[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.

[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?

[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.

[slowbird]

Originally Posted by ponjohn

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.

Nothing an iron head and flat tappet cam can't do. We should raise the bar some.

[PAUL K]

Originally Posted by slowbird

Nothing an iron headed flat tappet cam can't do. We should raise the bar some.

^^^^Truth^^^^ and I agree. A lot of money being spent for average results

[Dave Bisschop]

Originally Posted by PAUL K

^^^^Truth^^^^ and I agree. A lot of money being spent for average results

Really, please lay out some of these iron headed flat tappet combo's that are being bolted together by your average enthusiast and running sub 11.50's first time out in 3800+lb cars that have plenty of vac. at idle for power brakes and run on 91 octane. Not saying this kind of performance can't be accomplished with iron heads and a flat tappet as we've done it ourselves but the combo's are much less street friendly for your average owner.



Formula8, FYI we have dozens of customers running the hybrid setup like you are doing with zero issues using the Crane 99893 springs installed at 1.780-1.800".

Overall the hyd. roller set-ups have been very reliable and 95+% of the ones we've sold (well over a thousand at this point) are using Comp cams hyd. roller lifters and the 99893 springs and out of those we've had some issues with about 2-3% of the lifters. We have customers with tens of thousands of miles on their set-ups with no issues.

I'm all for having some extra spring pressure for a little more insurance especially for those running the solid roller lifters and turning higher rpm (above 6000), but having 200 on the seat and 600 open on a 245/252 .400" lobe lift cam is overkill. For years and about 500 passes (same set of Comp Cams 859 lifters) we ran a 279/283 @ .050" .650" lift solid roller in our 413ci iron headed engine in our 65 GTO with 200lbs on the seat and 575lbs open pressure going through the traps at 7500-7600rpm with no valve float issues, the lifters never failed and were put in a street motor when we sold the car.

Way more spring pressure than required not only eats up power it also puts more strain on valve train parts and cam bearings so while I always prefer to have a little extra, having way too much isn't the way to go either.

We use beehive springs on occasion and P-dude has a great set-up that he's proven to work very well, but at the end of the day I'm always looking at the most cost effective way to do things while maintaining long term reliability. For most of the hyd. roller combo's we do we've had nothing but success with using the 99893 springs and chrome moly retainers, we can certainly set-up customers heads using the same springs and retainers P-dude uses but there's a $400.00+ extra cost involved. There are some cheaper beehive springs available as well but we've seen some reliability issues with some of them so I just prefer a dual spring personally. quoting Steve C. this is a very good reason why "I've been fortunate over the last 20 years or so. I've only had one instance with a solid roller application that almost led to issues... I broke the inner coil on a dual valve spring and limped home."
If he would have had a beehive or single spring fail it would have led to catastrophic engine failure.

We do a lot of CNC porting and head machining work on LS heads for other shops in our area and what's interesting is that they are typically removing the beehives and going with a dual spring as they get into larger cams

[PAUL K]

Originally Posted by Dave Bisschop

Really, please lay out some of these iron headed flat tappet combo's that are being bolted together by your average enthusiast and running sub 11.50's first time out in 3800+lb cars that have plenty of vac. at idle for power brakes and run on 91 octane. Not saying this kind of performance can't be accomplished with iron heads and a flat tappet as we've done it ourselves but the combo's are much less street friendly for your average owner.

I assume this is a rhetorical question since you seemed to answer this in the last sentence of your paragraph above.

[Dave Bisschop]

Originally Posted by PAUL K

I assume this is a rhetorical question since you seemed to answer this in the last sentence of your paragraph above.

Not rhetorical at all as I stated the combo's are much less street friendly in comparison. What are good street manners? Ask 10 different people you'll probably get 10 different answers. Car set up is a HUGE factor on track performance. I had a customer (unfortunately passed away last fall) who raced a 77 bird in stock eliminator with a legal 350 Pontiac, stock heads (no porting at all) stock intake (no mods) less than 9 to 1 compression, stock .364" lift cam and the car ran a best of 11.27 @ 117mph 3500ish lbs, what do you think would happen if you put that engine in a typical street car? It would no doubt run way slower. The car was dialed in.

