suprmn Posted October 9, 2012 Share Posted October 9, 2012 I have done a significant amount of searching and cannot find answers to these questions.Truck is a 1961 B613T, 673 with a quadraplex,Does anyone have valve adjustment specs and procedures for a 673? I purchased a book that says to do it with the motor running. My preference would be to do with the motor off, so I am hoping there is an alternate procedure.I have been looking for rebuild kits for this motor and the only think I can find says "maxidyne convereted" Does anyone have any idea what that means?I am starting to see many posts that recommend not rebuilding this engine. I just purchased the truck and have not completely assessed the motor, I do know it is not the original motor to the truck, at least that is what the last owner said. But the blowby is pretty high and it was a working truck so I think the motor is tired. I am working on a restoration, but it will be as a personal toy for me more than trying to make it period correct. I would consider an upgrade in motor if it made sense. What would be the recommended motor for replacement?I would like to convert this to spin on oil filters. Any suggestions for a kit to do this?Thank You for your thoughts. Quote Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/ Share on other sites More sharing options...
39 Baby Mack Posted October 9, 2012 Share Posted October 9, 2012 As far as the valve adjustment goes the specs. used to be Intake .016" cold static or .014 hot running Exhaust .024 cold static or .022 hot runningThe trick is there are no marks on the dampener to set the valves statically.I used to use a belt that I made up that would slip snugly around the dampener with three lines marked on it spaced 120 degrees apart from one another.After barring the engine over by hand and watching the injection timing marks on the flywheel I would set the motor at T.D.C. on #1 cylinder.I would then slip my belt on the dampener and using a magnetic dial indicator base on the timing gear cover move the belt and base till they would line up with each other.Now you have marks to set the valves with.Start setting the valves with #1 where you are at to start with then bar engine 120 degrees in normal rotation (clockwise looking from front) to next mark andset valves on #5 and continue on in firing order 1-5-3-6-2-4.Ron Quote Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-141022 Share on other sites More sharing options...
terry Posted October 9, 2012 Share Posted October 9, 2012 I have done a significant amount of searching and cannot find answers to these questions.Truck is a 1961 B613T, 673 with a quadraplex,Does anyone have valve adjustment specs and procedures for a 673? I purchased a book that says to do it with the motor running. My preference would be to do with the motor off, so I am hoping there is an alternate procedure.I have been looking for rebuild kits for this motor and the only think I can find says "maxidyne convereted" Does anyone have any idea what that means?I am starting to see many posts that recommend not rebuilding this engine. I just purchased the truck and have not completely assessed the motor, I do know it is not the original motor to the truck, at least that is what the last owner said. But the blowby is pretty high and it was a working truck so I think the motor is tired. I am working on a restoration, but it will be as a personal toy for me more than trying to make it period correct. I would consider an upgrade in motor if it made sense. What would be the recommended motor for replacement?I would like to convert this to spin on oil filters. Any suggestions for a kit to do this?Thank You for your thoughts. Quote Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-141035 Share on other sites More sharing options...
terry Posted October 9, 2012 Share Posted October 9, 2012 They are a real easy engine to adjust the valves while running, and the maxidyne converted i believe is maxidyne liners with the heads scored for the fire rings. terry Quote Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-141036 Share on other sites More sharing options...
theakerstwo Posted October 10, 2012 Share Posted October 10, 2012 Here is the way to set valves on a 673 and manual will show it. Turn engine and i always jack one wheel up and put trans in high gear and have some one bump the wheel over when cold and set watching mating cyl and valve over lap. As exhaust valve closes and intake just starts to open is top dead center so its mating cyl is ready. ! and 6 is mating 2 and 5 3 and 4 is mating. Firing order is 153624. Specs is same as all six cyl makes. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-141181 Share on other sites More sharing options...
h67st Posted October 14, 2012 Share Posted October 14, 2012 How the heck do you set the valves with the engine running? I've done it on a motor with hydraulic lifters, but never one with solid lifters. Quote Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-141672 Share on other sites More sharing options...
theakerstwo Posted October 15, 2012 Share Posted October 15, 2012 Alot of old mack mechanics when i was working for mack tought you had to set them running but that was not so. Mac tools at that time made a spring loaded jumping screw driver just for that. And on top of that a feeler gauge didnt last long. I have did it also. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-141703 Share on other sites More sharing options...
Maddog13407 Posted October 15, 2012 Share Posted October 15, 2012 B613T would have originally had a END673T in it. would have been turbocharged. most early turbo engines didnt last long tho i have been told. if your END673 now is tired and needs rebuilding your best bet would be to find an ENDT675 or 237 as we all call them. you would need some parts and pulleys from your old engine but its basically an easy swap and you would gain the spin on filters to boot. the 675 is made for a 5 or 6 speed transmission but the quad will work as long as you dont hotrod it. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-141753 Share on other sites More sharing options...
scooter Posted November 9, 2012 Share Posted November 9, 2012 Inline 6 cylinder firing order 15 is to young, 36 is to old, 24 is just right 153624 Quote Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-145189 Share on other sites More sharing options...
39 Baby Mack Posted November 10, 2012 Share Posted November 10, 2012 Alot of old mack mechanics when i was working for mack tought you had to set them running but that was not so. Mac tools at that time made a spring loaded jumping screw driver just for that. And on top of that a feeler gauge didnt last long. I have did it also.I have a Mac jumping screwdriver, anyone interested??Ron Quote Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-145268 Share on other sites More sharing options...
theakerstwo Posted November 10, 2012 Share Posted November 10, 2012 I have a Mac jumping screwdriver, anyone interested??Ron I have one that is 45 years old but the spring is broke and just for fun i ask the mac tool man if it was still under warranty.It took about 5 weeks but mac told him it was not ever sold by them.I tryed to use it when i was young but could bot see no reason. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/27728-mack-673-questions/#findComment-145269 Share on other sites More sharing options...
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