Thanks George.
I have 4V iron heads. Two sets. I have closed chambers and open chambers. Both have home "porting" where I smoothed things out and cone shaped the valve bosses. I use a Holley Strip Dominator intake, 750 DP carb, Hooker 1 7/8" primary long tubes with 3 1/2" collectors 3" exhaust for the street open headers at the strip.
Rpm peak? I guess that would be up to you. I can shift accordingly. My car goes through the traps at about 6300 - 6400 rpm around 115 mph. Currently I shift at about 7000 rpm.
I have a couple converts also. A 3000 stall lock up Edge and a 3500 non lock Lentech.
I hope this info helps. If not, let me know what you want to know.
I'm looking for a solid roller cam as I have the expensive Crower HIPPO
Lifters already. Also if you have spring specs let me know I have more than my spare
Of springs to pick from.
Thank you
Danford1
Here's the first cam spec. I'm using the same lobes as mentioned previously, I couldn't find any better. There's a very limited amount of solid roller street lobes to choose from. Look the spec over, as you'll see I've just moved things around a bit. There's more overlap, and the overlap event is not quite centered on top dead center, the intake valve is opening sooner, exposing the intake system to more piston motion, making the engine lope at idle as you prefer. Or at least that's the plan.
Application: Ford 351 Cleveland solid roller tappet street cam
Grinder: Comp Cams
Lobes:
High Energy Street Roller
Intake #1474
Exhaust #1476
107° ATDC intake lobe mathematic centerline
114° BTDC exhaust lobe mathematic centerline
280°/288° advertised duration (284° average)
236°/244° duration at 0.050"
0.3666"/0.3666" lobe lift
0.020”/0.020” lash
0.634”/0.634” theoretical valve lift (1.73:1 ratio)
0.614”/0.614” net valve lift [(lobe lift x 1.730) – lash]
0.603”/0.603” factual valve lift [(lobe lift x 1.70) – lash]
Indicators
44°/44° intensity (advertised duration – duration at 0.050)
35° major intensity claimed by Comp Cams
Overlap at 0.050” = 19°
Lobe separation angle = 110.5°
EVO = 78° BBDC
IVO = 33° BTDC
Overlap = 63°
EVC = 30° ATDC
IVC = 67° ABDC
Application: Ford 351 Cleveland solid roller tappet street cam
Grinder: Comp Cams
Lobes:
High Energy Street Roller
Intake #1474
Exhaust #1476
107° ATDC intake lobe mathematic centerline
114° BTDC exhaust lobe mathematic centerline
280°/288° advertised duration (284° average)
236°/244° duration at 0.050"
0.3666"/0.3666" lobe lift
0.020”/0.020” lash
0.634”/0.634” theoretical valve lift (1.73:1 ratio)
0.614”/0.614” net valve lift [(lobe lift x 1.730) – lash]
0.603”/0.603” factual valve lift [(lobe lift x 1.70) – lash]
Indicators
44°/44° intensity (advertised duration – duration at 0.050)
35° major intensity claimed by Comp Cams
Overlap at 0.050” = 19°
Lobe separation angle = 110.5°
EVO = 78° BBDC
IVO = 33° BTDC
Overlap = 63°
EVC = 30° ATDC
IVC = 67° ABDC
Here's my other idea. This single pattern cam raises peak horsepower by about 500 rpm, into the range of 6500 rpm. There's more overlap than the first one, the intake valve opens even earlier than the first one, it will lope harder than the first one. The torque curve has been moved 500 rpm higher, the low rpm performance is declining as is intake manifold vacuum.
