terry Posted November 26, 2023 Share Posted November 26, 2023 1 hour ago, JoeH said: I've only had to do a head on these once, I did it by the book. Torque to 200, drive around got an hour, retorque. Its a pain to have to deal with all the intake tubing, and those valve covers are horrible to seal. Gotta do them dry and do not go above torque spec. To many guys try to use silicone and squeezes the gasket out. terry 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542524 Share on other sites More sharing options...
RS Disposal Posted November 26, 2023 Author Share Posted November 26, 2023 44 minutes ago, terry said: To many guys try to use silicone and squeezes the gasket out. terry Good to know. I was planning on using silicone cause I know my rocker covers were leaking Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542527 Share on other sites More sharing options...
mechohaulic Posted November 26, 2023 Share Posted November 26, 2023 small center punch make random divots on bottom side of valve covers ; using light film of high tack between valve cover and rubber gasket held gasket in place, NOT silicone but high tack(if it's still manufacture). with the small punch marks on cover the gasket didn't have a 100% smooth surface to slide out. Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542529 Share on other sites More sharing options...
Joey Mack Posted November 26, 2023 Share Posted November 26, 2023 JoeH?? I was looking for the thread with your MR. I was curious how it is coming along.. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542532 Share on other sites More sharing options...
RS Disposal Posted November 26, 2023 Author Share Posted November 26, 2023 4 hours ago, mechohaulic said: small center punch make random divots on bottom side of valve covers ; using light film of high tack between valve cover and rubber gasket held gasket in place, NOT silicone but high tack(if it's still manufacture). with the small punch marks on cover the gasket didn't have a 100% smooth surface to slide out. It does look like Permatex does still offer "high tack" Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542553 Share on other sites More sharing options...
JoeH Posted November 26, 2023 Share Posted November 26, 2023 1 hour ago, RS Disposal said: It does look like Permatex does still offer "high tack" Trust me. Absolutely nothing. Don't use hi tack, don't use silicone, don't use anything. Check the valve covers for "straight" sides, the mating surface bows outwards when you over tighten. Wipe the mating surfaces down real well so there's no oil residue or anything else on them, put the gasket down, cover on, make sure the gasket is sitting right under the covers, then torque them up. High tack and rtv silicone and anything else will lubricate the gasket and it will squeeze out. You will never get them to seal properly for any length of time unless you do them dry. Our '79 endt676 we could never get to seal up. We tried high tack and rtv and it always leaked. Then we did it dry once and we've been leak free for years now. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542567 Share on other sites More sharing options...
Joey Mack Posted November 26, 2023 Share Posted November 26, 2023 if you have the old gray rubber gaskets or the black ones that are attached at the business end, , you can re-use them.. you will see how the crush on them makes them just a tick wider at the mating side.. You can flip them over, they will fit snug in the valve cover groove.. the cover bolts are shouldered so they will only go down so far before they stop... to me this is not a crappy way to do this, its just using both sides of them.. of course, you have to determine if they are to far gone for re-use... Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542568 Share on other sites More sharing options...
JoeH Posted November 26, 2023 Share Posted November 26, 2023 While I've only had to replace one head on these engines, we've had the valve covers off plenty of times. Last time was to delete the jake brake, we have a weak valve springs on one cylinder and the disk on top of the valve stem that the jake actuator pushes on kept popping out, so after the 2nd time it popped out we pulled the plug on the jake. Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542569 Share on other sites More sharing options...
JoeH Posted November 26, 2023 Share Posted November 26, 2023 1 minute ago, Joey Mack said: if you have the old gray rubber gaskets or the black ones that are attached at the business end, , you can re-use them.. you will see how the crush on them makes them just a tick wider at the mating side.. You can flip them over, they will fit snug in the valve cover groove.. the cover bolts are shouldered so they will only go down so far before they stop... to me this is not a crappy way to do this, its just using both sides of them.. of course, you have to determine if they are to far gone for re-use... These don't have a valve cover groove. Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542570 Share on other sites More sharing options...
Joey Mack Posted November 26, 2023 Share Posted November 26, 2023 Ok, I thought we were talking about 4 valve engines... Sorry.... Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542571 Share on other sites More sharing options...
RS Disposal Posted November 26, 2023 Author Share Posted November 26, 2023 4 minutes ago, Joey Mack said: if you have the old gray rubber gaskets or the black ones that are attached at the business end, , you can re-use them.. you will see how the crush on them makes them just a tick wider at the mating side.. You can flip them over, they will fit snug in the valve cover groove.. the cover bolts are shouldered so they will only go down so far before they stop... to me this is not a crappy way to do this, its just using both sides of them.. of course, you have to determine if they are to far gone for re-use... I actually have 2 sets of new gaskets Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542572 Share on other sites More sharing options...