By your statement about people spending a lot of money and getting average results basically says that you feel I don't give people good value for their money. I take that personally as I've dedicated my life to the Pontiac Performance hobby and I'm certainly not getting rich doing what I do but I enjoy it and its my hobby too and the customer feedback I get keeps me motivated to do it till the day I die. My motto from day one was to provide my customers with proven products that do what they are supposed to do in the most cost effective way I can find and not require a whole bunch of tuning etc. to get respectable performance out of their cars. This is a never ending pursuit.

I feel some of the statements that have been made are misleading, I really doubt ta man is going to go faster bolting on a set of ported iron heads and a sliding in a flat tappet hyd. cam with everything else in his combo staying the same and running on 87 octane.

[ponjohn]

Originally Posted by Dave Bisschop

Really, please lay out some of these iron headed flat tappet combo's that are being bolted together by your average enthusiast and running sub 11.50's first time out in 3800+lb cars that have plenty of vac. at idle for power brakes and run on 91 octane. Not saying this kind of performance can't be accomplished with iron heads and a flat tappet as we've done it ourselves but the combo's are much less street friendly for your average owner.



Formula8, FYI we have dozens of customers running the hybrid setup like you are doing with zero issues using the Crane 99893 springs installed at 1.780-1.800".

Overall the hyd. roller set-ups have been very reliable and 95+% of the ones we've sold (well over a thousand at this point) are using Comp cams hyd. roller lifters and the 99893 springs and out of those we've had some issues with about 2-3% of the lifters. We have customers with tens of thousands of miles on their set-ups with no issues.

I'm all for having some extra spring pressure for a little more insurance especially for those running the solid roller lifters and turning higher rpm (above 6000), but having 200 on the seat and 600 open on a 245/252 .400" lobe lift cam is overkill. For years and about 500 passes (same set of Comp Cams 859 lifters) we ran a 279/283 @ .050" .650" lift solid roller in our 413ci iron headed engine in our 65 GTO with 200lbs on the seat and 575lbs open pressure going through the traps at 7500-7600rpm with no valve float issues, the lifters never failed and were put in a street motor when we sold the car.

Way more spring pressure than required not only eats up power it also puts more strain on valve train parts and cam bearings so while I always prefer to have a little extra, having way too much isn't the way to go either.

We use beehive springs on occasion and P-dude has a great set-up that he's proven to work very well, but at the end of the day I'm always looking at the most cost effective way to do things while maintaining long term reliability. For most of the hyd. roller combo's we do we've had nothing but success with using the 99893 springs and chrome moly retainers, we can certainly set-up customers heads using the same springs and retainers P-dude uses but there's a $400.00+ extra cost involved. There are some cheaper beehive springs available as well but we've seen some reliability issues with some of them so I just prefer a dual spring personally. quoting Steve C. this is a very good reason why "I've been fortunate over the last 20 years or so. I've only had one instance with a solid roller application that almost led to issues... I broke the inner coil on a dual valve spring and limped home."
If he would have had a beehive or single spring fail it would have led to catastrophic engine failure.

We do a lot of CNC porting and head machining work on LS heads for other shops in our area and what's interesting is that they are typically removing the beehives and going with a dual spring as they get into larger cams

Dave, thank you for taking your valuable time to add to this thread.

[TCSGTO]

Originally Posted by slowbird

Nothing an iron head and flat tappet cam can't do. We should raise the bar some.

How many of these can run 92 pump and have more than 1 good stop with power brakes in a real 2 ton street car?

[PAUL K]

Originally Posted by TCSGTO

How many of these can run 92 pump and have more than 1 good stop with power brakes in a real 2 ton street car?

