Cam Oil Restriction Plugs

Production 289 HiPo blocks had no oil restrictors in them. Performance modifiers did many things to the HiPo. Shelby did many things to the competition 289 HiPos, but much less to the production HiPos for the GT-350 street versions.

Bo,

Marvin McAfee of MCE Engines in Southern California has written a number of articles on small block blueprinting. He uses the galley orifice plugs in his motors. You might get in touch with him and see if he sells the parts.

http://www.mustangandfords.com/techarticles/m…lding_mistakes/

Edited by - round2K on 03/08/2007 14:26:34

Try Ford Racing or Summit Racing. Are these the restricters you are referring to?

[Blocked Image: http://static.summitracing.com/global/images/prod/large/fms-m-6799-a302_w.jpg]

Edited by - kar-nut on 03/08/2007 16:13:53

Bo, If your friend is using a flat tappet cam, you may want to tell him that a lot of people are now not recommending using these oil restrictors due to the issues involving flat tappet cams and new oil formulations mandated by the EPA. There is a ton of info about this on the Bob Is The Oil Guy website. Dave.

The problem seems to be getting new, flat tappet camshafts through the critical break-in period. Engine builders all across the country were reporting camshaft failures which was finally traced to the fact that the oil manufacturers removed Zinc from motor oil. This was done for emission purposes?

Most of the present day engines use roller cam followers which do not require Zinc.

There are a number of cures for this:

1) Do not restrict oil galley passages. As much oil as possible needs to splash around the camshaft area. Street engines will never know the difference.

2) Use GM EOS (Engine Oil Supplement) This product has been around in one form or another since the 1960's. Besides Zinc, this product contains Moly.

3) Good old "STP" is said to contain the required additives. I haven’t tested this and frankly, I would have a hard time pouring STP in my Shelby.

4) Polish the bottom of new lifters with oil soaked Crocus cloth. Use Comp Cams camshaft lobe lube.

I use 1/2 bottle of GM EOS in my car at every oil change.

The oil formulation issue is a complicated subject which Bill summarizes well. From what I understand the main issue is with the critical break-in period but even broken-in cams are having problems. Part of the problem is coming from offshore inferior cam stock but evidence suggests that the reduced amount of zinc in newer oils is partly to blame.

The amount of zinc additive, or ZDDP, is being reduced because it fouls catalytic converters. The problem is our older flat tappet engines need ZDDP because it's an excellent lubricant for metal-to-metal contact, i.e. lifter-to-lobe surfaces.

Another issue is oil drain intervals. ZDDP is sacrificial, it's levels are reduced with use. If you don't drive your HiPo much and change your oil every 500 miles or so, then the new formulations probably won't be a problem. But if you drive the car a lot and extend your drain intervals past 3000 miles you might have a problem.

In addition to the solutions Bill mentions, another approach is to use heavy duty diesel motor oils like Shell Rotella T or Chevron Delo. These will work perfectly fine in our engines and still have fairly high amounts of ZDDP but even in these the levels are being reduced due to emission issues.

FWIW, I'm just crudely summarizing the stuff I've read on the website mentioned above. There's lot's of people who post there with way more knowledge on this subject.

I did a bit of research before firing off my new motor, as the subject of cams going flat due to a lack of zinc is very real if you ask machinists and cam grinders. There are a handful of additives that contain zinc to aid in break in, and to be used on an ongoing basis. Crane sells a zinc break in addiditive, and Chevrolet sells a product called EOS for the same purpose. Lucas has an additive that is also recommended due to the zinc content.

There are a number of engines that need extensive modifications to the oiling system to keep them alive at 7000+ RPM. The non-side oilier FE Ford engine we used to run in Super Stock eliminator car took some specialized drill bits and a lot of time, and these engines were using roller camshafts. The 289 doesn't suffer from these problems. In light of the present situation with the lack of critical additives in the available oil, the only thing I would do would be to be sure there were screw in plugs in the front three lifter galleys. IMHO, restricting oil to the lifters is not necessary and courting disaster.