Hey Jeff, Thanks for chiming in here, good to hear from you again. Yea its been a couple of years... Hope you are feeling well. Thanks for the words of support. I darn near bought your engine... Darn freight costs anyway Thanks for the tips, its looking like I'm pretty well set up from that perspective at this point. I'll post some pics of the suspension setup soon. Glad to see you back on the board again. Stay in touch. :TU: GG
Reasons behind simplicity.... South Side "type" bars. The nice feature of a South Side style of lower control arms is they have no bushings, just a solid bushing. In order for a rear to twist, it has to be at an angle to the frame. Without rubber bushings or a solid eyelet bushing, the rear only twists the amount of what the frame and rear mounts allow with flex. Rubber bushing allow the bolt to twist in the control arms so the rear can twist independant of the frame. On regularly driven street cars, these S/S and Lakewood type arms can cause stress cracks on the frame and rear so be aware of this. They are a solid piece and do a very good job at keeping the car going straight down the track. I feel rubber bushings should not be used in anything faster than 10.50 depending on weight. You get too much "rear-steer" from rubber bushing flex that can put you into a wall on a bad track. If you feel you are driving the car all the way down the track, this would be one of the main things I would look into. :Smarty: :TU:
hood I could use those measurements Graham and anything else you think I might need to place an order when you have a chance. Lot's of good info here on this thread as I need to order up some parts and redo my suspension in the rear for a street/strip application. I currently have stock arms, airbags,CE shocks hanging from a moser 9 inch 4.11 rearend. If you ever install the 308 cam are cars will be very similiar indeed. My car was originally the same color as yours too before I cloned it to a GS with the rotted one I had. Later Greg
Hi, good stuff, At what point is going to the good anti roll bar or what ever its called needed? I am at very low 1.5 60s with a best of 1.489 and my car leaves almost level from what Yvonne tells me. I have never seen a good video of it leaving but Yvonne has got pictures and it looks pretty lame to me for a 1.49 60ft. But then I foot brake my car from almost idle so maybe that makes a difference from a trans brake leave. On a good day it will lift the front tires about 3 or 4 inches just for a second and then go back down. The battery is still in the front of my car which I plan on moving to the back this spring.
Greg, Been busy at work, I should have replied sooner. The 69 ST2 hood measurment I gave VFN was 10 5/8". From the rear center edge of the hood, to the beginning edge of the Scoop. I'll PM ya. Nice 69 there.
Engine Mathamatics and Cylinder Pressure Concerns Here is the current cam spec with the TA`413. The dyno sym matched fairly close to the actual dyno numbers recorded upon break-in which were posted earlier in this thread. There have been concerns raised on this thread about Bigger Bore 464 Hi-Compression, Detonation / Premature Rod Bearing Failure Issues with early closing intake valve cam timing, that would be the result of higher cylinder pressures... As long as one burns the best fuel... +C112 or better, how can there be detonation issues? o No: My question is "What about Turbo and Supercharged Buick engines?"... With umteen pounds of boost, don't they have signifigantly higher cylinder pressure? They seem to stay together... Current IVC is 46 degrees after bottom dead center. Cranking compression is as listed above... As high as max 240 PSI. I'm also running at 3000 ft above sea level. But that still shouldn't matter right? Just trying to figure it all out... Please provide some insight here. What is the main issue if any? Thanks, I look forward to your replys.
Racers and Builders, input needed here. Ran across this example a while back: http://www.v8buick.com/showthread.php?t=40049&highlight=cylinder+pressure Not trying to beat to death my TA 413 cam vs. Cylinder Pressure issue but I'm still scratching my head on this one. How concerned should I be? In the fall/winter '06 the bottom end will be upgraded. Quote (Hey Rick, the cam I'm running is not a BLOWER cam, I got it 2 years ago. It's a TA 413 ground on 110 degree lobe seperation. The cam has 234` intake and 244` exhaust with 500` lift on both intake and exhaust. After taking it to the machine shop, they told me they checked the cyclinders and each where out of round. They also said it looked like the rings never seated properly. I should have known that after having new bearings put in but haveing the same 30,000 mile rings put back in it with just a honning job was a bad idea. I now have to have it bord to 40 over to make them round agian.)Quote I now remember thinking how odd it was for the oil to turn black quickly right after changing it, ( carbon getting into the oil because of blowby ). This time I'm switching to forged pistons and putting in a set of NEW moley rings. I'm also going to have some of the dish area in each piston cut out to lower the compression to 8-1. Felpro has a new performance intake and head gasket for a 455 that I'm going to use. Your right about not blaming the supercharger, I just had alot of blowby because of the rings not seating right. I really hadn't thought about changing cams. I talked with ATI and they said what ever I do, make sure to reinstall it straight up, not advanced. I had installed 2` advanced before I got the supercharger.
