Oil Restrictor FFR GTM LS7
10-30-2014, 09:12 PM
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Oil Restrictor FFR GTM LS7 First post after reading nearly every oil restrictor issue out there. I've got an LS7 configured for a GTM with a Petersons dry sump tank plumbed "in" and "out" of the passenger side fore and aft ports directly to the upper and lower return and supply ports. The engine has the stock oil filter but the lines that run to the cooler were blocked off with a non-ported plate.
When I started the car, I noticed I did not have pressure or it was very slow building up and I shut it down. After verifying gauge connections, I started it again and oil went to 25 PSI but dropped as the engine warmed up. I ran the engine RPMs up once it warmed up but pressure did not rise. It simply dropped slowly from 25 to about 7 PSI. It continues to do this.
After troubleshooting for several weeks (thinking, reading, checking for metal etc) nothing made sense until I found out I had the wrong type of blockoff plate. I was told that it needs to allow oil to flow between the inlet and outlet to the cooler.....a simple loop in theplate itself serves the same purpose. Mine did not have this. I thought I found the problem but before I button things up, someone told me I probably damaged the oil restrictor. My fear is that once I get things back together, I'll have fixed the cause but not the damage to the restrictor (barbell). My question is:
1.)How likely is it that the ports being blocked completely would render the restrictor useless to the extent the filter is being bypassed?
2.) Is it possible to verify the presence of a bad restrictor?
3.) What occurs physically with the restrictor? It appears to be built like a double ended honey dip- O-ring at the rear, leaving the Honey dip (Look that term up
)at the front. Does the front end deform or bend or does the entire shaft collapse?
Because this is a GTM in the build process, I have access to the back of the engine but the Transaxle is currently installed. Probably a day or two to gain access to the rear cover. If the likelihood is low that the restrictor is damaged or there is a way to test it's functionality, then I'd like to give it a shot.
Does anyone have experience with this? I would sure appreciate all the comments I could get on this.
Thanks a million in advance!
John
My build site is
http://GTM410.com
The pictures of the engine and descriptions of the oil system and petersons tank are there n detail.
http://files.hgsitebuilder.com/hostg...e/dsc06373.jpg
When I started the car, I noticed I did not have pressure or it was very slow building up and I shut it down. After verifying gauge connections, I started it again and oil went to 25 PSI but dropped as the engine warmed up. I ran the engine RPMs up once it warmed up but pressure did not rise. It simply dropped slowly from 25 to about 7 PSI. It continues to do this.
After troubleshooting for several weeks (thinking, reading, checking for metal etc) nothing made sense until I found out I had the wrong type of blockoff plate. I was told that it needs to allow oil to flow between the inlet and outlet to the cooler.....a simple loop in theplate itself serves the same purpose. Mine did not have this. I thought I found the problem but before I button things up, someone told me I probably damaged the oil restrictor. My fear is that once I get things back together, I'll have fixed the cause but not the damage to the restrictor (barbell). My question is:
1.)How likely is it that the ports being blocked completely would render the restrictor useless to the extent the filter is being bypassed?
2.) Is it possible to verify the presence of a bad restrictor?
3.) What occurs physically with the restrictor? It appears to be built like a double ended honey dip- O-ring at the rear, leaving the Honey dip (Look that term up
)at the front. Does the front end deform or bend or does the entire shaft collapse?Because this is a GTM in the build process, I have access to the back of the engine but the Transaxle is currently installed. Probably a day or two to gain access to the rear cover. If the likelihood is low that the restrictor is damaged or there is a way to test it's functionality, then I'd like to give it a shot.
Does anyone have experience with this? I would sure appreciate all the comments I could get on this.
Thanks a million in advance!
John
My build site is
http://GTM410.com
The pictures of the engine and descriptions of the oil system and petersons tank are there n detail.
http://files.hgsitebuilder.com/hostg...e/dsc06373.jpg
11-01-2014, 10:48 AM
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I'm trying to get my head around how you have this plumbed. The factory oil pump fittings in the front of the engine are plumbed to the oil cooler and the rear (oil filter fittings) you have plumbed to the oil tank?
