[Jay S]

Class racers in stock eliminator started really pushing for roller cams when cam cores started to get hard to get a couple years ago. John Partridge who owns Bullet racing cams was pushing NHRA hard for the change. I never heard anything more, don’t think they got anywhere.

Solid flat tappet cams cores are still really hard to get, I bet a 60311 is a 4 or 5 months wait. 60311 should be 520HP with the parts mentioned. Would be a fun combo . If you want more power than that, probably need a different cam.

[Skippy597]

Originally Posted by Jay S

Class racers in stock eliminator started really pushing for roller cams when cam cores started to get hard to get a couple years ago. John Partridge who owns Bullet racing cams was pushing NHRA hard for the change. I never heard anything more, don’t think they got anywhere.

Solid flat tappet cams cores are still really hard to get, I bet a 60311 is a 4 or 5 months wait. 60311 should be 520HP with the parts mentioned. Would be a fun combo . If you want more power than that, probably need a different cam.

That sounds about perfect so that's great to hear. Like I said I'm piecing it together so maybe I'll order it now to have it when I need it. Also thought about calling bullet cams and having a custom grind but the 60311 seems pretty darn close to what I want.

[grivera]

Originally Posted by PAUL K

That is a good sign. As long as the lifters are quite you should be in good shape. What we've learned is if the lifters or a lifter makes noise it needs to be addressed immediately... Regardless of what the lifter manufacturer tells you.

Can you elaborate on this? I was under the impression a mild ticking HR lifter while annoying isn’t necessarily a sign it’ll cause an issue. Seems it’s common place for the Lunati/Morel lifters to tick.

[PAUL K]

Originally Posted by grivera

Can you elaborate on this? I was under the impression a mild ticking HR lifter while annoying isn’t necessarily a sign it’ll cause an issue. Seems it’s common place for the Lunati/Morel lifters to tick.

Yes, I guess there can be what some folks call normal ticking. This is usually due to the design of the cam profile and can be exaggerated by spring pressure. The ticking to be alarmed by is the type that sounds like a loose lifter or a noise that develops.

[Formulajones]

For me it depends on the engine and it's intended use. I don't worry about what may or may not fail. It's such a small sample size it just doesn't register for me.

Flat tappets have been perfectly fine for me both solid and hydraulic. Both of my daily drivers have one of each. I just nitride all the flat tappet cams and run a lifter that lubes the lobes. They've both been going fine logging nearly 60,000 miles on each of them over the last 5-6 years. In fact the solid flat tappet engine the lash hasn't even budged at all during all that time.

I've got engines out here with hydraulic rollers that have been together for 25+ years with a lot of street driving and abuse at the track (and street for that matter) and never had a valve cover off of them since. Other hydraulic rollers I've done in recent years are still running fine.

Pick your poison and run with it

[Steve C.]

Skippy597
If you call Bullet Racing Cams ask for Tim Goolsby at extension 102.

Bullet offers their own design lobes as well as UltraDyne lobes.

Not necessarily a recommendation here but evaluate the difference between your proposed Crower 60311 intake lobe with the UltraDyne F66 lobe here on the Bullet website:

https://www.bulletcams.com/Masters/u...nemasters.html

Keeping in mind these lobes may not be rated at the same tappet lift, but note for conversation the Ultradyne lobe has 12 degrees less seat duration with the same 247 degrees at .050" duration.
That might be positive with a lower compression ratio. In addition the UD lobe has more valve lift, 0.520" vs 0.505".


.

[Jay S]

Originally Posted by Skippy597

That sounds about perfect so that's great to hear. Like I said I'm piecing it together so maybe I'll order it now to have it when I need it. Also thought about calling bullet cams and having a custom grind but the 60311 seems pretty darn close to what I want.

The Crower 60311 is kind of a next step over a RA4 HFT cam, but in a mechanical. Depending on which dual quad intake you have, I think a RA 4 HFT cam (SPC-7) would be 490 to 510 HP, the 60311 would be 500 to 520 HP. The smaller comp 245 sft cam would make 460-480 HP. The bigger comp 246 would probably be in between a RA 4 and the 60311 with more mid range power.

