Bypass filter for a Chevrolet ?

[user151]

I removed the oil cooler / bypass from my Chevy 4.3 V6 (same as a SBC). I can screw the threaded thing back into the block and use the same filter (PF51 or WIX 51036) but then I have no bypass. So I could install a stock Chevy filter bypass adapter.

Two questions: 1) is it OK to run without a filter bypass? ... 2) Instead of installing a Chevy bypass adapter, is there a filter like the PF51 that has its own bypass, and should I even be asking this question?

Finally, I have never understood why GM installs a relatively expensive bypass adapter on their engines, when they could simply specify a bypass filter.... any ideas?

Tom

 

[TallPaul]

I would think there should be filters with the same thread and general specs with bypass that you could use.

 

[Gary Allan]

No, it's no okay to run without a bypass. Use a racing filter if you do (screen door material would be better).

This should work for you. The bypass is a bit high, but I don't think you'll run any trouble

Part Number: 51243
UPC Number: 765809512436
Principal Application: Various John Deere Engines + Equipment
All Applications
Style: Spin-On Lube Filter
Service: Lube
Type: Full Flow
Media: Paper
Height: 5.209
Outer Diameter Top: 3.663
Outer Diameter Bottom: Closed
Thread Size: 13/16-16
By-Pass Valve Setting-PSI: 16
Burst Pressure-PSI: 260
Max Flow Rate: 9-11 GPM
Nominal Micron Rating: 25

Gasket Diameters
Number O.D. I.D. Thk.
15614 2.834 2.462 0.200


This one has a more reasonable bypass setting, but ..BOY ..it must be used for explosion proof environments.

Part Number: 51581
UPC Number: 765809515819
Principal Application: Various Cummins (Turbocharger)
All Applications
Style: Spin-On Lube Filter
Service: Lube
Type: Full Flow
Media: Paper
Height: 5.178
Outer Diameter Top: 3.660
Outer Diameter Bottom: Closed
Thread Size: 13/16-16
By-Pass Valve Setting-PSI: 8-11
Burst Pressure-PSI: 1000
Max Flow Rate: 9-11 GPM
Nominal Micron Rating: 25

Gasket Diameters
Number O.D. I.D. Thk.
Attached 2.834 2.462 0.200

 

[user151]

Thanks Gary, but I should'a said I am looking to replace the wix 51036 with a 51040... The reason I took off the oil cooler / bypass adapter with the 51036 .... and want to go to a shorter filter like the 51040 but with a bypass ... is to get more clearance.

(Of course I could put in a GM bypass adapter and use the 51040)

I appreciate your taking the time to give me those refrences, is there a wix or AC Delco chart somewhere I could look up the specs like you quoted?

And any idea why GM would use a bypass adapter when they could just use a bypass filter?

Tom

 

[Gary Allan]

Here's another one ..it's primarily a hydraulic filter ..but fits the bill

Part Number: 51612
UPC Number: 765809516120
Principal Application: Power Steering on IHC Trucks
All Applications
Style: Spin-On Lube Filter
Service: Power Steering
Type: Full Flow
Media: Paper
Height: 4.338
Outer Diameter Top: 3.660
Outer Diameter Bottom: Closed
Thread Size: 13/16-16
By-Pass Valve Setting-PSI: 7-9
Nominal Micron Rating: 30

Gasket Diameters
Number O.D. I.D. Thk.
Attached 2.834 2.462 0.200

Here's one from Donaldson

P179342

Hydraulic Filters Product Attributes
A - OD (Inches): 3.82
B - Thread Size (Inches): 13/16-16
C - Length (Inches): 5.97
Product Type Description: HYDRAULIC SPIN-ON, DURAMAX
Primary Application: CASE IH 254686A1
Efficiency Beta 2 (Micron): 7
Efficiency Beta 20 (Micron): 17
Efficiency Beta 75 (Micron): 22
Relief Valve Setting (PSI): 50
Product Group: FH

I'd reinstall the in block bypass

Quote:
And any idea why GM would use a bypass adapter when they could just use a bypass filter?


So that would be racers could defeat it ..allowing them to feel that they've gained some advantage over Mopars and Fords?

 

[SuperBusa]

Originally Posted By: user151
Finally, I have never understood why GM installs a relatively expensive bypass adapter on their engines, when they could simply specify a bypass filter.... any ideas?


Good question ... I've wondered that myself. Maybe when GM designed that system (it's an old design) there weren't many (or any?) spin-on filters that had a bypass valve designed into them ... just guessing. But, it could also be that GM wanted to ensure that the right bypass setting was always there in their built-in valve instead of relying on a filter's bypass valve. They might have also thought their bypass valve was more reliable than a filter's. Just some guesses on why ... maybe a WWW search might come up with a valid reason.

 

[SuperBusa]

Found this on a net search. Sounds like the LS2 got rid of the built-in filter bypass vavle and went to a filter with a bypass vavle.

Oil Filter with Internal Bypass
The LS2 V8’s oil filter now features an internal filter bypass. The bypass is a safety device that protects the engine in the event the filter is neglected for an extended period of time. If the filter becomes completely clogged with debris, the bypass opens and does not allow the filter to restrict oil flow through the engine.

Previous LS2s had the bypass mechanism installed in the oil pan. Moving the bypass to the filter improves engine assembly efficiency and insures that the mechanism is fresh and unobstructed each time the filter is changed.

 

[TallPaul]

You could always re-install the factory bypass and run a filter with a bypass for a belt and suspenders setup.

Nice thing about a Chevy oil filter is that without a bypass valve the filter is much simpler. Nothing to go wrong.

What I would like is to have the oil pump bypass valve located in the block where you could take it apart without dropping the pan. I suspect mine has a weak spring.

 

[Gary Allan]

Quote:
Previous LS2s had the bypass mechanism installed in the oil pan. Moving the bypass to the filter improves engine assembly efficiency and insures that the mechanism is fresh and unobstructed each time the filter is changed.


(nod to XS650)

Translation: We decided to save some bucks. (I don't think, while I don't know, that they ran into issues with that setup).


..but not being up on my later evolutions of Chebby engines ..anyone got the fat on this "in pan" bypass? I have visions of some real convoluted plumbing scheme to incorporate a filter that's sitting somewhere in the exosphere compared to "in the pan".