Solid Roller:Advantages? Changes?

Ok Im debating on running a solid roller but what advantages do you have besides having a high rpm? Also what needs to be changed to run that? Just springs?

solid rollers are generally higher lifts, higher reving motors. i wouldn't bother unless you have a good set of aftermarket heads.

to do a solid roller, you need, solid roller rockers, look for the expensive ones with the oiling feature, thick hardened or chrome moly pushrods, check lengths for proper fit. a solid roller cam, yes they are different. and matching springs.

the plus side is, used parts tend to be cheaper because there's less of a resale market, but cams are usually best to have custom ground for your specific application.

I wouldn't suggest using used solid rollers. THe ones tha ti usually see are from race motors that beat @ 8000 + rpm. I wouldn't want one of those grenades in my motor.

Ok Im debating on running a solid roller but what advantages do you have besides having a high rpm? Also what needs to be changed to run that? Just springs?

You will need a solid roller cam (obviously), solid roller lifters, stout valvesprings, a good set of pushrods, 1 piece valves if you don't already have them (something a lot of people overlook) and a good set of rocker arms that will hold up to that kind of spring pressure.

There is nothing inherent in an SR cam that requires stiffer valve springs. Most SR designs need them because the ramps are more aggressive and they are intended for high rpm use. But a "small" SR used at lower rpm does not require mondo springs. That said, if a "small" SR cam meets your needs, you are better off sticking with a HR cam because it isn't giving up much (if anything) to the SR and you don't have to buy new lifters and put up with periodic valve adjustments.

As "melantin" and "limige" suggest, unless you are planning a high revving "extreme" setup you are best off sticking with an HR cam. Also, in addition to the parts mentioned, if you are going with an agressive SR cam and intending to use high revs, you should also upgrade the timing set.

Rich Krause

I'd go to a solid roller in anything turning 6500+rpm.

Another thing to keep in mind is that a solid and hydraulic with the same specs..... the solid will idle better as it has less effective duration. You'd need a bit more duration to take advantage of the solid in that comparison. Obviously, the maintenance is not everyone's cup of tea.

-Mindgame

While you're spending all that money, don't forget to check the valve-to-piston clearance. Bigger cams usually require greater-than-stock clearance.

c.

Solid rollers typically have more aggressive ramp profiles and the added spring pressure is required to keep the lifter on the lobe at all times and without setting up any odd harmonics. If you change to a solid roller make sure your computer has upped the rev limiter to match the limits of your valvetrain.

i wouldn't bother unless you have a good set of aftermarket heads.

.

Um don't say this around Steve Quinn ;)
The fastest NA LT1 with STOCK castings... 9 seconds thats good ol no rush racing :D

I noticed that you dont see many blown sollid rollers. Why is that? Is it because of the fact that you dont need the amount of lift that a sollid roller offers? Is it too much duration? What is it?

I noticed that you dont see many blown sollid rollers. Why is that? Is it because of the fact that you dont need the amount of lift that a sollid roller offers? Is it too much duration? What is it?

When you can make 600-1000hp with a low-maintenance hydraulic, why bother with a solid.

Sure, you see guys using solids in turbo and supercharged race engines but that extra maintenance is just the reality of racing in the first place. Those guys will take whatever little gains they can get. Not to mention, alot of those engines are still turning big RPM.

-Mindgame

-With a Street SR cam in your LT1's, what is the lowest we can go on the CL 108/109/110...stock pcm.. 7000rpm

-Will a SR cam help make a bigger power band, alot more under the curve?7000rpm,

-At what Dur will the car become a dog in the low rpm..can you make this up with gears,4:10/4:30 & compression 12.1DCR / 9.0SCR

One point that has been overlooked is that solid roller cams offer consistant lift. I have been told that these "little/ meaningless" gains that we are talking about here are 20-30 hp.....That is why I am thinking about going that route myself.

The newer HR lobes are nearly as aggressive (area under the curve) as the typical smaller SR lobes. That's why, as MG suggested, many blower guys don't bother with them.

Take a look at the lobe specifications in Comps catalog at www.compcams.com and compare the "big" HR lobes and the "small" SR lobes and you will see what I mean. For similar durations at 0.050" you will also see similar duration at 0.200" and similar lobe lift. If you actually look at two similar duration HR and SR cams side by side you can still see a difference, the SR lobe has more of a "square" profile (and hence more area under the curve) but the difference isn't huge. If you are after every last hp then go SR, by all means. But most street and street strip setups probalby aren't gaining much.

