The math's sound, the LSA's and centerlines were off a bit (mainly the differences at different lifts) which threw things off some, considering asymmetrical lobes vs symmetrical lobes. Dunno what's SMAR's getting all bent about unless I was his hero and this somehow deflated everything and now he's taking it out on me. lmao I realize I talk a lot. I figure it's there if someone wants to read it, and if not, then don't! Pretty simply, actually. Not that this matters much now, since the biggest blunder was in SMAR's thread which he has now deleted apparently as an act of spite. That's cool though, I had the forethought to save my formulas to my computer out of the thread last night because I suspected he might do such a thing. :moonu: To me, what's the funniest part, is that no one said a word about any of it. If I hadn't pointed out my own mistake, this whole thing probably never would have come up. SO either no one's paying attention to my words anyway (which is fine), or there's a lot more misunderstanding going on about camshaft science... ---------- Post added at 02:17 PM ---------- Previous post was at 02:10 PM ---------- He also deleted his comments in this thread ---------- Post added at 02:43 PM ---------- Previous post was at 02:17 PM ---------- This one goes out to Andy, who asked me a question about a certain camshaft build and I posted this response in the "Buick 350 Torque" thread which has since been deleted by SMAR. "Ok, let me try to tackle this one. Remember these are suggestions and I would certainly get second or third opinions. First, the static compression is incidental. It won't really matter as much where this lies (though it does matter somewhat depending on the power band). What matters most is where the dynamic compression lies, and the area you're asking for is the tricky area because it's the 'transitional' area where you're playing with numbers inside a 'safe' zone where you can be off a little bit and it not affect it that much. It really depends on what you intend to use it for. N/A? Premium pump gas? When a performance cam is in the middle range, it starts to get more sensitive to changes that will affect the optimal range of performance (as opposed to close to stock or balls out top end). Before, I was simply matching durations to flow numbers and their ratios, but there's more to it still, such as valve design and piston position when the valve reaches its peak lift. This gets into rod/stroke ratios and VEs at varying valve lifts compared to where it all happens depending on where the piston is. For Buick 350's, it's about 75* ATDC. I'm still learning about this part, and I'm sure my cam designs will change in the future based on new information I learn, so what you see in the past up to now and beyond are suggestions based on what I know thus far. It's my philosophy to learn the limitations of the engine, the modifications that would be required to breach certain engineering intents the original creators designed the engine for, and to work within those limitations with minimal modifications beyond the typical airflow design (intake, cam, heads, etc.). Know that the Buick 350's combustion and airflow design is very conducive to producing large amounts of torque in a wide area and at lower RPMs, though can also surprise in the upper RPM ranges as well, up to around 6200-6300 RPM where the stock rods seem to be limited (I heard 6500 was the "Red Line"). Most heads that flow those numbers will be heavily ported (maybe not 'max flow effort' type port, but some pretty heavy material removal). At those numbers of 250ish/170ish the ratio is exactly 68%, which indicates 7% exhaust emphasis needed for 'optimal' flow (75%-68%=7%). Most heads with this kind of material removal show exhaust having more flow at higher lift than intake, so split pattern will be likely on lift, though not necessarily. Also to consider is placing intake lobe higher within the flow plateau will permit it to remain within the 'sweet spot' for longer periods of time without affecting duration much. I suspect this is why we see a lot of lifts that are straight pattern, or off by a little in one direction or the other (more lift on intake or exhaust, but usually not more than .005 or .010 from each other). Buick 350 heads will function fine with less intake lift though, since the intake would still be well within the height of the plateau. Also something to consider (which I will endorse) is going straight pattern lift (or very close to straight pattern) because it puts even strain on the valvetrain for a more evenly distributed load and even wear. So maybe have lobes within .005-.010 of each other. Just like many off the shelf cams have. This is the gray area and would be the subject of more research on my part later on. For now, I'll go with what I already know with a couple dashes of instinct thrown in for