Popular Post Freightrain Posted yesterday at 06:00 PM Popular Post Share Posted yesterday at 06:00 PM It has started. Will take time, not sure how fast it will happen. I have legs made up to get it off the floor and I can drop the pan. Local guy has std pan that he will trade for my ESI pan(that won't fit my chassis). Found a couple loose exhaust rockers(like more then 1/8" lash)hope that isn't a cam failure! Didn't make any bad noises while running and had 70# oil pressure. Will investigate that further. My 3/4" IR won't break the head bolts loose, but was using adapter for 1/2" socket. Need to buy a good 3/4" socket and see if that improves the performance. Should have some updates next week? 6 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/ Share on other sites More sharing options...
70mackMB Posted yesterday at 06:04 PM Share Posted yesterday at 06:04 PM Welcome back Larry. .....Hippy 2 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578734 Share on other sites More sharing options...
Geoff Weeks Posted yesterday at 06:22 PM Share Posted yesterday at 06:22 PM 3/4" breaker bar and cheater pipe are my go-to for stuff like that. Cheap to replace if something lets go. I have a torque multiplier for going back together. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578737 Share on other sites More sharing options...
mrsmackpaul Posted yesterday at 08:15 PM Share Posted yesterday at 08:15 PM If my memory is correct, which is doubtful I reckon the head bolts are 220 pound so thats pretty tight, yeah a breaker bar and pipe as Geoff suggests is probably needed Paul 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578741 Share on other sites More sharing options...
Joey Mack Posted yesterday at 10:45 PM Share Posted yesterday at 10:45 PM Those head bolts are torqued to 205 lbft. A 3/4" breaker bar with a 3/4" socket should do it. 220 lbft is the highest i would go, when going back together, but 205-210 is plenty. Do you have the torque pattern, and it is 3 rounds tol done.. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578748 Share on other sites More sharing options...
fjh Posted yesterday at 11:06 PM Share Posted yesterday at 11:06 PM 5 hours ago, Freightrain said: It has started. Will take time, not sure how fast it will happen. I have legs made up to get it off the floor and I can drop the pan. Local guy has std pan that he will trade for my ESI pan(that won't fit my chassis). Found a couple loose exhaust rockers(like more then 1/8" lash)hope that isn't a cam failure! Didn't make any bad noises while running and had 70# oil pressure. Will investigate that further. My 3/4" IR won't break the head bolts loose, but was using adapter for 1/2" socket. Need to buy a good 3/4" socket and see if that improves the performance. Should have some updates next week? Just run the over head and check not the hard! Loose means nothing unless you’re on the valve set marks! That space is there to make the engine brake function! 220 is bolt tourque that said as Joey mentioned top end with studs ! Esi Engine 53 quart pan! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578749 Share on other sites More sharing options...
Freightrain Posted 22 hours ago Author Share Posted 22 hours ago No engine brake(dynatard) that I'm aware of. I would assume, like a gas engine, that even at TDC there should only be max clearance(.020?). Not +.150. all the rest that I could check without rotating it, were pretty close to .020 sumthin. Going by "feel". It's coming apart, so I will make sure things are okay. Could just be lack of maintenance. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578754 Share on other sites More sharing options...
Freightrain Posted 22 hours ago Author Share Posted 22 hours ago 1 hour ago, Joey Mack said: Those head bolts are torqued to 205 lbft. A 3/4" breaker bar with a 3/4" socket should do it. 220 lbft is the highest i would go, when going back together, but 205-210 is plenty. Do you have the torque pattern, and it is 3 rounds tol done.. Have to wait to get engine on legs, as it is just sitting on a few pieces of wood. Any big bar will have it laying on its side, on the floor! 😨 I remember the 673 was like 150#? when I replaced a few broke studs years back. At least that is what I pulled it to because that was all my torque wrench would go. 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578756 Share on other sites More sharing options...
Joey Mack Posted 22 hours ago Share Posted 22 hours ago I cant post the picture of my book. So here ot is for head bolts on your tip turbine. Lightly oil the bolt threads, amd washers and the top of the holes in the head. Not the block threads. 3 stages of torque is , 50-125-200 lbft. . I wish i could post the torque pattern. I will try again.. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578757 Share on other sites More sharing options...
Joey Mack Posted 22 hours ago Share Posted 22 hours ago https://photos.app.goo.gl/SYoBuVFDPgd92ayM7 Try this link 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578761 Share on other sites More sharing options...
Popular Post terry Posted 21 hours ago Popular Post Share Posted 21 hours ago Looks like you have bolts and not studs and nuts for headbolts, be sure to chase all threads and bottom tap and blow out bolt holes. Terry 3 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578763 Share on other sites More sharing options...
Popular Post Freightrain Posted 11 hours ago Author Popular Post Share Posted 11 hours ago Will do. Not my first motor rodeo. Been doing hot rod stuff for nearly 40 yrs. 3 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578772 Share on other sites More sharing options...