Application: Ford 351 Cleveland solid roller tappet street cam
Grinder: Comp Cams
Lobes:
High Energy Street Roller
Intake #1476
Exhaust #1476 (same)
106° ATDC intake lobe mathematic centerline
116° BTDC exhaust lobe mathematic centerline
288°/288° advertised duration
244°/244° duration at 0.050"
0.3666"/0.3666" lobe lift
0.020”/0.020” lash
0.634”/0.634” theoretical valve lift (1.73:1 ratio)
0.614”/0.614” net valve lift [(lobe lift x 1.730) – lash]
0.603”/0.603” factual valve lift [(lobe lift x 1.70) – lash]
Indicators
44°/44° intensity (advertised duration – duration at 0.050)
35° major intensity claimed by Comp Cams
Overlap at 0.050” = 22°
Lobe separation angle = 111°
EVO = 80° BBDC
IVO = 38° BTDC
Overlap = 66°
EVC = 28° ATDC
IVC = 70° ABDC
Application: Ford 351 Cleveland solid roller tappet street cam
Grinder: Comp Cams
Lobes:
High Energy Street Roller
Intake #1476
Exhaust #1476 (same)
106° ATDC intake lobe mathematic centerline
116° BTDC exhaust lobe mathematic centerline
288°/288° advertised duration
244°/244° duration at 0.050"
0.3666"/0.3666" lobe lift
0.020”/0.020” lash
0.634”/0.634” theoretical valve lift (1.73:1 ratio)
0.614”/0.614” net valve lift [(lobe lift x 1.730) – lash]
0.603”/0.603” factual valve lift [(lobe lift x 1.70) – lash]
Indicators
44°/44° intensity (advertised duration – duration at 0.050)
35° major intensity claimed by Comp Cams
Overlap at 0.050” = 22°
Lobe separation angle = 111°
EVO = 80° BBDC
IVO = 38° BTDC
Overlap = 66°
EVC = 28° ATDC
IVC = 70° ABDC
George. The second cam (single pattern) is very very close to the Comp Magnum 288R cam. Part number 32-771-9. I had that cam for a couple years. It run great. I shifted it at 7200 rpm
And ran a best of 11.54. The distributor gear portion of the cam got chewed up so I couldn't use it anymore. I replaced it with a custom cam that would be the equivalent to a magnum 280R, but Comp never made one. It has 236/236 duration and I think .609 lift but don't remember exactly. I believe a 112 LSA. At the time I also took off the CC heads and put on my OC heads and smaller 2400 stall converter. The car ran a best of 12.59. I'm not home right now so I can't look at the cam card. I like the cam as it lets me chug along in 4th gear with a locked converter about 1600 rpm without bucking and kicking. It has an burble at idle that I wish was a bit lopier.
Your first cam sounds like it might be between the Comp 288r and my current cam.
I'll have to wait a week or so until I get home to check.
I think I like the first cam. It would go into the car with 4v CC heads and a 3000 stall lock up converter. 11.9x would be perfect.
Danford1
And ran a best of 11.54. The distributor gear portion of the cam got chewed up so I couldn't use it anymore. I replaced it with a custom cam that would be the equivalent to a magnum 280R, but Comp never made one. It has 236/236 duration and I think .609 lift but don't remember exactly. I believe a 112 LSA. At the time I also took off the CC heads and put on my OC heads and smaller 2400 stall converter. The car ran a best of 12.59. I'm not home right now so I can't look at the cam card. I like the cam as it lets me chug along in 4th gear with a locked converter about 1600 rpm without bucking and kicking. It has an burble at idle that I wish was a bit lopier.
Your first cam sounds like it might be between the Comp 288r and my current cam.
I'll have to wait a week or so until I get home to check.
I think I like the first cam. It would go into the car with 4v CC heads and a 3000 stall lock up converter. 11.9x would be perfect.
Danford1
Ok George, I'm back...
I found the cam card of the current custom solid roller cam in my Clevo.
It lists the @ 0.050" lift valve events but not the advertised events. How would I convert what is here to the valve events you mentioned?
The cam uses the 1474F lobes for both intake and exhaust.
Thanks.
Danford1
I found the cam card of the current custom solid roller cam in my Clevo.
It lists the @ 0.050" lift valve events but not the advertised events. How would I convert what is here to the valve events you mentioned?
The cam uses the 1474F lobes for both intake and exhaust.
Thanks.
Danford1
Attachments
Images (1)
Lobe #1474 has 280° advertised duration.
Ground with 112° LSA and 106° ATDC ICL, the exhaust centerline = 118° BTDC
The valve events look like this:
EVO = 78° BBDC
IVO = 34° BTDC
Overlap = 56°
EVC = 22° ATDC
IVC = 66° ABDC
I've seen your comments on Blizz's forum about valve events and cam design for the 302, you're getting it. I love it when that happens. Figuring out the valve event data is a matter of being able to figure out the lobe centers, and knowing the advertised duration. I could probably crank-out some math equations, interested?
Ground with 112° LSA and 106° ATDC ICL, the exhaust centerline = 118° BTDC
The valve events look like this:
EVO = 78° BBDC
IVO = 34° BTDC
Overlap = 56°
EVC = 22° ATDC
IVC = 66° ABDC
I've seen your comments on Blizz's forum about valve events and cam design for the 302, you're getting it. I love it when that happens. Figuring out the valve event data is a matter of being able to figure out the lobe centers, and knowing the advertised duration. I could probably crank-out some math equations, interested?
Hi George. Sorry it took so long to get back with you. I usually get an email when someone posts to this topic, but it didn't work...
Yes I would like the equations, Thank you.
Also, on my present cam, couldn't I just re-degree it so my events are closer to 80 and 70?
Danford1
Yes I would like the equations, Thank you.
Also, on my present cam, couldn't I just re-degree it so my events are closer to 80 and 70?
Danford1
quote:
Originally posted by Danford1:
... couldn't I just re-degree it so my events are closer to 80 and 70 ...
