New solid roller ordered. Whew

Fred Ficarra · Feb 26, 2010

Re: New solid roller ordered. Whew,,

Oh Ron, I checked wobble too. I tried to follow your description of the test; dial indicator against the valve head that's pulled out of the guide, but still fully inserted. Pulled the valve away from the guage, zeroed it and pushed toward the guage. .0025 on the exhaust side. Too tight? The new valves feel like the old ones that have been going up and down for 35 years.

Z15CAM · Feb 27, 2010

Re: New solid roller ordered. Whew,,

The clearance between the Guide and Valve Stem in good shape is .001" for an Intake and .0015" for exhaust. You require a Special Dial Bore Gauge that will fit into the Guides to measure this accurately. Checking for Wobble at the Head of the Valve does give you a good indication as to the condition of the Guides.

You measure .0025" Wobble on the Valve Head of an exhaust port. Hummm I'm starting to wonder if them .004" and .006" Wobble figures I'm shelling out are Correct as they do seem somewhat big now that I look at them. I have SBC Head with fresh full length guides and valves and will do a Wobble Measurement to satisfy my curiosity and let you know what I get.

Man with that compression an Cam the Engine is going to THUNDER ;o)

Fred Ficarra · Feb 27, 2010

Re: New solid roller ordered. Whew,,

Z15CAM said:
The clearance between the Guide and Valve Stem in good shape is .001" for an Intake and .0015" for exhaust. You require a Special Dial Bore Gauge that will fit into the Guides to measure this accurately. Checking for Wobble at the Head of the Valve does give you a good indication as to the condition of the Guides.

You measure .0025" Wobble on the Valve Head of an exhaust port. Hummm I'm starting to wonder if them .004" and .006" Wobble figures I'm shelling out are Correct as they do seem somewhat big now that I look at them. I have SBC Head with fresh full length guides and valves and will do a Wobble Measurement to satisfy my curiosity and let you know what I get.

Man with that compression an Cam the Engine is going to THUNDER ;o)

Thunder? I sure hope so. Back in '69 with the L78 and M/T Super Scavengers OPEN (at the track of course) the sound was nearly fatal inside the car. Of course now days lots of racers are that loud,,, but still.
And to that end, the exhaust system from the headers back is getting a rest. Yep, removed it. It's holding up a wall in the garage. A pair of collectors and Super Traps will do the deed this season. I wanna hear the 'sound' again.:yes:

Z15CAM · Feb 28, 2010

Re: New solid roller ordered. Whew,,

He's my Valve Wobble Measurement using New Silicon Bronze Guides in a SBC 291 Casting with .310" Stem 2.02/1.6 Valves. Guide to Stem Clearance for Intake is .001" and .0015" for Exhaust Valve.

INTAKE VALVE WOBBLE- Measured at 1.100" on Stem from Top of Guide = .003"

EXHAUST VALVE WOBBLE- Measured at 1.100" on Stem from Top of Guide = .005"

There we go my .004"/.006" was not that out to lunch and would be considered the Extreme in consideration of Knurling Vs Guide Replacement. I might add that Knurling should never be considered a Long Term Fix.

I can't say how you Measured your Wobble to get .0025" for the Intake but you appear to be right on the Mark even with the Shorter Guide ;o) I think the Larger Diameter BBC 3/8"(.375") Dia Valve Stem may result in less Wobble Measured then say with a Smaller Diameter Valve with the same .001"/.0015" Clearance as it would have less tendency to Tilt due to the larger contact area within the Cylinder of the Guide.

Wobble is not a Definitively Accurate Measurement for Stem to Guide Clearance but does give you a Good Indication as to the condition of the Guide. Guides generally wear Larger at both ends with the Center remaining Intact. A worn Guide will look something like this " ) ( " , something like a Worn Cylinder in a Block that make Ring Gap to Vary and to cause them to Flutter. A Worn Guide will have an Oval Shape, pointing to and away from the line of the Rocker Arm, when looking into the Top of the Guide and is the Line you should use when Measuring Wobble as indication to the condition of the Guides.

HERE's a very interesting U-Tube Video of the Valve Train under Extreme Conditions. NOTE how much the Valve Stem can Oscillate with Improper Spring Pressure - Siish!:

Looks to be a Shaft Roller Rocker System with Manley Retainers.

