"and they are almost always rpm limited to 54-5600 rpm" The biggest issue we have been seeing with the hyd rollers is the lower end lifters have bodies that flex too much and too loose of tolerances with the plunger/piston assembly and as rpm increases oil will bypass right by the piston and out the top of the lifter around outer edge of the pushrod cup. What happens then is the lifter collapses and they won't rev and it seems just like valve float but in reality there is just no lift or duration or correct cam timing. What we have found is that the limited travel lifters by some companies work well but the best lifters out there are made by Morel. As I understand TA used Morel as the source for their lifters so that is a very good thing. The Morels are usually good to 6800-7000 rpm. With the right valvetrain combo. As far as the "fast ramp" Lunati cam goes, was the hydraulic flat tappet lifter collapsing from ramp acceleration or was it floating from not enough valvespring? Valvespring choice is critical with these cams. The cams are aggressive for an .842" lifter but they have all revved just fine in various engines for me. All the camshaft lobe knows is what diameter lifter it is designed for and as long as the bank angle has been ground correctly so the valve timing events are at the correct time the lobe design will work in ANY engine. I would look at the combination and ask why it didn't work because I can absolutely promise you it is not the lobe design by itself, it is the combination of lobe, pushrod, valvespring, rocker ratio, valve weight, etc. Congrats, Jim. That is a very nice running piece you should be very happy with it. I feel your pain on the dyno session, last time out I dyno'd 2 engines, 3 pairs of headers on both engines, 4 different carb spacers, 3 different fuels, played with spark plug gap, valve lash, ign timing, etc. I was on the pump from 8am to 6pm. It was a loooong day and I wasn't even sick. Get your rest and take the weekend off. You probably need it.:laugh:
I'm paddling that boat with you, Brotha ... seems like I need to re-think my game :shock: J.Dub - I know you've held 600hp as the loose rule for a stock block without anything holding its panties up ... any concerns now going foward ? Larry prolly wont push the "Ludacris Speed" button and see 5800 rpms but a few X's / year while others (who me ?) might see that shift light glow once or twice every time we have our ride out ...
I am by no way an engine expert but here is my observation. My 413 cammed 455 reveded like a small block chevy. Then I bent a valvle and broke some dampers on the valve springs. They were the "super stage 1's" from TA. Those springs were around 95# to 105# (measured) Decided I needed more spring and went with 135# opening dual springs. Now the motor does not rev like it used to. I thought it was caused by lowering the CR but the valvel springs are the more likely culprit. My solution is custom cam (need it for the blower anyway) and going to solid lifters.
Yeah, that must by why I have to run 150# on the seat and 385# open on a small block flat tappet solid that routinely sees 7300-7400 rpm dirt oval racing and NEVER has any signs of valve float or valvetrain issues. And that is with stock style stamped rocker arms and just over .600" lift. The valve springs MUST be matched to the combination but more importantly the entire VALVETRAIN must be designed to work together. The best way is with a spintron but whoa $$$$$$. The next best thing is to use the largest/most rigid pushrods you can find, the lightest retainers, keepers, and valves you can find (rpm considerations vs. $$$$ here as well) set up the CORRECT GEOMETRY which is a boat that is most often missed, and to find a valvspring that will control the valve events. The lighter the valvespring pressure you can run without valve float the better off you are with wear/longevity/and frictional losses being a consideration but there are limitations. Also, valve spring mass itself needs to be taken into account. Sometimes a triple valvespring does not work as well as a double with slightly less spring rate because the double only has to control the mass of 2 springs where the triple has to control the mass of 3 springs. If you don't believe me read up on your valvesprings at the PAC springs website. It is very informative. Now, as we go to more aggressive lobes we do need to increase spring pressure accordingly. That is why Pro Stocks are over #1200 open pressure at 11,000 rpm with 2.45" intake valves. The other thing we can look at is a valvespring that has better harmonic dampening designed into it such as a beehive. One such case is a 505 inch 8000 rpm big block Chevy that I take care of. Right now it has 3/8" .120" wall pushrods and triple k-motion valvesprings with an open pressure of 900# and 320# closed. We are going to switch to 7/16" .120" wall dual tapered pushrods and a dual spring with 300# on the seat and 800# open pressure. This spring is highly polished and is an interference fit between the inner and outer and should control harmonics well enough that I expect to see a power gain above 7200-7400 rpm or so but we won't know for sure until I try it. In this case, lowering the spring pressure and reducing harmonics at the same time SHOULD make more power but If I don't have enough spring to control the valve and it goes into valve float I will lose power and reliability. If in doubt and little extra spring is always better than not enough. Did you ever stop to wonder WHY you broke valvetrain parts? Even though the engine seemed to rev like a small block you were probably going into valve float at higher rpm which is very, very abusive to valvetrain components. If you want reliability you have to control the valvetrain, it may be the most important part of an engine build. All of this being said, the more area you have under the lift curve for a given duration the more power you will make. Period. Don't believe me? Compare a solid roller cam, Hyd roller cam, Solid flat tappet, and hyd flat tappet cam all with the same advertised duration and the same lobe seperation angle. The solid roller will have more lift because it is more aggressive and it will make more power because there is more area under the curve. And, of course, it will require a LOT more spring pressure to control the valve. See, the combination is what is important that's what you have to remember. I hope this does not seem like too much aimless rambling:Smarty: I am just trying to get people to start looking at the overall reason why one engine and/or combination will work well and if you change one thing it won't work at all. The overall combination is what matters the most and it all has to work together. Sometimes we don't get it right and we have to try again but that is what makes this so interesting.
