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Have a couple questions for you guys. Working on a inframe on a e7 350 mechanical. Do you guys recommend replacing head bolts and rod bolts? Also the cam looks good no flaking etc. What are your thoughts on replacing the cam? Im kind of new to mack motors but rebuilt plenty of deere, cat and cummins. Thanks 

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In my opinion!No to the bolts if the cam looks good leave it ! Pay close attention to liner height try to achieve 25 or better up to 28 thou!

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On Wed Jan 06 2021 at 1:51 PM, fjh said:

In my opinion!No to the bolts if the cam looks good leave it ! Pay close attention to liner height try to achieve 25 or better up to 28 thou!

I must have the wrong book because it says liner height at 10 to 12. It also doesn't tell me the torque for the side bolts on the mains

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The buttress bolts are 90 ft/lb  make sure the long bolts go on the right side of the engine on bearings 2&3 by the aux drive your mains are 210 ft/lb, and Fjh is correct with the height they can be .022-.027 under the same head as long as they are in that spec range 

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2 minutes ago, MACKX said:

The buttress bolts are 90 ft/lb  make sure the long bolts go on the right side of the engine on bearings 2&3 by the aux drive your mains are 210 ft/lb, and Fjh is correct with the height they can be .022-.027 under the same head as long as they are in that spec range 

I appreciate the info. And my book does say 22 to 27 on liner height. I misread it when i scanned it quick. Im assuming you check the liner height and get them right then put them back in with the seal? Correct me if im wrong on that.

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Yes, check height then when you reinstall , put the seal on the liner with Mack RTV at the liner seat  , I use Mack grey nothing else , other guys may have another RTV that works for them , I just use the Mack RTV

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9 hours ago, John3406 said:

I appreciate the info. And my book does say 22 to 27 on liner height. I misread it when i scanned it quick. Im assuming you check the liner height and get them right then put them back in with the seal? Correct me if im wrong on that.

Yup ! And no More than 2 thou variance between Liners Under the same Head! Also I your old Liners are at the (low spec 22) I would shim them 4 thou if the engine is 400hp or more ! That being said ! in your case It ran before with no head gasket issues It Will  Probably run again fine !

just sayin

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On 1/6/2021 at 1:07 PM, John3406 said:

Have a couple questions for you guys. Working on a inframe on a e7 350 mechanical. Do you guys recommend replacing head bolts and rod bolts? Also the cam looks good no flaking etc. What are your thoughts on replacing the cam? Im kind of new to mack motors but rebuilt plenty of deere, cat and cummins. Thanks 

I reuse head bolts unless they have pitting or heavy rust. I replace rod bolts on E6/E7/Etech engines, never reuse, that's our company policy. Just a note, main bearings are the same on #2,3,5&6. #1 looks the same but it is not, the tang is slightly offset. If you mix that bearing then you loose all crank thrust. Seen many tech's scratch their heads trying to figure out why there is no crank thrust after replacing main bearings. Good luck

 

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21 hours ago, turckster said:

I reuse head bolts unless they have pitting or heavy rust. I replace rod bolts on E6/E7/Etech engines, never reuse, that's our company policy. Just a note, main bearings are the same on #2,3,5&6. #1 looks the same but it is not, the tang is slightly offset. If you mix that bearing then you loose all crank thrust. Seen many tech's scratch their heads trying to figure out why there is no crank thrust after replacing main bearings. Good luck

 

Yeah i noticed the mains are different.  I put the cam n lifters in and put the mains in. I do have a question on the liners. On top of the liners there is about 3 different steps. Where do you measure the height? Also my old liners had oring up towards the top the new liners do not have an oring. Did mack change that? This is a mechanical e7 with back half of pump electronic. Thanks 

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Mack did away with the o-ring...  On the liner there is the tall ring(step) around the liner, measure the low groove just outside the circumference of the tall step.. you will use a small amt. of Mack Gray sealant on the shelf in the counter bore to seal in the coolant. the head gasket will take care of the top... jojo

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On Sat Jan 16 2021 at 10:49 PM, turckster said:

 

 

Thanks guys for all the info. Big help. Does anyone know the part number for the sealer for the liner counterbore. I dont want to use the wrong stuff and have a leak

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On 1/17/2021 at 8:32 AM, Vmac3 said:

Be on the lookout for a white paint mark on a crank journal. That means that journal was undercut by .002" from the factory. 

Also The rod cap is usually stamped with an M2 If its 2 thou under Double check your shells to be sure ! They did this some times rod by rod Worth checking! Use the mack stuff Or Permatex Ultra Gray/black  works fine!

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On Sat Jan 16 2021 at 10:49 PM, turckster said:

 

 

Ok guys. Called mack dealer told them i needed the silicone for the liners. They delivered it down to the shop and they sent permatex ultra copper. So i called them and they claim thats what they use now on the liner counterbores. That sound right to you?

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