OTOH, if you want to use the biggest cam possible and still be streetable SR has advantages. Looking at lobes with comparable durations at 0.050" and comparing the advertised duration will tell the story. The SR cam will have longer seat time less duration) for the same duration @ 0.050" and will therefore have a bit better idle and a little more vacuum. But the differnce isn't huge. A SR may allow you to get away with another 5 degrees or so without becoming unmanagable on the street.

Rich

I hate to be the guy who always pees in the pool…… But I basically ruined three stroker engines breaking solid lifters of the street. Sorry but that was a bit too much for my budget.

Currently running a HR setup reving to 7000 rpm with no problems. So unless you’re planning on turning more rpm than that, I certainly wouldn’t bother. This is with Comp R lifters and an AFR HydroRev kit.

Lobe profiles of solids vs hydraulic and effective lift/duration, is a bit over my head. However, it sure seems the gap has to be pretty close with the newer HR grinds and lifters out there.

BTW The CTS-V race car run HR cams to 7900 in the LS1. The LS1 engine could do that easily with the right cams.

At a point it makes more sense to go SR because the durations would warrant it. Most 220-240 duration cam doesn't need to be a SR, 240+ could use it though.

As everyone has said, oiling the lifters, running the right spring pressure and having GOOD lifters is going to go far.

Bret

In my current LT1, Headers, Comp Extream cam 230 x 236 x112, comp (self aligning) 1.6 RR's, I pushed it to 7000 rpms at the track one night and the RR's had to be adjusted, one to the point that the car just limped home (home is 5 miles from the track).

The new motor (sitting on the engine stand) has all "Comp": Non Self aligning RR's with guide plates, Cam, Lifters, 7/16" studs, etc. Yes I will have to make maintenance adjustments but it is a drag car only. Expensive, you bet!!

BTW The CTS-V race car run HR cams to 7900 in the LS1. The LS1 engine could do that easily with the right cams.

Bret,
Have you seen actual specs on that engine? From what I read it was ~500 hp @ 7200rpm. Dry sump engine and a very well blueprinted hydro-roller.... 7200 seems reasonable.

Hey, you know what they say.

If you want to make a hydraulic rev... you just need to make it act like a solid. ;)

If you have more info on the CTS-V Race engine I'd love to see it. Doesn't seem to be a whole lot of information out there on it... other than the fact that it's an "LS6". Big whoopty doo.

-Mindgame

Bret,
Have you seen actual specs on that engine? From what I read it was ~500 hp @ 7200rpm. Dry sump engine and a very well blueprinted hydro-roller.... 7200 seems reasonable.

Hey, you know what they say.

If you want to make a hydraulic rev... you just need to make it act like a solid. ;)

If you have more info on the CTS-V Race engine I'd love to see it. Doesn't seem to be a whole lot of information out there on it... other than the fact that it's an "LS6". Big whoopty doo.

-Mindgame

September Car & Driver did a thing on SCCA World Challenge Grand Touring Cars, 3R Viper, 3R Racing Corvette, Champon Racing Audi RS 6 and GM Racing Cadillac CTS-V. C&D's Techical Director, Larry Webster says:

"The (CTS-V) V-8 engine has a number of significant changes over the stocker. The stroke has been shortened by 9.0 mm (.354 inches) and the bore increased by 6.2 mm (.244 inches). Displacement is 5.8 liters with the shorter stroke permitting more revs. At Sebring, the engine redlined at 7900 rpm, 1400 higher than stock. But after the car's dominating first outing, where Andy Pilgrim stormed through the field, the allowed revs were cut to 7000 rpm. For it's horsepower, (GM Racing's Dave) Spitzer would only say that it makes more than 500."

That makes the 99 mm x 92 mm LS6 street engine a 105.2 x 83 or 4.14 x 3.27 engine. Hmmm... the stroke approaches a Nextel Cup engine, and the bore is .015 over a 400 CID SBC, and about .040 less than a Cup engine. If average piston speed is directly proportional to stroke, the 7900 of the race engine is about the same as 7100 on a stocker. The new 7000 limit makes piston speed at 7K about the same as a stocker at 6400. Shoot, my 97 C5 A4 is shifting at 6300 now with 80K on the clock.