good measure. Also something to consider is the lobe intensity. I've been told by a very respected source that 55* to 60* is an "ok" range for the Buick 350. Going less than 50* creates a very aggressive lobe intensity better reserved for roller designs because of the strain on the lobe and lifter on flat tappet designs. This is exacerbated by lifts that go much beyond .450" @ 1.55 ratio. It's also good to have a little extra lobe intensity on the exhaust to help it open and close quicker than intake, as you will see on many aftermarket cam designs. This helps to overcome the extra exhaust duration needed for the head flow ratio so the exhaust valve doesn't open too soon, robbing the engine of power. To answer your question now, here's my camshaft suggestion based on your criteria: 112* LSA installed at 4* advance makes for 108*/116* I/E centerlines. 9.75:1 SCR goal for 8:1 DCR requires inlet valve closing at 61* ABDC for 8.00:1 DCR which equates to 266* @ .006 'advertised' duration for intake. (266 divided by 2 plus 108 (ICL) minus 180 = 61) This means for your power band goals you're either going to have to raise SCR, accept a lower DCR, or advance the installation to more than 4* advance. Why? Because 266* @.006 is much too low for your goals and keeping the valve intensity within acceptable parameters. Example: @ .050 duration, subtracting 50 from 266 leaves us with 216, which puts the cam's power band to be slightly less than the TA 212 cam, which you want a bit more, not a bit less. Plus the cam's lobe intensity is borderline and would wear out quicker. Your cam goals should look more like 275*-280* for intake @.006, with a lobe intensity in the high 50's putting your @.050 duration around 220*. You can shoot for smoother lobe intensity for a longer lasting cam grind (that I've spoken about in the past), but then to do this you need to raise duration @ .006 to levels where overlap affects idle quality and vacuum; however, lobe intensities in the 60's are still good (Crower level 3 camshaft uses 66*/61* hydraulic variance for I/E respectively). This would make your duration goals for .006 look more like 285*-290* with intake duration of around 220*-225* @ .050. Exhaust duration needs to be around 7% more than this @ .050, narrowing down to about 4-5% @ .006, but would put overlap in a range where vacuum would be poor. Soooo.... .306/.308 lobe (.4743/.4774 @ 1.55) lift ".474/.477" 112* LSA installed at 4* advance makes for 108*/116* I/E centerlines. 221*/237* @ .050 = 6.8% and 16* exhaust emphasis; overlap = 5.00* (TA 212's is 4.00*) 279*/293* @ .006 = 4.8% and 14* exhaust emphasis; overlap = 62.00* (TA 212's is 62.50*) hydraulic variance/lobe intensity = 58*/56* I/E (same as Crower level 2) SCR @ 8:1 DCR: 10.26:1 @ 67.5* inlet valve closing ABDC. DCR @ 9.7:1 SCR: 7.58:1 Recommended compression: 9.75-10.25 for premium pump gas, though anything over 9:1 would work. Cam will idle similar to, or maybe slightly lopier than TA 212 but have similar (maybe slightly better) vacuum (13"-15") @ ~750-800 RPM. Slight improvement on idle quality and vacuum, or at least retaining similar characteristics providing for a good street/strip cam. Moderate improvements to power without sacrificing longevity or streetability. Power should start coming on very strong around 2700-2900 RPM pulling hard to 5700-5900 RPM with overrev potential to 6200-6300 where setting the rev-limiter is highly recommended. Would work with a 2500 flash stall, though a 3000 would be better. Ideally suited for street/strip use would be the VP 1800/3200 converter from Jim Weise. Those numbers are nominal flash for a healthy big block. This Buick 350 would probably flash it at around 1600/3000 for low/high stall, which would be perfect for this combination. This converter would have to be used with a VP TH400 (or maybe even an ST300?) set up for switch-pitch. Alternatively for overdrive trans, a 200-4R with a 2800 lockup converter would work very well also. Well there ya go. I hope it's not too far off the mark. (I'll come back later and edit if I see any errors) " ---------- Post added at 03:21 PM ---------- Previous post was at 02:43 PM ---------- It is my understanding that 'tighter' (meaning closer together) LSA's mean the intake and exhaust events happen in closer proximity to each other, which narrows the power band and lowers the RPMS at which they'll all occur in relation to the duration for each lobe. It also means that since the power is more concentrated in a narrower area, the power within that area will be greater, while the power outside of that area will be weaker, when compared to a 'wider' LSA profile. This will create behavior characteristics of what I'd like to call a 'twerky' cam that will idle rougher, get less gas mileage have less manifold vacuum at idle, more overlap...all the things that you'd expect out of a 'hot