Tue Jul 29, 2014 11:07 am

performance tune up - Page 2 IMG_20140729_110009887_HDR_zpsuvlupuh3

" />well I went ahead with the tune up this morning, and I found the cause of my misfire....I was glad to find seven if the eight plugs nice & tan except #8. (They were gapped at .060, I lowered to .045 per msd's chart Ray posted) Apparently the auto zone stuff I put on a few years ago was substandard Wink

thanks everyone. John

by bracketchev1221 Tue Jul 29, 2014 1:12 pm

So how does it run now?

by dynchel Tue Jul 29, 2014 1:16 pm

She runs really good, now if I could completely fix the damn wheel hop I'd be happy ...lol

by bracketchev1221 Tue Jul 29, 2014 1:37 pm

Put more power in it. Once it completely blows the tire off, no more wheel hop. Very Happy

by dynchel Tue Jul 29, 2014 1:42 pm

Lol I wish.

by 77mali Tue Jul 29, 2014 1:42 pm

That'll do it. Were they all gaped the same? Funny how only 1 terminal was fried. Glad it's running well.

by dynchel Tue Jul 29, 2014 2:43 pm

They were all gapped at.060.

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