Early Ford V-8 Club Forum

EFV-8 Club Forum / General Ford Discussion / Main bearing seized

Reply to Discussion | New Discussion << previous || next >>

Posted By Discussion Topic: Main bearing seized -- page: 1 2     BMora 06-28-2010 @ 12:22 PM reply profile send p.m. Member Posts: 30 Joined: Oct 2009 My main bearing seized up and marked the crank. The engine is undergoing a rebuild and just wanted to make sure that I wasn't being over or undersold on what should be fixed. Obviously the bearing needs to be replaced and the crank has already been corrected. All gaskets will be replaced. Is there anything else that I need to be aware of? 37RAGTOPMAN 06-28-2010 @ 1:50 PM reply profile send p.m. Senior Posts: 1961 Joined: Oct 2009 make sure ALL your oil holes in the cam bearing and main brg's inserts are lined up and have the block boiled out and blow out all the oil holes. and get the LARGER OUTPUT oil pump, and make sure the cranks spins in the block before you install the rod and pistons, try not to overlook anything, hope this helps 37RAGTOPMAN KEEP ON TRUCKIN,,, supereal 06-28-2010 @ 4:21 PM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 A seized bearing always is due to lack of oil, or insufficient clearance when assembled. It is likely that the oil passages in the crank are filled with sludge and other crud. Have the shop open the crank and hot tank it, followed by probing the passages to loosen any deposits. The openings should then be tapped and fitted with plugs when done. We did an 8CM Merc crank last year that was almost completely plugged. Inspect all old cranks to see if they are clear. We then check the balance to be sure it is within tolerance. FrankM-RG5 06-28-2010 @ 4:54 PM reply profile send p.m. New Member Posts: 135 Joined: Oct 2009 make sure that I wasn't being over or undersold on what should be fixed. You really need to give us more info. Was this a fairly fresh rebuild that failed or a high mileage engine that finally gave up the ghost? Or maybe it jusy got over revved. As others have said you need to make sure all passaes are clear both in the block and the crank. Sometimes when you get into things enough you get a "while I am here" approach to freshening up things like valves and rings. BMora 06-28-2010 @ 5:47 PM reply profile send p.m. Member Posts: 30 Joined: Oct 2009 More Info: Oil starvation is suspected due to 60 years of sludge build up. Engine low mileage (7,500 miles) Never rebuilt, only 2 valve springs replaced. Block has been tanked (cleaned) and primed, no cracks detected, will be pressure tested. #2 cylinder has pitting so a re-boring/honing of all the cylinders has been prescribed. All pistons and rings to be replaced (few cracked rings found along with normal flathead cracks in the sides of pistons). Valves to be replaced with adjustable valves for sake of rebuilding process ease; nobody wants to file away anymore (have heard that some of these are too soft and could be problematic?) Everything else better than expected by shop, due to low mileage. supereal 06-29-2010 @ 3:46 PM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 Did read that right, only 7,500 miles in 60 years? I have seen that before only in old fire trucks. The worst thing to do to an engine is to seldom drive it. We try not to start any vehicle unless it can be driven at least ten miles. This burns off the moisture in the oil pan and exhaust system. Given that many old engines used non-detergent oil, and often sat for long periods, it is a wonder any of them survived. It is a tribute to the early engineers who designed them to be overbuilt. It certainly isn't that way today. BMora 06-29-2010 @ 4:25 PM reply profile send p.m. Member Posts: 30 Joined: Oct 2009 You read that right, and you are correct, it is a fire truck. TomO 06-29-2010 @ 6:00 PM reply profile send p.m. Senior Posts: 7253 Joined: Oct 2009 You should have all valve springs replaced while the engine is being rebuilt. I would go with the 80 lb oil pump,a new pressure relief valve and a new oil pressure sender. The cam bearings should also be replaced after hot tanking an engine. Low mileage on a fire engine does not always mean that there are low hours on the motor. Fire engines are driven short distances to a fire, but then the engine either idles while the fire is extinguished or runs a pump to pump water. Tom 37RAGTOPMAN 06-30-2010 @ 6:15 AM reply profile send p.m. Senior Posts: 1961 Joined: Oct 2009 If the engine is hot tanked, replace the bearing like TOM O said the hot tanking eats the bearing and desolves them, if left in there overnight for sure, AWAYS replace the CAM BEARING when you have the engine apart,this is were you loose oil pressure if worn, 37RAGTOPMAN KEEP ON TRUCKIN,,, ANY AUTO MACHINE shop has the SPEACIAL TOOLS if not LEAVE BMora 06-30-2010 @ 11:51 AM reply profile send p.m. Member Posts: 30 Joined: Oct 2009 Does the oil pump and line flow to the cam shaft and keep it flooded with oil at 40lbs of pressure? I thought that the oil pump pumped it front he pan to the filter and then back into the pan?

<< previous || next >>

PAGE: 1 2

NOTE: YOU MUST BE A REGISTERED USER AND BE LOGGED IN TO POST (and reply to) messages in this forum. If you are a first time user, please click the CREATE A NEW ACCOUNT in the masthead above to register and Log In. After that, all you do is LOG IN to enjoy using this site.

DISCLAIMER: The V-8 Club does no independent testing of any of the opinions, thoughts or suggestions presented in the website on the Forum, in the Tech Tips section, or any section. A reader should consider the website to be a forum wherein differing solutions to a particular set of circumstances may be discussed. Ultimately, the selection of an item for an individual's vehicle must be based upon the independent study of the vehicle owner in consultation with people in the hobby and restoration experts.

EFV-8 Club Forum Home | Back to Home Page | Contact the Webmaster

Copyright © 2009 - EFV-8.org
Powered by < CF FORUM > v.2.1