mack31 Posted February 12, 2011 Share Posted February 12, 2011 The Yeadon Fire Co. in Delaware County PA aquired their 1948 Mack 85LS. I need to know what kind of motor is in it. All I could find is Thermodyne. When running the motor oil shoots out of the oil fill. Need some help finding what might be wrong. Thank you. Quote Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/ Share on other sites More sharing options...
Rob Posted February 12, 2011 Share Posted February 12, 2011 The Yeadon Fire Co. in Delaware County PA aquired their 1948 Mack 85LS. I need to know what kind of motor is in it. All I could find is Thermodyne. When running the motor oil shoots out of the oil fill. Need some help finding what might be wrong. Thank you.Does the engine run alright? I've seen that symptom when the crankcase is overfilled, or a piston busted through the compression ring lands pressurizing the crankcase. Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72683 Share on other sites More sharing options...
mack31 Posted February 12, 2011 Author Share Posted February 12, 2011 It ran great but they try not to run it much as the oil comes out under pressure and makes a mess Quote Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72684 Share on other sites More sharing options...
Rob Posted February 12, 2011 Share Posted February 12, 2011 It ran great but they try not to run it much as the oil comes out under pressure and makes a messAre you talking a pencil stream, or a mist coming from the oil filler?Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72685 Share on other sites More sharing options...
mack31 Posted February 12, 2011 Author Share Posted February 12, 2011 I havent seen it done myself I just saw the aftermath. They stated it came out of the oil fill and it was all over the running boards. Quote Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72687 Share on other sites More sharing options...
Rob Posted February 12, 2011 Share Posted February 12, 2011 I havent seen it done myself I just saw the aftermath. They stated it came out of the oil fill and it was all over the running boards.Make certain the "road draft" tube that runs from near the top of the engine, (usually in the valve cover if overhead valves) down the side of the engine and discharges to air under the vehicle is not plugged. If this pipe is plugged, crankcase pressure builds and will force oil out the breather cap in the valve cover. This can be a mess. I've seen small rodents plug these which are usually about an inch in diameter.If you are streaming oil out of the breather, oil fill, or dipstick tube, there is a problem either in the filter, regulator, compression in crankcase, or over fill.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72688 Share on other sites More sharing options...
fifth wheel Posted February 12, 2011 Share Posted February 12, 2011 It could have one of these engine models, EO 519 ci, EP 611 ci, EY 707 ci.FW Quote Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72690 Share on other sites More sharing options...
mack31 Posted February 12, 2011 Author Share Posted February 12, 2011 Is there a way to tell the difference Quote Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72692 Share on other sites More sharing options...
fifth wheel Posted February 12, 2011 Share Posted February 12, 2011 Engine number on block right front gear case boss.FW Quote Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72693 Share on other sites More sharing options...
fxfymn Posted February 12, 2011 Share Posted February 12, 2011 Is there a way to tell the differenceAccording to Harvey Eckert's book "Mack Fire Trucks 1911-2005" all LS85's were equipped with the Thermodyne 707 gasoline engine.Send the chassis number to the Mack Museum with a request for all the information they have on the truck. You will find the chassis number affixed to the base of the officer's seat or attached to the plate behind the shift on an open cab model. If it is missing it is stamped into the frame adjacent to the left rear wheel. It should be "LS85-10.." They will send you the engine type and serial number along with any applicable manuals they have within a couple of months. They do not charge for the service, but a reasonable donation is appreciated to compensate for the cost of the research.If you still need to confirm the engine model right away, and you can not locate the SN on the block, I would call the museum to see what they could give you.Have you done a compression or leak-down test on the cylinders yet? If you are concerned about blow-by the first test is a compression test, followed by a leak-down test if the compression is marginal or varies greatly from cylinder to cylinder.Just remember: When you are troubleshooting an issue the big stuff jumps right out at you; otherwise its usually something minor that you have overlooked because you have convinced yourself that the worst case scenario is inevitable. In other words don't go looking for a blown cylinder because its probably a plugged hose.Everybody here loves to see pictures of anyones find. Quote Money, sex, and fire; everybody thinks everyone else is getting more than they are! Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72706 Share on other sites More sharing options...
hunior Posted February 12, 2011 Share Posted February 12, 2011 (edited) Hey! Your Thermodyne will be either a 510A or 707A, I found my number on the upper front of the motor (right/passenger side).Mine is ENF 510A 52-74. Hope this helped. Edited February 12, 2011 by WECO1MACK505 Quote Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72725 Share on other sites More sharing options...
mack31 Posted February 13, 2011 Author Share Posted February 13, 2011 Thank you for everyones help i will let you know how i make out and i will post a picture. Quote Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72772 Share on other sites More sharing options...
fxfymn Posted February 14, 2011 Share Posted February 14, 2011 One other tip; The "road draft" tube is just that; its designed to create a venturi effect to purge the crankcase when the rig is driven. It doesn't work when the rig sits idling beyond just allowing pressure to escape the crankcase. This alone shouldn't cause the oil puking you described, but you need to be aware of this so you know there may be vapors present in the crankcase when the truck sits idling.A real long shot; Did anyone add a PVC valve to the engine and plugged the road vent to make it work? If so make sure the PVC is not plugged. Quote Money, sex, and fire; everybody thinks everyone else is getting more than they are! Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-72911 Share on other sites More sharing options...
mack31 Posted March 4, 2011 Author Share Posted March 4, 2011 The only numbers I could find on the passenger side front of the motor were 5000 and 500005. Any ideas? Quote Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-73949 Share on other sites More sharing options...
Art Lawrence Posted March 8, 2011 Share Posted March 8, 2011 The best thing to do is to take the serial number and contact the Mack Museum. They can supply you with build sheets and sometimes delivery photos....ArtThe Yeadon Fire Co. in Delaware County PA aquired their 1948 Mack 85LS. I need to know what kind of motor is in it. All I could find is Thermodyne. When running the motor oil shoots out of the oil fill. Need some help finding what might be wrong. Thank you. Quote Art Lawrence arthur.lawrence@firetruck.com Gaithersburg, MD Link to comment https://www.bigmacktrucks.com/topic/17945-need-help-with-an-85ls/#findComment-74188 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.