Following up on Steve’s comments, from Bullet we have done a 112 LSA, 247*, 255* @.050”, which is a Ultradyne grind with .35” and .36” lift lobes. IMHO, it is a better grind than the 60311. With bigger rocker arms it puts the lift up around .6 lift. We run the lash tight, usually .015” on the intake and .020” on the exh hot. My guess is it would beat the 60311 by at least 20HP with more explosive mid range. So it would be around 520 to 540 HP. Compared to a 60311, the Bullet has faster opening ramps and slow closing ramps, more duration at .2”, but it is very easy on springs. Not totally sure, but, IRC, I think the recommended springs for the Bullet require less spring pressure than a 60311.

Bullet has tight lash SFT cams that gain more power yet, plus on your round port engine there really is no reason to add extra lift on the exhaust. You have quite a bit to gain by going custom.

I have a Bullet roller cam similar to a SD road paver in one car, 631” lift, 245*, 253*@.050”. Tim at Bullet had it ground for me. It idles about like a RA 4 cam, slightly rougher. I have solid roller lifters on it with very tight lash (Tim’s idea!). It is very very quiet, you can not tell it has a roller cam in it at all. It’s quieter than my 6.0 LS and my 5.7 gen 3 hemi’s with HR cams. My guess is it would be 580HP in that combo.

[Lee]

Originally Posted by Steve C.

Should you choose to go with a solid roller set up keep this in mind....

Inadequate oiling, excessive spring pressures and the hammering effect associated with VALVE LASH play a significant part in the failure of the roller, needle bearings and axle.
BUT very important, the lack of adequate valve spring pressure to control the valves is a potential KILLER.

.

I assisted with an "autopsy" of a dead 455, over in Germany. Turned out that the shop installed a set of springs designed for a 1.650" IH on a set of heads with an 1.800" IH. HR cam. The seat pressure ended up being about 65#.

The cam and lifters were hammered into oblivion within a few hours of running. Lifter bores were cracked, but that wasn't caught until after the motor was re-rebuilt, and quickly failed again.

[Steve C.]

Thank you Lee for that great example to reinforce my statement.

TID BITS.........

"If we were to sum up the role that the valve spring plays in regard to its function as part of the overall valve train with one word, that word would be control. Considering that it is the predominant part responsible for keeping all of the valve train components in constant contact with the camshaft lobe, it’s easy to see how important getting the correct amount of spring pressure can be. Insufficient or excessive pressure will cause engine performance to suffer, along with the possibility of damage occurring, which can be severe. In conjunction with getting the correct pressure, there are other areas to address that will make sure you’re getting the best spring for the application."

https://www.enginebuildermag.com/201...ring-pressure/


"The valvetrain is one of the areas where properly matched parts are vital to ensure that the engine functions properly and the valvesprings are the key to this.

https://www.dragzine.com/tech-storie...ring-pressure/


.

[grivera]

Originally Posted by PAUL K

Yes, I guess there can be what some folks call normal ticking. This is usually due to the design of the cam profile and can be exaggerated by spring pressure. The ticking to be alarmed by is the type that sounds like a loose lifter or a noise that develops.

My 64 has an annoying tick from the left cylinder bank - audible in video. It’s been like that since new and goes away with increased RPM. The roller cam is pretty mild 230/236 .520 lift and 114 LSA - engine is a 461. Engine has about 110 miles on rebuild. https://youtu.be/phfRvXbB9Lg?si=R9duhONfY5Swscjp

[Skippy597]

Originally Posted by Jay S

The Crower 60311 is kind of a next step over a RA4 HFT cam, but in a mechanical. Depending on which dual quad intake you have, I think a RA 4 HFT cam (SPC-7) would be 490 to 510 HP, the 60311 would be 500 to 520 HP. The smaller comp 245 sft cam would make 460-480 HP. The bigger comp 246 would probably be in between a RA 4 and the 60311 with more mid range power.

Following up on Steve’s comments, from Bullet we have done a 112 LSA, 247*, 255* @.050”, which is a Ultradyne grind with .35” and .36” lift lobes. IMHO, it is a better grind than the 60311. With bigger rocker arms it puts the lift up around .6 lift. We run the lash tight, usually .015” on the intake and .020” on the exh hot. My guess is it would beat the 60311 by at least 20HP with more explosive mid range. So it would be around 520 to 540 HP. Compared to a 60311, the Bullet has faster opening ramps and slow closing ramps, more duration at .2”, but it is very easy on springs. Not totally sure, but, IRC, I think the recommended springs for the Bullet require less spring pressure than a 60311.