I like the idea that the pushrod engine had an rpm limit imposed, but the DOHC Audi didn't. Yeah, pushrods are dead.

My $.02

September Car & Driver did a thing on SCCA World Challenge Grand Touring Cars, 3R Viper, 3R Racing Corvette, Champon Racing Audi RS 6 and GM Racing Cadillac CTS-V. C&D's Techical Director, Larry Webster says:

"The (CTS-V) V-8 engine has a number of significant changes over the stocker. The stroke has been shortened by 9.0 mm (.354 inches) and the bore increased by 6.2 mm (.244 inches). Displacement is 5.8 liters with the shorter stroke permitting more revs. At Sebring, the engine redlined at 7900 rpm, 1400 higher than stock. But after the car's dominating first outing, where Andy Pilgrim stormed through the field, the allowed revs were cut to 7000 rpm. For it's horsepower, (GM Racing's Dave) Spitzer would only say that it makes more than 500."

That makes the 99 mm x 92 mm LS6 street engine a 105.2 x 83 or 4.14 x 3.27 engine. Hmmm... the stroke approaches a Nextel Cup engine, and the bore is .015 over a 400 CID SBC, and about .040 less than a Cup engine. If average piston speed is directly proportional to stroke, the 7900 of the race engine is about the same as 7100 on a stocker. The new 7000 limit makes piston speed at 7K about the same as a stocker at 6400. Shoot, my 97 C5 A4 is shifting at 6300 now with 80K on the clock.

I like the idea that the pushrod engine had an rpm limit imposed, but the DOHC Audi didn't. Yeah, pushrods are dead.

My $.02

Good stuff! Thanks for that info Jon. I'll have to check that C&D out.

Hey, it looks like the makings of a nice endurance motor doesn't it? Could use a rod ~6.4" no problems. That puts the max piston speeds right where you said. Then consider that the pistons, pins and rods are probably quite a bit lighter than stock and that motor's not even working hard. :lol:

Is Katech building these motors or did they say?

-Mindgame

Is Katech building these motors or did they say?

-Mindgame

Good call.

http://www.katechengines.com/index.htm

BTW The CTS-V race car run HR cams to 7900 in the LS1. The LS1 engine could do that easily with the right cams.

Thats because they use advandced beehive shaped springs, which cutdown on harmonics, which is what really limits rpm potential.

Thats because they use advandced beehive shaped springs, which cutdown on harmonics, which is what really limits rpm potential.

Sure... that and weight. Anywhere you can reduce mass on the valve side of the valvetrain is a big plus. I don't know the "rules" for that class but I'm sure that if they could, they'd use titanium valves, retainers and the beehive springs to get that weight way down. If no titanium valves, then definitely a lightweight SS valve... hollow-stem etc..

You're right though, it's a whole system of parts that contribute to the reduction in harmonics and mass. The camshaft core plays in that too.

-Mindgame

You're right though, it's a whole system of parts that contribute to the reduction in harmonics and mass. The camshaft core plays in that too.

-Mindgame

Hollow camshafts like LS engines: what are the advantages?

Larger diameter bearings, and therefore the lobes can help also.

Is this the time/place to discuss why?

Is this the time/place to discuss why?

Good question. Let's let this one marinade another month.

For those whom I have offended with my tangency... I apologize. [exit stage left]

-Mindgame

Good question. Let's let this one marinade another month.

For those whom I have offended with my tangency... I apologize. [exit stage left]

-Mindgame


tangency, as to go off the subject? IMO, discussing how valvetrain parts' mass, configuration, material, etc. relates well to the original question.

Perhaps folks skip right to a high spring pressure solid roller setup when they reach some target rpm where a HR "won't work". That's the brute force method; there's also the finesse method or elegant solution which involves lower mass, lower inertia, fewer harmonics valvetrain bits. I thought we might be going there in this thread.

So is NASCAR going to limit Cup engine rpm with a gear rule? Did/will they ban stuff like titanium pushrods, which are very costly to make. Imagine drilling a 2mm hole thru a solid 7-8 inch long ti bar to start making a pushrod. That's some expensive "tubing". :)

Hollow camshafts like LS engines: what are the advantages?

