1pig24 Posted November 16, 2008 Share Posted November 16, 2008 I have an 86 rs688ls with e6 350 2v. it has front air to air and fuller 10sp trans. I would like to upgrade to e6 4v or e7 mechanical with jake brake. will my accessories bolt up? is the physical size of the blocks the same? Any other engine suggestions? Quote Link to comment Share on other sites More sharing options...
fjh Posted November 16, 2008 Share Posted November 16, 2008 Physicly pretty much the same depending on what truck the engine is coming from!First big problem you may encounter is the front mount.RS is cradle mounted on the front cover!The e7 has a bolt on mount!compresors differ sum .Water pump s differ from model to model!With out setting em side by side !I'd be sceptical anything is possible with a little time thou!I could for see lots of little and some big glitches!The RS did come with a 4 valve e6 at one point just before they did away with the model! Quote Link to comment Share on other sites More sharing options...
1pig24 Posted November 17, 2008 Author Share Posted November 17, 2008 Physicly pretty much the same depending on what truck the engine is coming from!First big problem you may encounter is the front mount.RS is cradle mounted on the front cover!The e7 has a bolt on mount!compresors differ sum .Water pump s differ from model to model!With out setting em side by side !I'd be sceptical anything is possible with a little time thou!I could for see lots of little and some big glitches!The RS did come with a 4 valve e6 at one point just before they did away with the model!not to worried about the little stuff. I have all winter to work the glitches out. mostly concerned with physical dimensions. dont want to cut firewall out or have to move radiator. Thanks for your help. Love this site. Quote Link to comment Share on other sites More sharing options...
fjh Posted November 17, 2008 Share Posted November 17, 2008 not to worried about the little stuff. I have all winter to work the glitches out. mostly concerned with physical dimensions. dont want to cut firewall out or have to move radiator. Thanks for your help. Love this site.No fire wall cut!The front mount compressor and the water pump will be your main stumbles!also the jake puts the valve covers real tight to the heater hoses!that again is simple stuff! Quote Link to comment Share on other sites More sharing options...
HK Trucking Posted November 17, 2008 Share Posted November 17, 2008 The O.P. said:I would like to upgrade to e6 4v or e7 mechanicalThe E7 mechanical engines have the compressor in the same place as the E6 - buried down on the right rear. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment Share on other sites More sharing options...
fjh Posted November 17, 2008 Share Posted November 17, 2008 The O.P. said:The E7 mechanical engines have the compressor in the same place as the E6 - buried down on the right rear.HKHis e6 compressor accesory is not direct swap over thou!Also the power steering pump mounts on the front on some models lots of little things to think about is all!As long as the e7 has all of the above bolted to it .he will have somthing to work with! Quote Link to comment Share on other sites More sharing options...
bulldogbred Posted November 18, 2008 Share Posted November 18, 2008 I made a similar switch in a 75 RS700L from a 2 valve to a E7400, the biggest issue I ran into with my truck was we had move the radiator back for a front mount intercooler because my old motor had a tip turbine. Otherwise I can not remember other big issues, oh yeah motor mount was different on the front mine had the old style front motor mount and we had to switch it to the newer one to match up with the E7 Quote Link to comment Share on other sites More sharing options...
1pig24 Posted November 18, 2008 Author Share Posted November 18, 2008 The O.P. said:The E7 mechanical engines have the compressor in the same place as the E6 - buried down on the right rear.yes it is, along with the married power steering pump. are the accessory drives the same bolt pattern, size, etc.? Quote Link to comment Share on other sites More sharing options...
1pig24 Posted November 18, 2008 Author Share Posted November 18, 2008 I made a similar switch in a 75 RS700L from a 2 valve to a E7400, the biggest issue I ran into with my truck was we had move the radiator back for a front mount intercooler because my old motor had a tip turbine. Otherwise I can not remember other big issues, oh yeah motor mount was different on the front mine had the old style front motor mount and we had to switch it to the newer one to match up with the E7did you just simply modify your front crossmember or is there a western crossmember that will bolt up. Shouldn't be that hard to fab somethin up. I'm already set up with front air2air. Quote Link to comment Share on other sites More sharing options...
fjh Posted November 18, 2008 Share Posted November 18, 2008 yes it is, along with the married power steering pump. are the accessory drives the same bolt pattern, size, etc.?The compressors are diffrent but some have provision for the steering pump!the oil feed tube on the 7 is bigger than the E six. Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted November 18, 2008 Share Posted November 18, 2008 The compressors are diffrent but some have provision for the steering pump!the oil feed tube on the 7 is bigger than the E six. Then your saying the Holsit will not work on a E6. I am glad you told me that because i have a Holsit on a junk engine that i was saving for my E6 if and when i need one. Quote glenn akers Link to comment Share on other sites More sharing options...
fjh Posted November 18, 2008 Share Posted November 18, 2008 Then your saying the Holsit will not work on a E6. I am glad you told me that because i have a Holsit on a junk engine that i was saving for my E6 if and when i need one.Glenn I have never tried to mix and match!But my obsevation is the e7 tube is a larger od than the e6 by quite a bit!No great loss on the holset thing! they anit all what there cracked up to be! Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted November 18, 2008 Share Posted November 18, 2008 Glenn I have never tried to mix and match!But my obsevation is the e7 tube is a larger od than the e6 by quite a bit!No great loss on the holset thing! they anit all what there cracked up to be! Cummins had alot of trouble out of the early ones but they got that straight. Quote glenn akers Link to comment Share on other sites More sharing options...
bulldogbred Posted November 26, 2008 Share Posted November 26, 2008 did you just simply modify your front crossmember or is there a western crossmember that will bolt up. Shouldn't be that hard to fab somethin up. I'm already set up with front air2air.[/quoteWe used an existing cross member from an E7 and made it fit in my frame because the 2 valve had a different mount Quote Link to comment Share on other sites More sharing options...
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