sounding' camshaft. Wider LSAs create behavior characteristics similar to stock grinds, but with higher RPM power bands relative to the durations. Main thing that affects lobe longevity is the lobe intensity (or hydraulic variance, as I've said in earlier posts. Means the same thing). The less duration between .006 (advertised or 'seat' duration) and .050 indicates a faster ramp profile (opens and/or closes faster) and indicates the strain between the lobe and the lifter (greater strain plus greater spring pressures = faster wear) unless you go roller cam. Also to consider with faster ramp profiles is that somewhere around 5200 RPM the lifters have trouble keeping up with the lobe ramp speeds and would bounce on the lobes (float) in what they call 'lifter crash'. This phenomenon is a gray area for me so my description for it may be a bit off, but the basic idea is retained. Idle characteristics will revolve around where the overlap is at .006, as well as .050. This will determine whether the idle is smooth and vacuum is high or the idle becomes erratic/choppy (lopes) and the vacuum goes down. This is why wider LSA's tend to have smoother idles when compared to narrower LSA's for any given duration. Wide LSA decreases overlap, which is the key player in idle and vacuum. Because wider LSA's move centerlines further apart, valve timing events move further apart, and is why the power band is wider--events happen sooner and cease later, which can affect the engine's power because if events happen too soon or too late, cylinder pressures can be compressed too late or released prematurely. There's more to it than just tossing down some numbers and matching duration ratios to flow ratios on heads, as I have discovered. Ideally, one would want to find that 'sweet spot' to match not only head flow and ratios, but where the timing events are best suited @ lift and how far apart they occur (Lobe Separation Angle). Still learning here myself. I'm always happy to share any information I learn so that it can benefit others as well. Equally important is to describe how things work, not just say 'this is what you need'. This teaches others to be able to do it for themselves and spreads the knowledge amongst the community. Better understanding means better decisions and less money spent because it was done right the first time. There's also that feeling of confidence, knowing that what you're doing/buying/building is what you really want, with no surprises or disappointments. Gary
Do you have any idea how childish you are...this is stuff we did in second grade, I thought most of us grew up, but I guess a couple of us have not. I know, lets denote a forum for making fun of peoples screen names, I'll bet I could come up with some pretty hurtful stuff, but I'm not a juvenile. Lets just quit the kid stuff, OK?
Sorry did I hurt your feelings too? You and smores must be friends. Sorry but when some new b thinks he can come here and trash long term members... They will get bombed on that's it point blank!
We should calm this One down. It's turning into a Sandbox Nyaa Nyaa fight. Gary is a good man and has admitted his mistakes. He doesn't deserve to be jumped on. Plus He's pushing on harder than I would. You Go Gary. :TU: PONCH
What are the cam specs on the engine in the two cars there in your garage??? I know one is a nailhead and the other is a 350..... Nice looking rides!!!
Thanks Ponch. I'm just trying to help others and myself at the same time. This stuff helps me a lot too. I hope others can find some use for it as well, and if not, well it's not for everyone. I take the insulting posts with a grain of salt. We can get worked up over simple stuff that doesn't really matter in the long run, and after some time has passed, we reflect back on it and see it for what it is or was. I've nothing against anyone, and I'll give anyone the benefit of the doubt, even after some harsh exchanges. People are people. I also realize I have my faults too. I can be a bit abrasive sometimes when my patience has run thin, and I talk a lot. On the forums, I don't think talking too much is necessarily a bad thing, since more information can be gleaned. I also like to space my paragraphs out so it's not such a chore to read, and can make locating specific information easier. I don't have pics of fancy cars and engines coupled with real-world hands on experience building 101 engines and discovering my mistakes the hard way. What I do have are words, thoughts, and some ideas that I feel are pretty sound. I'm not a professional engine builder, though I have done some engine building in the past and have owned a few Buick engines (and Buicks), both small and big blocks, so I'm not completely all talk, no action. Philosophy and theory are my meat and potatoes. I'm pretty well educated and knowledgeable in science and math as well as Buick engines, so my contributions