Bullet has tight lash SFT cams that gain more power yet, plus on your round port engine there really is no reason to add extra lift on the exhaust. You have quite a bit to gain by going custom.

I have a Bullet roller cam similar to a SD road paver in one car, 631” lift, 245*, 253*@.050”. Tim at Bullet had it ground for me. It idles about like a RA 4 cam, slightly rougher. I have solid roller lifters on it with very tight lash (Tim’s idea!). It is very very quiet, you can not tell it has a roller cam in it at all. It’s quieter than my 6.0 LS and my 5.7 gen 3 hemi’s with HR cams. My guess is it would be 580HP in that combo.

Jay you are wealthy with knowledge, thank you. Well that settles it I'll call Tim and chat with him. I've never ordered a custom cam before should I make any requests on it or just let him decide. Should I just tell him I want something similar to a 60311? Is 112 a good lsa to stick with?

[Steve C.]

Offer the compression ratio, intake-to-exhaust ratio, verified installed height, etc

[Skippy597]

Originally Posted by Steve C.

Offer the compression ratio, intake-to-exhaust ratio, verified installed height, etc

Thank you Steve. So I have just speedmaster heads that I am cleaning up and having a valve job done to them but don't have a height mic, do I need to buy one? Also curious if anyone knows how much lift the speedmaster valves will support?

Also huge thank you to this forum and everyone on it for help, always enjoy and appreciate the wealth of knowledge on here.

[Steve C.]

Here is some information on Speedmaster heads with flow numbers and intake-to-exhaust ratio percentages. however do note this info is regarding their CNC heads. More searches here with 'Speedmaster' could provide specifics for your application, including combustion chamber volume to help determine your compression ratio using your engine parameters. Their published information should yield the installed height, my guess it's probably 1.800". Keep in mind a valve job could alter it.

https://forums.maxperformanceinc.com...ht=Speedmaster


.

[Jay S]

Originally Posted by Skippy597

Jay you are wealthy with knowledge, thank you. Well that settles it I'll call Tim and chat with him. I've never ordered a custom cam before should I make any requests on it or just let him decide. Should I just tell him I want something similar to a 60311? Is 112 a good lsa to stick with?

Tim will tend to pick out a bigger profile that has more lift on the exhaust. I would have him either keep the lift squared up or put a little less lift and acceleration on the exhaust.

I usually have at least an intake profile picked out. I would start with an F18 profile (280*@.020”, 247*@.050”, .35” lobe lift, and suggest a 112 LSA…, tell Tim what your combo is and let him pick the exhaust. The F67 would be the same lift with less acceleration, but that is a 10* split. I would shoot for an 8* split, maybe even a 6* (more duration at .050” on the exhaust). With a 6* split the LSA might need to be narrower than 112*, probably 111*. Any wider, like a 114 LSA and it will loose power and raise the power band higher than you need, any narrower and you’ll loose a lot of idle quality and any chance of running power brakes.

The NF cams are tight lash profiles, you can drop the duration at .050” down some and the will have more lift than the F series Ultradyne’s. Those you could run on a 110 LSA if you wanted. I think Tim will suggest an F, but it doesn’t hurt to ask. (F is .026” lash design, NF is .016” lash design).

Tim will very likely be familiar with the 60311 Crower if you want to compare them.

[Tim Corcoran]

With regards to my inquiry as to why OEM hydraulic rollers are for the most part trouble free and retro fit hyd rollers in our Pontiacs seem to have a lot more issues and of course that annoying tick. Based on your responses and my own observations I will summarize.

1. Tie bars
2. Not enough oil pressure to the lifter, especially at idle. In some cases, there could be excessive leakage due to worn lifter bores.
3. Small diameter cam core compared to OEM depending on cam profile. May not matter with low lift and shorter duration non-aggressive lobes.
4. Too little or too much spring pressure for the application.
5. Improper preload based on the needs of the specific lifter used.
6. Poor quality control of lifter manufacturer and having inconsistent leakdown rates.

Anyone like to add anything to the list?

