Well, just to start this off, you wanted a noticable idle, you got a noticable. Some of this has been mentioned before by other folks but I feel some of it needs repeating. Your current cam has 28 of overlap @.050" while the previous cam only had 6.5. There is no way that old cam had less lowend power than the new cam unless something was amiss in the engine. I agree 5-7" sounds about right for that much cam. 28 of overlap is a lot which will cause the low vacuum and if your compression isn't really as high as it should be that will also cause a lower vacuum. I'd say you really need about 10:1 for that cam to really work although you could get into knock problems with full timing because of the weight of your car. I'm not sure how you are messing with it but you have to stick to a particular rpm to measure at. I wouldn't worry about in-gear vacuum other than a final adjust of the mixture screws. If it won't stay running in gear you just do the left foot on the brake and the right giving it a little gas to keep it running. The best thing to do is have the cam degreed in. The second best thing you could do is set it to +4. If you don't know where it is and it is actualy straight up it is as good as retarded when the chain starts to stretch. Which could be a reason you say it pulls well at the top end. 90% of the time a cam is better to be advanced than retarded. The big problem as far as installing the cams identically is you don't know if they are ground the same. One could be right, both could be right, or both could be wrong. Do you feel lucky? You really shouldn't have to beat a Holley carb to death, especially an 850 DP, to get it to idle. You should have power valves lower than your idle vacuum but they don't cause richness at idle even if they are opening. The reason you get pullover from the main circuit is because the the throttle plate is open too much pulling gas from the main circuit. That is the reason you drill holes in the primary throttle blades. That allows more air into the engine without unseating the throttle blades too much and keeps them in the area where the transistion circuits work for off idle. When you are going to have a rough idling cam the best bet would have been to get a carb with secondary idle mixture screws and it would also have a secondary throttle plate adjustment. For maximum throttle response in a heavy car you would have been better served by a Holley 950HP that is based off the 750DP. The smaller venturies would make a huge difference in throttle response in your car. Even better would have been an 850 vacuum secondary Avenger carb. No throttle response problems what-so-ever. The slight performance gain the DP carb has would be completely negated by the vac. sec. street response. Something else. That intake has got to be a complete waste of time on your vehicle(heavy) and IMO is pretty much a waste on any car that isn't running 12's, at least. On my '76 Century which weighs in at 4250 with me in it the SP1 was only worth .1 sec/1 mph and I'm running solid 11's. You'd be better served with a B4B, a 1" 4-hole spacer, and whatever carb you want. At the very least get a 4-hole under that carb if you have hood clearance. One place I think you made the right move is with the converter. From the way you describe it I'd say it would flash stall to about 3-3200 rpm off the line with traction because of your weight/torque which would work nice with that cam. If you are used to driving a stock converter just about any higher stall converter feels "different". Yours doesn't sound too bad to me. Maybe a bit slippy on the road but not bad. That converter is probably the reason you feel it makes great low end power. An easy way to check what it is trying to lock up at for cruising is to climb a long hill reasonably steep and just give it enough gas to go 60-70. Not hard on the gas but enough to keep up. The tach will find a spot where it likes to hang out. As far as the 200 4R trans goes make sure it is beefed up nicely with as much good stuff as you can afford. A heavy car/high torque at low rpm every time it shifts is completely different from a GN setup. The V6 with no boost combined with the fairly light weight of the GN puts almost no strain on the trans in day to day use. I really have to second the motion to use Rhoades lifters to help out with idle vacuum and beef up the low end torque. That is where you should be concerned with that car. The only thing they do is make some noise akin to soild lifters which you probably will not hear. With your cam there will still be plenty of lope left over even with them. It is a win-win. 6000 rpm is a waste of time with that setup. It probably peaks out around 54-5500 with that tight lobe center. It may pull higher but it isn't doing anything. The only real way to know if everything is working right is a couple of TnT's at the track. Don't be fooled by spinning tires. When you get some good sticky tires on and nail it at the drags guys often wonder what happened to all that tire spinning torque? It just "feels strong" doesn't mean much either unless you have a decent amount of experience. Performance "feel" is relative. The man who drives around town in a '74 Impala is usually impressed by how "fast" a stock '76 Corvette runs. Not saying yours isn't fast. Just saying you never know until you know. Ask Yards about his boat experiences.
-I'm not complaining about the idle at all...Im actually not complaining about any of it. I LOVE THIS CAM! As far as messing with the Holley, it idled just fine but I had to crack the primaries open too much and thats why I drilled the holes. Right now only .040 of both the pri and sec transfer slots are visible and will the 2 holes in the blades it idles just fine at 900-950 rpms. -I realized after mesing with the nozzle size that the convertor wasn't the reason the car was stumbling at idle so the convertor is just fine honestly. -The comp Buick cams come with 4* advance built into it, at least thats what it said in the card info. I agree what i did was not in any way optimal but it seemed logical as the cam gear only bolts on one way and when you line up the dots to the crank gear it came out in the same position as the 455's cam at TDC. -As far as the car wanting to die when i come to a stop, it's probably dirty seats or improper float level. I didnt have the problem when i was using the primaries as the idle control and they were cracked wide open so it's just a matter of tuning. -Tuning the carb is what it is. It was a used unit when i got it and I rebuilt it witha kit from Holley. The car started and ran just fine with it bolted on with no mods. I am simply spending the time to optimize for my combination. It's a learning process for me that I enjoy doing. -I hear you about no really KNOWING about how fast it is, at least on the bottom end until i track and/or dyno it but I can compare it to my old combo and it feels stronger than it ever did with my 455. I DO need some better tires though and hopefully that will be happening the next few months. -The 200R4 I have was built for 600hp supposedly. -I'll look into the Rhoads lifters for sure although, other than brakes and vacuum advance...why would higher vacuum really be necessary? -As far as SP1 vs Dual Plane...I did that on my 455. Went from dual to SP1 and I did notice a loss of low end torque but the gain up top was well worth it. These engine make so much torque already giving up 20-30 to gain top end speed (not power) is worth the trade off for me. i don't think I'm in the 12's with this car but solid 13's...and I'm basing this off of how my GTO was when it was stock. -I DO appreaciate everyones advace and have already incorporated some changes based on it, so I'll keep everyone posted as to how things continue to play out.