here have value. I'm certainly not the smartest egg in the bunch, but I don't do too bad. I try to respect my elders and that includes anyone who knows more than me, not necessarily chronologically older; as well as respect and help those who don't know as much. I could never in good conscience suggest something to someone knowing they'll be spending money on it, if I didn't firmly believe in what I was saying. I also give disclaimers stating such, always recommending second opinions. Thanks to everyone for being my online friends. We learn a lot from each other here, and that's one of the things that makes this site so awesome. :TU: SMAR: peace bro! No hard feelings. ---------- Post added at 02:26 PM ---------- Previous post was at 01:59 PM ---------- Another thing I'd like to add is about agreeing or disagreeing. It's ok to disagree with someone. You can say so, then say why you disagree. More information can be learned this way because everyone has a point of view. It's healthy to look at things from various angles if one is truly interested in learning. I'm certainly not exempt from my own advice. Even in the ugly things said, one still learns how the person really felt or thinks. I've said mean things to people here before, and I'm sorry I did. I should have put it milder. People are more receptive to positive attitudes and suggestions. It's still just blah blah blah, whatever Gary. That's cool too. We're all different. Jeder tut's auf seine Weise (each does to his/her own way/knowledge) to quote a Rammstein lyric. Peace
I'm surprised and disgusted by the name-calling that came and went as people replied then deleted their words over time on this thread. I have had some HUGE disagreements with folks here in the past, and we dealt with it easily. Devon
Hi Devon. I deleted One of mine. I gave some lip to a Member/Poster and I was completely wrong. We PMd and are cool. I just have to wake up a little more in the Morning before Posting on here. Take a few pills and chill First. I don't like digging in anyone's Guano for nothing or disagree with them with harsh language. I usually shrug my shoulders and move on. To each His own. Sean, Are YOU talkin to ME? Yes, One is a 401 the Other a 350. I'll see this Winter if I can get my 425 overhauled and drop it in. I'll have to paint it Green Tho. a '66 is Red. A re-stamp and swear it's stock. Right now my Skylark will eat my GS in the Quarter. Cant have that. I have another cam for it too. I went bigger cuz I have Everything ported out. Cool air system too. So I'll see if another cam will make a little difference. Right now in my 350 I'm running a Poston GS-114 cam. I picked up a Crower and plan on putting it in this Winter. A lot of plans but no ambition. I hope to get Something done. I picked a Crower cuz all TA has for Small Blocks are 110 LSA. The Crower is 112. That's the widest I could find. I don't need the Rump Rump on my croozer. Just Power when I punch it. Poston Intake 480 lift. 486 exhaust. Dur, Adv. 270. ex. 276 Crower Intake 496lift. 505 ex. Dur adv. 284. Ex. 290. It Should make a Difference. I'm using TA Stage 1 Springs with the Damper taken out. Thanks for Liking my Cars. I've wanted a Gran Sport since I was 15 at the Buick new model intro back in Sept 1964. I'm gonna get me One of those someday. So after close to 50 Years I got one. I love it. I just hope I can afford to keep both cars. Ins. on 4 Cars and 2 Bikes is a Killer. But a guy has to have Some Fun. Later. PONCH Haffway There. But it's Stock I tell ya, It's Stock.
Hey Ponch, check the cam card on that Crower. I don't remember seeing one for those specs for a Level 3 for Buick 350. Make sure you have the correct one. Another consideration is the TA Stage1 350 single springs were only supposed to handle lifts up to .500 (perhaps less with proper coil bind parameters) so you may want to check that cam again. Just a heads up bro. :TU:
Hey Gary you big jerk. :TU: I had the card in front of me when I put in the numbers. I know they quit making some cams after I ordered this One. They also had a big sale on the Ones they had left, 99.99 for a cam. Not too bad. I also saw on the card that it has 0 overlap at .05. They had the numbers for a 1.6 ratio rocker so I re-did the math for 1.55. Those are the numbers I put here. They're probably wrong. It has the lobe lift on it so I went from there. As far as the spring stack, I'll have to check it out before I start it up. But then again, That's all TA had for a 350. If I were running a 455 I'd have a Dozen choices. It's too bad Poston is gone. They had a lot of stuff for Small Blocks. But things are getting more scarce for us small block guys. Oh well, that's the way it is and will keep going. Thanks for the Help. :bglasses: PONCH
Steve Long ground cams for KB and Poston...he's still grinding today and uses KB lobes. Search here if your interested.
