!!!!!CALLING CAM EXPERTS!!!!!

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Tnx, J Par.... I am actually probably going to go with a Howards mechanical flat tappet with their profiles for a .904 lifter. I want a lower duration than listed as a catalog item but have picked out one of their lobe profiles for that lifter size... I just need to confirm with them that it can be done all OK and get a PN, and some detailed profile data to determine P-V clearance.
 
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Of course, there’s conflicting info in the article.
When they’re discussing the graphs, they talk about how the tighter lsa has the wider powerband.

When they’re listing the pros and cons of narrow vs wide, they say the wide lsa has the broader powerband.

I feel it’s just another one of those “it depends” items.
 
The " calling cam experts " title of this thread is also the answer.
I had an unground lobe billet for my 48 degree heads and called Bullet.
It's been a couple years , but I seem to recall Ken as being the guy I spoke with.
We spent at least 20 minutes on the phone as he interrogated me.......I wanted a lot , as the car would see street duty too.
He asked about head flow numbers , compression , gearing , transmission , car weight etc. etc.
He decided on a 626 lift , 260 & 268 @.050 with a 106 center line.
I degree'd the intake lobe to 102 as recommended and tightened up the lash a tad , it seems to work very well.
Crisp street manners.....instantaneous throttle response and it revs as high as I need it to.
I didn't have the $$ to dyno the motor , but it pulls past 7000.
Even if there were shelf grinds for the 48 degree deals , I would have still called someone in the business and picked their brains.
 
Of course, there’s conflicting info in the article.
When they’re discussing the graphs, they talk about how the tighter lsa has the wider powerband.

When they’re listing the pros and cons of narrow vs wide, they say the wide lsa has the broader powerband.

I feel it’s just another one of those “it depends” items.
If you look at the graphs, the wider LSA has the 'flatter' torque band but it is lower overall (in the range where the dyno numbers are valid). That is what the 'visible V8' model in my head says it should be. But it is a relative % flatness thing; may or may not what you want in the given application.
 
The " calling cam experts " title of this thread is also the answer.
I had an unground lobe billet for my 48 degree heads and called Bullet.
It's been a couple years , but I seem to recall Ken as being the guy I spoke with.
We spent at least 20 minutes on the phone as he interrogated me.......I wanted a lot , as the car would see street duty too.
He asked about head flow numbers , compression , gearing , transmission , car weight etc. etc.
He decided on a 626 lift , 260 & 268 @.050 with a 106 center line.
I degree'd the intake lobe to 102 as recommended and tightened up the lash a tad , it seems to work very well.
Crisp street manners.....instantaneous throttle response and it revs as high as I need it to.
I didn't have the $$ to dyno the motor , but it pulls past 7000.
Even if there were shelf grinds for the 48 degree deals , I would have still called someone in the business and picked their brains.
Isn't it nice to talk to an old-school guy who's willing to take the time to hear all about your build and what you're doing so he can give you the best possible product? Interrogation! LOL I love it!
I'm fortunate enough to live close enough to have this last time just went down and chatted with him for a while about it in person. When I came to pick it up it was still on the lathe and just got finished polished LOL
Oh yeah and the place is like cama-Palooza. Till then I never seen a cam that was bigger than me!
 
If you look at the graphs, the wider LSA has the 'flatter' torque band but it is lower overall (in the range where the dyno numbers are valid). That is what the 'visible V8' model in my head says it should be. But it is a relative % flatness thing; may or may not what you want in the given application.
if you're not doing anything call and chat him up see what he says? You don't have to buy nothing...
 
Well yes and no.. I emailed Jones cams on their form with very complete info on engine and application, plus what I was looking to do application-wise, and got a cam grind anyone would have picked out of a catalog. When I asked a straightforward question, I got no answer. Not impressed at all.

To be fair, I'll give it a few more shots with other custom grinders and will hope for a better outcome, but I know far more about cams from direct experience, readings, and by reading posts by experienced 'knuckleheads' like here on FABO.
 
While the specs might look the same the grind is not... The ramp profiles Mike has available are endless... my experience with his stuff is very good.
 
The other thing about custom cams is....... not everything needs a custom cam.
Sometimes what’s in the catalog will work just fine.
And....... without testing multiple cams.... who’s to say which is actually the “best”.
 
Agree With Krooser
except for FT hyd cams where AFIK he only has the one special designed for late 440-Motorhome low compression etc
which actually works quite well on small blocks
A point missed is that LSA is a red herring, a diversion, a crutch
specify IO IC EX O EX C and let lsa fall where it does
 
The other thing about custom cams is....... not everything needs a custom cam.
Sometimes what’s in the catalog will work just fine.
And....... without testing multiple cams.... who’s to say which is actually the “best”.

I'd say most times, with the exceptions being those instances where a given performance window will be run in. LSA is arrived at by averaging a combination of cam timing events. You can "narrow" the LSA by retarding the intake valve event, or the exhaust valve event, or both. Nevermind a lobe centerline on an asymmetric lobe. It's very complicated, so much so that experimentation is the only way to find out what will work. Ask a successful Stock Eliminator racer how much of the budget is spent on dyno time and camshafts...
 
