"I can't get no..."

[Patrick H.]

Re: "I can't get no..."

OK. Transplant is complete. Re-assembled without leaks and started fine. Now we wait to see if it holds fuel. Film at 11:00 - TOMORROW.

And Patrick - there is no discernable difference between the two parts when viewing from the outside. Only the rubber within is on one and not the other. See attached photo of the housing without the valve. The paper filter is the same. It's now in, so I can't get a pic.

BTW, if you draw mechanical next week, just know that this didn't work and I put some NOS pixie dust on it to get it right .

A little bird already told me I'm Mech next week.

Now I want to know how to get one of those fancy fittings.

Patrick

[Don L.]

Re: "I can't get no..."

A little bird already told me I'm Mech next week.

Now I want to know how to get one of those fancy fittings.

Patrick

Let's see if this works, first.

[Joe L.]

Re: "I can't get no..."

Don,

I've never seen a check valve built into the inlet fitting of a Quadrajet. My "assumption" is that what you have is a Edelbrock-inspired addition. Usually the "check valve" is just a rubber "flap" on the back of the paper fuel filter.

You can try this on your 72 but the guy doing Mechanical next weekend might note that it doesn't look like an original.

What kind of filter does your Edelbrock Q-jet use? Any pics of that too?

Patrick

Patrick-----


I agree. I've never seen an original Q-Jet, at least through 1974, with a check valve in the inlet fitting. It's possible that later Q-Jets might have used one, though. However, if they did, I don't know if these pieces would be retrofitable to earlier Q-Jets.

All 1970-81 Corvettes except 70-72 LT-1, used fuel pumps with a return line.

[Clem Z.]

Re: "I can't get no..."

GM uses a check valve in the inlet of the filter. i will try and post a picture. sorry for got to retitle the picture.

[Joe L.]

Re: "I can't get no..."

GM uses a check valve in the inlet of the filter. i will try and post a picture. sorry for got to retitle the picture.

clem-----


The only carb inlet filter I can find that was ever used used on Corvettes that used an integral check valve was used for 1976-81 models. This filter, GM #5651803 aka Delco #GF-471, is just a little over 2" long, though. So, it will not fit into the inlet fitting of 1968-75 Rochester Q-Jets. 1968-75 require a filter which is 1" long.

[Clem Z.]

Re: "I can't get no..."

clem-----


The only carb inlet filter I can find that was ever used used on Corvettes that used an integral check valve was used for 1976-81 models. This filter, GM #5651803 aka Delco #GF-471, is just a little over 2" long, though. So, it will not fit into the inlet fitting of 1968-75 Rochester Q-Jets. 1968-75 require a filter which is 1" long.

the check valve can be installed in any Q jet paper filter just by removing the original gasket glued to the filter and installing a check valve like i posted above. if the corvette in question does not have a fuel pump to tank return line the check valve is not needed. also if the carb does not have a windowed needle seat.

[Clem Z.]

Re: "I can't get no..."

clem-----


The only carb inlet filter I can find that was ever used used on Corvettes that used an integral check valve was used for 1976-81 models. This filter, GM #5651803 aka Delco #GF-471, is just a little over 2" long, though. So, it will not fit into the inlet fitting of 1968-75 Rochester Q-Jets. 1968-75 require a filter which is 1" long.

i think a GF-470 is the 1" filter with a check valve

[Joe L.]

Re: "I can't get no..."

i think a GF-470 is the 1" filter with a check valve

clem-----


Yes, I confirmed that the GF-470 is the 1" fuel filter with an integral check valve. However, this filter was never cataloged for any Corvette application. Nevertheless, it might be a very good addition to any 68-75 Corvette using the 1" paper inlet filter of GF-427 (68-74) or GF-441 (1975).

The only thing that would worry me a little bit is why GM didn't supercede the non check valve filters with the check valve style?

[Patrick H.]

Re: "I can't get no..."

clem-----


Yes, I confirmed that the GF-470 is the 1" fuel filter with an integral check valve. However, this filter was never cataloged for any Corvette application. Nevertheless, it might be a very good addition to any 68-75 Corvette using the 1" paper inlet filter of GF-427 (68-74) or GF-441 (1975).

The only thing that would worry me a little bit is why GM didn't supercede the non check valve filters with the check valve style?

Any idea what the GM long numbers are? I haven't found them using the GF numbers listed.

I also found them on Napa's site.
Without the valve is SFI 23044 or FIL 3044.
With the valve is SFI 23051 or FIL 3051.

I wonder if they flow less? Or if GM was just saving $ because most applications did not "need" them? I want to see now if they have one for my Cutlass. That car needs one.

Patrick

[Joe L.]