SMAR STANDS FOR SUPERIOR MOBILE AUTO REPAIR. Ben in business over 15 years built hot rods, sleepers and everything in between. Just a sample AMC 304, Buick 350/ 455-464, Chevy 283,350, 383, 388 Ford 289, 302, 351W4V 357, 392, 410, 428 Olds 350 ,403, Pontiac 389 2x3,Toyota 22RE T. Saab V4 I have to repair vehicles daily just to stay alive. I don't have the luxury of telling my customers theory's and maybe ??? There is very little said on this site that the can't be found on other MACHINEST / CALCULATOR SITES. I deleted all my posts to stop the **** talking. And for the past week I have just done what I have done for the past 7 years and read posts some good some bad. But it still bothers me how people can post answers/solutions and yet have little to no experience. Maybe it's a NEW ENGLAND thing (We have a low tolerance for bull sh..)
If the site is not useful then why are you on here? You need to change your attitude or people are going to continue to attack you.... You attack others so why would you be surprised when what goes around comes around? We all get along great and we agree to disagree often, so maybe try to fit in instead of complaining about other people.
Smar being in the business a long a you have you should know and understand folks like Gary and such are working toward a greater good. It takes a heck of a man to admit he's wrong. Also did you notice Gary is the only one even trying to figure out cam combos in the sbb section? Why not add your knowledge instead of bein An a$$. Texas has this (ZERO) tolerance thing that made me say what I said. I'm sorry....
I was always up front about my knowledge (or lack thereof) and experience. I theorize and offer suggestions to stimulate thought. I know a thing or two and I'm not always right, but then neither is anyone else. I'm still learning about camshaft design, and I have new knowledge to share, but I'm holding off because I don't want to give any wrong impressions or have someone misunderstand and think I'm the Bible of camshaft knowledge, which I'm far from it. I respect those with more experience than I because experience is the best teacher in the long run. I know this because I have a lot of experience in autobody repair and know the ins and outs and fully understand what it means to have hands on experience with something. But that still doesn't mean tossing around ideas is a bad thing. That's why I let people know that it's just ideas. If it's not your cup of tea, that's cool. I still feel confident we can all find a middle ground upon which to stand and agree or disagree and respect each other's viewpoint. Having said that, I do know with certainty that there's far more to designing and engineering than there is 'turning wrenches' and using parts already designed for something. I'm doing this so I can pass along the knowledge so maybe someone can benefit from it. It's my little contribution to the community, for what it's worth. I speak with people from other countries and notice that demeanors and outlooks vary widely amongst people based on their origins and cultures. I have no problems with getting along with whomever I try to communicate with, when the effort mutually exists. Often when people post answers to questions, they have either experienced it for themselves, or they are simply relaying information they have learned some other way, usually by reading someone else's responses to similar issues somewhere else. When a history teacher talks about things to teach others what happened in the past, it's not because they were actually there and saw it with their own eyes. They're just passing along what they were taught while learning it for themselves. Redundancy is always good for learning. Read it in more than a few places, research it, and if the outcome is similar, you can be fairly confident that the information is at least somewhat accurate. Glad you posted again. I am, and it appears others are as well, willing to get along. It may not happen immediately, but it may eventually if you put forth an honest attempt (if you're willing). So water under the bridge and all that. I'm willing to move on. No hard feelings. :TU: Gary
I think thats fair. I'll post when I think I can help , and when it looks like were heading down a path of to much theroy I will bite my tounge (or should I say hands) jump off and let things play out. The reason for all the negitive was It seemed to me (not everyone) but to me alot of posts stared out with someone needing help and then 2 pages later it snow balled into all sorts of machine shop pro. and T3-T4 turbos (And I guess thats more my hang up)
Nah that's cool. If you think it's heading in the wrong direction, slap me up side the head a little. I value your thoughts and input. We're all catalysts for each other's learning. I WANT to be corrected if I'm wrong. The absolute last thing I want to do is misguide anyone's actions or thoughts. Throw in your 2c if you think something needs a hand. I'm all for it. As long as you're somewhat gentle with your critique, I think others will respond positively to it if they're sensible. Meanwhile, I'll try to hold myself to a higher standard of responses and advice and not get too far off the path. :TU: The awesome thing about this whole ordeal is we can (and are) learning from each other to make this a better place for visitors and members alike. So instead of getting all bent about something, I'm actually grateful for your input because it helped me see another viewpoint of the picture. Gary
