Blocking off external bypass valve on SBC?

[Brons2]

I was perusing videos on YouTube when I came across this:



I mean, for a hot rod that you only drive in warm weather, this might not turn out so bad. But it seems like it's a bad idea for any weather that's remotely cold, if you can't get enough flow across the filter, you're going to have oil starvation.

 

[ZeeOSix]

You don't "blow up" and oil filter (ie, expand the can or blow-out the base seal) from not having a filter bypass valve. The pressure inside the oil filter is controlled by the oil pump pressure relief valve - not the filter bypass valve. Guys like this who build race engines will usually also install a high volume oil pump that has a higher pressure relief setting ... that puts more oil pressure on the oiling system and oil filter. It also increases the flow and therefore the delta-p across the oil filter.

If there is no filter bypass valve, it would be possible to implode the center tube of the oil filter. The filter bypass valve is there to also protect the oil filter from damage by collapsing the filter guts from delta-p. Anyone running a race engine really needs to use an oil filter designed for racing engines if they want to ensure the filter is going to survive.

If I was building a race engine like this that has the filter bypass in the block, I would block-off the bypass but then use a racing oil filter with a bypass valve in the oil filter that has a pretty high bypass PSI setting ... especially if running a higher volume oil pump with a higher pressure relief setting, and using thicker oil has a factor on all of this too.

 

[Chris142]

The how To hot rod Chevy book all recommended doing that. I did it to mine 30+ years ago with no adverse effects.

 

[BlueOvalFitter]

If I was building a race engine like this that has the filter bypass in the block, I would block-off the bypass but then use a racing oil filter with a bypass valve in the oil filter that has a pretty high bypass PSI setting ... especially if running a higher volume oil pump with a higher pressure relief setting, and using thicker oil has a factor on all of this too.

+1
When I used to build the old school SBC engines, I would block off the bypass for the first 25 minutes of breaking in a cam.
A lot of people that build/have built the old school SBC engines know this. Melling HV oil pumps was my choice back then (M-55HV with the pickup welded in place).
When I would build an everyday, run of the mill SBC (NOTHING high performance), I never blocked the bypass.
Man, this brings back some old distant memories.

 

[bullwinkle]

I seem to remember higher than OEM bypass springs for the SBC block bypass, that would help send extra oil to the journals(?)

 

[ZeeOSix]

I seem to remember higher than OEM bypass springs for the SBC block bypass, that would help send extra oil to the journals(?)

What controls the oil volume to the engine is the oil pump and the pump's pressure relief setting. Not the filter bypass valve.