And the stock '66 401 cam (with the 114 degree lobe centers) Actual valve lift/ then duration...with stock rockers/ vs Tom's rollers Stock rocker ratio approx 1.6:1 @ max lift TT Roller ratio approx 1.9:1 @ max lift INTAKE Max lift with stock rockers= 0.448" Max lift with TT Rollers= 0.514" Lift/ Stock rocker duration/ Roller duration/ change 0.100"/ 199 deg/ 208 deg/ +4.52% 0.200"/ 161 deg/ 173 deg/ +7.45% 0.300"/ 120 deg/ 140 deg/ +16.67% 0.400"/ 70 deg/ 103 deg/ +47.14% 0.500"/ --0---/ 34 deg/ :grin: EXHAUST Max lift with stock rockers= 0.425" Max lift with TT Rollers= 0.498" Lift/ Stock rocker duration/ Roller duration/ change 0.100"/ 198 deg/ 206 deg/ +4.04% 0.200"/ 158 deg/ 1701 deg/ +7.59% 0.300"/ 113 deg/ 135 deg/ +19.47% 0.400"/ 49 deg/ 96 deg/ +95.92% 0.500"/ --0---/ --0---/ What surprised me about adding the high ratio TT roller rockers to a stock cam was it produced similar or more duration at valve lifts over 0.200 than a Poston NH400 cam using the stock rockers!
Intake lobe is #5201 Exhaust lobe is # 5203 A couple of the older cams I have here all have the intake centerline near 110 degrees....is that typical? I measured 0.267" Intake and 0.261" Exhaust on my '66 401 cam. Rollers increase the duration significantly at the higher lifts!:grin: One of the cam gurus said' you can't have the intake valve open fast enough'..... Now I'm seeing why the fast lobe designs and roller rockers are so beneficial. Looking at GSGTX's exhaust lobe (#5216), it's not a fast ramp design. It's actually very close to the Poston NH400 exhaust lobe. ....Is exhaust valve opening rate less critical? The older adjustable rockers were cast iron and had a ratio of 1.5 I did see a set of the later alum 1.6 rockers converted to adjustables ....any idea what that costs? Someone on the Yahoo group once posted the stock pushrods flex at higher rpm's....and cost 10-15 hp! I wonder if lighter, stiffer pushrods really do make a difference? Yeah, stock pistons suck. And the $360 cast replacements suck too!:rant: Not everybody can afford $800 custom pistons just to run a decent cam!!
Does anyone know how I can permanently save all this information? My printer has crapped out and it will be at least a month before I can replace it. Thanks. JC
John, I highlight the text with the mouse cursor, then hit 'Copy". Open up a new Wordpad document, then 'Paste'. Or to save it as a picture, use the 'printscreen' button and paste it into MS Paint. I've built up quite a reference library from data found online.
**Intake lobe is #5201 Exhaust lobe is # 5203** I wonder why Comp used both exhaust lobes for the cam? The 5201 has 133* @ .200" lift, #5203 has 140* at .200". The 224* intake lobe, #5433 has .495" lift so maybe it was due to that? How about the 1.9 ratio though, that would give lifts of .595" & .608" respectively! The stock pistons would take those lifts and 224*/230* without any PTV issues? WOW! 0.200"/ 161 deg/ 173 deg/ +7.45% 0.200"/ 175 deg/ 186 deg/ +5.91% Will, you are measuring differently than Comp as they have the duratios at 133* & 140*. Taking the Comp numbers at .200*, not the 161* & 175* you have listed. Any explaination? Thanks for the work and if you could get the numbers to match we could compare T's 1.9's on the same playing field. Tony
Hello: This is a super thread and am enjoying it immensely. With the Title saying "425 Camshaft Questions", and most of the data being given for a "401", this will change a lot of the possible duration that can be run right? If someone, "ME" had a 425 Nailhead "Which I do" and was going to freshen it up. What would be the optimum Cam Shaft for me? 1) 65 Riviera (4400 pounds? + me) 2) 3.23 Posi 3) Standard Rally Wheels with maybe a one or two size increase (Depending on what can be run without Rubbing in the front) 4) ST 400 Trans, Stock Switch Pitch Convertor (Would like to run a independent switch to have a kick at the light from time to time) Does Convertor need to be tweeked? 