[P@blo]

Originally Posted by Tim Corcoran

With regards to my inquiry as to why OEM hydraulic rollers are for the most part trouble free and retro fit hyd rollers in our Pontiacs seem to have a lot more issues and of course that annoying tick. Based on your responses and my own observations I will summarize.

1. Tie bars
2. Not enough oil pressure to the lifter, especially at idle. In some cases, there could be excessive leakage due to worn lifter bores.
3. Small diameter cam core compared to OEM depending on cam profile. May not matter with low lift and shorter duration non-aggressive lobes.
4. Too little or too much spring pressure for the application.
5. Improper preload based on the needs of the specific lifter used.
6. Poor quality control of lifter manufacturer and having inconsistent leakdown rates.

Anyone like to add anything to the list?

Train boxcar weight?

[Jay S]

Originally Posted by Tim Corcoran

With regards to my inquiry as to why OEM hydraulic rollers are for the most part trouble free and retro fit hyd rollers in our Pontiacs seem to have a lot more issues and of course that annoying tick. Based on your responses and my own observations I will summarize.

1. Tie bars
2. Not enough oil pressure to the lifter, especially at idle. In some cases, there could be excessive leakage due to worn lifter bores.
3. Small diameter cam core compared to OEM depending on cam profile. May not matter with low lift and shorter duration non-aggressive lobes.
4. Too little or too much spring pressure for the application.
5. Improper preload based on the needs of the specific lifter used.
6. Poor quality control of lifter manufacturer and having inconsistent leakdown rates.

Anyone like to add anything to the list?

The thing that stinks the worst on a HR cam is the damage that happens when they do fail. Sometimes the hydraulic lifter compensates not adding much noise, while eating away at the cam. Then it digs in and risk’s breaking out lifter bores or a link bar.


OEM’s have taller lifter bores also, another advantage. They also have a different style check valve that is supposedly more sensitive than retrofit lifters. The different check valve design is one of the reasons some folks have made some efforts to fit LS HR lifters in Pontiacs.

I am not sure how much extra oil pressure helps HR issues. The ticking and whirling noise is more to do with the spring rate and performance cam profile overwhelming the plunger. The bleed rate and tolerances are pretty darn important, and need to be up to the task of controlling the valve terrain against the spring pressure. If the bleed rates are poor more oil pressure won’t help much.

I had a oil pressure issue on one of my modern cars with a HR cam. I thought it was a sensor issue or electrical glitch. The issue was going on for months, my wife’s car, if she restarted the engine, everything was back to normal. I had her pull over and restart the car when ever it happened. Then it started being more frequent, and it happened while I was driving down the interstate. I decided to watch the oil temp gauge to see if it would increase, figuring I’d either hear lifter noise or see a increase in oil temp if the pressure gauge was correct. I watched the oil temp gauge for 6 miles @70 mph down the interstate, everything seemed fine, oil pressure said zero. After mile 6 it gained 1* on the oil temp, mile 7 it gain 5* and appeared it was going to keep climbing. I shut it off and had it towed home.

That is how controlled the bleed rates are on newer OEM engines, the bleed rates are a direct effect of the spring pressure and lobe design. I never heard any lifter noise at all after 7 miles with no oil pressure.

How far could you go with most performance HR cams in a Pontiac with no oil pressure and have no lifter noise? Especially those that already operate loud or tick. I think it could be measured in feet, not miles.

[Skippy597]

Would it be beneficial to go with a single pattern cam? Or should I stick with 6-8* more on the exhaust.

[Jay S]

Originally Posted by Skippy597

Would it be beneficial to go with a single pattern cam? Or should I stick with 6-8* more on the exhaust.

.

If you want to keep up with a dual pattern cam that has a bigger exhaust the single pattern needs to be about 5* bigger than the 8* split cams intake duration. The single patterns usually need higher octane even though it pumps less compression than the dual pattern cam with the bigger E/I split.
Street cars with full exhaust I like the 6* to 8* dual patterns better.

To match the top end power of the dual pattern cam the single pattern ends up having a choppier idle and less vacuum, and usually does not hold on to power as well after the engine hits the peak power, the trade off is the single pattern has stronger mid range and tends to be a little more efficient at cruising RPM’s.. If that describes what your looking for a single pattern is ok.