Your engine has a stock 2-4bbl setup? Can you send pics?

As for the oiling issue, here is a link: http://www.trifive.com/forums/showthread.php?t=11342

This should answer alot of questions if you look through all of the pages. It includes the areas that need to be machined to make it full-flow oiling.

 

Your engine has a stock 2-4bbl setup? Can you send pics? No dual 4's, a single stock 4 bbl wcfb with dual exhaust.

As for the oiling issue, here is a link: http://www.trifive.com/forums/showthread.php?t=11342

This should answer alot of questions if you look through all of the pages. It includes the areas that need to be machined to make it full-flow oiling.

I read thru this post, but the only mention I see about the cam oiling is that if you align the 2 holes in the rear bearing with the block oiling holes, you can then ran a sb cam without the flat surface! Is that truly the only issue? Thanks

 

Mine was ground such that the two holes were connected. Not sure if that helps.

Ahh... no 2x4bbl... got it. Thanks!

 

Here is a picture a 327 with the rear cam bearing removed. Notice how all three holes from the oil galleries are connected by the annulus (ring) machined into the block. High pressure oil from the main gallery flows around the annulus on the backside of the cam bearing and out to the lifter galleries. The main difference between the 265 and the 327 oiling is the location of the hole from the main oil galley. The yellow dot is where the passage from the main oil gallery on the 265 is drilled. You can see that if you install a standard cam bearing in a 265 the oil supply from the main gallery will be blocked off and no oil will get to the annulus or out to the lifters. The modification consists of grinding a groove between the high pressure oil hole (yellow dot) and the annulus machined in the block that feeds the lifter galleries. The groove needs to be made big enough to provide a sufficient supply of oil to the lifters. You can do this yourself or have your machine shop do it.

Now you can install a standard rear cam bearing and use any standard small block cam and lifters in your 265.

 

Where does the yellow dot go?

 

Where does the yellow dot go?

Watchdog - The yellow dot needs to be connected directly to the annulus.

Hey Ed, is there any chance you could post a picture of the area under the rear cam bearing on your 265?

 

A picture of your block would be a great addition to this thread. Everyone running an original 55-56 V8 needs to know about the oiling issue with these engines. With the addition of the pictures the administrator might even make this thread a sticky. :tu

You are correct about the cam plug being knocked out from inside the block. A length of pipe through the cam bore and a BFH should do the trick. Once the plug is out of the way the rear cam bearing can be driven out from either side. A socket or a piece of pipe that is slightly smaller than the cam bearing O.D. can be used as a driver.

I will be pulling and rebuilding the 265 that’s in my car this summer. I plan on doing the oiling mod to it (if it has not already been done).

Here is a Chevrolet drawing of the stock 265 oiling system for your viewing pleasure:

 

Ok, here are 2 pictures of the 265 block rear camshaft bearing. The first is with the cam bearing still installed. You can see the 2 holes in the bearing.

The second is with the bearing removed.

Steve I'll let you explain how the oil flow works rather than attempting it myself. If you want me to forward the pictures direct to you, let me know Thanks a lot. Ed

 

Thanks for the pictures Ed. :tu:tu:tu

 

Here is a picture of a '55 cam with the 'flat' surface on the rear journal.

 

Question.
I am using an oil priming tool to get pressure up to my rockers. I can get great pressure (50 psi) but nothing to the rockers. I am getting oil filling up the distributor hole though:


IS this just because the priming tool is not sealing well against the oiling hole in the distributor shaft or is this normal?

Does the motor need to be rotating to get oil up to the rockers?

Thanks guys.

 

Does the motor need to be rotating to get oil up to the rockers?

You won't get oil to the rockers with the primer tool. If you have 50 lbs. of oil pressure you are good to go. You will get oil to the rockers when you fire it up.

 

Eldon - Your primer tool needs a bushing with a groove like the one in the picture to build oil pressure in the lifter galleries. Without the bushing you will have a major leak where the lifter gallery intersects the distributor hole.

 

Here is the one I am using. I wonder if it is just off a little bit, enough so that it doesn't give proper sealing. Could there be another problem?

 

Ahhhh.... that is good to hear. Thanks you! You made my my day!

 

Hi all Zac from far down under , i have posted meny question in the past on this site about the 265 motor and how to get oil up to the rockers .
As we did not have Chevs with v8 in them till the early 60's. I found out by myself trial and error .
I did ever thing that has been talked about on this site , but still got a real rattle at 80 kms and on startup .
But now it is just great , as i made the slot in the cam a bit deeper to throw more oil up and then put a mellings high volume oil pump in "END OF PROBLEM".
Do'nt forget the 265 oil pump is 3/4 of a inch longer that 283/350 oil pumps, and sumps are a bit deeper on the 265 , but just keep lots of oil in the 265 sump as i do .
Hope this helps and save you lots of money for i had 2 motor re builds and new parts just to find this simple problem solved by $45.00 oil pump.

 

I put a custom-ordered comp cam in mine and rather than cut the oiling groove in the cam like original, we decided to try cutting the groove in the cam the ENTIRE circumference rather than just the flat spot like original. That way oil can get to the rockers 100% of the time, rather than maybe 25% of the cams revolution. Theoretically the rockers would still oil with the cam standing still. This also means no modifications to the block are necessary. I have 30 psi at idle with 5w30 oil.