5) TT Roller Rockers 6) Stock Pistons, Rods, and Crank 7) Stock 2X4 intake with Stock Carbs (Rebuilt) ============================= Done By: Carmen Faso 716.693.4090 - J&C's Parts 7127 Ward Road North Tonawanda, NY 14120 8) Distributor Rebuilt 9) Heads Rebuilt with Slightly Oversized SS Valves, New guides, Updated Seats, and Intake Bowl Ported ============================= 10) T/A "Shorty" Headers Ceramic Coated 11) 2.5 inch Exhaust all the way back, using Chambered Mufflers with 2.5 ID. May, or May not use a Resonator Purpose: Have Fun, Would like the car to get as good performance as possible without having problems with: A/C P/B Piston Valve Clearance or anything else Detrimental Will probably never Run over about 5500 RPM's, unless I know I can do it safely. (Now know they can run at 7100 rpm's, who knows?) Engine is numbers matching, and I don't want to destroy it. I will save ALL parts that have been switched out. Will go ahead and upgrade Timing Chain, AND anything else that people here can advise to make the engine run Better, Stronger, Faster. (Don't want the $6,000,000 Engine ;-) lol) $64,000 Question What CAM/Lifters etc. should I run on this Engine? (Please be specific) I love the torque of the NH and how they make a Heavy car feel a lot lighter. I want to have and enjoy the car for the rest of my days, and pass it down. Car will have the body manicured and painted after this update. I don't mind having a Cam cut, I just want the Best/Strongest Cam I can put in it and take advantage of all of the other work being done, (listed above) and not destroy the Engine. BTW: Except for a Romp here and there, it will not be run hard for long periods of time. ===================================== Given all the Knowledge here, I would be really thankful for your help with this. The Nailhead have a lot to give, and I want it what it has. Split Intake and Exhaust Values, LSA @ 110, 112, 114, ???, Lift?, Supplier?, other necessary Specs needed for installation? Thanks for any and all help. Best Regards, Ty O'Neal
Ty, go with a cam that is close to or a little better than the old Buick 091 cam... and rebuild with quality stuff, melling, perfect circle, trw, ect.... do as much of the mechanical stuff as you can your self... cuts cost...big time... definitly big exhausts... port match the intake, heads, and exhaust manifolds.... cant reccomend headers,,, they crack, leak, rust, bend, rattle , rub,,, ect... instead port match , extrude hone, the stock exhaust manifolds... and put them back on without gaskets... strongly consider the stock single 4 intake manifold with my Doc dual plane mod and a big single carb...less expense, and easier to maintain... then get the dual quad set up if you just want ''wow''.... definitly recurve the dist, definitly go with the switch pitch trans, definitly go with 3.42 or slightly lower posi... keep stock size buick ralley wheels.. invest in a good cooling system... lighten the car as much as possible... Remember, you are moving a big heavy car, and torque is what does it... go for a good torque cam... then with the sp trans and a lower gear out back you will really surprise some people...
:grin: I know I'm still trying to figure all this stuff out! Just wish I had a dyno to test all these cams! Tony, the lift and duration figures I posted were measured at the valve, so that takes into account the effect of different rocker ratios. See post #74 for the duration figures measured at the camshaft.
Ty, I like Docs advice! With the bigger cams (bigger than a TA-25 for example), you'll start to lose low-end torque to gain high-rpm power. I still haven't figured out what lobe centers are best....I'm hearing different opinions. The 65-66 Skylark GS used a smaller torque converter than the big-cars....result was a higher stall speed. I get 2000/3000 in mine. You can use a ST300 converter for the same result! Jim Weise at Tri Shield Performance can rebuild them for a couple hundred $ if you want something bulletproof.
does that software yield a useful comparison? it does not look like those simulation results provide anything close to Erik's 425 dyno results. if i'm reading the plot correctly, the HP is off by 15% and at the wrong RPM. since HP curve is derived from the torque results, that means the torque profile isn't correct (peak is too low rpm and dropping faster than actual results) if true, makes me question cam comparison validity. plotting the experiment vs. simulation may provide clues on how to tweak the simulation input parameters for improved accuracy. i have a graph of Erik and Ted's dyno results and will add your simulation when i find the graph.
I've said from the very first thread where me and Walt started playing around with Dyno2000/Dyno2003, that they aren't going to give dead accurate results. What they are good for is comparing one combo to another. By tweaking duration, LSA, etc, you'll see what should happen from one combo to another. Will the motor make that exact HP and TQ figure? Probably not, in fact I'd be surprised if it did. But you can try different cams, different head flow data sets, and pick and choose what specs you want your motor to have by comparing one combo to another. At this point it's not most accurate simulation we've got, since nobody has a real dyno to play with :grin: .
