K10 Project

[JoeliusZ28]

Had a couple breakthroughs on this project recently. First, I got a detailed vacuum diagram with clear labels and found there was a line in the wrong place that proved to be causing one of the problems I was having a year ago. (and to fix it i temporarily bypassed the affected components). Hooked everything back up properly and the engine ran its best yet. However, I was still unhappy with what the distributor was doing. Always seemed like way too much timing at part throttle cruise and none at low-rpm or wot. One of the mechanics at Brian's shop told me to try a generic non-ESC distributor from summit for $90 because he believed it was more than just the springs and advance that were not optimal on the ESC distributor. Turned out he was right. I installed the new distributor and out-of-the box the truck instantly ran better yet again. After about 5 hours fine tuning the advance and timing its now ACTUALLY making decent power... heck it even managed to break a tire loose without a clutch dump And I still think i can squeeze another degree or two of timing out of it, going to try that friday.

Long story short, i should have canned the original distributor a LONG time ago.

[JoeliusZ28]

Not much to see here but old vs new:

[MP81]

Wow, so it (mostly) was the distributor causing your issues all along? Crazy...

[JoeliusZ28]

Yep. Emissions timing curve. The ironic part? Theres a LOT less stinky exhaust fumes coming out of it now.

[MP81]

So that was built into the factory junkstributor?

And I'd bet there is...their twisted sense of "emissions" back then probably caused them to be worse than if they weren't so heavy handed with it.

[JoeliusZ28]

The weights/springs/advance would all have been setup different along with the 4-degrees of knock retard that the ESC could step in and provide. Also I'm running the advance on manifold vacuum instead of ported. Overall, a lot of differences for something that looks pretty much exactly the same.

I did also modify this new one a bit with the advance limiter.

[MP81]

Beautiful, give it the advance it so desperately needs.

So no detonation issues any longer?

[JoeliusZ28]

Beautiful, give it the advance it so desperately needs.

So no detonation issues any longer?

Right now it is 100% detonation free and running well. I haven't touched it since my last reply here. I still think i can push another 1-2 degrees initial timing out of it and improve the advance response by putting it on a dedicated vacuum port. You know... really get that that 1 tire fire going.

[MP81]

It's not a true one-tire-fire until said tire is literally on fire.

[JoeliusZ28]

I'm just excited its capable of breaking a tire loose. Thats a whole new world of performance i havent been accustomed to on this truck

[MP81]

"There goes Joel again. One-tire-firing that damn truck"

[JoeliusZ28]

[MP81]

image_59516.jpg

Power intensifies.

[JoeliusZ28]

So the saga continues. Its burning oil pretty good now with all of this mediocre horsepower its making so its gotta come apart. Think I am going to start on it after this weekend. Kills me because it drives so well now.

I've really been struggling to make up my mind on what to do with this thing. Rebuild the heads on the 305 or say the hell with it and drop a 350 in? (I know full well that a 350 isn't going to just drop in and run perfect). I think my plan for now is to pull the heads and decide from there based on how everything looks.

[MP81]

Pulling heads really isn't too big of a hassle, so I'd say go that route first.