Main Bearing Feed Passage Oil Restrictions

Anson, l'm not sure I follow your question about #5 main feed but I'll try to answer it.
Since #5 main only feeds one rod bearing (#1 main feeds 1 rod but has a huge passage and #2-4 mains feed 2 rods each), I feel it's not crucial to do too much to #5 feed but because #5 bearing is wider than the rest of the main bearings I open up the restricted area on that feed also. I make sure #2-5 main feeds are a clean smooth 5/16" (#5 is no different) all the way up into the lifter galley. I like to utilize the front-to-rear feed balance line since:
a: It's a simple installation
b: It helps maintain oil pressure with larger clearances throughout the engine as well as a little insurance at higher RPM
I do open the right rear galley for a 90* 3/8" pipe fitting and make sure the ID of all the fittings as well as the entrance into the rear galley of the block is consistently sized to the feed line's ID. I figure why do any of these mods just to have a fitting neck down the flow diameter. I also go as far as to use a dremel tool to "port" the inside of the 90* fittings to insure a smooth 90* flow, but then I've been accused of splitting hairs on more than one occasion. Because the 3/8" 90* fitting is bulkier than the 1/4" 90* fitting, I like to tap deeper into the block to ensure clearance to the flexplate/flywheel. Just make sure your fitting doesn't protrude into the #5 main feed passage.
As I mentioned in my original article, these mods are not nesessary for every build.
Hope this helps answer your question.

Larry

 

My plan to help oiling on my Buick 350 is this belt driven pump combined with enlarged passages as well. This way there is a nice big pickup in the side of the oil pan, which feeds to the pump then directly into the engine...

 

save yourself time and money on band aid's and spend your money once and get an aluminum block.

 

What type of end is on your 90 deg fitting. ?The in side of fitting.

 

3/8"NPT Female In, ... 3/8"NPT Male Out.
I'm not sure if you can see how I cleaned up the inside 90* of one fitting in these photos and left the other untouched.



Larry

 

I'm familiar with restrictive fittings . I do the same. How are you connecting the braided line to the fittin in pic

 

Thanks Larry,
I know you don't use braided rubber line, I'm thinking a female 45 deg flare compression fitting?

 

I used 1/2" copper tubing with compression fittings on my old 464. It worked great and was easy to bend. My goal is to maintain at least 7/16" (4.375) ID all the way throughout the entire balance line, ... including making sure the rear galley entrance is 7/16". I just have this thing about using rubber in a pressure line even though my 26 ton log splitter is equipped with hoses. I'm still going with hard lines but probably won't use compression fittings anymore as they look too industrial for my liking. I have a few ideas I'm toying with and will let you know what I'm using this time around. I have used these Aeroflow Full Flow fittings in the past and may revisit them.



Larry

 

You could Braze on a 90deg elbow fitting instead of the brass elbow. You can get long radius elbows that keep same diameter . You now I just need one more pic around the corner there

 

7/16 line seems pretty big, at what point do you think one might be pulling too much volume away from the fromt?

 

Thanks, so your using 7/16 as well? and you drill through the top. Does that line have tefalon tubing in the midddle

 

Here is a photo of how the back looked. I drilled and tapped the bottom of the 90* fitting for a 1/8" NPT oil pressure line fitting, .... then ran a copper line to the left side and installed a fitting at the bell flange. That way everything is pretty much out of sight. After hanging around one of the larger hot rod shops in the Midwest.... (StreetWorks Hot Rods) for the past 5 years you get used to hiding lines/hoses/wiring as much as possible for that clean look. The other photo is as the engine was run 20 years ago and you can hardly see any more than necessary (as far as the balance line goes). Now that I'm completely redesigning the whole look of the engine bay it should be even more uncluttered and No More Red/Blue fittings or hoses for "Bluzilla". I'm going to cut back on the Chrome stuff and do away with the silver braided lines. Funny how less is more as I get older.



Larry

 

I just thought I would mention that the exact same type of restriction the cam bearings pose on the main bearing feed passages is present in the main lifter galley, .... behind each lifter where the lifter bore protrudes into the galley. Slide a lifter in #8's exhaust lifter bore and look in from the back of the block into the right galley and you will see what I'm talking about. No wonder #7 rod bearing can be problematic for some, especially when the rear section of the galley is necked down from 1/2" to 7/16" along with the lifters squeezing down the ID. Once again, this doesn't pose an issue most of the street driven applications.

Larry

 

Nice pics. Have you ever done a front rear before and after pressure test comparison. ? I would be curious to see how much the fromt goes down. I will be finding out hopefully one of these months before any more years go by geting mine back together. All this information really helps though. I have a street driven application but when im on the freeway there is always some opening that I have to floor it. I will even take the long late nite freeway loop home from work just to floor it.
Looking at this motor from the bottom 455 1975 block, makes me wonder how you hone it with the main webs so close.

 

I'm thinking its being diverted from the front , so the front would go down by a little bit.