RS Disposal Posted November 26, 2023 Author Share Posted November 26, 2023 2 minutes ago, Joey Mack said: Ok, I thought we were talking about 4 valve engines... Sorry.... nope, mine is just a 2 valve endtb675 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542573 Share on other sites More sharing options...
JoeH Posted November 26, 2023 Share Posted November 26, 2023 (edited) New gaskets are a must. This is an ENDTB, so it has Dynatard not jake brake? Does the Dynatard use a riser under the valve cover? The Jake does, so you need 2 valve cover gaskets per head, one for the riser and one for the valve cover. I've never had a Dynatard so I don't know how they're set up. Edited November 26, 2023 by JoeH Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542574 Share on other sites More sharing options...
RS Disposal Posted November 26, 2023 Author Share Posted November 26, 2023 11 minutes ago, RS Disposal said: nope, mine is just a 2 valve endtb675 my rocker covers just have 3 bolts that go thru the top with shoulders on the bolt Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542575 Share on other sites More sharing options...
RS Disposal Posted November 26, 2023 Author Share Posted November 26, 2023 9 minutes ago, JoeH said: New gaskets are a must. This is an ENDTB, so it has Dynatard not jake brake? Does the Dynatard use a riser under the valve cover? The Jake does, so you need 2 valve cover gaskets per head, one for the riser and one for the valve cover. I've never had a Dynatard so I don't know how they're set up. yes, it is a dynatard. Wish it was the jake brake. About the only thing it is good for is to help with the shifting of the 5 speed. No where near a good as the jake on my other truck when coming down canyon. And no, there is no riser Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542576 Share on other sites More sharing options...
JoeH Posted November 26, 2023 Share Posted November 26, 2023 What's your other truck? The Jake brake on these isn't much use for anything other than shifting, but it makes a world of difference as a shift aid. Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542577 Share on other sites More sharing options...
JoeH Posted November 26, 2023 Share Posted November 26, 2023 These are 11 liter engines so they really just don't have much potential for engine braking. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542578 Share on other sites More sharing options...
RS Disposal Posted November 27, 2023 Author Share Posted November 27, 2023 2 hours ago, JoeH said: What's your other truck? The Jake brake on these isn't much use for anything other than shifting, but it makes a world of difference as a shift aid. My other truck is an Autocar with a Cummins N14. Unfortunately that one has transmission problems that I really should of fixed before now but life just keeps getting in the way. LOL 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-542582 Share on other sites More sharing options...
RS Disposal Posted December 12, 2023 Author Share Posted December 12, 2023 (edited) I did get my truck running, but locating a rebuilt turbo is getting impossible. Does any of you guys hjave a source to try or a source for a seal kit for this 4LE-303 turbo. This one leaks oil out the exhaust side Can anybody tell me what the difference is between the 4LE-303 and the 4LE-292 or 4LE-556. The pictures I am seeing they look similar Edited December 12, 2023 by RS Disposal additional question added Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-543354 Share on other sites More sharing options...
JoeH Posted December 12, 2023 Share Posted December 12, 2023 I put this turbo on my 1979 endt676 about a year ago. Got it through my local Mack dealer, Bergeys. May have been about the last one they had in stock. Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-543357 Share on other sites More sharing options...
JoeH Posted December 12, 2023 Share Posted December 12, 2023 Here's a couple more pictures to drool over... Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-543358 Share on other sites More sharing options...
JoeH Posted December 12, 2023 Share Posted December 12, 2023 FridayParts Turbo S3B085 Turbocharger 631GC5134 174840 199453 Compatible for Mack Truck E6 Replacement https://a.co/d/g7huQZv The things Amazon has for sale never ceases to surprise me.... Not bad at $600... 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-543359 Share on other sites More sharing options...
JoeH Posted December 12, 2023 Share Posted December 12, 2023 The X in the part number on my turbo just means rebuilt. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-543360 Share on other sites More sharing options...
JoeH Posted December 12, 2023 Share Posted December 12, 2023 (edited) Sorry to confuse you with yet another turbo model added to the possibilities. Just rechecked, you're running an ENDTB 675 which will be the 237hp variant! Sorry this turbo is for the 283hp variant! I do have a 237 endt-675 sitting outside my garage, I'll see if it has a tag on it tomorrow! Edited December 12, 2023 by JoeH Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-543363 Share on other sites More sharing options...
JoeH Posted December 12, 2023 Share Posted December 12, 2023 Can you post a picture of the exhaust side of your engine? I have 2 endt675 motors, one from a U model the other is in an R model. I think the exhaust manifolds are the same, but seeing yours will help me compare to the U model I have. Quote Link to comment https://www.bigmacktrucks.com/topic/73314-looking-for-1979-mack-engine-head/page/6/#findComment-543364 Share on other sites More sharing options...
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