[78w72]

Originally Posted by tom s

John,the last 3 sets have been Comp with no issue,going with them again.Tom

how many turns past zero lash are you setting them too? i had a set of the "old" comp & they started ticking after a short time, comp replaced them under warranty with the "new" 857s. new ones call for 1/2 turn past zero & the old ones were 1 full turn.

[tom s]

I have not actually set them my self.The last 3 engines were put together by diff people.2 by Joe Sherman racing and one by Walker Automotive.I will ask.Tom

[ponjohn]

Originally Posted by ta man

I have 7 years on my Comp Hyd rollers and Crane springs..no issues.

Do you know the spring pressures?

Thinking here...there has got be a reason why the Hyd rollers are not durable. P-Dude had a big hyd roller in 535 shifting at or above 7k rpm. He swore by hyd rollers.

Is it the brand? Is it the spring pressure? combo of both? KRE says on their website they have used Lunati Hyd Roller lifter with good success. What about an isky product?

I guess my thought is, if you are going to run a hybrid setup then why not just run a street solid roller and make a lot more power?

[ta man]

I have no clue on the spring pressure.I did have to shim the springs when I assembled the engine since the heads were setup for a Comp 290b solid originally.

[tom s]

Spring pressure really helps and proper oil.Most run too heavy oil with them.Im going to run 180 on the seat with my 421 SD engine.Tom

[Formula8]

Originally Posted by ponjohn

I guess my thought is, if you are going to run a hybrid setup then why not just run a street solid roller and make a lot more power?

I don't think there is a lot of experience with solid street rollers and certainly no guarantee that a lot more power would be made. At least not a lot that I could find. However, many have run the OF/Hybrid and the results are well known relative to HP,TQ, 1/4 mile times, RPM range, vacuum and idle quality. Not to mention we know what lifters, springs etc that work with this combination. I don't have a need to be a "pioneer" with a $1000 investment that I really didn't want to make in the first place.

[Steve C.]

"I don't think there is a lot of experience with solid street rollers....."

There have been examples of street Pontiac's with solid roller cams in High Performance Pontiac magazine and Pontiac Enthusiast magazine ever since I've been involved in the Hobby. The last hydraulic flat tappet cam I bought was a Comp 280H in 1990, it wasn't long after that I changed to a Crower 60450 solid roller cam and have been using nothing but solid roller cams since then.


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[TCSGTO]

Originally Posted by Formula8

I don't think there is a lot of experience with solid street rollers and certainly no guarantee that a lot more power would be made. At least not a lot that I could find. However, many have run the OF/Hybrid and the results are well known relative to HP,TQ, 1/4 mile times, RPM range, vacuum and idle quality. Not to mention we know what lifters, springs etc that work with this combination. I don't have a need to be a "pioneer" with a $1000 investment that I really didn't want to make in the first place.

I agree. If a solid cam is larger it will make more power than the HR but you'll have to pile on more spring and more lash so longevity is compromised. A similar sized SR will make similar power but need more monitoring/maintenance.
The Comp Magnum HR lobes have been proven over & over to turn at least 6K RPM with the dreaded Crane 99893 spring with SR lifters. One could run a 160/450 spring for that warm & fuzzy feeling but why run 200/600 and have to replace/rebuild lifters regularly unless you like that sort of thing?

[tom s]

I have run 200 on the seats for more than 15 years on the comp hyd roller cams!That was what I was instructed by Comp to do.This has been argued for years.Nothing is better for both lifters and cams to control lifter bounce.Tom

[tom s]

FYI,said to be the best solid roller lifter is Jessel,their pontiac lifter is a SBC with diff link bars as I think most pontiac lifters are!Tom

[Steve C.]

Another of Pontiac Dudes comments.....

"Faster ramps require higher springs to keep the lifter on the cam at rpm. Having built quite a few track championship hyd cammed roundy round engines, I here about float. Not the lifter 99% of the time, it's not the right spring package."


I'm wracking my brain to try and remember the fellow that posted here on PY about his longevity using solid roller cams in his Pontiac. If memory serves me right he had over 20,000 miles and two, maybe three, Hot Rod Pour Tours with the car.

And I know of others with even more miles on their solid roller equipped vehicles !


COMP CAMS....