I guess you're at Mock-Up Stage. After Degreeing and installing a Hi-Perf Cam always Check Valve to Piston Clearance. I roll a Bead of Plumbers Putty, just under 1/4" in Diameter, and place an "X" pattern of it across the 2 Valve Reliefs of #1 Piston, Spray the Valves with Rust Check (10W40 will work) so it will not stick to the Valves, Mount the Cylinder Head, with a few Head Bolts using the intended Head Gasket, and turn the engine through 2 Cycles. I use a Razor Blade to dissect the Putty and measure with a Dial Caliper.

The General Minimum Valve to Piston Clearances are .080" Intake and .100" Exhaust. The Valve is always closest to piston upon Opening and Closing. As you advance a Cams position the Intake Valve becomes Closer and the Exhaust Clearance further. I have my 288AR installed at 104 Degrees which is 2 degrees advanced off the recommended 106 degrees to increase my DCR. My clearances are .080" for the Intake and .130" for the Exhaust with 25.7cc Domed Spd-Pro Pistons and a .019" Shim Gasket. Moving the Cam 2 Degrees either way seems to change clearance approx Plus and Minus .010" either way.You can add another .020" if your running a .039" Composite Gasket for them Alu-Heads. I believe all BBC TRW/Speed Pro Pistons have identical Valve Reliefs and designed for Stock Application to clear 1.19 or 2.21/1.88 Valves. Your 282/290 at .020" duration and 1/4" shorter stroke, which moves the piston away faster, should propose no issues. Just remember when your checking the putty to observe the clearance between the Edge of Valve to sides of the Relief notch in the Piston when running a 2.21" or larger Intake Valve.

Z15CAM · Feb 28, 2010

Re: New solid roller ordered. Whew,,

I have my 288AR installed at 104 Degrees which is 2 degrees advanced off the recommended 106 degrees to increase my DCR. My clearances are .080" for the Intake and .130" for the Exhaust with 25.7cc Domed Spd-Pro Pistons and a .019" Shim Gasket. Moving the Cam 2 Degrees either way seems to change clearance approx Plus and Minus .010" either way.

If I had that cam installed at 106 Degrees my Clearances would be .100" Int /.120' Ext.

Fred Ficarra · Feb 28, 2010

Re: New solid roller ordered. Whew,,

Will do Ron. Now if Harold would just answer the phone. He seems to have fallen off of the planet!???
Did anyone notice the end of the video? The valve is seen rotating as if it's in contact with the seat at the time it's rotating. What we're seeing IMHO, is the spintron stop-action showing the valves rotation after it has lifted from the seat, and that's a very good thing. It keeps valves working for more than a minute or two. I question the producers of the video and ask what's in it for them?
Also, the rockers are perfectly stable. Neat. If my car needs a roll bar, it'll be done on the same street as the inventor of the spintron lives. With any luck I can talk to him about this video. Thanks again Ron, gotta call Harold again. Well, maybe not. Don't want to be a pest.
Edit; Anybody see valve float in that video? I didn't.

Fred Ficarra · Mar 1, 2010

Re: New solid roller ordered. Whew,,

Harold is OK!!! Whew.:hurray: He's gonna send an email progress report to me this afternoon. Lunati has the cam scheduled to grind so I should get my stuff later this week.
We talked about the valve-float video. He said, without looking at it, we were seeing valve spring resonance. The spring can lift off of its seat as much as .250. That's why we have steel shims for our aluminum heads. Also the inner and outer springs resonate at different rates. Probably why we saw the valve tipping from side to side. Find a cure=get rich.

OK, Herold didn't say all of that stuff. I took analytical license.:yes:

Everett#2390 · Mar 2, 2010

Re: New solid roller ordered. Whew,,

Valve float has been, and will be, with us forever. The OEM's use dual springs of different rates to compensate/combat harmonics. This is the event you're seeing.

Harmonics so pronounced, the spring compresses on its own, valve off its seat and maybe collide with the piston. Springs can be made of heavier wire diameter, but then the rate is so large, the valve will cup at the head when slammed against the seat and can be pulled through the seat into the port. Bigger wire diameter and through use, the spring loses its rate, becomes weaker through fatigue, just like bending a length of wire in your fingers, it breaks/fractures. Hence the reason Comp racers check the spring pressures after X number of runs, and change them out between rounds or events when the pressures start to fall off - preventative maintenance.

Stiffer springs, more friction, short life. Weaker springs, less rpm's, longer life. Heat destroys springs, more oil, cooler spring, but then, more equals oil windage/friction. This is why Comp racers use molybendum grease, the stuff doesn't wear off, to lube the rockers and stems and have a spare string of springs hanging on the wall, and keep oil from the top end.

JMT's. Think electric solenoids for valves and camshafts - ECM controlled, it's coming in the future.