Yes but the events are going to be about 3 degrees short on each end. Doesn't hurt to try it and see what happens. A good exhaust system really helps make up for the exhaust valve opening later than ideal. The early closing of the intake valve simply boosts dynamic compression.
My time is limited at the moment due to the Concorso Italiano occurring next week. I'll work on the equations as time permits and reply here when I'm done; if not before the Concorso then afterwards.
Thanks, no hurry on the equations.
Here is the cam card on the off the shelf Comp 288R solid roller cam. It is close to the second cam you recommended.
Danford1
Here is the cam card on the off the shelf Comp 288R solid roller cam. It is close to the second cam you recommended.
Danford1
The events we are truly interested in are the "seated" valve events. The point where the valves just lift-off the seats or just touch-down on the seats. In lieu of that information we use advertised duration, because its the best information we have, i.e. its closer to seated valve events than duration at 0.050. Duration at 0.050 has its uses too, but not when we are trying to define the characteristics of an engine's power band based on seated valve events.
You'll need 4 pieces of information, usually available
_________________________________________________________________________
Valve Events:
EVO = (Advertised Exhaust Duration ÷ 2) – (180 – Exhaust Center Line)
IVO = (Advertised Intake Duration ÷ 2) – Intake Center Line
Overlap = IVO + EVC
Overlap = Average Advertised Duration – (LSA x 2)
EVC = (Advertised Exhaust Duration ÷ 2) – Exhaust Center Line
IVC = (Advertised Intake Duration ÷ 2) – (180 – Intake Center Line)
___________________________________________________________________________
Other Terms:
Average Advertised Duration = (Advertised Intake Duration + Advertised Exhaust Duration) ÷ 2
LSA = (Intake Center Line + Exhaust Center Line) ÷ 2
Exhaust Center Line = (LSA x 2) – Intake Center Line
Intake Center Line = (LSA x 2) – Exhaust Center Line
____________________________________________________________________________
One other term I find useful to calculate from time to time is overall valve event duration which is the total duration in degrees of crankshaft rotation between the moment the exhaust valve begins to open and the moment the intake valve fully closes. Overall valve event duration must encompass at least 510° of crankshaft rotation to make it possible to open the exhaust valve at 80° BBDC and close the intake valve at 70° ABDC. There are two methods to calculate that figure:
Overall valve event duration = EVO + 360° + IVC
or
Overall valve event duration = (Advertised Intake Duration + Advertised Exhaust Duration) – Overlap
You'll need 4 pieces of information, usually available
- Advertised Intake Duration
- Advertised Exhaust Duration
- LSA
- Intake Centerline
_________________________________________________________________________
Valve Events:
EVO = (Advertised Exhaust Duration ÷ 2) – (180 – Exhaust Center Line)
IVO = (Advertised Intake Duration ÷ 2) – Intake Center Line
Overlap = IVO + EVC
Overlap = Average Advertised Duration – (LSA x 2)
EVC = (Advertised Exhaust Duration ÷ 2) – Exhaust Center Line
IVC = (Advertised Intake Duration ÷ 2) – (180 – Intake Center Line)
___________________________________________________________________________
Other Terms:
Average Advertised Duration = (Advertised Intake Duration + Advertised Exhaust Duration) ÷ 2
LSA = (Intake Center Line + Exhaust Center Line) ÷ 2
Exhaust Center Line = (LSA x 2) – Intake Center Line
Intake Center Line = (LSA x 2) – Exhaust Center Line
____________________________________________________________________________
One other term I find useful to calculate from time to time is overall valve event duration which is the total duration in degrees of crankshaft rotation between the moment the exhaust valve begins to open and the moment the intake valve fully closes. Overall valve event duration must encompass at least 510° of crankshaft rotation to make it possible to open the exhaust valve at 80° BBDC and close the intake valve at 70° ABDC. There are two methods to calculate that figure:
Overall valve event duration = EVO + 360° + IVC
or
Overall valve event duration = (Advertised Intake Duration + Advertised Exhaust Duration) – Overlap
Thank you for the formulas. I printed them out.
I used them to figure the events listed on the 288R cam card. Everything worked out as listed.
If a cam has the events at advertised duration, can we figure out what the events are @ 0.050" lift?
That brings me to another question, why don't cam cards list both valve timing events, adv and @ 0.050 ?
Danford1
I used them to figure the events listed on the 288R cam card. Everything worked out as listed.
If a cam has the events at advertised duration, can we figure out what the events are @ 0.050" lift?
That brings me to another question, why don't cam cards list both valve timing events, adv and @ 0.050 ?
Danford1
Hi, building a roller cam engine to bypass the issues with spotty flat tappet quality / declining oil quality leading to flattened lobes. The goal is for a powerful street engine with good vacuum and idle.
