Early 265 Chevy V8's...

I think Roothawg has the answer, and it might be the cause of the problem. If it has a 57 carb, then someone may have put a Duntov cam from a 57 in it and it doesn't have the notch on the rear cam lobe for oiling and that might be the cause of the problem. The motor has to come down anyway so pull the cam and see if the rear lobe has a good sized notch in it to pick up oil. If not you have the source of the problem. I remember the pain of finding this out in 1956.

 

There was no notch in the cam, first thing I saw when I got over there. Hes got it in the shop now and we'll see where it goes from there. Everything else looked good.

 

In the picture above: The ram horn exhaust is a little bit later. Also the 55 intake was a one off year. The temp. sending unit was mechanical and at the rear of the intake on drivers side.

 

Do the .040 replacement pistons have valve clearance notches ? Would be interesting to know if was built up before the 283 became easy to find.
Thanks,
302

 

Does abyone re pop those valve covers?

 

Does anyone have a picture of the notch that is supposed to be in the rear of the cam or maybe a better description on how to modify a later model cam to work?

thanks,
Roger

 

I need a pic of that too!!!

 

Roothawg hits a likely culprit here. These motors, when built right were durn near bulletproof. Never had an oil problem and they would turn good revs all day.

 

Eckler Cl***ic Chevy has a very good explanation of the oiling differences between early and late 265 blocks. Do a search under "265 Chevy cam notch" . My '57 265 block has a circular groove that allows full oiling without the cam notch. Early blocks required the use of a rear cam bearing that had two holes, these had to line up with oil galley holes in the cam bearing bore. Later bearings while the same exact size would cover one or the other of these two holes! So even if the cam was notched oiling could still compromised. Eckler's article shows how to modify the block to remedy the situation. Good Luck!!

 

55 265s had a slot or groove machined in the back of the camshaft for oiling the lifters,at least the engines with hydraulic lifters did,im not sure if solid lifter engines did,or if the 56 and 57 265 had a camshaft like the 55,but i think that it did,i have had to kick a blonde and a redhead out of my head to recall this stuff, hope it is appreciated

 

Both styles of '55-'56 camshafts had the oiling notch in the rear journal, but the notch in the solid lifter cams is smaller. Also, a '55 engine with a solid lifter cam isn't automatically a Corvette engine. Early '55 265s all had mechanical lifter cams until overzealous drivers overrevved them and pulled the rocker arm studs out of the heads, at which point Chevrolet went to hydraulic cams as a built in governor of sorts. If you compare a '55 head to a '56 head, the '56 head will have taller rocker stud bosses for increased grip range in an attempt to avoid stud pulling.

 

It looks like the first thing he needs to do is find out exactly which block he has.

It was a normal hot rod thing for guys to swap in a 30-30 cam in these engines back in the 60's. Most Chev parts counter guys didn't even have to look the number up because they sold so many of them. And the cost over th counter at the local Chev dealer was pretty close to 30 bucks at the time.
You did have to have notched pistons or the valves hit the pistons though.

What Brandy was saying is that these aren't "rare" engines that you have to go to the rare engine parts supplier and pay three prices.

Several online suppliers sell pieces and complete rebuild kits for good prices or you can walk into parts houses like CarQuest or Napa and order the parts.

If the engine ends up being junk, drop in a later smallblock and go cruising.

 

Does anyone have a picture of the notch that is supposed to be in the cam?

 

Its just a flat spot on the round journal

 

Get the #'s and go to Mortec.com.

 

So, is the flat spot just in the center of the rear cam journal, say about 1/2" long and maybe 3/16" wide as if you just milled a small flat on the journal using a milling machine?

The reason I ask is because I have an original 1955 265 that will get a modern hydraulic cam, but I do not have the original mechanical cam that cam in it to look at to modify the new cam. The engine has already been rebuilt so I do not want to take the route of slotting out the internal p***age in the block.

 

I just took a quick measurement of the slot on the rear journal of a used 265 hydraulic cam I've got lying around. It is .500 wide, 1.180 long, and .200 deep. Remember, a mechanical lifter cam had a much shallower and shorter slot.