Larger diameter bearings, and therefore the lobes can help also.

Is this the time/place to discuss why?
I've been told by pretty reliable sources that the gun-drilled LS series cams are to help kill harmonics.

The larger cam bearings allow huge area under the curve.

Would it be a bad idea to drill down the middle of a cam for a regular SBC? Both ends already have holes started. However, since those cams are a good bit smaller, I question the strength if drilled? And even then, what size hole would you use? Too many questions...

oh yeah, I noticed that Comp has hydraulic roller small journal SBC lobes with durations up to 262* :) These aren't full race ramps either. Obviously somebody must want these huge durations for them to make it.

lobe -- adv - .050 - .200 - lift - w1.5 - 1.52 - 1.6 - - 1.7
3152 - 329 - 262 - 172 - .360 - .540 - .547 - .576 - .612
3117 - 324 - 262 - 177 - .420 - .630 - .638 - .672 - .714

For large journal BBC lobes they go up to 278*

I've been told by pretty reliable sources that the gun-drilled LS series cams are to help kill harmonics.

How does that work? Ask your source.

The larger cam bearings allow huge area under the curve.

Please explain. Area under which curve?

Would it be a bad idea to drill down the middle of a cam for a regular SBC? Both ends already have holes started. However, since those cams are a good bit smaller, I question the strength if drilled? And even then, what size hole would you use? Too many questions...
What kind of loads does a camshaft see? Torsional cycling loads, maybe? What does the material in the center of a torsion bar actually do? Think tubular anti roll bars.



Keep it going...

tangency, as to go off the subject? IMO, discussing how valvetrain parts' mass, configuration, material, etc. relates well to the original question.

Oh... well I misunderstood you when you said, "Is this the time or place for this discussion?".
Imagine that... a misunderstanding on a message board with a bunch of text flying around and no expressions to read! lol

I agree, I think the discussion has shifted in that direction. I wouldn't pin every theory in the world on the LSx examples though. Just one engine design in the big pot.

Perhaps folks skip right to a high spring pressure solid roller setup when they reach some target rpm where a HR "won't work". That's the brute force method; there's also the finesse method or elegant solution which involves lower mass, lower inertia, fewer harmonics valvetrain bits. I thought we might be going there in this thread.

To a certain point I agree... but I don't think that's entirely the case. Guys have been building engines and trying stuff out for a long time now. Yep, people are always in awe when they hear of a hydraulic lifter going 7500rpm or better. What they don't understand, in terms of the 1st gen sbcs, is all the work that goes into making a lifter act-right at those revs. Guys aren't simply buying Comp's, Crane's, whoever's, anti-pump lifter and throwing it in the engine. They're modifying the things to get rid of the pump-up. Their modifying the lifters to act more like a solid. The funny thing about it is this.... these guys, in order to be competitive are shelling out big $$ for modified hydraulic lifters just because the class says it has to be "hydraulic". Drives the cost of building an engine up.... especially when you consider the fact that a solid lifter would do the job just fine and give the guys with a little less cash a better chance of winning races. As for spring pressures, they're limited to heavier valvetrain components, so it's not so uncommon to see one of these "hydraulic" lifters with 250# or better on the seat. Just the price of valvetrain control with heavy parts at high rpm.

The cams you listed (AdioSS), they fall into this category.

The LSx is just one engine though. It has better valvetrain geometry and less pushrod angularity than your typical sbc layout. And why not? GM obviously learned some things along the way.
So, what works on the LSx is not necessarily indicative of what's going to work on every other small block engine.
On other engines like BBC, you have the same problems. Pushrod angularity... and it's especially bad on the race type heads. I think guys gave up on trying to make a BBC rev with a hydraulic a looong time ago. Same goes for the sbc in regards to pushrod angularity. Not near as good as the LS1. WRT race heads... there's no way I could even consider using a hydraulic roller cam with my heads. They don't even make a lifter with the offset.... probably cause it wouldn't last.

If you can afford all the nice lightweight valves, springs, retainers and locks.... sure you can turn some revs with a hydraulic. You can even do it with less spring pressure. The weak link in the whole shabang is the lifter. Aint exactly a lightweight when compared to many solids, and there's still that pump-up problem you have to deal with.

