TheSamba.com Forums
 
  View original topic: New rebuild and no oil pressure. Page: Previous  1, 2, 3  Next
Wildthings Wed Aug 08, 2012 5:31 pm

velo96 wrote: I only have the bentley manual. It doesn't mention packing the pump. I followed all tolerance and torque specs. My plan is to first see some oil pressure then start it up and run it at 2000 rpm for 20mins to breakin the new cam and lifters. Wildthings I'm scared to start it even with the pre lube without seeing pressurized oil first. I forced about a half a quart into the sender hole two days ago, is that sufficient? I am rotating with plugs out.

You want to do it immediately prior to attempting to start it so the galleys would be full and wouldn't have had a chance to drain down. Maybe rotate the crank 180° while adding the oil so that all the rod bearings get a goodly amount of oil to them. Oil is so viscous at start up temps you don't need much of any volume to get protection.

velo96 Wed Aug 08, 2012 5:35 pm

I added oil and cranked engine with no luck again. I'm starting to think I'm going to have to start taking things apart. I really tried to pay close attention to every step during assembly. Hope its something very noticeable. Is it ok to crank for a full minute? When I pure oil in the sender hole and crank it the oil quickly disappears. Is that normal? :(

Wildthings Wed Aug 08, 2012 5:44 pm

velo96 wrote: I added oil and cranked engine with no luck again. I'm starting to think I'm going to have to start taking things apart. I really tried to pay close attention to every step during assembly. Hope its something very noticeable. Is it ok to crank for a full minute? When I pure oil in the sender hole and crank it the oil quickly disappears. Is that normal? :(

The oil will disappear because the journal bearings are sucking it in, plus there is seepage passed other points. I don't know much about how people go about full flowing a case except that there are multiple ways of doing so. You need all the little steps to build your system to have been done correctly.

SGKent Wed Aug 08, 2012 8:44 pm

velo96 wrote: I added oil and cranked engine with no luck again. I'm starting to think I'm going to have to start taking things apart. I really tried to pay close attention to every step during assembly. Hope its something very noticeable. Is it ok to crank for a full minute? When I pure oil in the sender hole and crank it the oil quickly disappears. Is that normal? :(

did you crank it with the sender and plugs out? How long?

Is this the old case and pickup tube? Did you replace the o-ring on the pickup and what kind of o-pump are you using?

Don't crank it for a minute. If it works it will come up within 5 to 10 seconds if the oil sender is out. If the oil sender is in it may never come up.

Chris_914 Wed Aug 08, 2012 11:07 pm

Only two things left either the pump is not turning or is trapped in a bubble of air. One last thing I would try is to remove the pressure control spring and piston and give it one more shot at turning over. Put oil pan under cause if it does prime, lots of oil is going to dump out of the control passage. Be careful, at this point you really have to decide if you have a priming issue or a mechanical issue.

Desertbusman Wed Aug 08, 2012 11:31 pm

OK, here's the real deal-

You've been cramming oil into the sender hole trying to get pump prime. But that won't do anything. Oil might work it's way backwards to the pressure side of the pump gears (maybe) but it's the suction side of the gears that count. Oil in the outlet side pump cavity won't do anything. Suction side of the pump is where you need to displace the air that's in it.

With the plugs out so you can easily turn it, turn the engine backwards while you are introducing oil into the sender hole. Backward turning of the pump gears will feed the suction side cavity. It won't completely fill it as well as pre-packing but it should be enough to get the sucker pumping and the air purged out. :wink:

BUSBOSS Thu Aug 09, 2012 12:00 am

velo96 wrote: The modified type 1 pump is machined to fit the type 4 engine and the cam gear is machined to fit the modified type1 pump.

aeromech wrote: You said that you're using a modified Type 1 pump. I've never heard of that before but hey, there's a lot of things I've never heard of before.


I've never heard of this until just last week. Tell us more.

Desertbusman Thu Aug 09, 2012 12:35 am

I'm amaized that the topic of T-1 pumps on a T-4 is a surprise. :shock:

Modified T-1 pumps for T-4's are discussed here frequently. You T-4 folks don't have much choice when a pump is needed.
Here is a link to one. There are others and other sizes. Seems like John also has T-1 Mellings for t-4's.
http://vwparts.aircooled.net/Schadek-26mm-Oil-Pump...6mm-t4.htm

Just so the topic of pump blueprinting doesn't get started again. :roll:

BUSBOSS Thu Aug 09, 2012 1:07 am

Desertbusman wrote: I'm amaized that the topic of T-1 pumps on a T-4 is a surprise. :shock:

Modified T-1 pumps for T-4's are discussed here frequently. You T-4 folks don't have much choice when a pump is needed.
Here is a link to one. There are others and other sizes. Seems like John also has T-1 Mellings for t-4's.
http://vwparts.aircooled.net/Schadek-26mm-Oil-Pump...6mm-t4.htm

Just so the topic of pump blueprinting doesn't get started again. :roll:

Thanks! Sorry - it was a genuine surprise to me. I certainly don't claim to have expertise in an area unless I actually have it. I'm reading more about it now via the search function. And like many topic areas on TS, it seems ripe for controversy.