Z15CAM · Mar 2, 2010

Re: New solid roller ordered. Whew,,

There seems to be a less Harmonic Wave looking at Beehive Shape Springs in action. I'm referring to the Double Coil shaped like this "/ \"; NOT the Cheater Springs designed for Small Spring Pockets that are shaped like this "\ /"

Kind of funny when the Beehive Shaped Spring came out, it led to some confusion over the terminology. Puppies referred to their Valve Train having Beehives and Schooled Old Timers refereed to the whole Valve Train as the Beehive as we considered a Valve Train inconsistency if the Tappets didn't BUZZ like a Beehive.

Do any recall the Old "( )" Shaped Valve Springs that where used in Model T's - LOL

Fred Ficarra · Mar 2, 2010

Re: New solid roller ordered. Whew,,

With overhead cams there's a system that uses a rocker arm to follow the valve and force it closed. Springs did very little. I'd have to redesign it in my head so don't ask for details. It's cocktail hour.
Got it! It follows the push-down arm with another arm that pulls up. It works on the bottom of the retainer. There must be some kind of spring to take up the slack.
Seems it was a Honda design from the '70s.

Z15CAM · Mar 2, 2010

Re: New solid roller ordered. Whew,,

The Desmo (Desmodromic) Valve Train System is used by Ducati in most their Motorcycles. There are NO Valve Springs and utilizes a SOHC, Shaft Mounted Forked Rockers that ride 2 Cam Lobes per Valve, Hemi-Combustion Chamber and, in my opinion, is the Ultimate Valve Train Design. My Laverda 750SF is also a SOHC with Cam Lobe Interfaced Shaft Rockers but utilizes Typical Valve Springs to return the Valve and keep the Rocker on the Cam Lobe. Fords famous Cammer 2-Valve SOHC Hemi V8 engine was based on using Cam Lobe Interfaced Shaft Rockers. Cosworth where building DOHC Engines using both Ford and Chev Blocks about this time. My 69 Ford Lotus Cortina had a Push Rod, Cross Flow, Inverted Hemi, 4 Cly and the Heads had provisions to convert the engine to SOHC. Seems to me, very much like today, nobody knew where they were going with engine design back then - LOL

My Dream Engine then, and still is a SBC with Cosworth Heads, Hilborn Stacks and Faulkner Mechanical Fuel Injection with a Donovan Cam Gear Drive - What a Sweet looking piece of Art - Remember the Cosworth Vega. Siish! In 71, Toyota crucified the North American Muscle Car Industry, in my opinion, with their SOHC Inline 6 Crown Model.

71 S60 Crown, slightly smaller then a Dart: Believe me, its Hi-Perf. Came with 138ci 2.3L 120hp @ 5800rpm & 127ftlbs torque that was more like 160Hp and easily revved 6800rpm, InLine SOHC 6, BIG 3 BBL Holley Style Carb, 4 Spd/OD, Full Frame (stronger then our 1/2 Tons),Mine came with 15" Wheels (Not 14"), Heavy Duty Springs with Trailer Hitch, Front Dual Piston Disc-Brakes, Posi Rear and Heavy Gauge Skin that didn't Rust. If Americans didn't know better they might mistake it for a Barracuda or an AMC, perhaps a Beaumont - LOL - Never getting close enough to get a good look: Not the most Aesthetic Design; but it did grow on you and they where FAST and Handled Wonderfully. The more Inclement the Weather and Rougher the Roads, the better the Car Performed. I drove one through a summer and most the winter driving inhospitable conditions for 100rds of miles every week to remote Northern Ontario locations where I worked. Nothing I have driven compared to the way that Crown handled speeds over 8" deep Pot Holes and Slush or Snow, simply an Amazingly Tough and Predictable Fast Ride. My 84 242GL had the 4 Cyl ME 2.3L Multi-Port EFI Engine, 3SPd Auto/OD and didn't feel to have near the performance of the old Crown. Volvo's have been my Primary Ride most my life and wish I had that Crown today.

Ford's Cammer:

Picture that with Desmo Cam Lobe Interfaced Shaft Forked Rockers without Springs.
It might Fit under your M/T's ;o) GM and Chrysler cried WOLF to American Racing Authorities when Ford was about to unleash the Cammer and Ford backed down - No Doubt COST was the main issue. That's some Timing Chain.

Desmodromic Schematic:

Desmo in Action:

Desmo Tappet Adjustment:

I would not want to pay Shop Time for this Adjustment; but looks easy enough.