What would the equivalent hydraulic roller lobes be? And i "assume" the same 114 separation and lobe centerlines.
The equivalent Roller Cam from George P was discussed here:
https://pantera.infopop.cc/top...yd-roller-street-cam
"Ford 351 Cleveland hydraulic roller street cam
Grinder: Bullet Cams
Lobes:
Intake #HR275/330 (Symmetric lobe)
Exhaust #HR288/335 (Asymmetric lobe)
112° ATDC intake lobe mathematic centerline
117° BTDC exhaust lobe mathematic centerline
275°/288° advertised duration (281.5° average)
224°/234° duration at 0.050"
51°/54° hyd. intensity
Overlap at 0.050” = -4°
Lobe separation angle = 114.5°"
Thanks! I actually searched... but my google-fu is weak.
Hi George, I see you've updated this cam, I bought one 3yrs. ago and getting around to installing it (health issues) , however with all the spec's I don't see at what tappet lift you should achieve these. Bullet uses .050. but to get your numbers it seems .006 is close. Haven't degreed a cam in 35yrs so... and the they were Crane cams and their cams cards are top notch (not so much Bullet's). With my chain set I have to retard it 4 degrees ,I called Bullet they said they do grind their cams with 8 degrees advance, just seems to go against my brain to retard a cam. I'm sure I missed something.
Thanks Roger
Hi,
I am not the real George... 
...but I ordered a custom cam from Bullet in 2021, too. I can definitely agree on the lack of info on their cam card!
I also called them and they told me, my cam was ground at 0°. I confirmed it later with a degree wheel (sorry, I don't know the correct english word for it).
8° advance seems very odd, as for example the standard comp cams timing chains only have 3 options -4° -- 0° -- +4°.
At Bullet I had the best luck with one guy named Mike, I think he picked up the phone when you dial the 4 after their automatic message. If I were you I would try to talk to him.
Hope this helps you a little bit and as always: Sorry for my bad english!
Thank you for your feed back, and your English is spot on, I was talking to Chris (#105) , thinking I'll call back and re-confirm what he said. My timing set is a Roll Master from Australia which has 0-- +2°-- +4°--+6°--+ 8° and also minus -2-4-6-8° degrees. Re-degreeing my cam next week and to make sure I haven't taken to many hits to the head in the past.
@jake posted:Called Bullet Cam back up on this order and made them stick to the profile as George recommended including the 114 deg lobe separation angle.
Thanks for every ones feedback on this.
Jake
Hi @jake, how did the cam @GeorgeP recommended work out for you? I'm new to the Pantera community and I recently got a Comp Cam 280h to see how it works out in my Pantera. It has Closed Chamber 4V heads, and flat top pistons. I'm going to test it out and if I don't like it, I'm going to order the one George recommends.
Cam Style:
Hydraulic flat tappet
Camshaft Use:
Street/Strip
Basic Operating RPM Range:
2,000-6,000
Intake Duration at 050 inch Lift:
230
Exhaust Duration at 050 inch Lift:
230
Duration at 050 inch Lift:
230 int./230 exh.
Advertised Intake Duration:
280
Advertised Exhaust Duration:
280
Advertised Duration:
280 int./280 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
0.530 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:
0.530 in.
Valve Lift with Factory Rocker Arm Ratio:
0.530 int./0.530 exh.
Lobe Separation (degrees):
110
Again, not the real George here...but it seems nobody else wants or can answer. so I try it.
My theoretical thoughts of your cam:
As a rule of thumb a single pattern cam like yours (intake duration = exhaust duration) is optimal for a head that does not differ more than 80-80% between intake and exhaust flow. (I have never seen flow numbers of OEM heads, that are at 85%, so I absolutely can't understand why e. g. compcams produces so many single pattern cams for all types of engines)
Because the original 4V heads are a perfect example of flow difference between intake and exhaust
(Chart by the real George ) 
https://pantera.infopop.cc/top...975#1598208419816975
At 0.500 lift for example the exhaust port flows less than 70% of the intake port.
That is why GeorgeP chooses these lobes with such big difference between intake and exhaust, to help the exhaust port.
In addition you have a tight LSA of 110°, this will cause reversion into the intake at low rpms.
If I would have to guess:
You will have a narrow rpm-band where your engine has "steam", how narrow depends on the rest of your engine. This doesn*t mean, that your car will be undriveable.
What GeorgeP tries to achieve is a broad torque curve like a stock cam but using modern lobes and more duration, but NOT using a tighter LSA. Perhaps you can look at it as stock+1.
If your car runs with that cam, please tell how it feels, and in what rpm band it drives best.
Edit:
After rereading my own post, I felt the need to add: "Sorry for my bad english!"