Darth_V8r

iTrader: (4)

I wanted the benefits of a solid valve train with DD reliability. Putting around with shims took 2 hours. I put 20k miles on that setup without ever adjusting it. Made a **** ton of power on demand, revved far better -- cleaner, quicker, and higher RPM -- than the hydro valve train ever did, and when I built the 428, I did the same thing as I did on the 346. Probably never build another hydro valvetrain.

handyandy496

iTrader: (9)

Congrats on your numbers! Good to know they have varied thickness sized lash caps but .001 yikes.
Nice explanation here!

speedtigger

iTrader: (16)

Actually, you do have to make a solid roller camshafts lift greater to account for lash. If you have .010" lash, you will need .010" more lobe lift to account for this. If it is a .024" lash setup, you will need to make the lobe lift .024" greater to account for this.

Our LLR low lash solid rollers for standard deck LS engines are .010" lash. This is because the lash on a standard deck, aluminum block and aluminum head LS engine will grow about .010" between a cold engine and one at operating temperature. This allows you the absolute minimum lash for quiet operation. Just set the lash to "0" cold and it will open up to .010" when warm.

The LLR is definitely much quieter than the standard lash stuff.

Just to clarify, when it comes to the iron blocks, it is the opposite. In an iron block and head engine, the valve train components actually grow more than the block and heads. So, as they get warmer, the lash actually tightens a couple thousands. So, if you wanted to do an LLR on an old school iron setup, you might set the lash at .012" cold to achieve .010" hot. That may be what you meant, I just wanted to be specific.

big hammer

I set my LLSR’s on an aluminum engine in the -.001 to -.002 range

00pooterSS

iTrader: (40)

Either way, very cool. After reading your posts and others about LLSR i'm sold on the idea.

Darth_V8r

iTrader: (4)

@00- thanks!!!

@hammer - judging by your results, looks like a great approach.

@speed - yes, you said better what I meant. I thought you'd lose more lash than 002 on an iron block, but I did know iron would go the other way - losing vs gaining lash from thermal expansion.

Nostang

iTrader: (4)

Great read and explanation. Thank you for the write up.

speedtigger

iTrader: (16)

It is not that the iron "goes the other way" so much it is that the steel valve train components grow more than the iron does. More-so on the exhaust side due to the heat.

rednari2

iTrader: (1)

Let me get this straight. On a Gen 1, the lash is set 11, 9 and clatters when cold. It tightens up when warm and quiets down.

Are you saying the opposite occurs with aluminum? That the lash is set 0-3 cold and opens to 12-10 when hot?? Or expands equally so that it remains 0-3 when hot?

This is getting better. I have to wrap my head around this one!

Che70velle

iTrader: (6)

That’s exactly what we are saying. The lash opens up about .010” in an all aluminum application, due to the aluminum “growth”, or expansion from heat.

NAVYBLUE210

For my LSX Iron Block with Aluminum Heads my Builder
Used .006" Lash cold per Kip/Stevens spec in order to
Reach .010 hot.
Just another data point.

pantera_efi

iTrader: (1)

Hi ALL, MANY of the engines I work with USE Lash Caps to set the Valve Lash.

THUS NO SHIMS REQUIRED ! (No-NON OEM Rockers either)

My FIRST Road Race Car was a Formula V, a VW engine powered car.

That engine had adjustable rockers with MY setting of ZERO lash when COLD.

Thus again, GOOD tech from Jake ! ("0" lash)

The 496 "question" OR my method for the >001" :

I install the Lash Cap on a valve, then clamp it on my Souix Grinder Tip Vice, then a "kiss" of the stone.

Lance

rednari2

iTrader: (1)

Ok. For an iron headed Gen 1 since the block and the valve train are both iron, the 11. 9 gap closes up from from block and head expansion.


But, you suggest 0-3 on an all aluminum motor because it will loosen to about 10 when hot. This obviously mean that the aluminum block and heads expand at a greater rate than the iron valve train, thereby creating valve lash.


Ok, but whats with the fixed rockers. Is there some benefit from them instead of using adjustables to set cold lash at 0-3. Does it make more power?


So, Cranes 22, 20 recommendation for a cold LS motor now makes sense, since the aluminum block will out expand the iron valve train by about 10 thousandths thereby giving you approximately 10 thousandths when hot.


Also, for those who have quieter motors, are you setting the hot lash to less than 10?

