FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: justintyme73 on November 01, 2021, 09:41:36 PM
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Hey all,
Picked up a project 390 this weekend. New build, the guy I bought it from ran with a small cam for less than 500 miles, wanted a bigger cam and it failed on break in, pretty common these days, but I've never dealt with it. Gonna start taking it down this next weekend.
Can this be flushed out satisfactorily at home? if the cam bearings look ok can they be run or will there be too much metal embedded in them. What do you guys usually do?
Specs are pretty decent on the parts, I'm ahead on that even if the block would be toast. It has a balanced reciprocating assembly with JE forged pistons, supposed to be at zero deck height, 10.5 to one, Promax heads, Harland sharp rockers, new water pump, hoping to salvage it to make a decent runner
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It's a crap shoot for sure. I'd pull the pan as well and check the rod bearings on #1 and #5 as with the FE oiling system, crap in the oil from the cam would hit the front rod and main bearings first. Still, others have done the flush job if only 1 cam lobe got wiped. More than one...I'd pull the whole engine down. You should btw get a number of other opinions here. Just sayin'!
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So we have all taken short cuts, plenty of SBCs ate cams in the 80s and we changed the cam and the oil and pressed on
However, I can't say it's a great idea. The rear cam/crank passage is a 90 degree, every cam bushing could hold crap behind it, nooks, crannies, shelfs....
Easy to clean, a cheap brush kit, some air, etc is easy once you pull all the oil galley plugs
Depends on value of the engine, how lucky you are, etc. Never a good idea to have metal in the oil
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Since it is apparently out of the vehicle I would say it's a no brainer and complete tear down with removal and replacement of cam bearings and oil passage cleaning. Then you know exactly what you have. If you don't do your own work then it becomes a bit more debate-able as I am not very trusting of other peoples work.
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We are doing a 429 right now that ate 14 lobes , ruined everything for the most part , crank turn , all new bearing including cam and oil pump , oh what a mess . I would recommend complete tear down , go roller now and get it over with
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So to be clear I'm definitely taking it down, I just want to know if I should clean it out myself and I can reuse the cam bearings, or should I go all out and take it to a machine shop and have it tanked and new cam bearings installed
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At this point, for the price of the hot tank and new cam bearings that brings a lot of "peace of mind" knowing that it's clean
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I agree if its out of the car get it boiled out and new freeze plugs.
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you got a lot of decent parts with that engine,if you got it at a bargain,its a no brainer to tear it all the way down and start from scratch and in the end you will be happy knowing what you have.
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Minimum, complete tear down, clean oil galleries, new cam brgs, rod & main brgs.
You never know what's lurking in a gallery that wants to eat a main brg.
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Thanks for the advice guys, Hopefully I can get it torn down and inspected this weekend, and I will plan on just taking it to the machine shop for a cleaning and new cam bearings.
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Just did one of these that a cam went flat on about a month ago. Of course the right answer is to completely disassemble and clean it . However , how many lobes went flat ? Did they take all the material off the lifters too ? Just how much crap are we talking about ? I did the one with one flat lobe . Dropped the pan . pulled some caps . Got a nice roller from Brent and converted it and the owner couldnt be happier....
Step one dont go back with another flat tappet !!! 8)
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If there's metal, I would take it all apart - same thing I did with the first dragster 393C that ate a cam gear. Lots of fine metal in the system. I just thought it easier to wash every single part and look at every bearing shell and just start from scratch with clean parts. If it had just swallowed a bunch of water like one of my 302's did years ago, pumping several gallons of diesel through the motor with the oil pump really cleaned things up. That might be a decent pre-lim option to get as much debris into the oil filter as possible. Get a few oil filters and a 3~4 gallons of diesel. Run a gallon through for a bit, drain/change, do over.