Plus and minus of lifters with additional flow to top end.

[guesscrazy]

Got a set of WFO Larrys 842se lifters for my new build. What are the benefits and any negatives?

[98fxstc]

I have the 2313SE lifters and have now fitted the travel reducers
They are good
The 842SE's are supposed to be a better lifter
but I would have got the travel reducers with them

few posts here discussing the limiters/reducers
those that have them are very happy
those who don't, don't know any different

[Thermodyne]

The plus is more oil to the rocker box.

The minus is more oil to the rocker box.

It all comes down to how much oil do you need up there.  And how bothered are you when the excess carries over into the breather vents.

Most people up the oil pressure when they build a twin cam motor.  I don't know why, but they do.  With the pressure boosted there is already extra oil to the rocker box.  Then you add a tappet with a hi volume metering setup and you get even more oil up there. 

I like to keep the pressures down and use standard metering tappets.  But that's just me.

[q1svt]

The story goes, when HD was developing the twin motor, it had a higher [than today] oil flow to the heads.   One of the issues that was discovered was the motors oil temp was higher than they wanted.  To fix the issues they added an oil cooler [NOT], they simply reduce the oil flow to the heads.

When valve springs compress & expand, that action creates heat. Oil is used to cool that heat, even in motors that are water cooled...  When Valve Spring get hotter than designed, they fatigue, lose spring pressure, and break...

More oil is good, just need to address cooling of oil.  HD and aftermarket oil coolers have too high oil temp thermostat  ...  If you look at other motors that are air cooled in performance applications OIL is used as an additional cooling source.

[Thermodyne]

The story goes, when HD was developing the twin motor, it had a higher [than today] oil flow to the heads.   One of the issues that was discovered was the motors oil temp was higher than they wanted.  To fix the issues they added an oil cooler [NOT], they simply reduce the oil flow to the heads.

When valve springs compress & expand, that action creates heat. Oil is used to cool that heat, even in motors that are water cooled...  When Valve Spring get hotter than designed, they fatigue, lose spring pressure, and break...

More oil is good, just need to address cooling of oil.  HD and aftermarket oil coolers have too high oil temp thermostat  ...  If you look at other motors that are air cooled in performance applications OIL is used as an additional cooling source.

Seriously?  Oil is not used for cooling in race motors?  They don't spray piston undersides with oil.  They don't spray oil directly on valve springs?

On a Twin cam the oil that goes up the push rod lubes the rockers and valves, and it cools the springs.  Nothing has change with this.  Same set up from Evo to Twin Cam.   Ya it picks some heat up from the head surface, but not enough to make it oil cooled.  No more heat is picked up than was done with an Evo or Shovel head.  On a Twin Cam the oil gets over heated from spraying the back side of the piston.  And with limited piston skirt to transfer heat, spraying the piston is pretty much mandatory. 

Yes the oil thermostat is set a little high on the Harley adapter, but its the flow through the adapter that is the real issue.  There just is not enough.  And the location of the cooler is less than optimal. On the TC you can change that oil thermostat to one with a lower setting.  But it does not lower the maximum high temp on a long hot ride.  It just lowers the temp that oil begins to flow through the cooler.

[q1svt]

Seriously?  Oil is not used for cooling in race motors?  They don't spray piston undersides with oil.  They don't spray oil directly on valve springs?

You really need too get out more...   LMAO



SAE International - https://www.sae.org/publications/technical-papers/content/2016-01-8100/

MAHLE International - https://www.mpulse.mahle.com/en/do-and-get/8064.jsp

Comp Cams - https://www.motorator.com/blog/gm/comp-cams-chevy-ls-engine-valve-covers/#.XcLI7y3MwzU

AND THESE ARE Not even air cool motors   

[dsvracer]

a must read for anyone who wants to make more power and reduce break downs from oiling problems. thanks dsv

[q1svt]

On a Twin cam the oil that goes up the push rod lubes the rockers and valves, and it cools the springs.  Nothing has change with this.  Same set up from Evo to Twin Cam.   Ya it picks some heat up from the head surface, but not enough to make it oil cooled.  No more heat is picked up than was done with an Evo or Shovel head. On a Twin Cam the oil gets over heated from spraying the back side of the piston.  And with limited piston skirt to transfer heat, spraying the piston is pretty much mandatory. 

Interesting NO Change...

There are/were many articles written, but here is a current one from Cycle World, 2016 twinnkie history.

"Now a discovery split the temperature problem in two. If reducing oil temperature to make an oil cooler unnecessary is a paramount goal, engineering saw how to do it; circulate less oil to the engine's hottest parts – the cylinder heads."

There are many more quotes that'll show problems with the Twin-Cam engineering.  A very good reads:
https://www.cycleworld.com/harley-davidson-twin-cam-v-twin-motorcycles-history-big-twin/