My boss took the pump with the big spring off,clamped the small spring and shaft in a vise with light tension then give it a easy pull it came unstuck.
looks like it floated the pump spring and jammed the shaft.
It was so fare in the pump it would not even touch the cam rod
That is what I call pump float
That's just shaft float. Pump float is when you knock it clean off the motor. Take out that lash cap, if it's not already in your oil pan.Originally Posted by 69camaro5speedefi
This one has a whipple holding it down,the intake was clearance for the lt4 pump and it was still rubbing so maybe that helped
I am going to make a tool so I can check lobe to pump clearances,the way I checked it looks like with out the lash cap it will be just touching
but even with the extra .070 more the shaft was stuck much more then that.
what % lobe did you have on your cam I think this was 37%ish
i have a stock cam lobe.
even with all LT4 gear, supplemental lift pump, overcommanding rail pressure, etc......we still need meth. fuel lobe doesn't negate the need for it.....honestly, if I knew for sure I would have to run meth at all, I would have left my entire fuel system stock and just added meth.
you need meth this is a every day driver here, its the 4th one I have done over the years for this guy he has a 05 suburban 582 twin turbo I did in 06 if he wants to really go fast lol
Just looking for 7 or 8 lbs on this 427
Yes meth is killer for power with boost I done couple junk yard builds 5.3 and 5.7 one e85 one on pump with meth
both with 3 years on them, great power easy on parts
Wait so you have a blown 427 without meth? What does it put down?
16 degs timing, 6.5 lbs ,12.00 afr, 3rd gear ,with 8 speed trans, gmc yukon denali 5 inch drive shaft, that was like 3rd pull when pump locked up
I have a superflow 845 that's there dyno jet numbers
really just getting started my day job is kicking my ass so I been behind getting it done
numbers seem little low but I Had a car run 10.80s with 468 hp on my dyno
really just a tuning tool for me
I got lucky for over 10 years of street tuning it was time
I think you forgot to put the power number?
What I am getting at is when you get around 600 rwhp you run out of fuel..... Watch your injector pulse width, keep it 5.5 ms maximum and don't go over 350 SOI.
Last edited by Higgs Boson; 03-07-2016 at 10:41 PM.
lol i did 442
Ok then you should be ok with no meth but that doesn't sound like much from a blown 427....?
I just did a LT4 ZO6 with a 38% lobe and running full tank of E85 and still have room left.....it made 725 wheel through auto.....our 2016 camaro with LT4 pump and stock LT1 injectors made 775 on race gas....the bigger problem is the lift pump....we have been running them down into the low 40's and still hitting the target lambda....
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IDC, IPW, RP?
I wasn't comfortable with 40psi, wanted it to maintain 70.
Didn't want RP to drop from 20 to 12
Didn't want to run 12.7 AFR
Didn't want to run 35% IDC or 11ms PW
For me, 70, 20, 12, 20, and 5.5 are the right numbers. :-)
Howard your pushing more than the factory 20mpa out of those lt4 pumps aren't you lol
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I went as high as 25 and did not see any appreciable increase in actual delivery so I just left it at 19. Still would need meth....Howard your pushing more than the factory 20mpa out of those lt4 pumps aren't you lol
I have been pretty zoned in on several project cars all of which are 2016's and have gone from stock to 800-1000 HP. As we have been increasing airflow we have been carefully monitoring the fuel strain. The LT4 pump is not a bad unit and seems to be hanging better then I thought as commanded and actually are not too far off. When we first installed our TT system on the 2016 Camaro with stock system we noted that at 660 wheel the LT1 high pressure pump would drop to 8 Mkpa from a commanded 15. We then installed the LT4 pump and it held 15 no problem even with the LP pump at 48 psi. We then pushed the power up to 775 wheel by jumping commanded to 20 (like a stock LT4 engine) and the LP pump was down to 42 lbs.Howard your pushing more than the factory 20mpa out of those lt4 pumps aren't you lol
I will also say this......unless you have a 5 gas analyzer; you can't really believe you lambda is correct in the combustion chamber. This being said.....if your not wasting fuel then you have fuel that can be used to feed the engine. Injector timing (as has been discussed often here) is also a place to "optimize" fuel usage.
I don't see a problem running the LP pump a bit lower "as long as" you can still stay in control of combustion fueling.....we are going to test the cause and effect of feeding the HP pump either 60 psi or 38 psi and see its impact.
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Piggy back ECU and 8 extra injectors. Fixed!
Anything special need for the lt4 pump swap? Tuning wise? Or is it copy and paste from zo6 file?
LSX AM 444
Runner up in points 2011
3rd in points 2012
8.14@166 all motor
Driver/ Tuner car 414 Texas mile 263.2mph
copy and paste unless you have a 2014 then disregard the voltage table under the Fuel Pump criteria (not injector). 2015 should be the same values as Z06 anyways.
Just pump info or soi and eoi too? I have a truck with a Whipple that makes 600 with stock pump. We replaced the injectors and pump with z06 stuff, I tried the copy and paste and the pressure drops to 150psi even thought it is commanded to go up. Truck is a 2015 GMC sierra Denali.
LSX AM 444
Runner up in points 2011
3rd in points 2012
8.14@166 all motor
Driver/ Tuner car 414 Texas mile 263.2mph
i leave soi and eoi stock. btw eoi is only applicable for split pulse fueling, which is not used or only used at start up, leave it stock. SOI gets raised to a maximum of 355 only where needed when you are running out of fuel. it only helps a little bit.
what drops to 150? rail pressure? that's only 1 MPa which is not enough. you want to keep MPa up around 15 and low side at 70 psi. injector pulse width needs to stay under 5.5ms.
you should be fine all stock with 600whp but as you get over that you will need to change parts. once you get into the 675+ territory you will start needing meth.
some tuners are comfortable going over 5.5 or letting low side drop to 40, etc and I guess as long as the injector isn't maxing out then you can do whatever you want, I just like to see actual match commanded.
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