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Discussion Starter #1
Anyone have a good diagram of oil flow thru a 4age? I found one for a FWD 4age but it's a little fuzzy and hard to tell which way the oil flows.

I'm specifically interested in learning how the oil flows into and out of the oil filter sandwich. Does the oil flow thru the filter then to the oil cooler, or is the flow split with part going to filter and part to oil cooler? And, is the oil pressure sender immediately before or after the oil filter?

A diagram with arrows indicating flow direction would be a big help!

James
 

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Discussion Starter #2
Anybody?

Does the oil flow thru the filter then to the oil cooler, or is the flow split with part going to filter and part to oil cooler -- or some other way....
 

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From what I could see when tearing down a spare motor I had, all the oil flows thought the filter, at which point some gets diverted to the oil pan via the oil cooler and the rest goes into the oil gallery where the oil pressure sensor is. What sucks is that the oil flows through the filter from the outside in so that trying to tap the body of the oil cooler adapter gets you dirty oil. If you removed the cooler fitting and valve you could get clean oil at full pressure via the passage in the oil cooler adapter from the center (filtered flow) to the outside.

The best way to verify this (it's been about a year since I pulled that motor apart) is to remove the oil cooler adapter. You can follow the bump along the side of the block that contains the passage from the oil pump.
 

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Open open the 4ag oil sytem picture on Bill Sherwood's site:
http://www.billzilla.org/4agstock3.htm

My guess is that the oil in the oil pan enters the oil pump. The oil pump sends the oil to the oil filter. The oil enters the oil filter sandwhich plate and through the oil filter. If the oil pressure is excessive, the pressure opens the oil relief valve in the oil filter bracket and a portion of the oil is diverted to the oil cooler. The oil sent to the oil cooler drains into the oil pan. The oil that passes through the oil filter to the crankshaft and camshafts and eventually drips back into the oil pan. I am not sure if the oil pressure sender is before or after the oil filter

Again this is a guess. erwendell may be correct. At least this post bumps the issue back to the top and someone hopefully will respond with a more confident answer.
 

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Discussion Starter #5 (Edited)
Reason I asked is, I want to relocate my oil filter using the adapter pictured below. It has two In ports and two Out ports. The Out ports simply split the flow. I was thinking of sending flow equally to the filter and cooler via the Out ports. The filtered oil would return to an In port, and the cooled oil would go to the oil pan. The other "In" port I could then use as a source for clean oil to a turbo.

It's hard to tell, but This diagram on the online parts page for a smallport FWD 4age seems to indicate that the oil goes to the cooler on the dirty side of the filter. I think you're right, Ron, that oil only flows to the cooler when oil pressure has reached a certain point.

On my setup flow to the cooler would be continuous. I'm trying to decide if that would be a bad thing or if it would make any significant difference.

By the way, this is an AE92 SC longblock that didn't come with a sandwich plate -- and didn't have an oil cooler system.

James

 

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Ron said:
Open open the 4ag oil sytem picture on Bill Sherwood's site:
http://www.billzilla.org/4agstock3.htm

My guess is that the oil in the oil pan enters the oil pump. The oil pump sends the oil to the oil filter. The oil enters the oil filter sandwhich plate and through the oil filter. If the oil pressure is excessive, the pressure opens the oil relief valve in the oil filter bracket and a portion of the oil is diverted to the oil cooler. The oil sent to the oil cooler drains into the oil pan. The oil that passes through the oil filter to the crankshaft and camshafts and eventually drips back into the oil pan. I am not sure if the oil pressure sender is before or after the oil filter
I think you got it except for the red part, that valve opens only when the pressure builds up to the adecuate levels so it doesn't damage the rest of the engine and flows through the oil cooler. I think the sender itself is actually before the filter and feeds right of the pump but it would make more sence for it to be after the filter so I'm not sure of that.
 

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Ok, I stopped by my storage unit today and looked at one of my spare engines. I was right about everything except the design of the oil cooler adapter. The cooler gets dirty oil, not clean.

Flow diagram: pickup>pump>filter>oil gallery>pressure sensor>bearings
> >oil cooler valve>oil cooler>pan
>pressure regulator>pan

There is a pressure regulator(bypass actually) in the oil pump. The pressure sensor is seeing clean oil out of the filter which is why HKS used that port as the source for turbo oil. The oil cooler gets dirty oil when there is excess that can be diverted from engine. I'm not entirely positive how the oil cooler valve works but it must be thermostatic is some way else it would pass the most oil during cold start when oil pressure is highest entering the filter. I don't see how you can split the oil supply between engine and cooler without some sort of limiting valve. The restriction of the bearings must be much higher than that of the cooler so I suspect most of the oil would bypass them in favor of the cooler.

When I go back to being turbo powered I'm planning on drilling though the side of the stock oil cooler adapter and having a piece of aluminum tube welded in to which I can thread a fitting. That will give me access to the inner filtered flow. I want to keep my ac and the only way you can tap off the pressure sensor port and do so is to copy HKS and remote mount the sensor on a manifold. I'm going to keep it simple by doing a bit of complicated fab work.

edit: For some reason my attempt at ascii art wrt to the flow diagram isn't working. I'll try to get buy with a drawing package after class tomorrow. Also, I took pictures of the oil passages into and out of the filter and oil cooler adapter if anyone's interested.
 

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Discussion Starter #8
I would like to see the pic. I'm thinking at this brief moment in time that I will take the filter sandwich off my NA motor and swap it onto the SC block and use the stock system to send oil to the cooler. I will use the remote filter adapter pictured above, but plug the second "out" port. The second "in" port would feed oil to my turbo. Seems like it would work pretty much the way you're thinking, Roy, without any drilling involved...

James
 
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