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Discussion Starter · #941 · (Edited)
Videos of the scope session:



I have no patience for video editing, so I apologize that I talk a lot in my videos haha

In the first video, I mentioned the burn line was jumping around. This was due to me trying to pick up a secondary waveform free air inductive next to the coil, and the jumpiness was due to the AC signal generator making signal on channel 2, and channel 1 was not coupled to a ground state so the ebb and flow of channel 2 was influencing channel 1.

Once I went directly to coil primary on channel 1 in the second video, it was finally bound to the chassis ground state and was no longer influenced by the feedback on channel 2.

So ignore that comment, burn line was solid once no longer looking at the free air pattern lol.
 

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Discussion Starter · #943 ·
Have you Ohmed out the spark plug wires? Which spark plug looks different?
All old spark plugs look identical, stupid Purell fuel cleans too damn good lol. Changed the plugs with new for good measure.

Plug wires are probably the same resistance, based on the spark events on the scope and how even eacj firing event looked, but I'll check with a meter too.
 

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Seems to me the crower springs suck the seats in .001-2" after a bit, or maybe they stretch the stem, usually just a wear in thing, and will go back to regular service intervals for application after the first lash adjustment.
 

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Discussion Starter · #947 ·
Seems to me the crower springs suck the seats in .001-2" after a bit, or maybe they stretch the stem, usually just a wear in thing, and will go back to regular service intervals for application after the first lash adjustment.
You know, after sleeping on it, I realized that the track day was literally the longest time this engine has ever physically been run. I've adjusted the valves a few times after getting the engine up and running, and after the dyno, but not after such a hard run.

I wonder why after raising the rev limiter 1k it caused this? Like @Oldcivicjoe said, something probably got stretched or finished seating, not sure what.

I'll be inspecting for significant lash changes, then measuring resting valve heights on all of them looking for any signs of significant seating or stretching.

I'm curious if the high exhaust temps during racing conditions could have caused the exhaust valves to fatigue and stretch?

Lots of good stuff to check out :)
 

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Discussion Starter · #949 ·
No way to track EGT's right? Maybe that's something that gets added for next years Hyperfest.
Not currently, but it would be a good idea! If I move to a better manifold, something with thick wall stainless, I'll add EGT sensor provisions for each runner right near the flange.
 

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Not currently, but it would be a good idea! If I move to a better manifold, something with thick wall stainless, I'll add EGT sensor provisions for each runner right near the flange.
Well, we will have the capability to build that now......................the ol TIG Rig needs to get to work lol
 
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Discussion Starter · #951 ·
Didn't have a chance to get outside today, watching kids and stuff while the wife was at work, but will try tomorrow when she gets home to investigate the grey car a bit more closely.

I did however end up taking advantage of Xenocron's 25% off, and bought goodies for the B series :)
  • ITR oil pump
  • ACL race main and rod bearings
  • Speedfactory B16 H-Beam connecting rods
  • JE Proseal HG
  • Gates B16 blue timing belt
  • GE cam seal

The HondaRulez COP kit came in today, I won't install it until I get the misfire/backfire problem figured out. It is a pretty slick little kit though!
 

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Discussion Starter · #952 ·
So I got a chance to get out to the grey car tonight. Pulled the valve cover to start looking for anything obvious with the valvetrain.

Nothing. Valve adjustment before the track was set to .009" intake and .011" exhaust, they tightened back up to .008" and .010" respectively. Nothing super out of the ordinary or unexpected.

No obvious valve spring damage or problems either, poked at all of them unloaded with a screwdriver a number of different ways, nothing jumped out at me.

Retainers and keepers all look ok, and again just from a visual and the fact that the lash isnt crazy out of the ordinary, I highly doubt a stem stretched something silly.

Tomorrow I will do a leakdown test to see if maybe I burned an exhaust valve or something, but still, something just isnt quite sitting right with me. This all happened after setting rev limiter another 1k, so its hard not to discount that fact, but I wonder if whatever is going on would have eventually happened regardless of me messing with rev limiter?

To get the level of loaded backfires I'm getting, something significant must not be right with the valvetrain somewhere, hopefully a leakdown will tell me more.

But I will also swap distributors tomorrow, again, just for the hell of it.
 

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Discussion Starter · #954 ·
Guys, I'm kinda torn on the B series, i want inputs lol.

I stopped short of buying pistons for it, because that becomes a critical pivot point in the build.

I am 90% sure I'm going to go low boost, 10.5:1 CR in the B series, since the car is already setup to support a turbocharger.

BUT, hear me out lol.

I've always loved the idea of an NA high CR, high RPM B series, with NA response and reliability, and with high CR on E85 I dont see why 220whp couldn't be attainable with the right cams, intake and exhaust. Especially for a track day car where screaming everywhere wouldnt be a problem, going NA for its reliability benefits is tempting.

What do you guys think? I'm slowly experiencing the overhead a turbocharger places on a track car with an engine that wasnt designed for it, all the extras needed to handle the power and keep it cool. While I know the B series would be a platform for turbo far above the D, the NA reliability for track abuse is tempting.

What are your thoughts?
 

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Don't need turbo to be fast. a surgical instrument is better on a road course than a sledgehammer.
 

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Discussion Starter · #960 ·
Don't need turbo to be fast. a surgical instrument is better on a road course than a sledgehammer.
This right here :) This dude has sort of been an inspiration for the NA thoughts, his performance with the D13 is amazing.
 
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