351 Cleveland Oil Restrictors – 351C Oiling Fix

related Hot Rod article

https://www.hotrod.com/articles/hrdp-1205-351-cleveland-oil-restrictors-351c-oiling-fix/

Is this really necessary for a performance build?

Ray

Conventional wisdom back in the 70's and 80's was that Ford put extra oiling in the top end to make the engine quieter for Grandma. When I was weekend racing, I had the oil restrictors installed and ran a high volume oil pump with high pressure spring. I wanted more oiling in the bottom end, where things get ugly in a hurry if you don't keep it oiled. We didn't have the special cam bearings and push rods then, at least that I was aware of, but that seems a lot simpler way to accomplish the same thing.

Steve

Tim Meyer has the trick cam bearings for Clevelands.

With regard to High Volume oil pumps, I had a situation when my very experienced engine builder decided to install a HV oil pump in my 351C 4V with hydraulic lifters and mild Melling cam. That build lasted only about a couple of summers before I started having high oil loss/usage . Not thinking there was anything major wrong, maybe just the valve guide umbrellas going bad, it finally got to the point when I took it back to the shop. Upon stripping it down, they found that the first two cam lobes,  lifters, main bearing and rod bearings where totally shot. No other mods were done. So after doing some research, it was obvious that the HV pump was the reason. Fortunately the shop stood behind their work and rebuilt the motor under warranty, but this time with a standard pump. The total damage was all main bearings , cam bearings, cam and lifters. At this time I also removed the flat top KB pistons and installed KB dished pistons to drop the compression to 10:1. As for the valve guide seals, they installed a newer type that have springs in grooves around the stem (if you can picture that!)

That was coming up to 5 years ago and since then zero problems. The motor pulls strong and uses very little oil per season, about 1500 miles or so.

That was my experience with an HV oil pump that likely was not set up right and was totally not needed in a stock rebuild. Okay, I know, next time take it to a Cleveland rebuilder!! Hopefully there won't be a next time.

Geoff.

I just had my engine rebuilt and decided not to go with the lifter bore bushings. But I did use the thick wall pushrods. Reason I didn’t use the bushings is cause the lifter bores were in good shape and I won’t be running over 6000 rpm very often, so I didn’t really see the need to.

I also went with a std. volume oil pump and the reason for that is because all of my bearing clearances are normal. No need for a hv pump.

One thing that I did not see mentioned in the article. They did not say anything about the clearance around the lifters. A tremendous amount of oil comes out around the lifters with a wet lifter galley.

That was one of the first areas my old boss looked at was the lifter bore clearance. He had contact that he could get lifters ground to fit and did not have to put the bronze bushings in like most do.

The lifters are ground on a center less grinder and only take seconds to grind. You do not have to set up each lifter like grinding a crank shaft you just feed them into the machine.

If you know someone with a grinder you can get the lifters either hard nickel plated or hard chrome and then you hone the lifter bores to a given size and grind the lifters to fit.

On the high volume oil pumps and also high pressure. On the racing engines we worked on you would actually see the oil pressure wash out the bearing surface like a small ditch would wash out with water. Once it started it was over.

Racing engines have a very short life at best.

No expert on the oiling for the racing but for street I would only check the lifter clearance, use the restricted cam bearings and maybe the pushrods.