Hmmmm. An oil comparisons, written and conducted by Amsoil, claiming that Amsoil is better.... interesting.

 

Just curious. Who did you have dyno tune your M8 and what Tuner did they use?

 

think Steve Cole early on mentioned about a potential concern of coking in the oil passages, but may have been someone else...I'm sticking with conventional like I always have, but added the fan assisted oil cooler which so far looks like the way to go in reducing oil temps, and change it at 3K ish or as necessary...can't imagine that combo/plan torturing the additive package enough to keep it from performing adequately..I just don't care to go 5K regardless of circumstances and I sure don't care to dump spendy synthetic at 3K...time will tell tho

 

If I had not worked today I would have changed the oil today and put the bike on all Amsoil. Bike still has less than 200 miles on it. Will ride it to work in the morning. This weekend they are calling for a ice storm. So maybe next weekend I will get to put modern lub in my vintage modern motorcycle.

 

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I don't think of myself as an oil expert but do have more then a few yrs under my belt researching & testing motor oil for a project i was working on along with 4.5+ decades under me belt wrenching bikes/cars including rebuilding motors & restoration work etc giving me a well rounded background.

So with that said i will give your question a shot & say i think your concern using std dino holds merit because it could cause the issue your reff to if it gets hot enough for long enough period of time.

So to be safe i rec you use a quality motorcycle/v-twin specific 20w-50 full syn oil like for example Spectro's Golden(semi-blend) or Platinum (full syn) motorcycle oil/M1-v-twin/Amsoil-MCV mfg's and not run it more then 4k-5k miles even though some oil mfg's state & or rec going 6k-8k+ miles on their full syn oil in an HD V-twin i'd not do it or rec it either.

HD's full syn syn3 oil placed in top 5 of 17 20w-50 bike oils tested in a lrg oil test Amsoil did a few yrs ago but i didnt like the way it performed in summer heat in my 09 96" vs Spectro's 20w-50 bike oil for HD's.

HD's Syn3 had more valve/lifter noise along with lower oil pressure (especially in summer heat) in my bike.

Also use a quality hi efficiency oil filter specifically mfg'd for use with full syn oil ,M1,amsoil,Bosch,Valvoline,Purolator and others offer them.

HD's 5 micron oil filter seem's to be a decent / adequate oil filter too.

I use either Spectro's semi-blend or full syn 20w-50 that's specifically designed & formulated for lrg disp HD V-twins,also use spectro oil thats specifically designed & formulated for the diff operating cond's in the prim case using spectro 85wt prim oil (mineral oil) & spectro 75w-140 syn 6spd trans oil.

I change the motor oil & filter @ 4k-5k miles max on HD's 5k mile rec,change prim case oil when motor oil & filter is changed @ 4k-5k miles vs HD's rec 10k mile prim case oil change and change trans oil @ 10k miles or 1yr (whichever is 1st) vs HD's rec 20k mile trans oil change.

Good luck.

Scott

 

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" added the fan assisted oil cooler which so far looks like the way to go in reducing oil temps "

Your on the money with that statement.

I installed a fan assisted oil cooler on my bike 2 yrs ago which reduced oil temp in summer heat approx 50deg F which resulted in multiple improvements in engine perf & overall riding comfort right off the bat which are as follows:

NOTE-KEEP IN MIND IT'S ALSO THE OIL'S JOB IN AN HD V-TWIN TO REMOVE HEAT FROM THE MOTOR SO WHEN OIL TEMP IS REDUCED APPROX 50DEG F IN SUMMER HEAT MOTOR TEMP IS ALSO SIGNIFICANTLY REDUCED @ THE SAME TIME TOO.

* OIL PRESSURE @ IDLE & CRUISE IMPROVED BY A SOLID 10-12PSI.

IT WEN'T FROM BEING 7-8-ISH PSI @ IDLE & 32-35-ISH PSI @ CRUISE WITHOUT THE FAN ASSISTED OIL COOLER TO NOW A SOLID/CONSISTENT 18PSI @ IDLE & 45-47PSI @ CRUISE USING SAME MFG'S GRADE 20W-50 MOTORCYCLE OIL IN 90+ DEG F SUMMER HEAT.

* VALVES/LIFTERS NOW REMAIN QUIET.

* MOTOR STOPPED DETONATING.

NOTE, TECHRON CLEANING OF CARBON FROM COMBUSTION CHAMBERS,PISTONS,VALVES & INJECTORS JUST PRIOR TO EVERY MOTOR OIL & FILTER CHANGE WAS PARTIALLY RESP FOR REDUCING/STOPPING DETONATION TOO)

* MOTOR NOW RETAINS MOST OF THE POWER,TORQUE & CRISP THROTTLE RESPONSE IT USED TO ALWAYS LOOSE IN WARMER SUMMER HEAT.

* HOT RESTARTS POST FUELING UP IN SUMMER HEAT ARE NOW FASTER/EASIER DUE TO BATTERY/MOTOR/STARTER ALL BEING LESS HEAT SOAKED.

* BIT LESS HEAT IS HITTING THE RIDERS NOW TOO.

I also installed Wards Cooling Fans that are designed to reduce temp in heads & upper cyls too which is a good thing ,but they weren't a large contributor to reducing oil temp 50deg f in my bike in summer heat which is where the fan assisted oil cooler shines vs non fan assisted oil coolers that fall on their face efficiency wise when a bikes sitting still @ stoplights & or when in slow moving traffic due to lack of airflow thru the oil cooler in those cond's.

Scott

 

Thanks for chiming in Scott.

I'm only going synth in the motor for the concern stated previously - those exhaust valve cooling ports. Like you, I'll be adding a fan assisted oil cooler come spring. Also, I've looked, and it doesn't appear Howard's fans are going to be useful on these new heads.

Gonna be a learning curve over this next year; should be interesting.

 

SW Thomas The tuner is an HD pro street tuner and Smokey Mountain HD did the install and the dyno run.

 

Harley actually prefers performing the smart tune on the dyno instead of riders doing it, Claims results are better on the dyno because you can cover all the cells.

 

Oil Coking is the side effect of cheap lubricants, not top grade "True Synthetics". Your logic is backwards actually. There are more benefits to a True Synthetic that what many people who have no understanding of lubricant technology realize. Sure, it's a bit more investment, but no big deal if you are performing the service yourself. In fact, oil analysis have proven 3K oil changes with top tier lubricants is a waste. The lubricant will have more life remaining.