I'm not speaking for Slowbird, but the GTO in his signature ran 11 flat with iron heads, pump gas compression and an HC-04 HFT camshaft. Later it ran 10.1 with a similar HFT cam and ported E-heads. I have personally used the HC-04 cam with Rhoades lifters and ran into the 10's with power brakes and no driveabilty issues. An HFT cam that ran 11's would not have any problems pulling around a two-ton car and operating vacuum accessories... if everything was set up properly.

[ta man]

Originally Posted by slowbird

Nothing an iron head and flat tappet cam can't do. We should raise the bar some.

Try 87 octane,850 rpm idle,13.5 inches of vacuum,11.40's/119/120mph with a mild 3.08 gear,mild convertor,3900 lbs..driven 200 miles to the track roundtrip.Running the same valve springs and lifters since SD assembled the heads in Dec. 2008!Pretty easy to achieve.....

Plus my wife ordered these heads to surprise me with no clue what she was doing other than Dave and Marcel asking her questions to ask me!Homerun in my books!

[70f400]

Plus my wife ordered these heads to surprise me with no clue what she was doing other than Dave and Marcel asking her questions to ask me!Homerun in my books![/QUOTE]

She needs to call my wife! Very Impressive combo ta man

[Dave Bisschop]

Larry not sure what Darby is talking about, but I've always run them at .006-.007" Hot, which has worked well. While there are a fair amount of guys running the solid roller lifters on the hyd. roller cams, the reality at least for the cams I've sold is that most run hyd. lifters which is really my recommendation for most applications.

[Dave Bisschop]

Originally Posted by ta man

Plus my wife ordered these heads to surprise me with no clue what she was doing other than Dave and Marcel asking her questions to ask me!Homerun in my books!

ta man has a very cool wife!! It was fun figuring out what questions she needed to ask him to figure out how to set up the heads, keep that woman happy!! she's a keeper!LOL

[ta man]

Originally Posted by Dave Bisschop

ta man has a very cool wife!! It was fun figuring out what questions she needed to ask him to figure out how to set up the heads, keep that woman happy!! she's a keeper!LOL

Any time she questions when I buy parts...I tell her honey its those damn heads..I have to keep the car going faster and faster.....

[Steve C.]

Curious.

My buddy that switched from a XE242 solid roller rated with 0.016" valve lash to the Magnum Hydraulic roller lobe and solid roller lifters with a 0.006" lash found the valvetrain 'noise', as Cliff mentions, a bit quieter. Than what ?, everyone will be a different judge. Personally I enjoy the sound of a solid roller valvetrain. But other than less clatter might we consider with a limited use hobby car, driven once or twice a week and a few drag outings, the tighter valve lash has little impact. Do these XE solid roller lobes beat themselves to death

But, just a hunch.

Or even the Hi-Tech .420 rollers at 0.020

[PAUL K]

Originally Posted by ta man

Try 87 octane,850 rpm idle,13.5 inches of vacuum,11.40's/119/120mph with a mild 3.08 gear,mild convertor,3900 lbs..driven 200 miles to the track roundtrip.Running the same valve springs and lifters since SD assembled the heads in Dec. 2008!Pretty easy to achieve....

Your car runs good! I ran a similar combo as yours but with ported cast iron heads and less compression. It ran a best of [email protected] mph. I had 3.42 gears but did use a 29" tall tire, however, I used a stock 2.48 gear set. The 455/3.08 gear setups have worked well over the years. Back in 1977 a board member here ran a 1968 Firebird in the first Muscle Car shootout. He ran mid 12's with 3.08 gears, 8:1 compression and gasket matched heads. He either won the event or was runner up.

[slowbird]

Originally Posted by slowbird

Nothing an iron head and flat tappet cam can't do. We should raise the bar some.

This was just my opinion based on my experience. Nothing wrong with running mid 11's with alum heads and hyd roller.
For what its worth our 69 Grand Prix with power brakes, iron heads, hyd roller and tri-power weighing 4150lbs runs 11.70's