How to kill a CJ without trying.

[Joe-JDC]

I tried to retire a few years ago, but it seems folks just keep asking for help with the old iron.  I have done three CJ iron intakes in the last 6 weeks, and hopefully, this one is the last one.  When I turned the intake over to scribe the ports, I noticed that there was some coking pieces coming out from under the tin.  The manifold had been glass beaded at some time in the past, and was painted Ford blue.  As I was finishing up the work, I turned the intake upside down and more pieces of old burnt oil coke kept falling out from under the baffle.  I decided to remove the rivets and see what was under there.  NEVER glass bead an intake manifold and not remove the baffle and clean it thoroughly before putting it back on an engine.  This is why......

Joe-JDC

[gt350hr]

  Thanks for the heads up Joe. Many have been bitten by the shot blast /glass beading thing.
 BTW  How much gain do you see for all that hard work on the ports?

[427mach1]

That could have gotten ugly in a hurry.....  Good catch and good advice.

[machoneman]

Many race engine shops, for some many years now, do not glass bead and only if needed, do crushed walnut shells or other media that dissolves. Many are the pics on the 'Net of glass beads stuck in ring lands, bearings, under tin shields, in locked-up oil pump gerotor assemblies and more.

[GerryP]

I think the most destructive device ever invented are those cleaning discs.  I'd see TV builders cleaning block decks, heads, and intakes with those discs and thinking they're going to mystified why they got a bearing knock in that build.  That carbide dust is very, very hard to clean out of parts. 

[Joe-JDC]

Average cfm for a stock C80E-C, or C90E-C iron intake is ~271 cfm.  I can pick the average flow up 70-90 cfm with diligence and time to a 1247 gasket size.  A good gasket match is only good for about 40 cfm.  I go into the ports at least 6-7 inches and straighten up and contour the flow towards the inside turn of the exits. I have not found the 1246/CJ size to benefit flow and in some instances it drops the flow because you can't keep the taper correct.  Joe-JDC

[475fetoploader]

If I glass bead an engine part, I run it through the dishwasher. No the wife doesn’t approve. But the glass is gone.

[Katz427]

Unfortunately ,after glass beading, many glass beads are broken and inbed in the surface of aluminum. I'm not sure about iron, but when you look under a magnifier the broken beads are there, plain to see. We were not allowed to use glass beads, only on any engine or transmission cases, only walnut shells. No matter how well cleaned, the darn little glass particles would eventually show up.

[gt350hr]

  +1 Impossible to get all of the glass out until heat and vibration does when the engine runs. Too late then.