Popular Post fjh Posted 9 hours ago Popular Post Share Posted 9 hours ago 13 hours ago, Freightrain said: No engine brake(dynatard) that I'm aware of. I would assume, like a gas engine, that even at TDC there should only be max clearance(.020?). Not +.150. all the rest that I could check without rotating it, were pretty close to .020 sumthin. Going by "feel". It's coming apart, so I will make sure things are okay. Could just be lack of maintenance. It likely has a dynatard cam just no head gear ! nope you need to to follow the firing order to set the valves! 3 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578784 Share on other sites More sharing options...
Geoff Weeks Posted 8 hours ago Share Posted 8 hours ago 20 minutes ago, fjh said: It likely has a dynatard cam just no head gear ! nope you need to to follow the firing order to set the valves! Caught me out the 1st time I ran the overhead on a Mack. Couldn't figure out what I did wrong! Once learned never forgot. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578786 Share on other sites More sharing options...
mechohaulic Posted 8 hours ago Share Posted 8 hours ago 27 minutes ago, fjh said: It likely has a dynatard cam just no head gear ! nope you need to to follow the firing order to set the valves! that was a major challenge back in the day for the "old school folk" who had the white soap stone to mark the rockers after adjustment since more than one valve on opposing cyl could be adjusted same time. then this dynatard engine comes along.- WTF I just adjusted that cyl why all the slack on exhaust. read the book !! what book; they weren't printed yet. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578787 Share on other sites More sharing options...
Popular Post fjh Posted 8 hours ago Popular Post Share Posted 8 hours ago 10 minutes ago, Geoff Weeks said: Caught me out the 1st time I ran the overhead on a Mack. Couldn't figure out what I did wrong! Once learned never forgot. Joey has mentioned this Many times on here ! Can't stress it enough! Many get caught on it! 3 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578788 Share on other sites More sharing options...
Geoff Weeks Posted 8 hours ago Share Posted 8 hours ago 15 minutes ago, fjh said: Joey has mentioned this Many times on here ! Can't stress it enough! Many get caught on it! Yeah, my "education" was decades ago, but I still remember that today. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578789 Share on other sites More sharing options...
Freightrain Posted 7 hours ago Author Share Posted 7 hours ago I've run valves, so I understand the procedure. On my hot rods, I always do one cyl at a time. They have cheat sheets on how to do multiple cylinders at a time but I never do it that way. Ever. Even after getting grief for it. "Oh, you're taking too long". Whatever. This having so much lash surprised me. Why does it require so much for a "dynatard" cam? What is special about it? I'm just glad it isn't a cam lobe problem. I did the valves on my 237 and the Jakes without issues. I know Jakes are different but I followed the sequence and they work fine. I want to transfer the Jakes over to this engine, if possible. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578790 Share on other sites More sharing options...
mrsmackpaul Posted 4 hours ago Share Posted 4 hours ago Have a read through this thread, ut may help or maybe just confuse the Dynatard understanding Paul Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578792 Share on other sites More sharing options...
Freightrain Posted 4 hours ago Author Share Posted 4 hours ago Ok, it makes sense. It uses an adjustable rocker cup to apply extra lift to open the valve instead of a Jake housing. Normal setting it has lash, once pressure applies it pushes rocker further opening the valve. Kinda ingenious actually. 1 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578793 Share on other sites More sharing options...
mowerman Posted 3 hours ago Share Posted 3 hours ago Well Larry I’m glad you decided to go through it that’s what I would’ve done I’m sure most of us … bob 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578794 Share on other sites More sharing options...
davehummell Posted 3 hours ago Share Posted 3 hours ago I used to have to work on 675's with the dynatard but I haven't touched one in almost 40 years so my memory of setting them up is a blank. That 300 will make the B into a hot rod compared to your 673 when I installed the 260 hp it was a noticeable improvement. I am very glad I spent the money for the jake that is on my present engine. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578797 Share on other sites More sharing options...
Freightrain Posted 2 hours ago Author Share Posted 2 hours ago The 237 is a huge upgrade from the 673. Can't wait to see it with new motor! I found out last winter that my throttle was not quite wide open at WOT. I adjusted the arm just a touch and WOW what a difference. It really pulls the hills now. It was good but that last little touch of fuel made a big difference in keeping speed with my trailer on steeper hills. Always had to drop a gear, now I can almost not have to. Can't imagine another 100hp? 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578798 Share on other sites More sharing options...
fjh Posted 2 hours ago Share Posted 2 hours ago 2 hours ago, mrsmackpaul said: Have a read through this thread, ut may help or maybe just confuse the Dynatard understanding Paul Rockers and valve covers and push tubes to make it work! The Jake’s should work from the other engine! As it works off cam lift! Dynatard is rather feeble! Jake is moderately better! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578804 Share on other sites More sharing options...
terry Posted 1 hour ago Share Posted 1 hour ago Larry , i might have missed it, gonna run the triplex behind it? Terry Quote Link to comment https://www.bigmacktrucks.com/topic/75768-300-rebuild/#findComment-578806 Share on other sites More sharing options...
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