Here's another Spring-Less System with Push Rods - Can't see this being a Hemi and looks cumbersomely heavy with too may moving parts - Notice they don't Rev the Engine - LOL

Here’s some more Racing Trivia. The Term “Super 7” was Marketed by MFGr’s to Advertise their Hi-Perf Retainer Product after Engine Inspectors discovered a CHEAT where Teams in Stock Class Racing had the advantage to WIN by redesigning the OEM KEEPER (LOCK) that mates the Stock 7 Degree Retainer to Valve interface; thereby, raising the Retainer by .020”. This allowed room for Taller and Heavier Springs, thus more Revs. I believe the Cheat was discovered when a Racing Team tried to run a -.020" Lobe Base Cam; meanwhile, the KEEPER modification had escaped Inspectors for some time - Back then who would think about inspecting a Keeper. To day, you can Raise or Lower a 10 Degree Retainer by +/-.050" using a Keeper based on the Super 7 CHEAT.

As usual I got carried away and spend too much time editing - LOL

68Lemans blue · Mar 2, 2010

Re: New solid roller ordered. Whew,,

Thanks Ron....Happy motoring

Fred Ficarra · Mar 2, 2010

Re: New solid roller ordered. Whew,,

Ron, you need a WOMAN!!!

The coffee is good this morning so I remembered where I first saw the valve return system mentioned in my last post. Yep, Honda. 1964 or so. The 450 vertical twin. I'll paraphrase what Hotrod Magazine said about it. Able to leap tall buildings in a single bound, faster than a speeding bullet, more advanced than an Indy Ford.
The return arm was controlled by a torsion bar. Slick. The guy talking in the Ducati video seemed a little unsure. He wanted the clearance checked at TDC. (?????) And didn't he talk about clearance on the return arm. How can that be? And the graphic at the bottom of the screen says 'hydraulic lifters'. Clearance?
And the last video sure looks like a SBC, but with so few examples out there, it's hard to be certain. Also the announcer says the system will free-up untold amounts of horsepower. Wrong. All cams use about 3 horses. No matter how strong the force needed to push down on a spring, there's another one pushing up. Well, single cylinder engines excepted. And that is what makes my valve invention less desirable. (no, I'm not telln')

Z15CAM · Mar 2, 2010

Re: New solid roller ordered. Whew,,

Fred: Notice the Exhaust Port of that Ducati Engine, almost, Exits the Cylinder Head right off the top of the Cylinder head. You can't get, much, less restriction then that. The Valve Guide Angles between the Intake and Exhaust are tight and close to being parallel to the Bore and at 90 degrees to the Top of the Piston.

No wonder 2 Cylinder Dukes can Win competing against 4 cylinder engines that Waste Design Space, use Heavier Components and work against Valve Spring Pressures.

YES the Tappet Adjustment is somewhat tedious but not that complicated in my world.

I'm still married but have been separated for 6 years after 15 years of marriage and raising 6 children (She came with 3). YES I'm bored but for sake of self-preservation, I DARE NOT live with that Woman, no matter how attracted I am too her - LOL

Fred Ficarra · Mar 2, 2010

Re: New solid roller ordered. Whew,,

Z15CAM said:
Fred: Notice the Exhaust Port of that Ducati Engine, almost, Exits the Cylinder Head right off the top of the Cylinder head. You can't get, much, less restriction then that. The Valve Guide Angles between the Intake and Exhaust are tight and close to being parallel to the Bore and at 90 degrees to the Top of the Piston.

No wonder 2 Cylinder Dukes can Win competing against 4 cylinder engines that waste Design Efficiency and work against Valve Spring Pressures.

The world of big motorcycles ain't your daddy's Honda 90 anymore.:noway:
Drag racing is a real eye-opener.

OK, back to the video. He's talking about clearance at the bottom of the keeper. (he meant retainer) How can that be??? The valve must seat, not be loose. And notice, he never gets a guage under the retainer unless he pushes down on the arm. I rest my case.

Z15CAM · Mar 2, 2010

Re: New solid roller ordered. Whew,,

I agree he did not use correct terminology a couple of times describing what he was doing but I totally understand the procedure as I've set Rocker Arm to Cam Lobe Interfaces numerous times on Ducati 350 Singles and 750SS's but that was many Years Ago. You see that Rocker Shaft Spacer Clip, I usually had to look for it for an hour after I remove it - LOL - I think he did an excellent job. You must consider that you are playing with the clearance difference between 2 Cam Lobe Profiles to obtain the recommended Upper and Lower Clearances using one Rocker Arm; which if I recall is about, .002" top / .004" bottom totaling .006". The Desmo Valve Train is awesome and unbelievable the way it Revs SO Effortlessly. Once set you only have to check the clearance once a Season, as you're playing with Low Weight Components and no Spring Pressure.

