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sump clearance
https://slantsix.org/forum/viewtopic.php?t=52969		 Page 1 of 2
Author:  '67 Dart 270 [ Tue Aug 06, 2013 8:15 pm ]
Post subject:  sump clearance
My sump doesn't touch the pan even without the gasket on the block yet. This video says that the sump should rest on the bottom of the pan. Go to 9 mins in the video.

http://www.youtube.com/watch?v=3ZvM_aoq8OI

If I loosen it out just one turn it's too loose, flops around. I'm sure this is the original sump and oil pan. Should I use a lock nut on the threads to make sure I get enough length so that the sump rests on the bottom of the pan? I think the clearance is about 1/4" between the pan and sump bottom with the gasket on.

thanks all,

BG
Author:  Sprag [ Tue Aug 06, 2013 8:58 pm ]
Post subject: 
I went with just what's shown on that video, the pan was actually held up a hair by the pickup before being bolted down so the pickup was in firm contact with the sump (engine was inverted on stand). It took quite a bit of finagaling to get it right though, I thought something was amiss at first but I kept dinking around with the rotation of the pickup tube and finally got it. It only takes a few degrees of rotation to make a noticeable difference in the pick up position so it would seem that going 'one turn' like you said is way off base to me.
Author:  '67 Dart 270 [ Tue Aug 06, 2013 9:13 pm ]
Post subject:  clearance
I meant that the tube is snugly threaded and doesn't move, and although parallel with the bottom of the pan, it's 1/4 clearance, not resting on bottom of pan. But if I rotate a full turn out so it's closer to the pan, its too loose, not snug in the threads any longer (though oriented correctly, parallel with bottom of pan).

I was thinking of using a lock nut so I could spin it out further and get it closer to the pan, then lock nut to hold it firm. Might come loose though (could use thread lock on it). Might just get a longer sump, but if anyone can tell me that 1/4 inch clearance is OK....

I hate to deviate from what Mother Chrysler says in the Master Service Bulletin video...

BG
Author:  Sprag [ Tue Aug 06, 2013 10:03 pm ]
Post subject: 
OK, I misunderstood you, sorry.

The thread is NPT (tapered) so I doubt you'll find a lock nut that fits (I hope I'm wrong though).

All I can add here is to relay my experience with other stuff and to say that if you (or other guilty party :lol: ) forces a tapered pipe thread fitting too far beyond the point that you want for the magic to happen, the thread becomes opened up or 'spread' too far to remain tight at a higher position. To fix this in other applications, I'm aware of successful attempts using thread locking compound that sets hard and holds a fitting in position without the tapered thread being super tight or 'wedged' together. That might work for you since the pickup tube really can't go anywhere once the pan is forced over it and the thread locking compound should keep the threads sealed just fine.
Author:  CNC-Dude [ Tue Aug 06, 2013 11:19 pm ]
Post subject: 
The pickup should not contact the bottom of the pan, it cant draw any oil into it if is, it needs to have at least a 1/4" of clearance off of the bottom of the pan floor.
Author:  Dart270 [ Wed Aug 07, 2013 4:40 am ]
Post subject: 
IIRC, the factory says it should contact the bottom of the pan. I always always do this to prevent rotation, and give the best chances the pickup will not be uncovered on braking/cornering/accel. There is a relief there to keep the triangular opening uncovered even when the flat part is down on the bottom of the pan. I have done this on probably 10 motor/pan builds over the last 20 yrs and have road raced, drag raced, and street driven these combos.

Lou
Author:  Charrlie_S [ Wed Aug 07, 2013 5:27 am ]
Post subject: 
The factory manual does say the pickup should contact the bottom of the pan. However I would prefer to have the pickup tight in the threads, and slightly off the pan, then to have the pickup loose. With the threads loose, it can suck air.
Author:  Sprag [ Wed Aug 07, 2013 5:44 am ]
Post subject: 
A few random pics from intergalactica to illustrate what Lou mentions, the built-in relief or offset on the bottom of the pickup that allows the rigid shield part on the bottom of the pickup to be in direct contact with the pan.

This one has the shield with the offset like our oe slant pick up. Notice how the sheet metal shield is contoured to provide space above the bottom of the oil pan so the screen is in oil:

Image


This one on the other hand, has no shield and would spell certain doom if it where flat against the oil pan (there would be no room for sucky). We would want this one 1/4" or so off the floor of the pan.

Image

Lou, I like how you said direct contact with the pan will keep the pick up from rotating, I think this will fix the problem for the op, it's not like the pick up is going anywhere once it's buttoned up (especially in my engine where I have large baffles in the pan, even if loosey goosey, the pickup would not be able to turn very far before it was up against a baffle, no way in heaven it could unscrew and fall out). I would still want something on the threads to seal them just in case but I'm probably just being paranoid with that.