If that's the case you have some things to switch around. Oil tanks are meant to be pumped into and out of, not used inline. It appears that you are just pressurizing the oil tank and passively bleeding oil back into the engine.
If that's the case you have some things to switch around. Oil tanks are meant to be pumped into and out of, not used inline. It appears that you are just pressurizing the oil tank and passively bleeding oil back into the engine.
11-02-2014, 08:14 AM
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http://gtm410.com/engine---ls7-build...-tank-mounting
Between this pictures and the web page I have dedicated to this part of the build, you should be able to. The blockoff plate is mounted over the ports where the oil cooler lines begin above the filter.
John
Between this pictures and the web page I have dedicated to this part of the build, you should be able to. The blockoff plate is mounted over the ports where the oil cooler lines begin above the filter.
John
Last edited by DIY; 11-02-2014 at 08:21 AM.
11-02-2014, 03:49 PM
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I was looking at the air filter so the engine plumbing was backwards in my head. I see now the intake manifold is on backwards. Your plumbing looks correct.
I have yet to see a barbell fail. You should be able to pull the rear oil cooler line and see the shaft.
You could also attach an oil pressure gauge in various places along the plumbing to see where you are loosing pressure. Try attaching a gauge right in the galley in the front of the engine before the oil cooler.
The top plate can lose an o-ring and be bleeding oil pressure from the lifter galley. There is a galley plug behind the front cover that can easily be forgotten. You might recreate the suction side of the oil pump with clear tubing to make sure you aren't sucking air.
I have yet to see a barbell fail. You should be able to pull the rear oil cooler line and see the shaft.
You could also attach an oil pressure gauge in various places along the plumbing to see where you are loosing pressure. Try attaching a gauge right in the galley in the front of the engine before the oil cooler.
The top plate can lose an o-ring and be bleeding oil pressure from the lifter galley. There is a galley plug behind the front cover that can easily be forgotten. You might recreate the suction side of the oil pump with clear tubing to make sure you aren't sucking air.
11-03-2014, 07:33 AM
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Yes, The intake is on backwards. Forgot to mention that part. Thats part of the GTM mod to the engine install.
Now that I have the new oil cooler blockoff with a tapped boss (and it does allow flow between the "In" and "Out" to the cooler), I'll run it to see what it does. I'm thinking it should be okay but if it isn't, I'll check the things you mentioned.
It seems very unlikely the oil restrictor would deform, collapse or break under pressure. There's a pressure relief valve ahead of it and I'm pretty sure the filter would blow first if the relief valve (#13 in the above image) didn't relieve. Just trying to rule it out so I don't remove the transaxle and rear cover only to find it was a total waiste of time. The more I look at the system, and assuming the restricctor is there, there's no reason at this point to remove it.
Thanks for coming back and diving in on this.
Now that I have the new oil cooler blockoff with a tapped boss (and it does allow flow between the "In" and "Out" to the cooler), I'll run it to see what it does. I'm thinking it should be okay but if it isn't, I'll check the things you mentioned.
It seems very unlikely the oil restrictor would deform, collapse or break under pressure. There's a pressure relief valve ahead of it and I'm pretty sure the filter would blow first if the relief valve (#13 in the above image) didn't relieve. Just trying to rule it out so I don't remove the transaxle and rear cover only to find it was a total waiste of time. The more I look at the system, and assuming the restricctor is there, there's no reason at this point to remove it.
Thanks for coming back and diving in on this.
11-11-2014, 07:33 PM
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The blockoff plate was the sole issue. I pushed a borescope up the port between the filter base and restrictor end. I could see it there in place. I bought one for insurance earlier but don't need it. I'll hold on to it and...maybe stir a drink or two now that I know I don't have a rebuild ahead of me.
Oil pressure is 80+ cold idle and goes down to between 35-60 depending on temp and rpm after warmed up for a little while. What a fiasco. Don't buy a flat blockoff plate for the oil cooler In and Out ports!
Thought you might like seeing it run.....
Oil pressure is 80+ cold idle and goes down to between 35-60 depending on temp and rpm after warmed up for a little while. What a fiasco. Don't buy a flat blockoff plate for the oil cooler In and Out ports!
Thought you might like seeing it run.....