Desertbusman Thu Aug 09, 2012 2:25 am

BUSBOSS wrote: it was a genuine surprise to me. It's always a surprise to me also how T-4 life is so different than our old simple, common, proven, basic, and well know T-1's. No surprises there at all.
Based on the many Samba topics there must be unknown mysteries or else design flaws with the T-4 lube system. Evidently both of those problems. Combine that with lack of parts availability and it must be a real experience owning a T-4 engine. Sorry, but it is somewhat interesting following some of the T-4 struggles.

curtis4085 Thu Aug 09, 2012 4:54 am

BUSBOSS wrote: Desertbusman wrote: I'm amaized that the topic of T-1 pumps on a T-4 is a surprise. :shock:

Modified T-1 pumps for T-4's are discussed here frequently. You T-4 folks don't have much choice when a pump is needed.
Here is a link to one. There are others and other sizes. Seems like John also has T-1 Mellings for t-4's.
http://vwparts.aircooled.net/Schadek-26mm-Oil-Pump...6mm-t4.htm

Just so the topic of pump blueprinting doesn't get started again. :roll:

Thanks! Sorry - it was a genuine surprise to me. I certainly don't claim to have expertise in an area unless I actually have it. I'm reading more about it now via the search function. And like many topic areas on TS, it seems ripe for controversy.

And here Im thinking it's a common thing that people use modified Type 1 pumps on type4 engines? I believe Jakes CS uses them and I know Adrian put one on my new engine he also puts his own design a oil check valve. Suppose to help with bleed down.

aeromech Thu Aug 09, 2012 6:37 am

I've started a lot of freshly built aircooled engines and have never experienced the lack of oil pressure caused by pump cavitation. I've never packed an oil pump with grease either. My feeling here is that there is another problem causing the lack of oil pressure.

velo96 Thu Aug 09, 2012 7:42 am

I have been cranking with the sender and the plugs out. It is the old case and I did replace the o-ring. I'm using a modified type1 pump. schadeck 30mm. Desertbusman I will make that my next attempt. Aeromech i'm starting to feel the same.

SGKent Thu Aug 09, 2012 7:47 am

aeromech wrote: I've started a lot of freshly built aircooled engines and have never experienced the lack of oil pressure caused by pump cavitation. I've never packed an oil pump with grease either. My feeling here is that there is another problem causing the lack of oil pressure.

the issue has been discussed to ad nauseam.

As for the OP's problem, he is either sucking air or someone screwed up with the modded pump. Incidentally I personally see great danger in a modded T1 pump used in a T4 after hours spent researching it. I'd probably do an iron melling before using a modded T1 pump based on the mods I've seen in T1 pumps. Try to find a pump on the T IV store web page.

SGKent Thu Aug 09, 2012 7:49 am

velo96 wrote: I have been cranking with the sender and the plugs out. It is the old case and I did replace the o-ring. I'm using a modified type1 pump. schadeck 30mm. Desertbusman I will make that my next attempt. Aeromech i'm starting to feel the same.

your pump does not appear to be turning. However since it is a T1 pump you can get to the cover and gears to confirm they turn. You can also pack it with Vaseline and see if that helps.

Chris_914 Thu Aug 09, 2012 7:50 am

aeromech wrote: I've started a lot of freshly built aircooled engines and have never experienced the lack of oil pressure caused by pump cavitation. I've never packed an oil pump with grease either. My feeling here is that there is another problem causing the lack of oil pressure.

I am with you on this but I am also thinking he has put oil in the top side as well and could just maybe have trapped air around the pump. Two other things I will assume is the oil cooler and oil filter are filled with air, the other is the oil filter has a backflow valve. As oil was added to the sump air was pushed into the pump, as well air in the cooler and filter was pushed towards the pump from the other side when added to the galleys by way of the sender port. It's been awhile since I closely looked at the oil pressure path but I was thinking that removing the control valve would give direct passage to the pressure side of the pump and let the over-filled sump oil flow into the suction side by gravity alone. Maybe it's the oil filter that needs to be removed, one of the two should head directly to the pump. If it doesn't prime this way there is either a blockage at the suction side or a mechanical issue.

Desertbusman Thu Aug 09, 2012 11:50 am

velo96 wrote: Desertbusman I will make that my next attempt.
That should be the easiest and quickest way to get it up and running. :wink:

bugger101 Thu Aug 09, 2012 1:01 pm

Desertbusman wrote: velo96 wrote: This is my first rebuild. Any Thoughts?

What did you use as a rebuild guide? Tom Wilson's engine rebuilding book hopefully. But he would have instructed you to pack the pump.

So really it's probably a good thing you havn't gotten pressure yet and started it up yet. What startup procedure are you going to follow? It's a serious make it or break it issue. the very first breath of life most likely determines it's future.


Not everyone needs tom wilson's engine book.

skills@eurocarsplus Thu Aug 09, 2012 1:07 pm

bugger101 wrote: Desertbusman wrote: velo96 wrote: This is my first rebuild. Any Thoughts?

What did you use as a rebuild guide? Tom Wilson's engine rebuilding book hopefully. But he would have instructed you to pack the pump.

So really it's probably a good thing you havn't gotten pressure yet and started it up yet. What startup procedure are you going to follow? It's a serious make it or break it issue. the very first breath of life most likely determines it's future.


Not everyone needs tom wilson's engine book.

oh no you didn't [-X

SGKent Thu Aug 09, 2012 1:20 pm

we had a brand new T4 pump do the same thing on our rebuild twice EXCEPT that when the oil sender was out or the oil pressure relief removed it pumped up in 3 or 4 seconds. Then it had pressure instantly when the sender or relief was screwed back in and the engine cranked again. Many of us here in the T4 have bleed down issues too so I believe that the pumps are cavitating which once the air is pushed out the pump works fine. However with an aftermarket pump one has another unknown added which is how well does the pump shaft mesh with the cam. As I indicated, I think the cover will have to come off and the engine get turned a little by hand to be sure the pump spins. Then pack some Vaseline in the pump and try again.



Powered by phpBB © 2001, 2005 phpBB Group