One of the advantages of switching to a solid roller is you can rev higher, another is you can run much faster ramps. Would there be an advantage of going solid roller if you were only revving to 6600 or so? 10 rwhp maybe?

J.

 

[quote]Originally posted by Crazyquik:
<strong>One of the advantages of switching to a solid roller is you can rev higher, another is you can run much faster ramps. Would there be an advantage of going solid roller if you were only revving to 6600 or so? 10 rwhp maybe?

J.</strong><hr></blockquote>

I was shifting my solid roller setup at 6600 rpms. It is all about area under the curve <img src="gr_grin.gif" border="0">

[ December 14, 2001: Message edited by: Jason99T/A ]</p>

 

Killer, I was under the impression that it wasn't really worth it unless you were gonna spin 7000 or so.

 

Another point - for a given power level the solid roller will have a much better idle and low rpm torque curve (as well as high rpm).


Chris

 

Can you run a solid roller with the stock LS1 heads? I'm gonna have to be a little bit budget minded for now, but I'd love to run a solid setup.

Thanks guys. <img src="gr_images/icons/cool.gif" border="0">

 

You cooooouuuld... But to do the solid setup, you have to machine out the valvespring seats and pop off the heads for a few reasons (notching the pistons, changing the lifters, in some cases machining out the pushrod holes, etc).
I dont think it would be worth it in the end without the added help of the better flow.

chris

 

Chris,

A solid cam (given close to the same specs) will idle better than a hydraulic cam? That's interesting and something I've never really considered. I guess I'm used to hearing solid cams just in race cars and not "street" solids. So, for instance, say you had a solid cam with the same .050 specs as a B1, the solid would idle better? Or, you could go with a little more duration for a few more hp and have a smiliar idle to a "lesser" hydraulic? Like Crazy, I thought solids were only better when you went huge with the can (i.e. hit the limit with the hydraulics), but is the example I listed above right? As you probably know, I'm pretty much stock now, but will have the $$$ soon to swat at the hp bug, and hearing this makes it seem like solid is the route to go.

John

 

First off for a solid and a hydralic to have nearly the same idle, you need a ton more duration at .050 in the solid. To idle like a B1 for instance, which is 221@.050, you would need over 235@.050 with the solid.

So in that instance you'd pick up power and idle better, but there is increased cost.

J.

 

thanks Crazy, that's what I was trying to get at. So, a 221 solid would idle a lot better than a 221 hydraulic, right? More or less, going solid gives you some "free" duration, although the cost and maintenance is higher. Sounds like a good deal to me.

John

 

btw, where are ya from in NC?

 

JP: yep! A couple of reasons

Let's say that overlap is one of the big determining factors on idle/drivability (or overlap and cylinder pressure).

Since a solid can open/shut the valves much quicker than a hydraulic you can achieve whatever you given flow value is (valve duration @ lift integrates vs. head flow) with less overlap, and with a quicker intake valve closing - so you end up with less overlap and more cylinder pressure for a given flow.

Or if we spec based on needing a certain overlap for proper scavenging, you can achieve a desired overlap and a desired flow value, and be done "sooner" giving you the ability to have an earlier intake closing/later exhaust opening.

Just think of it like a hydraulic with VERY quick lobes.

So in that context we can make the same power/more torque with better idle, or make more power at a given "drivability quotient" (whatever that is).


Now when comparing duration numbers (solid vs. hydraulic) you also have to take into account the lash. The lobe may have 250 degrees of duration where it would be @ 0.050 lift or more, but if we run 20 thousandths of lash then the observed duration will be much shorter - since we don't see any valve motion until the lobe is already @ 0.020. Generally people just subtract from 6-12 degrees (depending on the cam style, size, agressiveness) to convert between "solid" specs and "hydraulic" equivalent (idle/drivability wise).


Chris

 

Wow.. thanks for the explanation guys. Like I said, I never thought of solids to be more streetable than a hydraulic cam, but it makes perfect sense. It seems that solid is the way to go <img src="gr_stretch.gif" border="0"> .

John

 

I'm from the Triad/Triangle area.

 

That's the conclusion I came to also - except for the valvetrain adjustment (which shouldn't be too frequent, esp. if you use good parts (STUD GIRDLE! - anyone make one for a ls1?))

Chris

 

Old thread back from the grave. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I'm thinking very seriously about a solid in my upcoming 422.

The current hydraulic cam scheduled for it is a 240/240 .645/.645(1.8 lift) 114

What I get from reading this thread is that I could go with a ~250/250 .645/.645 114 and have similiar idle characteristics with the added power from the extremely fast ramps and added duration. The only drawbacks are checking lash every couple thousand miles(no problem) and possible shortened valvetrain life.

Is that about right?

John