At the same time, we greatly improved the steel used for the axle while providing stricter control of the needle sizes to better distribute the load. The second part of the solution was to develop new profiles and springs for street roller use. These new profiles work great in the 2,000-7,000 rpm band while requiring far less spring pressure than the older race profiles. Together, these changes make it so the only maintenance consideration in buying a street roller from Comp Cams is whether or not you want to have to set and check lash. I recommend going through and checking the valves along with your oil changes. If you run Poly-Locks, this is probably overkill. Once you know what the engine sounds like, you will most likely be able to distinguish the tick of loose lash."
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[TCSGTO]

Originally Posted by tom s

I have run 200 on the seats for more than 15 years on the comp hyd roller cams!That was what I was instructed by Comp to do.This has been argued for years.Nothing is better for both lifters and cams to control lifter bounce.Tom

Is this the one with the failed lifter? How many street miles?

[TCSGTO]

[QUOTE=Steve C.;5519826]Another of Pontiac Dudes comments.....

"Faster ramps require higher springs to keep the lifter on the cam at rpm. Having built quite a few track championship hyd cammed roundy round engines, I here about float. Not the lifter 99% of the time, it's not the right spring package."

True,for race set up.

I'm wracking my brain to try and remember the fellow that posted here on PY about his longevity using solid roller cams in his Pontiac. If memory serves me right he had over 20,000 miles and two, maybe three, Hot Rod Pour Tours with the car.

And I know of others with even more miles on their solid roller equipped vehicles !


COMP CAMS....

The second part of the solution was to develop new profiles and springs for street roller use. These new profiles work great in the 2,000-7,000 rpm band "while requiring far less spring pressure than the older race profiles."

[tom s]

I think the failed lifter was actually a Isky,been so long and have tried so many diff cams in that engine over the last 20 years.I know I had them rebuilt and are still in the engine.First can was a Isky solid roller,second was a 245-252 comp hyd roller,think the one in now is 236-244 hyd roller.Both comps were their high lift hyd roller lobes.Tom

[TCSGTO]

Originally Posted by tom s

I think the failed lifter was actually a Isky,been so long and have tried so many diff cams in that engine over the last 20 years.I know I had them rebuilt and are still in the engine.First can was a Isky solid roller,second was a 245-252 comp hyd roller,think the one in now is 236-244 hyd roller.Both comps were their high lift hyd roller lobes.Tom

You seemed to have very good service life out of yours. I'm just a little paranoid I guess after browsing the Chevelles forums & seeing all the failed lifters in BBCs with low miles. The Pontiacs seem to hold up much better.

[tom s]

they probably dont run enough spring pressure!Tom

[Steve C.]

Tom, do you ever feel we are beating a dead horse !


Valve springs are one of the most critical and most overlooked components in your engine. Proper selection of the valve spring begins with identifying the application and selecting all of the valve train components to achieve the engine builders’ goals.

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[tom s]

HELL YES!Everyone wants to use what is just enough and like you I have found virtually no downside from having more.Sometimes we find that just enough might be the diff of a few hundred RPMs of added HP.A cam that gives up at 6000 with 160 on the seat might go 6500 with more.I was told by my guy at Comp to treat a hyd roller cam with solids as a solid roller cam.As I have found now with the advancement of hyd roller lifters with better tolerances and proper oil and springs they will make HP to 7000 with the right springs and induction.Tom

[Steve C.]

I've been fortunate over the last 20 years or so. I've only had one instance with a solid rollar application that almost led to issues... I broke the inner coil on a dual valve spring and limped home.

We have always run adequate spring pressure, checked the pressure and the valve lash once a year. Keeping in mind my application is a limited street, use hobby car application. NOT a dalily driver !

Again. You lose enough spring pressure and the lifter loses contact on the lobe as the valve closes, if this the situation after time the springs will further deteriorate to the point it can cause issues other than nosing over at rpm. When people call it 'valve float', more often than not this is what happens.

Gentlemen, remember a solid roller lifter on a hydraulic roller lobe IS IN FACT a solid roller cam application !

.


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[ponjohn]

Originally Posted by Formula8

I don't think there is a lot of experience with solid street rollers and certainly no guarantee that a lot more power would be made. At least not a lot that I could find. However, many have run the OF/Hybrid and the results are well known relative to HP,TQ, 1/4 mile times, RPM range, vacuum and idle quality. Not to mention we know what lifters, springs etc that work with this combination. I don't have a need to be a "pioneer" with a $1000 investment that I really didn't want to make in the first place.

I completely agree. The OF / 295 SD combo is good in most combos for mid to low 11's. It is hard to beat the level of performance from a proven combo.