330hp vortec crate motor timing issues

[Age08]

330hp vortec crate motor running with a L31 intake and a 411 roadrunner pcm in a 96 s10 blazer. I am currently running 82psi for fuel pressure with a walbro fuel pump. I have got good fuel at wot around 12:1 and its currently setup for sd tune.
I keep getting knock retard 8*starting around 3500-4k. The motor has a solid lifter cam. Here's a copy of my program and a datalogg session. 5.7BLazer_sd.tunLS1B_0001.efi

[hog]

That engine is a stock Vortec 350 with a flat tappet hydraulic 212º/222º 0.435"/0.460" lift 112.5ºLSA instead of the stock L31 roller cam with specs of 191º/196º 0.412/0.428" 111ºLSA.
Stock L31 Vortec 350 rated at 255hp@4600rpm/330 lb/ft@2800rpm which is about 310-320 gross hp.
The 330HO is rated at 330hp@5000rpm /380lb/ft torque@ 3800rpm.

82 psi is way too much fuel pressure Stock spec for those poppets is 62-66 psi. I'm wondering if that high of fuel pressure might be causing issues.

A nice little stock upgrade is to use your L35 V6 TC behind that 350. I used the same L35 V6 TC behind my Vortec 350 and get about 2800rpm of stall speed at WOT. Better launches and less rpm drop during WOT upshifts

What are your cam specs?

peace
Hog

[Age08]

Hog,

You are correct with the cam Lift: .435" I, .460" E.Duration @ .050: 212o I, 222o E.
here is a link for the same motor I have http://www.crateenginedepot.com/350-...007-P9417.aspx

As for the fuel pressure I had to run the higher pressure because @ 5275 rpm, 11.89:1 afr my injectors were @ 99% duty cycle, now there around 80%.

I am running the v6 TC backed up with a slightly beefed 4L60e trans.

Adrian

[Age08]

Hog

Here is my cam spec Lift: .435" I, .460" E.Duration @ .050: 212o I, 222o E, with 1.5 rockers

As for the fuel pressure I had to raise it because my duty cycle on the injectors where reaching 98% @ 5200 rpm. Now they are around 80%.

I am running the v6 tc,and the transmission was beefed up too.

Any ideas on why the knock retard?
I tried new fuel. Also new cap, rotor, plugs & wires.
This motor should have no problem with running 22-32 degrees advance with only 9:1 compression on 93 octane,
heres a copy of the data log before I added more fuel pressure, dyno5.efi

Adrian

[hog]

Hog,

You are correct with the cam Lift: .435" I, .460" E.Duration @ .050: 212o I, 222o E.
here is a link for the same motor I have http://www.crateenginedepot.com/350-...007-P9417.aspx

As for the fuel pressure I had to run the higher pressure because @ 5275 rpm, 11.89:1 afr my injectors were @ 99% duty cycle, now there around 80%.

I am running the v6 TC backed up with a slightly beefed 4L60e trans.

Adrian

I thought you were running a differnt cam as you stated you are running a "solid lifter" cam, but you are running a hydraulic lifter cam, if you are running the supplied 330ho cam.

Its surprising that you are running 98% duty cycle on the injectors with the only difference beteween a stock L31 Vortec 350 and the engine you are running is the cam difference.

Not sure why you are getting knock retard. Have you tried running high octane fuel? I used to get some false knock on a Vortec 350, so I installed an LT4 knock module and it solved that issue.

Try running some high octane fuel and see if its true knock or false knock.

Are you able to decrease the amount of knock retard vs knock counts via tuning?

peace
Hog

[Age08]

Not really when you think the stock poppet valve injectors are only 19 lb/hr @ 43.5, and 22 lb/hr @60 psi(stock fuel pressure).
If you do the math for N/A v8 engine making approx 330hp @ the crank with 80% duty cycle you need min of 25.8 lb/hr injectors. and running the stock injectors @ 82psi it makes them flow 26 lb/hr. Altermently I should of either ran the marine intake or ramjet intake so I wouldn't of been limited to the injector size. not to menition what I have is just about the max for this intake.
I meant hydraulic solid lifters. I am using high octance fuel.
I just noticed that torque mangement was still enabled so I'm gonna disable it, but I have little doubt that is the problem.