This may be where the low end is coming into play. If I'm not mistaken the stock Buick timing gear adds 4* advance. Again, if I am not mistaken, TA cams are ground straight up and the two I've degree'd in both came in 4* advance using the stock timing gears and both the 118 and the 290H cam's were 4* advanced. Now my question would be are you now running 8* of advance on the cam? That would bring the power band down lower, which would bolster low end power and feel. Only one way to know for certain =P That being said, I'm ordering the TA 9-way adjustable timing gear and plan on running the max amount of advance I can to bring down the power band a bit.
As far as the Rhoades lifters go the higher vacuum would help your efficiency at low/mid rpm range adding some torque and probably boosting mpg a bit. They would be worth it just to get a better idle out of it. It would just make it easier to tune. I ran them all the time back when I used to run around with big cams in. Cams are ground off all the time but sometimes you get lucky. For the few bucks it costs to get a degree wheel and dial indicator it is well worth the trouble. It would be right up your alley to get a setup and play with it. If you get the tools you can even do a quick check without taking the front timing cover off. With a heavy car anything that helps it get moving quicker helps the most. If top end is what you are looking for then you've got the right parts. You know it is running stronger than it was before and that is what counts.
Well, slight win today with the troubleshooting of the erratic idle and lower than spec vacuum. I removed the choke plate to eliminate the chances of it being a faulty choke/fast idle cam settings. Suprisingly, the car started and after some light feathering for about 30 seconds the car idled just fine in this 50 something weather. It was still acting weird so I got the carb cleaner out and started spraying around all the edges of the intake. Carb mounting base was ok, passenger intake to head good, then i get ot he dirvers side...i spray both intake ports and vroom! Instant increase in rpms. i retorqued the bolts but they were still within a quarter turn of the original torque i gave them. Sigh, guess that means the intake is coming off for new gaskets. YAY ME! LOL. I think I might pop for some Rhoads lifters and see how they do to help. Oh well, at least I'm making progress.
Great news! Keep us posted. My SP1 was worth 30HP over the B4B on the dyno. What intake gaskets are you using?
I was using the standard thickness TA gaskets with a cut valley pan. I'll try some thicker ones this time with some RTV around the ports.
No RTV around the ports. You can use spray tack or Edelbrock gasgacinch, http://www.summitracing.com/parts/edl-9300 RTV goes around the coolant ports at the end of each head, and in the corners where the rubber rail seals tuck under the head.
As problems go that is about the best kind of problem you can find compared to bad cam lobes or bent valves. If composite gaskets weren't sealing maybe the intake is being held up. I haven't heard of it on TA intakes but check that the intake seats easily over the locating pins without a gasket. If it seats to the head you are ok. Depending on how much the heads/deck have been milled I don't even mess with end seals. Just run a thick bead of RTV along the block from head to head. Or, maybe you just need the thicker one. What thickness were you using?
I ran into this problem where the rubber seals were holding the intake up, I had to ditch the rubber wall seals for RTV.
Got the Rhoads lifter and new intake gaskets installed today. I also decided to a little work to the carb.:Brow: Tomorrow, I need to seal up the radiator and figure out where the leak is coming from so I can HOPEFULLY seal it up.
Which version of the Rhoads lifters did you use? Did the stock push rods work out with your (stock, non-adjustable???) rockers? I don't remember if board members have indicated that longer push rods may be necessary.
I used the original Rhoads with the super lube groove. I didn't measure the preload on the lifters but they looked exactly the same as the lifters i took out. No movement, other than being able to spin them, in the pushrods once i torqued the rocker arm shafts down...I'm sure once I start it I'll find out for sure.
Some progress if you want to call it that. The Rhoads lifters did NOTHING for me other than lower idle oil pressure. I'm assuming they weren't operating as designed since I'm using the stock oiling system through the heads vs pushrods. So, out they went and back in with the old. I also decided to box my lower rear control arms. I'll post some pics later but it was suprisingly easy and they are SUPER beefy now. All I'm waiting on are the new bushings.
Noise and lower oil pressure is all I ever saw out of Rhoads lifters. Maybe a little better idle and vacuum. Never seemed worth it.....
Got my Moog heavy duty bushing in today. Took all of five minute with my bench vise, a piece of would and small piece of 3" exhaust pipe to press them into both sides.
Finally, made some progress on the ole girl. I got the pump changed out in the 2004r and got the transmission re-installed over the weekend along with the new aluminum radiator and electric fan setup. I also cut some of the tunnel braces for some much needed clearance for that huge 4" drive shaft. Still need to order a new pan as the current one leaks around the drain plug, hook up the lockup controller and add fluids. Oh yeah...got my new 15x8" Big Buick Ralley wheels today. > Stay tuned for more.
