TX Z06 02

PREFACE: Back during the summer, I was having issues with fueling during drag strip runs. I could watch fuel pressure drop (on data logs) to 40 psi about midway through a run. This happened on 2 separate trips to the drag strip, and each time I left the strip when I looked at data after the pass.

I troubleshooted each time and never really found a smoking gun. My fuel system was: Racetronix 255, KB BAP, Racetronix hotwire, FIC 720cc injectors on otherwise stock system. I pulled the pump and bench tested and never could recreate the pressure drop. What I ended up doing was drilling holes in the fuel canister to "swiss cheese" it.

My theory was that during hard runs, the canister would run out of fuel and I couldnt get fuel back in there fast enough through the sock/filter. I never had it happen again after modifications, but not 100% sure that is what fixed it.

Fast forward to turn of 2018. I got stuck driving my car in some nasty icy weather and it took me 1.5 hours to get home due to slow speeds. When I got home and parked it, there was a puddle of oil coming from under my BOV. I then did a compression test and found #1 cylinder lower on compression than the other 8 (175 psi vs 200+ on all others).

Leakdown test confirmed that #1 had considerably more leakage than the others.

So the teardown commenced. I pulled the heads, then ultimately pulled the engine. This was the first week of January. When I finally got everything apart, I found a busted ring land on #1 piston. It was still in tact, just broken...a ticking time bomb that I caught before catastophic failure.


So then it was time to decide what to do. I looked at some options for complete short block assemblies, but ultimately decided to rebuild my aluminum block. I have had numerous conversations with Bret (BlownBlueZ06) throughout this journey and continue to have discussions with him to this day. The build is continually evolving, but here is what I am at so far:

0.005" hone on my block
new CP forged pistons
new K1 forged rods
reuse stock crank (should support ~1000hp)
ARP main studs
tool steel wrist pins
AP gapless rings
clevite bearings
re-balance my crank with new rotating assembly
5 axis Ported 243 heads with new hollow stem valves
ARP head studs
Blower Cam - Howards 236/250, 0.625/0.625, 115 LSA
New supporting components (oil pump, water pump, crank sensor, cam sensor, etc)

Fuel system: E85 Setup
twin 450 walbros in tank
142# injectors
return style system with Holley Boost referenced fuel pressure regulator
Install Flex Fuel PCM, flex fuel sensor

Other things I am doing while i got it all apart:
Powder coat engine components gloss black with some traces of hot rod blue (pics to follow)
Hinson motor mounts
Hinson diff mounts
New treadstone intercooler
New dewitts cut-down radiator
Overspin my V2 or upgrade to YSi???

TX Z06 02

Broken Ring Land:




PC'd front and rear covers



Shaved and PC'd valve covers and Holley Fuel Rail (originally black)



PC'd LS6 intake:



Alltogether:

silver408z

Nice that you caught before it damages your block, crank, heads and more. Sounds like you will have a solid setup. Bret is great to deal with. He doing the build on my car and is very close to done.

m4bgringo

I take it this car has a blower on it? So instead of fuel pressure rising during a pass, it was falling? One pass and I would have parked it. I have seen plenty of people kill things running out of fuel. With a N/A engine with no power adder, it is hard to hurt an engine going lean, to an extent. Power adder engines though, not forgiving at all.

TX Z06 02

Sorry, didnt explain this well enough. I did leave the track after 1 pass both times it happened. The first time, I was assuming the problem was electrical - either the KB BAP or the Hotwire. I went home took it apart and couldnt find a smoking gun. Everything electrically tested out. I tested on the street, but cant stay in it that long to see if I could recreate the fuel issue. So there was only 1 way to truly test it: go back to the track.

The second time it happened, I left the track after 1 pass, went home and started looking for a mechanical issue. Pulled the pump, bench tested, etc. Still no smoking gun. So that's when I "swiss cheesed" the fuel canister.

It never happened after that. But the damage was already done.

ysb02

TX Z06 02

yessir!

Rkreigh

like to hear more about this! I'm wanting to go flex fuel but interested in retrofit of more modern ecm or other blownblue wizardry

or install the haltech if that works better!

TX Z06 02

Bret and I are working on it together. I purchased a P59 PCM from a 2005 astro van. I also purchased a flex fuel sensor to be installed in the fuel return line.

Bret will be doing the segment swap and everything associated with the tune to make it work.

Im sure the haltech is way better, but out of my price range.

TX Z06 02

UPDATE 03/20/18: Still waiting on pistons....

Turbo-Geist

Who did you order the pistons from and how long has it been?

TX Z06 02

ss4luck

I wasnt aware brett had the flex fuel setup down for the PCM swap, my car may have to come to TX once the new shortblock goes in

TX Z06 02

Pics of it coming back together.

https://imgur.com/a/V7GJ4KF

https://imgur.com/a/OZDeBCp

TX Z06 02

I added more pics of it coming together in the album.

Here's my favorite so far.

https://imgur.com/kihPD7m

Took it to Bret saturday and got he charge pipe built from blower to intercooler. He worked on the charge pipe from intercooler to throttle body but ran out of time.

It did start and run for ~15 minutes, but there was a noise in the drivetrain that i had to come home and drop the drivetrain to figure out.
I think I have that squared away now (loose flex plate).

Hopefully I have better luck next weekend.

Tusc

Could this be a trend with the Racetronix 255s? I bought two. The first one was DOA. The second one worked. Then I added the fuel pressure gauge and realized it wouldn't bump up past 42psi at any point, but more importantly when we tried to dyno tune the car it would crash to single digits. I refreshed ALL the wiring and grounds and tried with/without BAP. No change. I finally ordered the LPE version of the Walbro and it has been working 100% for me. Never less than 68psi.

This is the second Racetronix Walbro unit outside of my own two which I have heard of not delivering the goods in the past 12 months, that's 4 total I am aware of in that time. I am superbly happy with all their other products, but maybe they ought to check the QC on those Walbros before more clients burn their engines.

TX Z06 02

My problems were definitely NOT the racetronix fuel pump. My problem was the canister and in the wiring. I replaced the hotwire kit with a new one and drilled out the canister and never had a problem again.

MRc5z

TX Z06 02

My old hotwire kit was used when I bought it. The problem was a loose connection where it plugs into the factory fuel pump/fuel sending unit plug. I could literally touch the connection and the fuel pump would come on/go off. I tried messing with the prongs to get a better fit, but for $60, it was worth it to just replace it with a new one.

MRc5z