fjh Posted May 2, 2019 Share Posted May 2, 2019 Ah! my mistake So In my opinion you should be looking into an injector with bad or low cracking pressure or a valve hanging up! check your valve set first! does the engine have much blow by? Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-421808 Share on other sites More sharing options...
brettj3876 Posted May 2, 2019 Author Share Posted May 2, 2019 6 hours ago, fjh said: Ah! my mistake So In my opinion you should be looking into an injector with bad or low cracking pressure or a valve hanging up! check your valve set first! does the engine have much blow by? No not even 20k on the inframe and injectors from rochester. Possible we got a bad one? Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-421843 Share on other sites More sharing options...
fjh Posted May 3, 2019 Share Posted May 3, 2019 17 hours ago, brettj3876 said: No not even 20k on the inframe and injectors from rochester. Possible we got a bad one? Possible! was the pump redone? Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-421883 Share on other sites More sharing options...
brettj3876 Posted May 4, 2019 Author Share Posted May 4, 2019 12 hours ago, fjh said: Possible! was the pump redone? Got one online along with an econovance, both rebuilt. Since it was originally a 350 from the factory could the data file have something to do with it after upping the hp and going to lower comp pistons? The thing is that it only studders/smokes at light or no load. Once you step on the peddle it runs like a pissed off dog. No blow by and we haven't had to add a drop of oil on both changes so far Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-421929 Share on other sites More sharing options...
880joe Posted May 4, 2019 Share Posted May 4, 2019 Does the e7 have an offset and straight cam key like on the etech if so that may have to be changed to correct the timing Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-421949 Share on other sites More sharing options...
fjh Posted May 4, 2019 Share Posted May 4, 2019 14 minutes ago, 880joe said: Does the e7 have an offset and straight cam key like on the etech if so that may have to be changed to correct the timing Nope! Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-421950 Share on other sites More sharing options...
brettj3876 Posted June 16, 2019 Author Share Posted June 16, 2019 UPDATE. And long post Monday were taking a ride to Trovei and sons (huge mack graveyard in port jervis ny) to see about getting pump, lines, pedal, linkages everything to convert the 93 to mechanical. We found a local guy that does nothing but P pumps. From stock rebuilds to sled pulling 12 valves. My dads already been on the phone with him, explained the setup were running. Running the 15.3 pistons with big injectors and the s475 he figures lock it up around 25-26. He mentioned going flat top plungers and maybe different cut delivery valves. Either way the pump is gonna be rebuilt. Hooked up the prolink while pulling a loaded wagon. Says it has a 400 file in it. Anyways under full load it was getting 16-17 right on point for the 93 400 specs. The 350 file has 22 deg of timing full load and the 300 has 25 deg at full load. We tried getting cook bros mack in Binghamton ny to see about putting the 300 file in it. Going down in hp you think they would.......nope. Another strange mack quirk. The 1993 tune up manual we have lists specs and pump configuration for all E-7 and E-9s for that year. The 250 to 400 E-7 all have the same compression ratio of 16.9, but in most other literature it lists 375 and up 15.3 and below that 16.5. We hadn't heard of 16.9 until that tune up book. Bear with me So thats a big jump 16.9 to 15.3 plus adding big injectors and the huge S475. To compensate for the "extra" space and more fuel in the combustion chamber shouldn't the timing be bumped up more? I would think it would need to be and the pyro is telling me that too. The exhaust heats up faster than it should on a pull. Almost like before the inframe with stock turbo and the blixxton. 16-17 degrees is too far retarded for the setup we have now. We would love to stick with variable timing vmac but so far no luck getting a file from VoMack. I know someone here works at Watts, forget who but if i give u a vin can you try to work your magic? We'd be down there in a heartbeat. Thanks in advance and ill post pics of the 93 tune up book if you guys want. It even has the data file # and all the tech specs on the diff hp levels for 93 Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-425374 Share on other sites More sharing options...
JoeH Posted June 16, 2019 Share Posted June 16, 2019 Pretty sure it's Barry that "works" at Watts. Pretty sure he owns it? Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-425393 Share on other sites More sharing options...
j hancock Posted June 20, 2019 Share Posted June 20, 2019 On 6/16/2019 at 7:36 AM, JoeH said: Pretty sure it's Barry that "works" at Watts. Pretty sure he owns it? Watt's history. https://wattstruckcenter.com/company-history/ Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-425718 Share on other sites More sharing options...
JoeH Posted June 20, 2019 Share Posted June 20, 2019 Good history, impressive how many generations they've made it, usually family businesses fall apart by the 3rd generation. Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-425765 Share on other sites More sharing options...
brettj3876 Posted October 25, 2019 Author Share Posted October 25, 2019 https://youtu.be/LMps1A4uf5Q ok reviving this thread since i found out how to upload vids. If you go back and re-read you'll see what im talking about but the short of it is this Factory 350 vmac1 with 16.9:1 compression. We went with the lower comp 15.3 pistons and stage 2 injectors from Rochester + blixxton. It never smoked/missed before the rebuild and bigger injectors. And it only smokes under no load or light load conditions. We swapped out the pump and econovance to rule that out and still does same thing. Checked each injector and they're good also. Were going mechanical anyways (pump being built now) but figured a video would help with my explanation Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-434541 Share on other sites More sharing options...
BottleHauler84 Posted August 30 Share Posted August 30 On 10/25/2019 at 5:52 PM, brettj3876 said: https://youtu.be/LMps1A4uf5Q ok reviving this thread since i found out how to upload vids. If you go back and re-read you'll see what im talking about but the short of it is this Factory 350 vmac1 with 16.9:1 compression. We went with the lower comp 15.3 pistons and stage 2 injectors from Rochester + blixxton. It never smoked/missed before the rebuild and bigger injectors. And it only smokes under no load or light load conditions. We swapped out the pump and econovance to rule that out and still does same thing. Checked each injector and they're good also. Were going mechanical anyways (pump being built now) but figured a video would help with my explanation Brett did you ever get this truck sorted out? Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-557829 Share on other sites More sharing options...
Joey Mack Posted August 31 Share Posted August 31 Buddy, that post is 5 years old.. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-557840 Share on other sites More sharing options...
BottleHauler84 Posted Tuesday at 12:00 AM Share Posted Tuesday at 12:00 AM On 8/30/2024 at 8:18 PM, Joey Mack said: Buddy, that post is 5 years old.. Yeah i know, I was curious whatever came of it and weather or not he got it sorted out. Just found the thread interesting. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-562173 Share on other sites More sharing options...
Joey Mack Posted Tuesday at 12:01 AM Share Posted Tuesday at 12:01 AM Got'cha.. Quote Link to comment https://www.bigmacktrucks.com/topic/56938-whats-the-turbo-that-rochester-uses/page/2/#findComment-562174 Share on other sites More sharing options...
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