[McBrayer]

Just a couple of quick questions. I understand that the factory check valve can be a restriction point.

1. Where is the factory check valve located?

2. What is required to bypass it?

The installation of the LPE check valve is straight forward, so no help needed there.

Thanks

[Lt4zl1]

We even called them directly and they couldn’t answer where the stock zl1 check valve is located. Lol I have my blower off now and it’s no where up top I know that.

[scantone]

Originally Posted by Lt4zl1

We even called them directly and they couldn’t answer where the stock zl1 check valve is located. Lol I have my blower off now and it’s no where up top I know that.

Follow the braided fuel line behind the charger you'll see a silver clamp on the braid, the check valve is held in place by that clamp. I just installed the lpe valve this weekend. I cut the factory hose to see what the check valve looked like and I was amazed how damn small it was.

[Dixie ZL1]

Please post your findings. I purchased a Russell 650603 in-line check valve and haven’t installed it yet. I suspect it may provide some LPFP headroom.

I couldn’t justify the LPE price, so I didn’t the $40 Russel’s AN6 with another $20 in fittings

[Joshinator99]

Originally Posted by Dixie ZL1

Please post your findings. I purchased a Russell 650603 in-line check valve and haven’t installed it yet. I suspect it may provide some LPFP headroom.

I couldn’t justify the LPE price, so I didn’t the $40 Russel’s AN6 with another $20 in fittings

Does the Russell check valve neck down internally to smaller than AN6? Just wondering if an AN8 or AN10 check is the way to go, if that is the case.

[scantone]

The internals of the lpe are not like a standard check valve. I should have taken a pic but slipped my mind.

[Dixie ZL1]

Originally Posted by Joshinator99

Does the Russell check valve neck down internally to smaller than AN6? Just wondering if an AN8 or AN10 check is the way to go, if that is the case.

The Russell AN6 check valve flows the full rate of the stock 5/16” fuel line without restriction.

[Joshinator99]

Originally Posted by Dixie ZL1

The Russell AN6 check valve flows the full rate of the stock 5/16” fuel line without restriction.

Ok, good info. Thanks.

If someone does get a good look at the LPE check’s internals, that would be interesting to see too.

[Dixie ZL1]

That stock check valve has to be a flow restriction.

[EDFHOBBIES]

Uwe O. with XDI (what katech sales) explained that his setup fixed this problem.

Sorian was able to make mine, I picked up about 8psi on the lowside while using the DSX aux.

LPE is a great company but, you have to know what the f$#% your doing to make there fuel system work. It's not laid out or at least it wasn't last year for me.. Basically you can't go and buy there fuel system parts with out knowing a few things if you want that advertised 900 plus on all e85 to work right.

1. Big Bore Pump (*spaced correctly and measured)
2. Cam w fue lobe of 42% (not the aftermarket 32 and 38% for a normal LT1/4 pump)
3. Ck valve fix which they have now
4. A bad ass low side return style fore or aux return style capable of 100 psi and constant 80 psi that won't drop under heavy loads
5. plus 30 or 45 injectors (these can be anyone)

[mr911omar]

Originally Posted by scantone

Follow the braided fuel line behind the charger you'll see a silver clamp on the braid, the check valve is held in place by that clamp. I just installed the lpe valve this weekend. I cut the factory hose to see what the check valve looked like and I was amazed how damn small it was.

if it possible if you can post more pictures where and how do you place the lpe check valve

[mr911omar]

because in my case i found out the hard way, did the test drive and found out the high pressure pump is pumping only 2300 psi not 2900psi it should be

[mr911omar]

[EDFHOBBIES]

Most of the check valve problems are noise issues that are replaced by GM. Check valve is on the low side that feeds the high side and 99% of the problem is the low side not feeding the high side that will give you low pressure as well. If your making any power with the stock lt4 stuff it needs to be 70 psi under load not falling off I got mine up to 76 with a hiflow valve and the DSX low side that combo still didn't feed the LPE big bore pump enough it needs 80 psi continuously under load with no pressure drop what so ever!

what is you low side pressure I bet anything it falls off just before the high side!