2.5NA mufflers

[camo388]

I've got the 2.5NA with attached Series transmission, sitting in the LWT frame and starting gathering up fuel filters, fuel lines etc to start plumbing.
Also brought muffler and down pipe into the shop as these will be needed soon.  I notice on Adam's 90 that there are 2 mufflers, a large and a small.  I only have the large (NTC1614) but not the silencer exhaust, (either NTC 4617 or NTC 2701K).  Now I'm wondering if I should also be using this silencer exhaust as it will effect how I plumb up the exhaust?

Bruce

[ugly_90]

I have a spare 2.5 NA 90 muffler set I don't need. Let me know if you want it.

[camo388]

I may need part of your muffler set.  I haven't sorted out all my exhaust pipe yet, got called away.

[binch]

Let my start by acknowledging my ignorance on this subject.....but here's a thought.....    I've seen some folks strip out the muffler and rear resonator with not much difference in the noise level.   The question I have is.... will this open air way help or hinder the engine doing it's job?    Does the engine need any back pressure to operate most efficiently....?

Maybe you can get away with just one of the mufflers...... ???

[camo388]

I've found more of my "saved" exhaust pieces and do have both mufflers.  Now do I have room to fit both? as the LWT only had 1 muffler under the cargo area.  Having a bit of a look at things and see that the 2.25 gas engine exhaust pipe went above the cross members and along side the tranny.  No wonder I had warm feet.  The 2.5 diesel has bigger exhaust pipe so it may not fit in the same place.  Time will tell.  I don't like the idea of having to run it under the cross members but that only leaves the option of going through the cab interior.  :o
Bet that will put out more heat than the stock heater so will be wonderful for winter driving.  ;D

I was always lead to believe the exhaust was "tuned" to get the most out of the engine so a bit of back pressure was built in.  Drivers acceptance of noise level would be a huge factor and I would be very very surprised to see a Rolls with straight exhaust. ::) ;D

[Already a Rover]

The exhaust placement is problematic for LHD Rovers for sure - " Hot Foot."  A heat shield on the exhaust pipe is the best way to fix this, but I don't have one yet.  I tried wrapping the exhaust and it MAY have helped a little, but still gets hot in the summer.

I doubt a silencer will affect the engine much, but I don't believe they are stock and air-flow in these engines is an issue, so would not do-so if I was you.  I souped-up my engine with 60-over pistons, a 9:1 ported head, performance cam and  a 2" exhaust and it runs great.  If you can stand the noise, it will do 80mph on the hwy no problem.  Highway mileage (at normal speeds) was 24mpg last summer before I re-tuned the distributor, so I expect somewhat better now.