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#17749 01/15/2004 2:00 AM | Joined: Jan 2003 Posts: 48 Apprentice | | Apprentice Joined: Jan 2003 Posts: 48 | Hi, I have a '48 235 in my '47 1 ton. It has low compression and hit 95% on a leak down test. It smokes like a 747. Otherwise it runs fine... Anyway someone suggested that I use synthethic oil to reduce the smoke. I gather synthetic oil does not produce white/ blue smoke when it burns. I realize it would be a cosmetic fix only, but it would certainly be quicker and cheaper than a repower.
I know this has been discussed before, but here's the question: Should I pour in the synthetic or will it loosen up 55 years of crude and blow the engine?
Any advice, opinions, etc. appreciated.
Wilber
Don't read the directions, that'd be too easy.
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#17750 01/15/2004 4:00 AM | Joined: Mar 2000 Posts: 1,182 Red dot, center of chest ... | | Red dot, center of chest ... Joined: Mar 2000 Posts: 1,182 | About all you will get with synthetics is opinions.  Having said that, I've never personally used it, so I'm not qualified to comment from experience. I believe, however, that it would consume more oil because of the worn cylinders and rings. Synthetic flows more freely than petroleum oils, so I would expect it to get past the rings more easily. I guess you could try it and see what happens. And let us know.  | | |
#17751 01/15/2004 4:10 AM | Joined: Jun 2000 Posts: 2,773 'Bolter | | 'Bolter Joined: Jun 2000 Posts: 2,773 | Paul's right about synthetics.
Don't know what you have in it for oil now. I'd start by using a straight oil, SAE 30 or 40, depending on how far north you are. Also, put in a can of Restore, it might help. If not, I'd go with STP, but put it in a hot, running engine. I hate the stuff, but consider it a last resort to put off a rebuild.
Fred
52 3600
69 C-10
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#17752 01/16/2004 2:13 AM | Joined: Jan 2002 Posts: 622 Member | | Member Joined: Jan 2002 Posts: 622 | Why don't you just rebuild the motor? Burning synthetic oil will get expensive......
delete my account and pictures
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#17753 01/16/2004 5:35 AM | Joined: Jan 2003 Posts: 48 Apprentice | | Apprentice Joined: Jan 2003 Posts: 48 | I don't want to rebuild THAT engine as it has babbit bearings and everyone seems to agree that it would be a waste of effort, money, etc. I will repower the truck sometime but I have to find a good donor first and wait for the leaves to come out in the backyard - I am strictly a shade tree mechanic.
In the mean time I will try the various additives and synthetic oil and report back with my findings. The PO said he ran detergent oil and there is no crude on the stick, so it is worth a try.
Thanks for the comments.
Wilber
Don't read the directions, that'd be too easy.
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