I has a freshly built 462ci BB in a full body regal. The motor is zero decked clearance with 11.5:1 Ross lightwieght pistons, Set of Fully ported 430 heads, TA 408s solid camshaft, Double roller timing chain, SP1 intake, 1000 cfm Silver claw carb, 400 transmission with 4000 stahl, 4.10 rear gears, and a 300 shot of NOS. I took the car to the track and it has more power but I can't get it out of it. It turns up quicker and has a better response but it still runs the same as my stage 1 motor I took out of the car. It was a 462 ci 9.5:1 motor with bone stock heads on it with everything except the camshaft was a TA 608 camshaft hydraulic and the car still only runs 7.30's through the 1/8th of the mile. I think it is the converter but can someone give me some help please. I figure the motor should run some 6.80's in the 1/8th of the mile.
Yeh, we definitely need some et specs. It very well could be your converter, especially if it a cheep one. Cheep converters are bad about not tightening back up once the rpms rise after launch or just being way too loose. There also could be a bunch of other things that could be off. What is off is your times. I went 7.23 at 93mph on motor with my 3500 lb Stg 1 508 hyd cam 3.73 gears, 3200 stall and 2004r overdrive. You should be running 6.80's. Are you running any exhaust? THat cam is sensative about back pressure with all the exhaust timing on the 408 cam. Open headers or a short pipe with a straight through muffler is the only way to get good power out of that cam. But that is the best off the shelf cam for nitrous. THe motor is also going to be sensative on the jetting and tunning. A rich carb and bad distributor timing will throw you off in a hurry. Going back to the converter.... How high can you stall the motor just holding the brakes? If you can get 3500 or more by just holding the brakes, I would say its too loose. Thats a generic way of checking it but unless you have a playback tach to show you the rpms of your launch and run its hard to say. I found that my foot stall was about 500-800 less than the flash on the launch. Another way to tell is if your not getting much, if any, rpm drop between shifts.
I have open headers, It runs in the 92mph range. It seems to give up after the launch and when it went to high gear. I don't exactly know the 60ft times on it but I have sixtied with a car that has a 1.55 60ft. I don't exactly know the jetting of the carb but what is the jetting that u recommend. I have an ati balancer on the motor and can not get the timing right because the timing tab had to be modified for the balancer but to the best of my knowledge it is at 34 degrees.
Stuff Do you have the rear power valve plugged and jet extensions? THe stock jetting should be close but go up 8-10 on the rear with the power valve plugged. YOur not having a fuel delievery problem are you? What do you have for a fixed point on the timing cover to set you timing? If you dont have one, make one. PUt it in the general area of the original and you will be able to find zero from there. to find "0" degrees on you balancer put a piston stop in your #1 spark plug hole and turn the motor over carefully forward and backwards by hand until you come against the stop. Mark the point where it stops in both directions and split the difference. The center between the two points on your balancer is "0" degrees. THen you can figure your 30 degree point from there. ***** YOu will have to take off your rocker arms to do this so the valves will not hit the stop. YOu don't want to bend a valve doing this.******* The piston stop I have was in a cam degreeing kit but I'm sure you can make your own or buy it seperately. You may talk around and see if someone has one you can barrow. Make sure to round the edge of the piston stop where it touches the pistons as to not leave any sharp marks into the piston.
Yes I do have power valves in the rear of the carb. Do I need to block them off then go up on the jetting, I also think that I need to buy a fuel pressure gauge to see if the pressure is droping between passes.
helping your et Definitely! That power valve will suck air when the fuel goes to the back of the bowl on acceleration. YOu definitely need jet extensions too. Get the notched float with screw in extensions. I'd start with going up eight jet sizes and see how the car runs. Then go up two jet sizes on the front and rear to see if the car picks up any. Watch the mph since it will be more consistant than your et. I went from 7.60's to 7.30's installing jet extensions and removing the power valve and picked up 3 mph. I wouldn't even touch the nitrous until you know you fuel system is right. Do not forget to run a fuel pressure safety switch on the nitrous feed line. For $36 its not worth the risk of burning up a set of pistons. Once you get the motor dialed in, I'll give you a few tips on how to get an extra tenth or two out of the nitrous if your motor will take it. :Brow: you got the cam for it so it should.
I'm still running power vavle in the rear of my carb i'll have to try pluging it and you said 8 jet sizes that seems like alot i would have to go form 86 to 94 ??
