24vman Posted July 2, 2011 Share Posted July 2, 2011 hello, i am trying to decide on which injection pump to go with for pushing feul on my 87 r model with a e6 4valve 350hp. would american bosch push more fuel or the robert bosch?thanks Quote Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/ Share on other sites More sharing options...
Rob Posted July 2, 2011 Share Posted July 2, 2011 hello, i am trying to decide on which injection pump to go with for pushing feul on my 87 r model with a e6 4valve 350hp. would american bosch push more fuel or the robert bosch?thanksUse the one currently installed and have it adjusted to your liking. Go much over 350hp at any governed rpm and you'll need an engine shortly. In short, recalibrate the existing pump and leave it alone if you plan to run the same engine reliably. Not being a smart ass to your question. I've seen this exact scenario numerous times.Rob 1 Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80889 Share on other sites More sharing options...
theakerstwo Posted July 2, 2011 Share Posted July 2, 2011 Use the one currently installed and have it adjusted to your liking. Go much over 350hp at any governed rpm and you'll need an engine shortly. In short, recalibrate the existing pump and leave it alone if you plan to run the same engine reliably. Not being a smart ass to your question. I've seen this exact scenario numerous times.Rob I know your right.When you start hot rodding a mack engine and trying to work it ever day it will cost you a engine. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80892 Share on other sites More sharing options...
24vman Posted July 3, 2011 Author Share Posted July 3, 2011 (edited) Use the one currently installed and have it adjusted to your liking. Go much over 350hp at any governed rpm and you'll need an engine shortly. In short, recalibrate the existing pump and leave it alone if you plan to run the same engine reliably. Not being a smart ass to your question. I've seen this exact scenario numerous times.Rob i do see where your coming from , but i am wanting to do some sled pulling at the local fairs, and be somewhat competitive. the truck does not work anymore, its just a spare time project. so originally i was hoping to be in the 500hp range with some pump work, injectors and turbo. but are youu saying that the e-6 just cant handle that? any info is greatly apreciated by the way.thanks Edited July 3, 2011 by 24vman Quote Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80934 Share on other sites More sharing options...
24vman Posted July 3, 2011 Author Share Posted July 3, 2011 (edited) Use the one currently installed and have it adjusted to your liking. Go much over 350hp at any governed rpm and you'll need an engine shortly. In short, recalibrate the existing pump and leave it alone if you plan to run the same engine reliably. Not being a smart ass to your question. I've seen this exact scenario numerous times.Rob i do see where your coming from , but i am wanting to do some sled pulling at the local fairs, and be somewhat competitive. the truck does not work anymore, its just a spare time project. so originally i was hoping to be in the 500hp range with some pump work, injectors and turbo. but are youu saying that the e-6 just cant handle that? any info is greatly apreciated by the way.thanks Edited July 3, 2011 by 24vman Quote Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80935 Share on other sites More sharing options...
Rob Posted July 3, 2011 Share Posted July 3, 2011 i do see where your coming from , but i am wanting to do some sled pulling at the local fairs, and be somewhat competitive. the truck does not work anymore, its just a spare time project. so originally i was hoping to be in the 500hp range with some pump work, injectors and turbo. but are youu saying that the e-6 just cant handle that? any info is greatly apreciated by the way.thanksThe block is not strong enough to absorb the torsional stresses induced when "hopped up". It will crack internally and sometimes externally through the lower end.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80936 Share on other sites More sharing options...
24vman Posted July 3, 2011 Author Share Posted July 3, 2011 The block is not strong enough to absorb the torsional stresses induced when "hopped up". It will crack internally and sometimes externally through the lower end.Robhow about with the e-7 engines would they be better for this kind of project and hp range. Quote Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80938 Share on other sites More sharing options...
theakerstwo Posted July 3, 2011 Share Posted July 3, 2011 I know some guys set their engine up hot and get by with it but chances are when they change main brgs the bore is off or there is cracks in the main brg struts up to the block. I tore one down one time that was so cracked that the main bolts was holding the upper half up and the oil passage had to be leaking oil. It had been cracked long time.Always find that they are set up on the fuel.So i have said for years with small cubit inc engine like these be carefull about setting fuel up. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80940 Share on other sites More sharing options...
Rob Posted July 3, 2011 Share Posted July 3, 2011 how about with the e-7 engines would they be better for this kind of project and hp range.By far yes. It would also be a "slip fit" with minor modifications if a mechanical engine. Should you decide to do this get an engine that is complete. It gets expensive purchasing little pieces parts along the way.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80941 Share on other sites More sharing options...
24vman Posted July 3, 2011 Author Share Posted July 3, 2011 I know some guys set their engine up hot and get by with it but chances are when they change main brgs the bore is off or there is cracks in the main brg struts up to the block. I tore one down one time that was so cracked that the main bolts was holding the upper half up and the oil passage had to be leaking oil. It had been cracked long time.Always find that they are set up on the fuel.So i have said for years with small cubit inc engine like these be carefull about setting fuel up.so just by tweaking the pumps on them e-6 engines can do that much damage? Quote Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80942 Share on other sites More sharing options...
Rob Posted July 3, 2011 Share Posted July 3, 2011 so just by tweaking the pumps on them e-6 engines can do that much damage?That engine design is at it's limit when set to 350hp. It is basically an older design started in the early 1950's and constantly improved. The original design versions were only 170hp. It is also small in displacement, (672cid).Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80945 Share on other sites More sharing options...
theakerstwo Posted July 3, 2011 Share Posted July 3, 2011 so just by tweaking the pumps on them e-6 engines can do that much damage? Yes Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80946 Share on other sites More sharing options...
24vman Posted July 3, 2011 Author Share Posted July 3, 2011 well then i guess ill be looking for a mechanical e-7. i had no idea the e-6 engines were so weak. im glad i asked.thanks fellas. Quote Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80947 Share on other sites More sharing options...
Rob Posted July 3, 2011 Share Posted July 3, 2011 well then i guess ill be looking for a mechanical e-7. i had no idea the e-6 engines were so weak. im glad i asked.thanks fellas.I wouldn't make the statement that they're weak. Really wouldn't cause there are a lot of them that have run millions of miles when taken care of. They are a very sound and stable platform but at the end of their development ability would be correct. I really like the engine series. They are very easy and straightforward to work on and with. Usually pretty trouble free in operation but only as good as the treatment they are subjected to. Good luck with your project.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/19614-which-pump/#findComment-80949 Share on other sites More sharing options...
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