Mark T Posted 9 hours ago Share Posted 9 hours ago The 690 poked the pin through the adjustment on one valve. 690s had power Quote Link to comment https://www.bigmacktrucks.com/topic/75063-what-engine-brake-do-i-have/page/2/#findComment-568199 Share on other sites More sharing options...
Joey Mack Posted 9 hours ago Share Posted 9 hours ago Yep, but still needed help to even act like an engine brake.. we used to drill and tap the housings to put top oil feed lines to them to increase oil volume to get better performance, we either drilled the valve cover spacers or bought updated ones, and had to tap into the oil filter stand to get the needed oil from the turbo oil line port... What a joke, and put in a high volume oil pump... Only after a road test for diagnosis with hand written specs on a form to submit to Mack for approval.. It was a crazy time in early 2000's... Quote Link to comment https://www.bigmacktrucks.com/topic/75063-what-engine-brake-do-i-have/page/2/#findComment-568201 Share on other sites More sharing options...
Mark T Posted 9 hours ago Share Posted 9 hours ago I never understood that. The 680s had lots of oil pressure issues on the top.....and some didn't. I don't remember 690 on the E Techs being like that. Quote Link to comment https://www.bigmacktrucks.com/topic/75063-what-engine-brake-do-i-have/page/2/#findComment-568202 Share on other sites More sharing options...
Joey Mack Posted 9 hours ago Share Posted 9 hours ago The 690 was weak. I did a bunch of these upgrades and they were still, just decent. Its been a long time bud.. Quote Link to comment https://www.bigmacktrucks.com/topic/75063-what-engine-brake-do-i-have/page/2/#findComment-568203 Share on other sites More sharing options...
BronsonA2150 Posted 8 hours ago Author Share Posted 8 hours ago It’s really a shame that Jacob’s didn’t release that 349 sooner and give them more time to perfect the wear issues. I think they only made them a couple years before Cat went to the E model so they scrapped it. But if you look at the diagram of the operations you could really tell why they were so much better. I’m betting something similar could have been done with Mack Quote Link to comment https://www.bigmacktrucks.com/topic/75063-what-engine-brake-do-i-have/page/2/#findComment-568204 Share on other sites More sharing options...
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