Re: "I can't get no..."

Any idea what the GM long numbers are? I haven't found them using the GF numbers listed.

I also found them on Napa's site.
Without the valve is SFI 23044 or FIL 3044.
With the valve is SFI 23051 or FIL 3051.

I wonder if they flow less? Or if GM was just saving $ because most applications did not "need" them? I want to see now if they have one for my Cutlass. That car needs one.

Patrick

Patrick------

GF-470= GM #5651802

I believe your Cutlass originally used a GM #5650906 inlet filter, aka Delco GF-441. This is a 2" filter without check valve. If so, you should be able to convert to a check valve style filter by using a GM #5651803, aka Delco GF-471.

I think you will find that most, if not all, of these filters on the market now are derived from the same manufacturing source. Check for a "Made in India" embossment on one of the end caps to confirm this.

[Jim T.]

Re: "I can't get no..."

Don;

I think you have your finger on the problem with that check valve.

As for the Q Jets leaking, that is kind of an old tale now that most every good rebuilder checks for. It had to do with the main jet well plugs that sit in a chamber down in the base. Most rebuilders will put some extra sealer on them or use a plug that fills the cavity.

As for the Holley spread bores; I've had my fill of those. I don't like any carb that uses a gasketed surface below the fuel level. Also, those transfer tubes (primary to secondary) are prone to O-Ring seal leakage. No fun having the valley full of fuel. Then there is the air cleaner fit problem. A good Q jet will perform equal or better with half the fuss. Nothing like good old simple secondary dump instead of having to deal with an additional accelerator pump diaphragm, what with today's gas.

Stu Fox

Having used the Holley spreadbore since 1974 I have certainly had no problems to date with the transfer tubes (primary to secondary) with O-Ring seal leakage.
I always assembled my spreadbores using vasoline as a lubricant on the O-Rings to prevent damage during installation.
I am still using my original air cleaner that came on my 68 327/350. The base was an easy adaption. Removed the original fresh air vent that used a rubber hose to the chrome valve cover. Installed the same metal fresh air vent a few inches from the removed location which allowed the base to move/turn counter-clock-wise enough to fit over the Holley spreadbore and not interfer with the Holley's secondary's pump.
I used the dual snorkel original air cleaner on my 70 350/300 with the Holley spreadbore.

[Clem Z.]

Re: "I can't get no..."

i had a standing policy when someone brought in a holley replacement Q jet for work i asked that if they had the original Q jet i would rebuild it and if they did not like it better than the holley replacement i would redo the holley free. never had to do a holley for free. the leaks i found in those holley Q jet replacements were in the float bowl passage plugs. i pressure test at 9# pressure all my carb work before to find the leaks and after to make sure there are no leaks.

[Don L.]

Re: "I can't get no..."

The Feedback:

Was busy on Monday night, therefore, I couldn't check to see if the check valve made a difference. On Tuesday night, I did a few things to the carb before attempting to start the engine (not sure if related or not) and the engine still took what I think is too long to hook. Tried tonight and Voila! Cranked over only a couple RPMs and it hooked with strength. Fast idle good too. Think I have it!

Looks like those that are interested in using a filter of this type have their leads.

I appreciate everyone's help and advice. This is what makes this forum so great. Fixed my problem and I learned something new too.

[Joe L.]

Re: "I can't get no..."

i had a standing policy when someone brought in a holley replacement Q jet for work i asked that if they had the original Q jet i would rebuild it and if they did not like it better than the holley replacement i would redo the holley free. never had to do a holley for free. the leaks i found in those holley Q jet replacements were in the float bowl passage plugs. i pressure test at 9# pressure all my carb work before to find the leaks and after to make sure there are no leaks.

clem-----


Do you see any need for the use of a filter with check valve for a Holley application, either a Q-Jet replacement or a standard "square bore" Holley? I realize that very few original Holley applications used a fuel return line but ONE Corvette application did----1971 with LS-6. There may have been other 1970-72 Chevrolet applications that used a Holley with a fuel pump with fuel return line too.

[Clem Z.]

Re: "I can't get no..."

clem-----


Do you see any need for the use of a filter with check valve for a Holley application, either a Q-Jet replacement or a standard "square bore" Holley? I realize that very few original Holley applications used a fuel return line but ONE Corvette application did----1971 with LS-6. There may have been other 1970-72 Chevrolet applications that used a Holley with a fuel pump with fuel return line too.

no just the roch Q jet because the fuel inlet is below the fuel level in the float bowl when it uses a "windowed" needle seat. i will later post a picture of a "windowed" needle seat. "the windowed one is on the right." that slotted opening is on both sides so the fuel does not have to work its way up past the needle to get into the float bowl.