I am wondering the same thing, although the question in my head didn't involve the word "panties", so I like your version better, Alan. :laugh: Partial block fill or girdle or both part of Larry's build? Wouldn't want the Wizzard having an unanticipated ventilation event.
Alan and Ken, Rpm kills... much faster than power output. If he keeps the rpm down to a reasonable level, say shifts at 5800, then I have no worries about the bottom end of this motor.- has good rods, good balance job, purrs like a kitten. It's a good block with minimal core shift. Sonic test was better than a lot of them I have seen. After having seen Jim Byers motor make 900+hp repeatedly, and tearing it down to inspect it, I am more conviced than ever that rpm will kill much faster than power output. Mark, You say you have this cam and it will rpm- what is your setup, exactly. JW
Funny you should mention that Ken. I've been e-mailing Jim and keeping in touch that way through the entire build. This is a portion of one of those e-mails. " I was sitting here speculating on what your motor will make for power, and had to go back to the 1AH dyno sheet on my website to see.. that one with an SPX , my standard alum head, and a 288-92H cam made 575 tq and 556 HP.. almost exactly what Alan's ragtop motor made with a bigger cam.. interesting.. Man, I have to update that website with those motors, I don't build nearly any of them anymore like that.. I figured out that the 470 vs. the 464 is like an extra $100.. cheap for the insurance of good rods. I am actually building a Level 1 iron 470 right now.. I chuckled at my vivid statements that you need a girdle to run that power.. I have pushed these things out to just past 600 with good longevity results since the day I wrote that.. with a number of motors. I was a bit more conservative back then, but Hell, I wrote that page originally in 2003 I think.. or about 50 motors ago." I'm not too worried about hurting this engine, given the fact that I think I'll be keeping it under 6000 RPM, and I still remember Denny Manner telling me that "it's not the power that damages things, it's the RPM. I'm getting kicked off the track no matter what, I think:laugh:
:laugh: Jim beat me to it. RPM kills. I'm using 28" tall MT Drag Radials, so my effective gear is about 3.55, not 3.73. I'm thinking the RPM's should be fine.
I also had the "girdle" conversation with JW when building my motor. I chose not to do it as the budget was already....well.............a little over:dollar: ou: The TA 308S was abandoned for the TA510 to keep power band lower to build a more reliable non girdled motor I am sure these 470" builds will see a long life bouncing of a 5800 or 6000 rpm limiter:3gears:
I completely missed this thread until Larry gave me a call this morning and told me the great news. I don't think he slept yet Great new to Larry and great work to JW. I remember getting my heads back from JW and they almost look too nice to put them on, but hell thats when they really look nice, seeing them on a screaming 455, my GS still runs like a raped ape with those Stage 1 TE heads. One question Jim. When we dynoed my engine we used Hooker Headers with 2" primaries. We did nothing but a header swap from Rob Chilenski's headers with 2 1/8" primaries. The engine picked up 29.8 hp on the very next and proceeding pulls! Just wondering what the header size was. Maybe a 2 1/8" would gain you even some more HP. Though I am not sure Larry is too concerned being his GS is a street car and 600+ ponies is way plenty. No doubt Larry will be wearing the Depends for his first few rides down the quarter until he gets use to his new engine. Best of everything for ya Larry. And again Jim, great work!! :TU:
Not much. I kept thinking about what the car will feel like when I stomp it at the lights for the first time.:beers2:
Jim, I do not have this exact camshaft nor have I run this exact grind however I have run many of the Voodoo lobes on various engines and I have not had any problems with the camshafts themselves. The biggest problem I have run into is cheap lifters and/or improper valve springs. I have a hydraulic roller 454 Chev 231/239 with .620" lift that wouldn't rpm past 5700 or so until I changed lifters. Lifters were worth a pile of horsepower and now it will rev right to 6500. With unported aluminum oval port heads it made 585 hp/600 tq. Peak power is at 5800 but she revs right up now and the only thing I changed was lifters. I also have a 505 big Chevy street motor that has not been dyno'd but it does do rolling burnouts at 60 mph in 4th gear and pulls hard right to about 6500 rpm. That cam is a custom 244/244 with .630" lift. I also did a 427 small block Ford with a 237/245 hyd roller and .620" lift that made just under 600 hp on 91 octane until they made me detune it to 557 hp because the dad was scared of his 18 year old kid driving this in a '67 Mustang Fastback. How did I detune it? I took out the short travel lifters and installed factory Ford Racing lifters. Lost 42 hp just like that. I'm in the process of building a 489 inch big Chevy with a 251/259 Hyd roller with .660" lift that I fully expect to go to 6500 rpm and beyond.:Brow: You will notice that all of the above cams are hydraulic rollers but the same lifter principals apply to the hydraulic flat tappet cams. David Vizard ran into this same problem and helped develop a special oil just for hydraulic lifters and if I recall correctly it was worth a bunch of power just due to lifter collapse. I think you can buy the oil from "ultra pro machining" if you ever want to try