TY, what is your buget and time frame? If you are staying with stock pistons you will be limited and have no quench, for what it is, without decking the block. With stock replacement gaskets that becomes worse as the steel shims were about .015". For the cam go with a small high velocity style like GSGTX runs but maybe go smaller. Comp has a 212* and a 216* intake lobe under the XFI design also. These lobes will open the vbalves quickly and keep them open longer. Sorry TT but you are selling roiller tip rrockers and not true roller rockers. Just open a Summit catalog. A roller rolcker has BOTH a roller tip and the rocker where it mounts to the shaft has needle roller bearings also. Ty if the heads are not on the motor yet get them PORTED! Flow makes power and extra lift does not change a 5800 rpm peak/max to a 7100rpm beast. Show me the dyno dsheet and I'll apopogize. Other wise I'll have to call BS. Ty, since you seem cash limited, whio isn't, go stock pistons as you stated, run a small cam for evben more torque, maybe a 216*/231* on a 112*LSA, that will give you an LSA of -.5*, typical for the motor. The lifts at 1.6 will be .499" & .515". Use Borla Pro XS mufflers as they tested as the BEST performance muffler. Keep the carb at 750cfm, manufacturer of your choice. Withoiut the expense of the roller tip rockers you will have that more to spend on the converter for one. It can be reworked for $250. to have 3000rpm stall and a manual switch is something to do. Might as well stay with the gears you have. That should be a start. Contact GSGTX as he knows how to make a nail run as a 12.8x at 107mph on 3.23's and a 2-speed tranny is impressive. If you don't mind cutting a couple of hioles in the radiator support run a cold air system through it. That should be a start. Your biggest question seems to be the cam and GSGTX Has that down pat and can better serve you there. Good Luck. Tony
TY, what is your buget and time frame? I have the engine and Tranny out now. I am already changing all the bushings out, putting ion Disc Brakes, am scheduled to have any body work done and top get it painted. The Engine is just getting the Cams heads valves, intake carbs etc. worked on. The bottom end is in good shape. Not building a race Car just a fast fun street car that I can tear someone up with from time to time. If you are staying with stock pistons you will be limited and have no quench, for what it is, without decking the block. The Heads will be decked .30 With stock replacement gaskets that becomes worse as the steel shims were about .015". For the cam go with a small high velocity style like GSGTX runs but maybe go smaller. Comp has a 212* and a 216* intake lobe under the XFI design also. Can you send me a link to this? (Comp has a 212* and a 216* intake lobe under the XFI ?) These lobes will open the vbalves quickly and keep them open longer. Sorry TT but you are selling roiller tip rrockers and not true roller rockers. I think TT are true roller rockers NOT roller tip. Am I wrong? Just open a Summit catalog. A roller rolcker has BOTH a roller tip and the rocker where it mounts to the shaft has needle roller bearings also. Ty if the heads are not on the motor yet get them PORTED! Carmen Faso is doing the heads. I will be buying his top of the line model. Flow makes power and extra lift does not change a 5800 rpm peak/max to a 7100rpm beast. Show me the dyno dsheet and I'll apopogize. Other wise I'll have to call BS. Ty, since you seem cash limited, whio isn't, go stock pistons as you stated, run a small cam for evben more torque, maybe a 216*/231* on a 112*LSA, that will give you an LSA of -.5*, typical for the motor. The lifts at 1.6 will be .499" & .515". I don't know that I am Cash limited per se, I just don't know anything needs to be done to the pistons due to my application. Am I wrong here? From what I have seen, they look just fine. Use Borla Pro XS mufflers as they tested as the BEST performance muffler. Was looking at the 2.5 ID Cambered "Power Sticks", or "Power Rods" with a resonator if needed. The headers are T/A and are ceramic coated. Would these be a bad choice? Keep the carb at 750cfm, manufacturer of your choice. I was going to re-use the 2 X 4 carbs and intake since it was stuck on the engine to start with. I know they are not perfect, but they look great and I remember them as a kid. They also look really nice at shows. I am also buying Carmen Faso's Custom Distributor he puts out. His "Top of the line" unit. Withoiut the expense of the roller tip rockers you will have that more to spend on the converter for one. It can be reworked for $250. to have 3000rpm stall and a manual switch is something to do. This is a definite. Where would you suggest getting this done, and the hardware to go with it? Might as well stay with the gears you have. That should be a start. Contact GSGTX as he knows how to make a nail run as a 12.8x at 107mph on 3.23's and a 2-speed tranny is impressive. I have a posi, and I think I can get a set of 3.42's or a bit bigger, (Per "Doc") for the carrier. I'll keep you posted on this. If you don't mind cutting a couple of hioles in the radiator support run a cold air system through it. That should be a start. Your biggest question seems to be the cam and GSGTX Has that down pat and can better serve you there. Good Luck. Tony[/QUOTE] I will Contact GSGTX and Bounce some additional cam info off of him. Thanks Tony for you help. Regards, Ty
Ty, technically, Tom's Rollers are 'roller tip', and the TA Performance setup is 'full roller' with roller bearings on the shaft. TA setup will not fit under the 'Buick' cast alum valve covers, Tom's will. I'd vote for decking the block as opposed to shaving the heads. You'll reduce volume more per 0.010" cut, if increasing CR is your goal. There is a quench area around the flat outer area on the piston, but there's also quench between the piston dome and head chamber. Hard to visualize until you make a mold of the space between piston dome and the head. Quench basically pushes the air/fuel mixture into the center of the chamber towards the spark, leaving little mixture far away at the outskirts of the chamber. Result is a better burn with more power and efficiency. The quick-rate XFI cam and the roller-whatever rockers both accomplish the same goal....get the valves open faster. At some point, you may run into problems if they open/close too fast.... proper valve springs are necessary. Cam selection should depend on what rockers you decide to use. You don't want to overdo it, either in hi-lift, or too fast a rate. Converters are avail from Jim Weisse at Tri-shield. Look at the stickys in the transmission section for details. Carmen is a top-notch Nailhead guy:TU: He'll do it right.
