Goga Samsonadze

I have double checked timing marks, they are fine. I will post ignition and fuel maps tomorrow. As for cam grind, I have ordered degree wheel, and will check camshaft once it will arrive

00pooterSS

iTrader: (40)

Ignition timing is ignition timing.

Cam timing is cam timing.

When we say ignition we mean when the spark fires in relation to the piston location.

When we say cam timing we mean cam position in relation to the crank.

Glad you got a degree wheel coming, that will hopefully get you some answers.

ddnspider

iTrader: (26)

I believe you that it's installed dot to dot....the wheel will tell you if it's ground correctly.

Darth_V8r

iTrader: (4)

yeah, that's what I get for typing when I can barely think straight. I've seen idle spark bouncing around in the 10-14 range cause it, and that's why I said less than 15. 16.5 isn't going to blow anything up, agreed.

Another errant thought that I don't think has been mentioned yet. How's your PTV? Cam is pretty large. May be worth sticking a scope in a spark plug hole to look for eyebrows...

ddnspider

iTrader: (26)

​​​​​​I should have clarified....an AFR of 16.5 at idle won't blow anything up. I know you were talking about ignition advance and agree that undertimed could cause his issue.

NEstyle

iTrader: (1)

This crossed my mind, too, but then I thought that a domed piston would have valve reliefs, but who knows. If he does cut the heads and use a thinner gasket for more compression, things may get really close depending on the piston. On a related note, is it odd that a domed piston is only yielding 10.5:1 compression? What cc are the chambers?

Goga Samsonadze

Cylinder head are CNC ported LS3 pieces so chambers are 67cc as I remember. I have checked PTV when I was assembling engine. My wiseco pistons had valve reliefs but I placed piece of plasticine on the piston, put cylinder head on, torqued everything down and rotate crank few full rotations. when I removed cylinder head, there was no evidence of valve touching plasticine

Goga Samsonadze

Updates: I logged into Link ecu this evening, to get fuel and ignition maps, but unfortunately tuner locked them with password. Now the good thing: we swapped LS3 factory intake today, engine idle became much stable and calm even on 113LSA cam, engine won't detonate and tend to jump from the engine bay like it was before, there was noticeable gain in low end torque, so noticeable that rear CV joint was immediately broken after flooring down accelerator pedal within 4000rmp on 3rd gear while rolling with 10mph speed. header won't glow on idle or cruising speeds. today we ended up with broken CV joint, so we could test car better, but there is a huge difference. next deal is to check cam with degree wheel. I've got my cam card today, and it says that the crank should be at 30 degree BTDC on 0.006 inch lift, we'll see...

ddnspider

iTrader: (26)

vacuum leak?

Goga Samsonadze

yes, some noise of vacuum leak presents, gonna fix it tomorrow. why did you asked about it?

00pooterSS

iTrader: (40)

Sounds like you got the problem taken care of.

ddnspider

iTrader: (26)

Unless I misunderstood your post, all you did was swap intakes and most of your issues went away? If so, that screams of a vacuum leak as root cause.

00pooterSS

iTrader: (40)

I considered that, but it also says it was an ebay knock off intake. Who knows what kind of issues it could have had being a knock off intake

Goga Samsonadze

yes I swapped intakes, that's all for now, but I'm not sure about glowing headers gone away, because as I mentioned above we immediately broke CV joint, all I want to say that there was noticeable gain in low end torque, and engine idle was much better. but earlier with old intake manifold, we checked for vacuum leaks and there where none, so my problems were not vacuum leak related.

ddnspider

iTrader: (26)

Not sure how anything else related to the intake would cause glowing headers outside of a vacuum leak unless something related to the injector angle on the intakes???

Goga Samsonadze

injectors angle? how it is related to glowing headers?

ddnspider

iTrader: (26)

Lets try this a different way.....what is your theory why changing only the intake solved all your problems?

Goga Samsonadze

I did not dynoed it yet, yes it feels much better, but I'm not sure about numbers, I'm also not sure about glowing headers issue, because we drive the car just for 10 minutes or so. I can't say that all my problems solved, I wish i could, but not yet