Graham, To add to our phone conversation..... When using a power adder of any kind the camshaft is usually different than a naturally aspirated cam. When using a power adder.. blower.. supercharger... the compression is usually lower. When the mechanical compression is lower then you can run a cam that closes the intake valve sooner. When the mechanical compression is higher then you MUST use a larger camshaft to delay the intake valve closing point so you do not build to much cylinder pressure. I am just going to ask you a few question..... You say your cam is closing the intake valve 46 degrees ABDC. Why not close it at 2 degrees ABDC and let the engine build 360 psi of cranking compression? This is not done because the piston will NEVER make it to the top of the cylinder. It will build SOOOOO much pressure that it will be impossible for the piston to reach TDC. OK... so why dont we have the intake valve close at 170 degrees after ABDC? This is not good because the intake charge will be pushed back out of the cylinder, up into the intake and back out the carb. Which of course will build almost no cylinder pressure and therefore no HP. So.... you need to find the point at which you can build cylinder pressure while still being able to get that piston over TDC with the LEAST amount of resistence. This is the KEY!!! Its the same principal with N2O, Superchargers and blowers. In your post above the guy says ATI told him to put the cam in straight up vs 2 degrees advanced. He was told to do this because the engine was building to much cylinder pressure and pushing oil past the rings. Advancing a cam closes the intake valve sooner. Retarding a camshaft delays the intake valve closing point. So guys..... be carefull advancing camshafts. Another thing that will end up happening with your engine..... If you have a battery that is slightly week and you try to start your engine... the engine will kick back.... or turn in the opposite direction.. breaking the nose of your starter. I have learned all of this stuff the hard way LOL. I recommend that you go onto other internet message boards and ask the same questions. You can try RealOldsPower.com or Dragraceresults.com. Both are good sites. I wish you the best!!!!
John Z, Thank you for your detailed explanation. I appreciate your time to reply and share this valuable 'been there done that' information. I understand exactly what you are saying and have to agree, as it only makes sence. I'll be ordering another cam. Period. As Gary K said "220-225 psi would make for a Happy Engine to survive." I would have to agree with the premature the rod bearing wear issues also. Being the Race Forum I imagine there are some out there laughing at these "Grade 1 Page 1" questions"... But remember, we have all had to start somewhere. I'm glad this information is in basic laymans terms (to get the point across) for other newer prospective racers to take note and follow for their future buildups. Graham
Here is another similar explanation of cam timing by Dimitri N. Elgin, with the quoted emphasis on intake valve timing closure in relation to cylinder pressure. " Now, the last timing event is the most important, and the most critical to engine performance - THE CLOSING OF THE INTAKE VALVE. This event governs both the engine's RPM range and its effective compression ratio. If the intake valve closes early, say about 50 degrees ABDC, then it limits how much air/fuel mixture can enter the cylinder. Such an early closing will provide very nice low speed engine operation, but at the same time it limits the ultimate power output as well as RPM. Another problem with early intake valve closing that most people do not consider is that if you have a high compression engine, say 10:1 or higher, you will have more pumping loss trying to compress the mixture. This might even lead to head gasket and/or piston failure! These observations suggest that if you close the intake valve later the cylinder will have more time to take in more air/fuel and the RPM will move up. That seems simple enough, doesn't it? The later the intake valve closes the higher the RPM and therefore the more power, MAYBE? It turns out that if the intake valve closes past 75 degrees ABDC, you could lose most of your low-speed torque and if your static compression ratio is only 8:1, the engine will not be able to reach its horsepower potential. This should give you a better understanding of why the intake valve closing is the most important timing event. " The above quote was part of a very good write up on cam timing. This is the thread: http://www.v8buick.com/showthread.php?t=26217&highlight=elgin
Graham, Thats a great article posted on that thread. Very imformative!!! I dont know that changing the camshaft is your best option at this point. Your going to need to put a 308s cam in that thing to make a happy engine. Look into the possibility of reducing compression somehow. I say this because you are running a stock rod with no girdle. If I were independently wealthy I would give you the $$$ to re-dyno this engine after a compression change. I would be willing to bet you would gain HP by lowering the compression. Later.. good luck!!
John, Please send cash! :laugh: I was thinking along the same lines with the 308s as a possibility too. I also ran some interations on Dyno 2000 with the current 413 cam. I left the lift alone but played with the durations and IVC points. As one can see with the lift staying the same and widening the Lobe centers and IVC point, the parasitic pumping losses are reduced. IVC adjusted from 46 to 60 degrees. Duration and overlap adjusted somewhat too. The Sym shows a good HP increase with some TQ loss, directly relating to your theory. :TU: I'm also looking into the thicker head gaskets 0.080" as an alternative to reduce cranking compression as well. Stay tuned. :3gears:
Be careful with going with the thick head gasket your going to loose most of the quench and put it closer to detonation even with a lower compression ratio.
Good point and well taken Adam, I'm going to leave the TA Orange Crush head gaskets in place and leave the compression as is... for now. Have been working on the suspension lately, here are a few pics.
And began work tacking on the 3" Mandrel Bent TA exhaust and proportional electric cutouts. :grin: :3gears: Custom built drive shaft should be ready tomorrow.
Lookin good Graham. :beer Are you going to run an x-pipe? How about mufflers, have you decided what "song" you want your motor to sing to ya'? :Brow: Did you go with a alum. driveshaft or a steel one?
! Thanks Todd. All I have room for is a crossover pipe. Running the 3" DynoMax Shorties, and Custom Steel Drive shaft. :grin: Its A L I V E ! ! 14" Intake vac @ 875RPM. Steady. Some valve train noise apparent though...Looking into... Engine sure builds heat.... Ron Davis Rad cycling nicely.
