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[Twism_23]

Yes she runs much quieter and has very good power. I haven't had it dyno end yet, next month. I am hoping the changes help my motor have a long life.


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[HILLSIDECYCLE.COM]

Reher-Morrison established a battery of testing on springs many years ago, and was published in National Dragster Magazine, and found the ONLY loss was upon intial start.
Scott

 

[PanHeadRed]

The mother ship went to beehives in the 96" and 103" but kept the overkill springs in the 110", can't imagine their reasoning.

Profit, not performance.

[HD Street Performance]

"Lets take power loss off the table"

Ok Some good responses and the usual,  what you need to buy or what you need to read or what shop is the best lol
Steve Cole discussed the gm lifter as it relates to the topic. I try to avoid gm / harley comparisons but in this case I see the relevance.
Consider the Chevy L92 SUV motor
379" 402hp valve spring pressure 90lb seat @ 1.8" 264lb @ 1.3
Valves are heavy. 2.16 intake, 1.59 exhaust

Regarding the cvo 110 springs they are 175# on the seat and the damper design likely is introducing noise of its own in my opinion.

[HILLSIDECYCLE.COM]

What lift? lol.

[Steve Cole]

Now that your looking at the common parts between a GM LS motor and a HD look at the mass of the rest of the valve train. A HD rocker is heavier than an LS and the HD push rod is longer. So if we take the mass of the valvetrain from one and compare it to the other you could deduce what you may need to have since they both run similar camshaft profiles and RPM ranges. The big difference is one kills lifters  and the other doesn't. The heavy pressure valvesprings are not the answer IMHO and I think too many people use way to much pressure for what these engines are doing. Combine that with the low oil pressure and the lifter will take a beating.

We run lift in the .55" to .62" range in the LS engines with a big whopping 125 lbs on the seat and 330lbs over the nose, turn the engine 8000 RPM with no valve float or lifter issues. Make 600 Hp, so divide that down to the 2 cylinder HD engine and you would be right about 150 HP. Kind of funny how it all falls right in line,between the two eninges.

[TorqueInc]

 The majority of the small diameter dual/ no dampener  springs  (1.26-1.35) OD for the LS are right at home in the majority of HD builds and are very reasonably priced compared to most of the Harley specific  beehives and dual springs from .....everyone who sells them.

  Some are good to .675 lift......have used them under 660-2,640 S&S and a 647 RS and so far so good

  Joe Lewis from SEC Johnson concurs with Steve on the oil pressure ...not sure how you can argue the point.

  Far as noise I think the pushrods are also a big culprit....swapping out S&S adjustables for Trend fixed length tapered pushrods damn sure quiet's one down.

[HD Street Performance]

No argument here but the pressure stated is in conflict with other components in the system including and especially the piston oilers.

[HD Street Performance]

Remember the 1st twin cams, they had heavier valves and lighter springs. Tell you what with a TW37 they would pull a high 5k rpm at which time they were done breathing. No valve float.

[hrdtail78]

In comparing the two applications. I wonder what the difference in growth factor is.   Are the HD lifters working harder?  I have found setting a tad deeper helps with noise.  I really think I set them to run mid travel when hot.

My ideal oil pressure would be between 20-40 idle no matter what engine speed. 

[HILLSIDECYCLE.COM]

In comparing the two applications. I wonder what the difference in growth factor is.   Are the HD lifters working harder?  I have found setting a tad deeper helps with noise.  I really think I set them to run mid travel when hot.

My ideal oil pressure would be between 20-40 idle no matter what engine speed.

Good point.
Scott

[HD Street Performance]

Then when HD decided to consolidate parts inventories (XL) and equip the twin cam with beehives and lighter valves with 7mm stems they went up in spring pressure with the one size fits all beehive.
By the way the 16lb pressure number agrees with Delphi white papers and that is minimum. What I am suggesting is a relatively high spring rate and lower seat pressure to allow a faster recovery. All of that said enough pressure over the nose to control the valvetrain in the motors operating range

[INDEPENDENT_1]

Jason and Scott and anyone interested. In regards to pushrod depth into the lifter, I had a discussion with Bill Gaterman (Gaterman lifters) about this once because I noticed he had a different preload suggestion than other lifters. Gaterman is no dummy. He worked for crane for years and was Harvey Cranes right hand man IIRC for many years. His testing for his lifters showed that they lasted longest and operated quieter at something like .072 on the intakes and .063" on the exhaust or maybe it was vice versa but I agree with both of you guys, I have had better luck setting them a little deeper. I was on the phone with Steve Cole about a tuning issue that was the first time I had experienced the problem (bike would die after running about 3 seconds just at random different recording and sampling sessions and run perfectly most of the other times). He explained that because I was starting the recording before actually starting the bike, it sometimes caused this issue I was experiencing and only certain bikes at certain times would do this for no known rime or reason). That's just something I like to do so I can see what's happening during startup with IAC tables etc and told me to just start hitting the record button after the bike was running and it fixed the problem. Anyway, I started talking to him about this thread and he explained the harmonics of these motors, the lifters, pushrods and valve springs we use in them and that some run quiet and others do not that may have the same parts used in them. I'll let him explain his thoughts in depth on that but it sure made sense to me.

[hrdtail78]

OT. I have found slowing the sample rate way down helps the run for 3 second and die problem sometimes.

[HD Street Performance]

Oil pressure and feed is a little off topic but very relvant to the noise issue.
When I last spoke with Dan Thayer he suggested the cam lobe profiles had exceeded in terms of intensity what the rest of the valvetrain could follow. He proceeded to explain max oil pressure needed in the TC was 32 and bonneville runs were done with 10lbs
Some of what Steve mentioned I found interesting especially the influence of oil coolers,  had not considered that before.