Adrian

[hog]

I know of people running 330rwhp/381 on stock L31 spider setups using ported Vortec heads/LT4 hotcam on 383 cubes.
The stock spiders only become an issue when going forced inducted. I know of a ZZ383 being fueled by stock spider and its rated at 425hp/460hp.

A stock Vortec 350 allready runs about 310-320 gross hp, the 330ho 330hp and the HT383E runs 340hp. Seeing as GM released the HT383E directly for Vortec 350 replacement, there shouldnt be a fuel issue fuel wise with your 350.

Just remember that these are not typical injectors, they are poppet valves that are opened by fuel pressure and NOT electricity like a typical pintle/seat injector. The replacement MPFI conversion DOES use a conventional mini injector.
No one has flowed a spider at 43.5 psi, the 19 lb/hr at 43.5 psi is an internet myth, sometimes poppets dont even open at that pressure. IIRC that 19 lb/hr at 43.5psi was borrowed from the older 305 TPI specs.

Manufacturer supplied info from Delphi states that the poppets flow 23.1 lb/hr at 61.78 psi of rail pressure and the stock L31 calibration supports this with an IFR of 2.912 g/sec or 23.1 lb/hr, so you are starting off with more fuel than you thought.

Lyndon Wester does a flow matched set of poppets that he advertises at 26 lb/hr that work for his Vortec 350 supertcharged builds. He calls them his Blackwidow spiders. He takes a number of factory spiders and flwo matches each spider leg seperatley and clumps them together in a flow matched set of 6 or 8.

I agree with you that the 9.0-9.4:1 cr should do just fine on 93 octane, sorry I didnt catch that in your previous post.
When I had my knock issues, I ran 104 octane unleaded race fuel and was still getting the KR. I didnt have Tunercats 2 at the time, so I had no ability to do any PCM tuning, so I installed an LT4 knock sensor module in the Blackbox PCM and all was well.

By all means get rid of the TM, it is very pronounced on the Vortec 350's. To take off 100% I just raise the TM Enable coolant temp to max (around 151.5C on my software). But I agree with you, I odubt its your issue.

I just went through some old poppet posts over at the Pacific Performance Engineering truck site and there is talk about stock poppets not doing well at high pressures, lockup/leakage with horrible spray patterns. Some of the supercharger kit FMU's boost pressure up as well, but usually not over 80psi.

Some alternate intake manifold solutions
http://www.pacificp.com/forum/viewto...ghlight=poppet

1st part of this post has some guys that have already experienced poppet/pressure secenarios
http://www.pacificp.com/forum/viewto...hlight=poppets

These Vortec setups an be a pain sometimes.

peace
Hog

[Age08]

I would agree with you on the fueling but my dataloggin show other wise unless I wanted to live with almost 100% duty cycle.
As for the poppet valves there are still type of injector at the base which controls the fuel to the poppet valve. And from my understanding the spray pattern was actually improved with the added fuel pressure until around 100psi where the poppet valve starts to fail closed from over pressure.
And also i did install a walbro 255 lb/hr pump in the tank as well.
I'm gonna try to do some more testing this weekend by disabling the TQMangement, and playing with the knock values.

[hog]

Age08, any update on this. did you ever get this engine running better? I'm very interested in these Vortec GEN 1E engines.

thanks

peace
Hog

[Age08]

Hog,

I haven't had chance to try it yet. I made some changes to timming, fuel and injector flowrates due the no referenced fpr just to help idle.
Maybe this weekend I try it, I'm also gonna try adjusting the knock ses as well. I will keep you update with my findings I will get the bottom of this problem
eventually.