3 Key Variables to Harley Performance & Reliability 

Very nice. Did DD include the oil temp sensor with the gauges, or did you have to purchase that separately? Also, where is the oil temp sensor installed on the engine?

@@DKCustomProducts oil temp sensor is included. The sensor is located in the new oil drain plug.

Got it, thank you! 👍

Those number are close for the M8....but the temp of the rear just at the heat sensor, embedded into the rear cylinder head, that is what will be about 30-40 * hotter than the oil after it is heat soaked. We have a video going into more detail on that here- ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rWOdQOtDv6A.html Glad you are finding the videos useful/interesting. 👍😎👍 We appreciate your business. Feel free to email or call with any questions. Support@DKCustomProducts.com 662-252-8828

Coming soon! We are scheduled to record 2-3 more videos on HOW TO COOL them down this coming Tuesday afternoon.

We do not sell Oil Gauges. The one we use is from JES Customs. Kevin has used it for years. www.jescustomaccents.com/ Thank you for commenting! MB

Yep, it's coming...slowly but surely. :)

Many HD's did have an oil temp gauge, and an oil pressure gauge. That all went away with the M8's. No explanation given, but it is surmised that since right in the HD manual it says normal operating temperature for the oil is 230*, and since they run hotter than that, there were too many questions and complaints. So by not making that info readily available, it cut down on the number of complaints that they get.

Great question that address an age old myth. It is a sad state of affairs when HD is educating their employees, perpetuating the myth. Pure & simple, backpressure is counter-productive to generating power. You can read the Report on Facts & Myths regarding Harley exhaust at this Link- www.dkcustomproducts.com/harley-exhaust-myths-and-facts.htm The short of it is- Back-pressure fights AGAINST performance. Back-pressure holds back power, not unlike a 350 lb. rider will reduce acceleration more than a 150 lb. rider. The reason some folks think that back pressure is good, is because when they put a baffle in (which creates back-pressure) the bike runs stronger. BUT, it is NOT running stronger because of the back-pressure, it is running stronger in spite of the back-pressure, because it is reducing Reversion. (see above on how reversion robs power) It is wrongly assumed that the back-pressure that baffles create increases power. It is the reduction in reversion from baffles that increase power. The baffle is reducing power because of the back-pressure, but it is increasing power by Reversion reduction. In most cases the power gained by reduction of reversion is More than the power lost to back pressure, so there is a net gain of more power. But it is IN SPITE of back pressure, not because of it. What would be best is if there could be a reduction of reversion WITHOUT an increase in back pressure.

I've not noticed that, but it certainly makes sense...at least until the gas warms up. :)

@@DKCustomProducts thats just it. The first 20 odd minutes until the tank heats up. I fell the compression is a bit better. Be mindfully of my statement, see if its true. Or am I just crazy. Lol. Shiny side up... safe ride... 👍👍👍

@@michaelkozak7295 It makes total sense, and I am going to pay attention next time I get a fill up with cold gas on a hot day.

First off, thanks for following, and we appreciate your business. I did mention that if you have a good oil cooler the oil temp will normalize with the engine temp after about 45 minutes riding. You have Two oil coolers, so that is going to cool your oil more, making the disparity between the ET on the PV and the oil temp greater. I should have mentioned that on the M8 there is going to be a 30-40 disparity...oil temp of 230 one would expect an ET of around 260-270. It is on the Twin Cam's that you will see the number almost mirroring. If your oil temp is truly at 220 and your PV ET readout is at 320, something is amiss. That is a good oil temp, but that is too hot for the ET. Could be reversion, could be too lean of a tune, could be the cam, or if you do not have an External Breather System. Most likely it is a combination of all of those creeping your ET up so high.

Glad it was helpful!

Thank You, good to read you found it useful. 👍

Thanks!

Great question! There are just as many intake cycles as combustion cycles. During the intake cycle air is drawn in that is around 100* and fuel is injected that is well below 100*. Both the air and the fuel have a cooling effect on the cylinder walls, just as the combustion has a warming effect. Add to that a few more factors. The bottom of the piston is being squirted with oil to help cool it down. The cylinders are relatively thin with a significant amount of heat dissipation from the fins. When you look at the heat sensor that is in the cylinder head, on a properly cooled Twin Cam it will fluctuate between 190-230*. The head is subjected to more heat than the cylinder walls...it is where the exhaust valve is that the hot gasses exit thru. It is also a larger chunk of metal, and does not have anywhere near the heat dissipation with relatively few fins when compared the the cylinders.

@@DKCustomProducts Excellent reply. Thank you

Thanks! 👍

I have used the HD digital temp oil dip stick on many bikes, I like them, but most did not last more than a year or so before failing. You can also get an analog temp dipstick from JessCustoms. I have been using one of those for a couple of years now.

@@DKCustomProducts Thanks again, I’m a subscriber.

@@babybugspaw7085 Awesome, we appreciate it and hope you find the content useful!

Glad you are enjoying your ride! Both your oil temp and head temp are good. We talk about normal on a Sporty, and what is too hot on a Sporty in the following video, at the 1:25 mark. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rWOdQOtDv6A.html

@@DKCustomProducts Great Thank You for fast response & that my engine temp is Good ..so its Great to know its OK & Thanks for Video just clicked on it now to watch ..Thanks again for all Yall Do For the Harley Ridding Public Ill keep watching

@@jmead6121 Thanks for the good words. Enjoy your ride!

IAT temps are going to vary wildly, depending on many factors...which bike you have, what the ambient air temp is, what accessories you have (like fangs etc.) Next time I'm out I will monitor the IAT and try and remember to post back here some details.

In a round about way. With the PV you can monitor the AFR (air/fuel ratio) and if you see it is too lean, especially under a load, the engine will be running hotter than it should/would with a more ideal AFR. But the same PV will give you a direct read out of the engine temperature. So the AFR read-out is more useful in knowing if you are running optimally, and if it is contributing to excessive heat or not.

Most of us at DK Custom use Redline in the engine and trans, been using Syn3 in the primary for a few years. We have tried many other oils, Mobil 1, Amsoil, Royal Purple, Castrol, Valvoline, and much more. They are all good and do the job, but Redline seems to hold up the best and be the quietest. Can't go wrong with any good synthetic made for air cooled engines 20-50, 20-60, straight 50 & 60, all depends on the ambient temps. On those OEM air shocks they use push to connect fittings and hose and it is not unusual for them to leak. Clean them and make sure they are tight.

@@DKCustomProducts,No regrets ever following, I greatly appreciate your input,as I stated in another post this is our first bike ( street). Thank you.

We talk about the Optimum Temps for the Sporty Evolution engine in this video...starting at the 1:10 mark- ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rWOdQOtDv6A.html The short of it is between 320-375 F. The video linked above has some good info, as does this report link, down toward the bottom- www.dkcustomproducts.com/sleeper-performance-mods.htm

Thank you , dont know how I missed it , great info , appreciate you for taking time ,