Mike my pre-heater is awesome, the bummer is most TM's today are going blower/engine exhaust combo.
My little Legend stays around 230+* ATM it is the best thing I have done to the Legend for heat, it is 100% free meaning no extra fuel at all.
In fact it has made me change my whole outlook on my PC L. I am in a awkword kinda place, YES I WOULD LOVE a new TM but at the same time I love working on new things, and the truth is the Little Legend does fine for what I am cleaning, I honestly can't justify getting a new machine as of yet and limit my funds that I need to go to Tim and out progression on the ideas we have.
Many think I maybe making a ton of money on the filters but really that is not the case, yes they make us money but it is NOT what so many think. We have a very simple life and we have decided to keep it that way so we can keep moving forward with my other ideas.
So I have plans on just doing a restore on the PC L, and it is getting close to it.....I will go with a 25 hp Kohler and spin the blower a little more and probably call it good, the PC L my BIGGEST complaint has been heat, but with my pre heater I have a steady average of 200-205 ATW so to me that is plenty of heat.
It produces enough to keep my Zipper blowing a bit of steam out the sides as I clean and that is good for me.
I have poeple say that the pre heater is putting back pressure on the engine....this is not true the way we designed it...it is not possible the PC has a 1 1/4 pipe our pre heater is about 2.5" of internal flow so no restrictions in flow are happening.
I believe the whole secret to good heat is having plenty of water in reserve to work with, many Tm's of old had a water box that may have held a gallon or two, its purpose was to creat a loop for the pump is all......but as you can see the newer TM's as of latley are going with much larger water boxes, (and just better designs) but they have learned that ample reserve water is much easier to regulate temps, it is not as quickly altered as the system warms up, and once that optimum temp is reached we are now seeing more and more TM's capable of getting burner type heat from there systems.
My two buddies
570 and 870 are really two amazing TM's and after looking at them and trying them out all I can say is wow very very good heat, so much so it is almost impossible to get them to COOL BACK DOWN when the job is done.