Question on bypass restrictor

[handyman]

I think I may have installed a motor guard with out the restrictor orifice. Should I be worried?

I’ve had this motor guard for a long time but just now found the time to install it.

I’ve tapped off the oil pressure switch and put a self tapping hollow bolt in the oil pan. I can’t remember if this motor guard has the restrictor or not in the motor guard. (Old age strikes again)

It seems to run fine. Questions:

(1) Will it flow too much?
(2) Will it not filter as fine as it should?

 

[Harley Anderson]

The slower the flow the better, better filtration will be achieved and less chance of channelling. Most the "oil gods" on here recommend 1 quart a minute flow warm at idle. I am using a 1/16 restriction fitting on my frantz. Contact Ralph Wood on here.

 

[Lonnie]

What Harley said. Also consider where you place the restrictor. I'd put it as close to the source of oil as possible. Sounds like a useless detail but you pump won't have to top the filter and likes up when you start up to hit the restriction.

 

[unDummy]

It will flow too much and starve the engine of oil flow and PSI. Do NOT run engine without the restrictor. You can c-clamp the feed or return hose until you are sure that there is one there, or install a valve to pinch off flow if you don't want to use a restrictor.

What engine? Adjust flow for engine size. The generic quart/min is great for large engines. But if it is a small engine, pint/min should work well.

 

[mjo]

The main job of a properly installed flow restrictor is to prevent leaks. Without the flow restrictor on the inlet, there will be a higher pressure inside of the motorguard. You want the restrictor as close to the engine as possible so that leaks can be mitigated. Think of it this way, if your oil lines were to suddenly open up while driving, would you prefer a pin-sized hole or a much larger one?

 

[unDummy]

Leaks? NO
The orifice's job is to 'LIMIT' oil flow through the filter regardless of whether it is on the feed or return line or in the filter.

 

[Gary Allan]

I'm with undummy on this. If the restrictor is on the inlet, the pressure may be lower inside the unit initially ..but as it saturates, the oil is going to meet resistance and want to push the roll through the end of the canister. The restrictor flattens the flow curve of a new filter and a used filter more evenly over the life of the filter. Otherwise you would have a lots of filtration in the first half of the mileage ..and very little in the last half of the mileage.

 

[SWHeat]

I thought that if you used a sandwich adapter, you didn't use a restrictor at all? I was also under the impression that you could put the restrictor on the outlet of the motorguard, that way it would have less chance of getting clogged by debris.

Yes? No? Maybe?

I guess it is time to over engineer the hoses with the SS variety. Thanks mjo.

 

[Gary Allan]

Removing it's optional with a sandwich adapter. There you'll have a continuous 2 psid across the bypass filter. I think that I would tend to leave it on thinking more about it.

In the BP80A Amsoil puts the .030 restrictor on the outlet to avoid clogging ..or so I reason. I don't think that the MG restrictor is that small ..so it probably won't encounter any issues. Any debris would have to be HUGE to clog either ...but you should sensibly encounter less on the outlet.

 

[Harley Anderson]

If you have debris large enough to clog a restrictor fitting you have other problems to worry about.

The guy that made the hoses for my frantz used 5000 psi hydraulic hose, expen$ive and way overkill for a automotive application.

 

[handyman]

Thanks Guys, Good advice.
I will not run it until I check it.
I will check for the restrictor. If I find it then I will have one less thing to worry about.
If not then I have a 1/16 restrictor from Frantz. I will install it where I tapped off the oil pressure switch.

Being a belt and suspenders type guy (I like overkill) I like Mjo’s and Lonnie’s thoughts about locating it as close to the source as possible.

 

[Gary Allan]

Quote:

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If you have debris large enough to clog a restrictor fitting you have other problems to worry about.

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I tend to agree. The MG/Frantz type restrictor is HUGE and is also an orifice (at least on the MG). The .030 restrictor on the Amsoil BP80-A is a tunnel in comparison and half the diameter. You wouldn't have an oil passage that small on an engine regardless of the filtration used ..at least not one that wasn't easily serviceable or feeding a critical part.

Quote:

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The guy that made the hoses for my frantz used 5000 psi hydraulic hose, expen$ive and way overkill for a automotive application.

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Hydraulic hose is typically rated for 212F ..but the (also typical) 5000lb burst strength (that you mentioned) tends to index the security. You could have coke before you could ever generate enough pressure to damage the hose at automotive pressures. You can actually save mone using hydraulic lines if you can manage to fall into 12", 24", 36" lengths in your needs. They're very cheap compared to oil hose rated at 250F/300F (around there) albeit at vastly reduced pressure ratings.

I'd have no problem with using trans cooler line. It's got more than enough of a rating to handle anything that you may throw at it. ..but I can understand why you would want something of more substance.

 

[handyman]

Well I checked and it is installed in the input side of the filter.