some. Here is what I was trying to say earlier and I got off track: Obviously this camshaft did not work at all on this combination. I am not condeming the combination nor the camshaft though. I believe the cam should've worked as well as or better than the 413 but it obviously was not happy with something in the equation. You said it made more steam below 4000 and that tells me it was getting up on the cam but it should've held on to it until 5600 and then tapered off after 5900-6000. I don't know if using a set of limited travel lifters would have helped or more valve spring or a different valve spring. Sometimes the valve springs go into harmonics with one particular grind and not another and just changing to a slightly different spring will help the issue. I'm not doing any flat tappet stuff anymore except where the sanctioning rules make me just because I feel there is more reliable power to be had with the hyd rollers for the street. This was a very impressive build and it worked well. I am a little dissapointed that you did not have a good experience with the VooDoo as I have been running Harold's grinds for quite a few years and have not had any trouble with them at all. In fact, he is designing lobes for a 455 buick Hyd roller for me right now that will be ground by Lunati. The numbers we are talking about are 233/237 on a 108 seperation angle with .595" lift. I plan to have this engine on the pump end of March or so but it will not be the killer piece you built due to using a Performer intake for hood clearance/ low rpm part throttle performance and the heads do not flow as well as the pieces you had. I will post the entire build and the performance of the engine on the dyno when it has been completed though. I am expecting around 560 hp/580 tq or in that neighborhood. One thing to remember is that when Harold designs a lobe it does not matter what engine it is going in, what matters is the diameter of the lifter. That is what determines the acceleration rate of the lobe. The design of the engine then determines where the lobes must be placed on the camshaft to perform properly. Obviously with the smaller base circle of the Buick cam this does change the opening/closing ramps of the design some but that can all be accounted for. His designs are characteristically aggressive opening with a gentle closing to be easy on valvtrain and are not that prone to valve float when coupled with the right spring. What this means is that if he can get a hydraulic flat tappet to go to 7000 rpm in a small chev/big chev/Ford/whatever it should be able to rpm in the Buick as well. As long as the lobes are in the right location on the camshaft. My whole point is that to get an aggressive flat tappet to rpm you do need some valve spring behind it but that places more load on the lifter which can cause big issues with the cheap lifters we get. It acts just like valve float but it is really just the lifter collapsing, at least in my experience. Want to prove it out, put more valve spring on it and the problem just gets worse. Go to a beehive with a little less seat pressure and the engine starts to run a whole lot better. I will also concede that I have a different way of doing things and a different thought pattern to the whole prospect of building engines. Right or Wrong I have found a certain way of doing things that works for me. I can't get a wide lobe sep cam to run worth a $%^T ? everyone else loves them. Except for the Engine Masters guys, they have figured out the lobe sep deal also. I just don't like the power curve or the throttle response. They seem lazy compared to what I'm used to. I also like aggressive camshafts, lots of valve spring, etc. but you really have to pay attention to geometry and parts to get it to work and this take a little time, effort, and money. One of these days I'm going to call you and we can have an intellegent conversation about some of this. That might just be a threat. :laugh: The whole idea is to share our experiences as a community so that we can all learn and become better Buick owners because of it. I am so appreciative of everything that has been done for the 455 in the last 20 years because when I started with the Buicks the only thing going was Kenne-Bell and you couldn't get them on the phone, they would bill you and you wouldn't get parts, etc, etc. Then Mike T. stepped up to the plate and what he has done for the Buick community is unreal. We have off the shelf parts now that I only dreamed of 20 years ago thanks to TA. I hope that some of that made sense?o No: Later ------- Mark.
Jim, How did the engine rev with the roller compared to the flat tappets. Could you tell a noticeable faster rev from idle or not?
OK. I tried reading all 6 pages but gave up. If there are gains to be made with the 4-7 swap, why aren't ALL GM cams made like that? What would be the down side? And why wouldn't TA offer all their cams with that swap?
Congrats on the birth of you new engine. At that HP you should be 10.70's @ 125 + or _. If you don't have one a torque stap on the motor it may be a good idea. If I remember correctly you do not have a roll bar? I'm sure you know it but you'll be way past the point where one is required. If it hooks your car will twist without one. You should talk to some people who are running 10's on stock suspensions. Real stock, not 9"'s with relocated uppers. Jumping to that ET is a lot. There are a lot of people running 10's on stock suspensions but it takes a lot of tweaking to get it leaving straight. Out of curiosity, what timing did the motor like? Good luck!