Not sure solids are going away any time soon. More economical in the whole scheme of things.

-Mindgame

Good thoughts, Mindgame. That's where I thought the thread was going.

I agree, folks don't always read things the way we intend them to be read. The good thing is we can clarify what we said, or should have said. Maybe "This might be a good time and place for this discusson." would have been more appropriate. That was my intent.

Yep, in all the example you cited, especially BBC and offset pushrod SBC it makes lots of sense to use solids. The LSx valvetrain achitecture is a vast improvement over previous generations and does allow the more elegant solution of lower mass parts and straight line load paths so that HRs can work well.

When you get to OHC with hydraulic lash adjusters which don't reciprocate, rpm limits rise, of course.

Back to dynamic "cam twist". I haven't seen any data from Spintron testing that compares LS to SBC or BBC in that area. Has anyone here? There's more to gun drilling camshafts (an expensive operation for an OEM) than weight reduction.

I believe the Northstar cams may be hollow also. I seem to recall that the whole bank of gundrills at the GM Powertrain plant that produces Northstar cams went down due to a fire or something, and they had to subcontract the drilling for weeks. It took something like 4 or 6 gundrills runing 24/7 to keep up, and that was when Northstars were only in 3 or 4 Cadillac models. True, that's 4 cams per, but think of the number of LSx engines produced. That's a lot of busy gundrills!

Bret,
Have you seen actual specs on that engine? From what I read it was ~500 hp @ 7200rpm. Dry sump engine and a very well blueprinted hydro-roller.... 7200 seems reasonable.

Hey, you know what they say.

If you want to make a hydraulic rev... you just need to make it act like a solid. ;)

If you have more info on the CTS-V Race engine I'd love to see it. Doesn't seem to be a whole lot of information out there on it... other than the fact that it's an "LS6". Big whoopty doo.

-Mindgame

I was impressed with the 7900 HR motor myself. Mustang guys have been forced to do some high RPM HR drag racing and from what I heard from Ron Iskenderian in the limited conversation I had with him they go 7800rpm or more. The LS1 really seems like a good platform to do this on. I have recieved some requests for a high RPM street/strip HR cam for a LS1, I think it's doable but I don't know if either the driveablity or the RPM is going to be the limiting factor. A 7500rpm max street car could do very well on the track, it's just not the easiest thing to do when you want to drive the thing down the street on weekends and such. The lifters are obviously important here too, but the rest of the valvetrain is paramount to making power and making it work without issues up in the 6500-7500 range.

Bret

With these high RPM Hr cam's what kind of parts are they using.
What dose weight do to the v train..from the heavy to the light
sorry if i am not asking this ? right but i would just like to no how much diff there is in HP/TQ with the lighter to heavy stuff

the mustang guys are using pushrods that have a different size hole in it and a titan oil pump.

They're ALL running Titan pumps 94guy? I stand guilty... I'd use my x-ray vision for other things. ;)

I agree on the gundrilling OS. I haven't seen any examples but know of a few companies that offer the service... "Reed Cams" being one. Don't know that I'd opt for that on the standard sbc core for reasons stated. I've tried to dig up some info over the last year or so on the "why" behind the drilled cam core but couldn't really find a lot. I know GM aimed to lower valvetrain noise with the LS1 engine design, but I don't know if that played a part in it or not. I did read about one of the production Infinity engines which uses titanium valves. Not only because they reduce stress on the valvetrain but "they reduce valvetrain noise" as well. So maybe the camshaft serves the same purpose in the LSx, or perhaps "helps" the situation?

Bret,
If you really want to make a revver with a hydraulic lifter just do the same thing the SE guys do with theirs and modify the lifter. Joe Schubeck offers the service by the way. Can't see anything wrong with that for a street build as it doesn't compromise the integrity of the lifter... just keeps it from traveling/pumping-up as much. But yeah, with an rpm ceiling like that... it's bound to be a real fender shaker. Then again if everything's lighter (valvetrain) then it should rev higher on less camshaft duration. Which ties into what Schurters asking.

They're using the lightest components they can get within reasons of durability. If not titanium valves, then definitely lightweight SS. Titanium retainers and maybe titanium locks, not to mention the low mass spring.

-Mindgame