 

265 cam



I agree .. The groove should be all the way around the cam for constant oiling. I had one machined for my 265 ...BQ

 

Ok, how about this. The bottom of the original distributer has a groove cut half way around it which I assume is for oil to pass around yet all later model gm distributers have this groove "all the way"around. Can a later model distributer be used safely in a 265? also, I just rebuilt my 265 and went all stock on the bottom end and even had the original type slot cut in the cam but noticed that when I step on the throttle hard and the motor revs past maybe 4000rpms there is a loud rattling that sounds like lifters. Is this the oiling problem this thread is all about?

 

Yes. A 1957 and later distributor will work fine in a 265 without any modifications.

also, I just rebuilt my 265 and went all stock on the bottom end and even had the original type slot cut in the cam but noticed that when I step on the throttle hard and the motor revs past maybe 4000rpms there is a loud rattling that sounds like lifters. Is this the oiling problem this thread is all about?

Are you getting oil to the rockers? If you are not getting oil to the rockers you may not be getting oil to the lifters and may have a problem with the rear cam bearing. If the rear cam bearing is installed to deep or to shallow the holes in the cam bearing won’t line up with the slot in the cam and the lifters will starve for oil.

I test fit my rear cam bearing on the camshaft before I installed it. After I install the cam bearings into the block I bolted the sprocket to the cam shaft and test fit it to check the position of the rear cam bearing. The thrust surface on the sprocket is held against the front of the block by the rearward pull of the distributor/oil pump gear so with the sprocket installed and the camshaft all the way in the camshaft will be in the correct position to check the rear cam bearing.

The machine shop that rebuilt my 265 installed my cam bearing almost a 1/4 inch too far back. They also used a deep 2 inch freeze plug for the rear cam plug which kept my camshaft from going all the way in. The combination of the incorrectly installed cam bearing and the deep freeze plug would have caused the camshaft to not line up with the holes in the cam bearing.

55-57 Chevy V8's used a thin cam plug that measures 2 1/64 inch. Starting in 1958 Chevrolet went with a slightly larger diameter cam plug. The Dorman part number for the correct 55-57 cam plug is 555-046. The cam plug should be installed flush to 1/32" deep with the boss on the rear of the block.

To get it right I bought a cam bearing tool, the correct rear cam plug, and some new cam bearings and installed them myself. I hate to think what would have happened if I had of installed the engine in my car the way I got it back from the machine shop.

 

well , it only rattles when I run it at high rpm. it has about 250-300 miles on it now and the lifters are nice and quiet when driving normally but when you stomp it to the floor and passing gear kicks in and the revs get way up there, it sounds like someone shaking a coffee can full of rocks:confused0006: the instant you are back to normal rpms, its nice and quiet again. seems like if the lifters weren't getting oil it would be rattling at idle and would have locked up by now.

 

This sounds like severe detonation to me.

PR

 

Pull a valve cover and check if you are getting a good flow of oil at the rocker arms. If your rocker arms have a strong oil flow your lifters must be getting oil also, and something else is causing your rattle.

If the oil to the rocker arms looks weak you could have a partial blockage at the rear cam bearing. Hydraulic lifters pump more oil to the rocker arms at high engine speed. Notice how one of the cam bearing holes is partially blocked off in this picture. This would pass just enough oil to the lifters for idle and low speed but would starve the lifters for oil at high speeds. It’s critical that both cam bearing holes are lined up perfectly with the slot in the cam journal on these early engines.

While the valve covers are off it would not hurt to readjust the valves.

 

thanks for the help:wavey:

 

FarmBoy
you are a wealth of knowledge....thanks for all the wonderful posts
:congrats: :shakehands:

 

Steve,

If the front oil supply port that normally goes to the accessory oil filter has good pressure, the rockers / lifters should have good pressure too, correct?

 

No as the front oil supply is above the cam in the center. The lifters are oiled by the 2 side supply lines. In the back of the block there are 3 pipe plugs where the supply lines are. I had a 55 265 block that I installed a later model dual point distributor and lost the oil pressure to the lifters at wide open throttle. I took off the intake 2x4 by the way and drilled into the top supply line and tapped for a T . Then I drilled into the side supply lines and ran a tube to each from the T . Sounds crazy but it worked and the lifter noise went away. I can't imagine what someone thought when they removed the manifold. That was in 1979. I found out later about the 265 distributors being different and it had to be installed in a specific orientation to work properly.

 

Do not know Eldon, but Farm Boys post helped me greatly over 15,00 miles. :shakehands: See you at BG. :anim_25: :bowtier:

 

In order to get oil to both heads / lifters, the distributor HAS to be installed correctly. The distributor cap hold down clips MUST be perpendicular to the crank centerline.

When I was priming my 56 a while back, I used an old 55 distributor with the distributor drive gear teeth ground off.

I noticed that I could shut off oil to one or both cylinder heads just be rotating the distributor housing.

With the hold down clip perpendicular to the crank centerline, both heads got oil. Rotating the housing slightly shut off oil to the passenger side cylinder head. Rotating the housing a bit more shut off oil to both heads.

 

Ahhhhh, ok. Sounds like I need to go ahead and get a 55 distributor. Thanks guys!