Darth_V8r

iTrader: (4)

No, fixed rockers make the same power as adjustable. Roller tip adjustable will make more power vs the stock rockers with their "progressive" ratio. The advantage to fixed is "set it and forget it"

I do target 0-003 PRELOADED valves. In other words, cold, the valve is open between 0 and 003. It gains you more seat duration, but honestly the lobes are ground so that the 050 and 200 durations will not change much with the valves slightly preloaded. MAYBE a degree.

And your crane example math is backwards. If you set 20 thousandths cold on aluminum engine, you will have 30 thousandths lash hot, because aluminum expands faster than steel. So the distance from the cam to the rockers GROWS faster than the steel pushrod grows.

Zero grows to ten, 20 grows to 30

rednari2

iTrader: (1)

[QUOTE=Darth_V8r;19881642]No, fixed rockers make the same power as adjustable. Roller tip adjustable will make more power vs the stock rockers with their "progressive" ratio. The advantage to fixed is "set it and forget it"

I do target 0-003 PRELOADED valves. In other words, cold, the valve is open between 0 and 003. It gains you more seat duration, but honestly the lobes are ground so that the 050 and 200 durations will not change much with the valves slightly preloaded. MAYBE a degree.

And your crane example math is backwards. If you set 20 thousandths cold on aluminum engine, you will have 30 thousandths lash hot, because aluminum expands faster than steel. So the distance from the cam to the rockers GROWS faster than the steel pushrod grows.

Zero grows to ten, 20 grows to 30[/QUOTE
__________________________________________________ ___________
Then what you are saying is that Cranes is wrong. 22, 20 is listed on their site and when you talk to them. So, you are saying that even with adjustables, set the lash at zero or slightly less.

I believe the members of this forum understand the correct lash setting, but I do not understand why Cranes recommends more. I asked them about valve lash when I first called them to discuss a mechanical regrind of a 114 hydraulic cam I have. I thought 22, 20 was alot after my Gen 1 experience. I was told it was ok because of the way the cam is ground and that it needed a looser setting.

And now I read this. Go figure. Lol.

Darth_V8r

iTrader: (4)

Crane lobes are likely different. I would not categorically say they wrong.

pantera_efi

iTrader: (1)

Hi ALL, the provided "tech" from Rednair2 is not correct about the roller tip rocker arm. The two rockers, if identical, would be compared by the Valve Side Radius diameter with larger being better for HP.
The "lifters" such as a .866/.904 change adds HP, a know fact.
Thus the same engineering applies to Roller Tip Diameter.

I LOVE this thread due to the FACT that I have GREAT PROBLEMS with the HYD "bleed down" over 6000 RPM.

The SAD thing is that many here due not know how simple a Solid upgrade can be done AND at LOW COSTS.

Lance

CAMMOTION PERF

Yes, follow the manufacturers suggested lash. As said in the opening post, the lash is determined by the initial ramp design of the lobe. No one will know better than the company that makes the camshaft as to what lash settings it is designed to use.

CAMMOTION PERF

This is a great point! Changes in lash settings will have 4x more impact on the "seat". ".006" or "advertised" duration than it will on the .050". So, if you loosen up the lash .004" this will only change the .050" duration 2 degrees where it will change the seat timing about 8 degrees.

RB04Av

The settings the cam mfrs give on their web sites, are HOT. I.e. AFTER all thermal expansion has been accounted for.

.020" - .022" is pretty normal lash for a solid roller. Most of them I've ever dealt with have been anywhere from .016" - .024" in just about every kind of motor. With a few exceptions such as the old 30/30 Duntov. Doesn't matter whether it's LS, SBC, BBC, Frod, or what; the physics are the same no matter who cast the metal or how old it is. It goes more with cam design in general than any property of the "motor".

The .010" expansion thing is just A GUESS; a "rule of thumb", if you will. It's not exact but lots of us that have built solid cam motors with both iron and aluminum castings, have experienced this, and .010" substantially agrees with experience. Back in the day all SBCs and BBCs (for all practical purposes) had iron blocks, but heads could be either Fe or Al. In those, the ROT was .005" - .006" of lash GAIN w aluminum heads (heads grow more than blocks, since they get MUCH hotter), and .002" or so (mostly negligible) lash LOSS w iron heads.

As CamMotion says, the cam mfr designed the lobes, and their lash specs should be followed. (within some sort of limited experimental range perhaps...) So if Crane says .020", you could probably set them to .010" cold in an all-aluminum motor, and they'd be close to .020" hot. Ideally you'd want to set them that way then measure and see if it came out right when hot. Odds are it won't be too far off but I guess that sort of thing depends on how PRECISE you want to be. Me, I'd check, for sure.