BlackedOut LS1

iTrader: (4)

My tuner noticed some detonation so we couldn't finish the tune, after looking at his trends he concluded that It was probably clogged injectors. There was low fuel flow to one side of the motor. So I towed the car back to my engine guy to replace the injectors and fuel pump. later that night I watched the video of the pull and sent it to my tuner who wasn't paying attention at the time of the pull and and he said that wasn't good. The block is a fresh re-build, I was wondering if the rings had not seated properly? I drove the car less than a mile un-tuned with little to no acceleration, including on and off the trailer. Could that have hurt anything, I'm not an engine guy I don't know, all I know is I keep having minor problems and now I'm worried we'll have to go back into the block. Please let me know what you guys think, thanks.

KCS

iTrader: (20)

That's no bueno. Are your heads ported? Just a WAG, but a lot of people forget to put sealer on the rocker bolts in a ported head. The bolts protrude into the cylinder and when you have high manifold vacuum, the oil can find its way into the intake port and into the combustion chamber. It's pretty common but it won't necessarily destroy your engine.

Oil in the combustion chamber can also cause/aggravate detonation.

Darth_V8r

iTrader: (4)

That is detonation, like KCS said. My second ever trip to the dyno did exactly that, and there were three possible causes, and I addressed all three, but the main issue was the cam was off. The ICL was supposed to be 112, but was actually 103, which made my DCR something like 9.2. I replaced both the cam and the timing set, because I could never really tell which one it was.

The other two issues were I still had stock heat range plugs, which I swapped for TR6's, and my PCV was letting tons of oil into the intake, which is similar to what KCS described for the rocker bolts leaking oil into the intake ports.

BlackedOut LS1

iTrader: (4)

Advanced induction ported the heads, I would assume they have addressed everything?

Darth_V8r

iTrader: (4)

But did they assemble the motor? They wouldn't have sealed the rocker bolts - those have to be off to install heads and pushrods.

But first things first, fix the fueling issues. I just know when mine discharged like that, it was detonating, and Air fuel ratio was fine.

BlackedOut LS1

iTrader: (4)

Gotcha, Futral MotorSports assembled the engine, the fueling issues should be fixed soon.

Darth_V8r

iTrader: (4)

They know what they're doing. Hope getting the fuel corrected gets it for you

BlackedOut LS1

iTrader: (4)

So you think the fuel system may be the culprit? I'll let you know once it's done.

RockinWs6

Relax it only smoked on deceleration, could be the rings needs a little more run time or valve seals or rocker bolts needs sealing.

BlackedOut LS1

iTrader: (4)

Man I promise I'm tryna relax, this process has been long and expensive it's my first build and I've been stressed trying to get this thing back together and on the road.

RockinWs6

To be honest its not that's unusual for ANY high performance engine to smoke a bit on decell after a hard run. Its a very high vacuum condition that can suck oil easily past rings etc. Now if it smoked under acceleration I'd be worrying, You're fine.

BlackedOut LS1

iTrader: (4)

Well injectors, fuel pump, and fuel filter were replaced, but there still detonation around 4k-5k RPM. Tuner couldn't check fuel psi Bc I have FAST rails, still says there's some problem with fueling, idk what else to say. Futrals assembled the moter should I just take the car to them?

Darth_V8r

iTrader: (4)

So you ARE seeing detonation in the 4k to 5k range? If you do a compression test are your cranking compressions obscenely high? Mine are 200-210 right now. When my cam was off, they were 240-ish. I'm not saying futral screwed up, just that it's always possible the cam grind is 9 degrees off or something stupid like that.

4k to 5k is when cylinder pressures are the highest. Have you considered 100 octane racing fuel to see if it helps?

I hope all of the above makes sense

BlackedOut LS1

iTrader: (4)

Yeah on his last pull he saw detonation at 5k rpm, and could hear valve clatter., I think he said he only had 20-22 degrees timing. I'm at Futrals now and I'm gonna try and put them in touch with my tuner. I'm so pissed, I'm gonna miss Cruisin the Coast again now.

Darth_V8r

iTrader: (4)

Good luck. I hope you find it's something simple. Every time you add another detail, your symptoms sound like what mine did. I ended up having to run 19 degrees total timing to prevent detonation. Basically, we put the car in "safe mode" until I could get the problem corrected.

For comparative purposes, on the new build, Nic ended up right at 24 degrees. 27 is supposed to be best on internet searches, but I was making the best power on the dyno at 24.

KCS

iTrader: (20)

That's a good thing, it means your combustion is faster and more effiecient. The less timing you need to make the best power the better. The plug lights off before TDC to start the burn, but peak pressure should end up around 12-15 degrees after TDC. The less advance you need, the faster the burn is and less energy is wasted before TDC as the piston is coming up.

KCS

iTrader: (20)

That's not a little though, that's excessive. I've never seen that much on any of the engines I've built. Not even on my own engine.

BlackedOut LS1

iTrader: (4)

I was told it's safe to drive I just have to take it easy, for some reason fuel pressure or flow falls off and kills the engine if I give it a heavy foot, but still keeping it borderline under 4k RPM.

Darth_V8r

iTrader: (4)

I wouldn't expect that, given the new pump, injectors, etc. Any way to test for leaks?

BlackedOut LS1

iTrader: (4)

We weren't in a position to test but I didn't see any fuel on the ground or smell any. I asked him if fuel flow has changed in his graphs and he said it was a small change. So I really don't know if the previous injectors were fouled. All I can really do now is wait and see when Futral can take the car back and let them do their tests. I wish I could paint a clearer picture for you guys but this is way beyond my knowledge level!