Thanks for the further information. Can someone confirm whether or not the rear end of the 65 Riviera is a Buick 8.2, or a Buick 8.5? 8.5 Rear Gears http://www.jawsgear.com/Ring_And_Pinion_Gears-ChevyGMC-8.2/ 8.2 Rear Gears http://www.jawsgear.com/Ring_And_Pinion_Gears-ChevyGMC-8.2/ Thanks, Ty O'Neal
Neither, a '65 Riv has a 9 3/8in rear end. It's an oddball - nobody makes anything for them. If you want lower gears or a posi, your only source is used. Better start searching eBay now! If you keep your eyes peeled you might be able to stumble on a good deal. I just scored a used '63 posi unit for $125, although it did cost me about $100 to have it shipped. They usually go for atleast $300, soemtimes even more.
tyoneal, ta headers are fine they will help a lot.let me say this again if your going run XFI lopes you need way better springs. like 120-130 seat and 275-280 open.carmen has the stage 2 springs you need to shim them. the extreme energy is also a good cam.you can get away with a little less spring a stock stage 2 spring not shimed. in your car if it was mine i would run one size smaller then my 218-230. like a 212-214 intake.224-226 exhaust on a 111 LSA WITH A 109 CENTERLINE. call comp cams tell them what you want. do not mess with the converter if you do just grind the piston for 200 rpm more stall on high stall,DO-NOT bend the fins that will raise your low stall too.you will waste power,not worth it.with that cam and 323-342 gear you will have a lot of low end. 2x4s with 750 cfms are good.
================================== Here is an update on "Docs" Advice. From "Doc" Ty, go with a cam that is close to or a little better than the old Buick 091 cam... and rebuild with quality stuff, melling, perfect circle, trw, ect.... do as much of the mechanical stuff as you can your self... cuts cost...big time... definitly big exhausts... 2.5 Inch ID DOM Piping, with "Power Sticks" with built in resonator Their ID is also 2.5 inches Port Match the Intake, Heads, and Exhaust Manifolds Done if Flow into the next port is larger than the exiting Port ====================================== .... cant recommend headers,,, they crack, leak, rust, bend, rattle , rub,,, ect... instead port match , extrude hone, the stock exhaust manifolds... and put them back on without gaskets... Using T/A "Shorty" Headers with Ceramic Coating======== strongly consider the stock single 4 intake manifold with my Doc dual plane mod and a big single carb...less expense, and easier to maintain...then get the dual quad set up if you just want ''wow''.... Using Stock 2 X 4 Intake and Air Cleaner, Port Matched, and Jetted (Would consider. If you have the website, please pass it along and I will take a look out of it) ======================================= Definitely Recurve the Distributer (Carmen Faso will be suppling this) ======================================= definitely go with the switch pitch trans, (Will also investigate, Quick Pitch Torque Converters alternatives, "You can use a ST300 converter for the same result! Jim Weise at Tri Shield Performance can rebuild them for a couple hundred $ if you want something bulletproof.") ======================================== Definitely go with 3.42 or slightly lower posi... (Have Found a 3.55 to work with the 65 Buick 8.2 Differential) ======================================== Keep Stock Size Buick Rallye Wheels (Original Stock Rallye wheels have been found and will be used) ======================================== invest in a good cooling system...(Nothing done on this yet) ======================================== Lighten the Car as much as Possible...(Nothing done on this yet) ======================================== Remember, you are moving a big heavy car, and torque is what does it... go for a good torque cam... then with the Switch Pitch Trans and a Lower Gear out Back you will really surprise some people... ======================================== This is a total update so far in case someone wants to offer some advise and wants the current Progress Thanks to Everyone for their help so far. Ty O'Neal