EDIT - Charlie, thanks for mentioning the threads sucking air (I was typing the above ramblings when you entered your post), maybe I'm not too paranoid about using the sealer then :wink:
Author:  Sprag [ Wed Aug 07, 2013 5:59 am ]
Post subject: 
No joke, I set mine up so the oil pan would be forced into contact with the shield on the underside of the pickup. With engine upside down on the stand, the pan was basically balacing or partially floating on the pick up so most of the pan rails where slightly above the gasket until it was bolted down. I believe this is how the factory engineers designed it, the pan and pick up are married via a force fit for a few hundred thousand miles. No one is coming back to the dealer on the hook with a pick up laying in the pan.
Author:  '67 Dart 270 [ Wed Aug 07, 2013 7:36 am ]
Post subject:  clearance
Yes, I agree, it's not like it's going anywhere if I loosen it out, but I should seal the threads if so.

thanks all.
Author:  Dart270 [ Wed Aug 07, 2013 7:54 am ]
Post subject: 
I build/bend/extend mine so that the threads are tight in the block (w/Teflon tape as well) and the pickup hits the floor. Charlie's comment is right on. Air is a LOT less viscous than oil.

Lou
Author:  DusterIdiot [ Wed Aug 07, 2013 8:16 am ]
Post subject:  Yep...
Quote:
The factory manual does say the pickup should contact the bottom of the pan. However I would prefer to have the pickup tight in the threads, and slightly off the pan, then to have the pickup loose. With the threads loose, it can suck air.
I coat the threads with a light swap of RTV not really for sealing but as thread lubricant (much like plumbers to when assembling pipe runs), this helps thread the pickup in easier. I get the pick up about right and snug then do a test fit for angle and put a shop paper towel folded into quarters on top of the pickup to get a little clearance between the pickup and the pan (usually I have about one more full rotation on the pickup to take up the difference). Although the arguments are sound for putting it on the floor of the pan, I have seen a good number of slants in junkyards because we have bad roads in most areas here and one good dent in the bottom of the oil pan will close the sheet metal baffle and push the remaining screen against the bottom of the pan and starve the engine of oil and then windows the block, if the pickup is a little off the bottom it will take the dent and follow the new contour of the floor.

One last note, I also know that in certain high miler fleet applications locally that the pickup on the floor of the pan (mostly in 5.2/5.9's)
sucked up the 1/4" thick layer of coffee grounds, muck, and engine sludge from the bottom of the pan causing their demise as well, the engines were 10 years old and driven regularly and were given a monthly maintenance oil change from the pennzoil dealer in town.

2 cents.

-D.Idiot
Author:  Pierre [ Wed Aug 07, 2013 8:25 am ]
Post subject: 
One thread's worth isn't that much. I don't think that will make the difference between 1/4" and touching. If your going to have any clearance, I'd rather have a bit more and have it secure.

Move it a couple degrees either way to imagine it does loosen up. It doesn't take much for it to hit the crank. Depending on actual clearance it can move more or less.

What about heating the tube up and bending it a bit? May have to bend it in two places to make sure it stays parallel. Or cut the tube completely and weld in an extension.

Do you have a spare pickup? Maybe its the tube's threads that are worn not the block.

Edit: Woo... took me a while to post - didn't see Lou and DI's 2 latest.
Author:  CNC-Dude [ Wed Aug 07, 2013 9:26 am ]
Post subject: 
The top pic in Sprags post is typical of most pickup sumps and with the sheetmetal cover on the bottom of it provides about a 1/4" of buffer from having the screen contacting the pan floor, the other fully open pickup screen would have to have some sort of tweaking to prevent it from contacting the pan floor by the same amount of buffer.
Author:  '67 Dart 270 [ Wed Aug 07, 2013 10:25 am ]
Post subject:  pickup tube
Thanks all, no I don't have an extra pickup tube. I could cut/weld/extend, or...... I could use a thin female threaded coupler and another short male threaded piece of pipe, that would give me some distance without having to cut or weld or bend the existing. And, I agree, I'd rather have it firmly in place before I put the pan on...sleep better at night. The tube I have is in excellent shape, the screen looks perfect and I've cleaned it up all shiny like new, inside and out. Like you suggested, it's likely the threads are just worn from rebuilds, it looks like this pipe has been in and out a few times judging from what looks like vice grip marks all over it.

I don't mind a little clearance, but my 1/4 inch figure might have been conservative. I got it lined up parallel with the pan and snug in the threads, no gaskets yet and put roughly 1/4 inch high dollups of grease on the bottom of the pickup, laid the pan down on the block rails (no gaskets) and those grease blobs barely touched the bottom of the pan. With the gaskets on there it'll be a bit more than 1/4" clearance.

What's the pipe thread size of the pickup, anyone know? I'm at work, I can check McMaster Carr for collar/short pipe piece...
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