Fred Ficarra · Mar 3, 2010

Re: New solid roller ordered. Whew,,

Ron, any chance of posting a drawing/blueprint of the system? My pea-brain doesn't understand why there's suppose to be clearance on the bottom.

Z15CAM · Mar 3, 2010

Re: New solid roller ordered. Whew,,

Look at the PIC I posted earlier.

I see I made an ERROR in my description of the DESMO system when I stated that there was 1 forked shaped shaft rocker riding on 2 cam lobes. - There are indeed 2 independent rockers pivoting on separate shafts and riding their own Cam Lobe. One on top for Opening the Valve and one on the Bottom for Closing the Valve. With the Assembly Clocked at TDC, Unless I misinterpreted that Video, the Top Rocker runs with a .004" clearance and the Bottom Rocker runs with a .002" clearance equaling a total UpLoad Clearance of .006".

Earlier I said the clearances where .002" top / .004" bottom totaling .006", obviously I had it reversed.

why there's suppose to be clearance on the bottom.

If I recall that .002" Clearance has something to do with the Momentum of the Valve as it approaches the seat and Forces associated with Rising Compression as the Piston travels upward that may cause BINDING issues. You are working with a tracking clearance between 2 Cam Lobe Profiles. Interesting, why there would NOT be Zero Clearance which you would expect in order to keep the Valve seated at TDC on the Firing Stroke.

I found this Data on Adjusting the Desmo Valve System: http://www.ducatitech.com/2v/maint/adjust/ The Info concurs with the Video such that: "007 on the closers are extreme, they said that "up to 3 thou is OK". And "always run the openers at .004"."

This Guy says:http://www.ducatimeccanica.com/desmo_valves.html

Experience has shown that it's better to leave a little more clearance on the Exhaust opener. And trying to set a zero clearance on the closers is generally hopeless and *always* leads to some binding somewhere. It is much safer to run loose than tight. So the specs I've used for Ducati desmo valve adjustments for the past 25 years are:

Intake:
opener - .1mm (.004 inch)
closer - .025mm to .06mm (.001 inch to .0025 inch)

Exhaust:
opener - .15mm (.006 inch)
closer - .025mm to .06mm (.001 inch to .0025 inch)

Seems more in the Rhelm of my thinking; such that, the Upload Gap would be more like .005" with .004" on Opener plus .001" on the Closer. He allows .006" clearance for the EXT Valve Opener, +.002" for Heat Expansion I assume.

I'm sure I understood this some 40 years ago when I was servicing the 2 Ducatis but now I must concede that I have CRAFT Disease or perhaps Al-Timers is readily creeping up on me - LOL

In the meantime we wait for your parts ;o)

Fred Ficarra · Mar 3, 2010

Re: New solid roller ordered. Whew,,

There it is! A SPRING on the near valve closer! Remember when the guy in the video was pushing down on the closer to get the feeler guage in? He could only do it when he pushed down and moved the arm against a spring.

Yep, the spring takes up the last of the slack to insure a seal but isn't responsible for valve control. The closer-arm does that. And when he pushes down on the closing-arm, he's measuring clearance between it and its cam as if there were no spring. And that's hard to do because it's akin to a conventional valve being clearanced at the retainer, not the valve tip. So, with the closing arm pushing the valve up and closed, the feeler shows .004. When the closing arm is pushed down against the spring causing its other end to contact the cam, the added clearance gives .006. Cool. Us gearheads can do that blindfolded!
Edit; Note when the forceps are used. He backs away the cam to remove the retainer. He pushes down against a spring. The valve is still being closed by the spring that now doesn't have its cam doing the work.

Also look past the work, into the valve cover when he's changing the keeper. Yep, right under the opening rocker. There's the spring.
And not a word yet from Harold.

Z15CAM · Mar 3, 2010

Re: New solid roller ordered. Whew,,

By Jove you're right Fred there is a Spring on that Closer Rocker and works exactly they way you describe. Can't believe I missed that and can't believe my memory is that bad. Between us 2 Gear Heads we figured it out ;o)

This was an interesting puzzle and kept us occupied for a time, waiting for your Cam. They state that the Opening Rocker of the Desmo System requires attention every 6000 miles. Can you imagine the task of setting Lash on 32 Rockers if you had Desmo Heads on that 427 of yours - But man would it BUZZ - LOL.

New solid roller ordered. Whew

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