Most of us do not run wide open all the time
part throttle is a whole different ball game
those mag articles show more about intake close than about lca
what would happen if you ran all three at the same intake close (given it screws up the other events)
figure out where your intake close should be then figure out what lobe and rocker it takes to get the lift curve you want (get as close as you can)
remember that a long rod engine is more sensitive to intake close than a short rod motor (piston dwell around BDC)
opening the intake early does not help either
short rod motors have to open the intake early as the piston pulls away from tdc quicker than a long rod motor
MOPER has it right about most cams now are asymetrical
 
those mag articles show more about intake close than about lca
what would happen if you ran all three at the same intake close (given it screws up the other events)
That thought occurred to me when looking at the torque curves in the 2nd article.....how much was due to just that. But I have no way/idea to separate out that effect from the rest. The bump in the upper RPM torque curve with wider LSA is what has me a bit mystified..... not sure why that happens.
 
if you're not doing anything call and chat him up see what he says? You don't have to buy nothing...
Being in business myself, and never having enough time, I just don't tend to do things that can potentially waste the time of others. (Well, besides writing posts on FABO LOL.) Even going to the local machine shop, I don't waste their time until I am actually in a project and getting ready to buy some services. Just my philosophy....
 
Being in business myself, and never having enough time, I just don't tend to do things that can potentially waste the time of others. (Well, besides writing posts on FABO LOL.) Even going to the local machine shop, I don't waste their time until I am actually in a project and getting ready to buy some services. Just my philosophy....
In most cases I have to 100% agree I don't start talking about things until I have the money for it. Ted of PIR is quite the exception.. absolute old school guy who absolutely loves talking about this stuff and giving great advice and going over different scenarios. Quite honestly I'd rather you just come in and sit down and chat with me for a while is what he told me the last time I talked to him. For the longest time when he had the shop in what is now extremely trendy District of Portland I would always say why don't you just sell the property I mean and go to Hawaii and live it out? His passion for Hot Rodding and Building engines and talking to people about their engines and building them is what he loves. Was ready to retire LOL if you want to call it that a few years ago so he built, hand-built! A custom shop right next to his house out in the country where he took all of the highest end best pieces of his equipment and brought them basically home. Now he just does custom work only and all the cool stuff. it's almost like denying him his Passion by not calling him for advice...
And the last time I went over to pick up my cam from Ken at Oregon cam grinding (over in Vancouver Washington LOL) guess who was there? Ted from Portland engine rebuilding...LOL WHEN I LEFT THOSE TWO WERE BULLSHITING LOL
 
My last cam was custom ground for my combination based on how i will be using the car (street).I think over a period of a couple of weeks i near drove Richard at Ultradyne ( Bullet) crazy.We discussed every detail and what i needed for it's purpose.
I am restoring a '68 for this engine and have yet to drive the car.
Best to call an expert and tell him what you are doing with the engine / car
 
several articles on his website- all worth a read
remember he's not Elgin industries the big Detroit OEM supplier
 
All you guys have had some really interesting points.. Really enjoyable reads. As was said many times , most off the shelf camshafts are going to run great in our cars. I just like doing some experimenting.. Most of the time my experimenting is something that doesn't cost anything or very little. So to all us gear heads I think it's very important to do this when we can. To me its fun and very full filling. I know my Dad loved doing it. He did some off the wall stuff. Some of it worked . some didnt. But it was fun. We have the luxury of today's technology . we are really lucky. But we all still have fun trying different things. I really enjoy all yalls post. I have drag raced my entire life. Lots of people in my family have drag raced at some point in time. I was very lucky to have a Dad that taught me everything he knew. Dad always built his own motors , transmissions, rear ends he even has the stuff to do his own valve jobs. RIP in peace Dad. Thank you for teaching me how to do all those same things. The last 20 yrs of his life he got to see me build my own motors. My own transmissions as well as all my buddy's transmissions for all makes lol .!! And rear ends out the wah zoo changing gears for all makes. I guess what I'm trying to say is thanks for the education you guys have already given me on this form. The endless information is invaluable to me. I know a whole lot. But in the grand sceem of things. I don't. Thanks to everyone for always helping others and myself.
 
I have read what David Vizard has to say about cam design, and it impresses me. Vizard has decades of testing ,head porting and engine building under his belt, including some Indy car and foriegn motors.
Basically lobe seperation is a function of overlap breathing, and how many cubes that flow has to feed. A god set of heads on a 383 might like a 112 or 110 lsa, but the same heads bolted to a 512 stroker might want something as tight as 104! All those extra cubes desperately need the extra time to get airflow moving. There is five times more vacuum trying to get air moving thanks to well tuned headers than at ANY OTHER time in the induction cycle. Thats why the correct lsa is so important. Lots going on!
So far, overlap duration discussed is based on a single pattern cam. The duration on intake and exhaust lobes will dictate the rpm. Go to a dual pattern cam and for every four degrees extra exhaust duration, you have to spread the lsa 1 degree to keep the same overlap duration.
 
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As i recall, Vizards idea of what to is more important;
1st overlap degrees
2nd intake closing
3rd exhaust opening (will determine if cam is single pattern or dual.)
If the engine combo needs 60 degrees overlap, and intake close is 70 degrees btdc then the LSA is 110 and duration of both intake and exhaust are established at 280 degrees. Need an earlier exhaust opening of (edit) 4 degrees? 60 degrees overlap dictates an LSA of 112 to keep the other three valve events where they are.
So if you want a single pattern cam, all you need to know is two things. First, degrees of overlap. Second, intake closing point. The duration is picked for you by just those two events.
 
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