Jetting That may seem like alot of jet but that is the amount of fuel the power valve generally supplies. The range is 8-10 jet sizes with the power valve plugged. You just have to try and see if 8 or 10 works best for you.
i HAVE LOOKED AT THE REAR OF THE CARB AND IT HAS 98 JETS IN THE BACK WITH NO POWER VALVE IN IT. I HAVE TRIED THE CAR OUT AND IT HAS NOT PERFORMED ANY BETTER I AM GOING TO TRY AND PULL THE HEADS OFF AND SEE IF THERE IS ANYTHING TOUCHING IN THERE. I CAN FEEL THE POWER BUT CAN'T SEEM TO GET IT OUT. I NEED TO REALLY TECH THIS MOTOR AND GET IT RUNNING THE BEST I CAN. THE MOTOR IS NOT EVEN SPEEDING UP ON NITROUS IT IS ACTUALLY SLOWING DOWN WITH THE NITROUS. HOW MUCH RETARD DO I NEED WITH A 300 SHOT ON THE CAR. PLEASE SOMEONE HELP ME OUT. I REALLY WANT TO SEE THIS MOTOR GET OFF LIKE IT SHOULD AND SUPPOSE.
Hmmmm..... 98 jets are most likely too big unless your air bleeds are too big also. If your running rich you'll KILL your power especially on nitrous. Running rich might be safe but too rich will make it not run at all. If your spark plugs have color on the white porcelen you can see, your most likely too rich. Buick plugs run white when there in tune. I only run 93 jets in my Holley. If I had to guess I would say 82's in the front w/ a power valve and 92 's in the rear w/ the power valve plugged and that might be rich also. IF you are only racing the car, i would plug the front and rear. It eliminates one more thing that might cause a problem somewhere down the line. Make sure your nitrous solenoid is opening. If you run over 1200psi on the bottle pressure the solenoids might not be able to open. 300HP SHOT!? I like it! But you should see your biggest gain out of a 150 or 200 shot with your combination. Are you noticeing the motor rpm drop betwen shift? you might be just blowing through your converter. It will kill your et and mph just like a slipping clutch meaning it won't stop slipping until it reaches that point where your motor starts to flatten out after the power band. I'm sure you notice the shift but pay attention to the rpm drop. On any giving combination there is a limit on how much the motor is going to take in. If you can't pick up any by going up to the next high HP of nitrous and you've tried everything to tune it, you need to STOP! You either need: Converter, Cam, AND/OR more exhaust flow. If you try to push more in to a motor than it can use you will loose the motor with a quickness. The nitrous and fuel will build up in the intake then the distribution will drop off then one cylinder lean, one rich, then BOOM! Or a piston or gasket, rod, crank, Something will give. I think your motor will handle the 300 shot but you have to get it to where it uses it. Work on that motor combo. IF the car isn't a "pig" out of the hole meaning it needs more stall and gears it isn't set up right for a 300 shot. I know the 4.10's will work in the 1/8 and would be good for a motor setup but not for your nitrous on a Buick. That stall needs to only flash no more than 3200 at the most if you panning on getting good use out of the spray. If your getting 4000 or more on motor it just AINT going to work. With the spray working, the 4000stall will go to an easy 5500-6000. By then your motor is running out of breath fast. A 3000 stall will stall to 4000 on a small shot because of the extra torque its making. Good luck and keep us posted. The power there, you just got to look in the right spot.
THR SPARK PLUGS ARE NOT BLACK OR RICH LOOKING ON THE TIPS AND JUST SOME OF THE PLUGS HAVE BLACK AROUND THEM. i REALLY WANTS TO GET THE CAR TUNED TO RUN 6:80'S IN THE I/8TH AND THEN HIT IT WITH SOME OF THAT LAUGHING GAS AND GET DOWN TO THE NITTY GRITTY. I TOOK MY OTHER MOTOR TO THE SHOP FRIDAY IT IS THE SAME COMBINATION BUT WITH A TRUE FLATOP IN IT. WANT TO GET A HOLD OF A 6:04 CAMARO AND VEGA. HERE IS WHAT IS GOING INTO THE OTHER MOTOR. IT IS A .038 THOUSANDS WIESCO FLATOP PISTON, FULLY PORTED AND POLISHED 430 HEADS, TA 408S CAMSHAFT, BALANCED BOTTOM END, SP1 INTAKE, STOCK ROCKERS WITH THE ADJUSTABLE PUSHRODS, 1000 CFM BARRY GRANT, 4:10 REAR GEAR, TH 400 TRANS WITH A BRAKE, MSD DISTRIBUTOR AND MSD DIGITAL 6PLUS, IN A 1985 BUICK REGAL. DO U THINK THAT THIS ONE WILL GET THE NUMBERS I AM LOOKING FOR, BECAUSE THE ONE IN THE CAR IS THE SAME SETUP EXCEPT FOR THE PISTONS, THE ONES IN THE CAR IS A SET OF 11.5:1 ROSS PISTONS SETUP ON A ZERO DECK CLEARANCE. I REALLY NEED SOME HELP TO GE TIT GOING I WANTS TO RAPE ME SOME OF THOSE CHEVYS OUT THERE. SO FAR SO GOOD JUST WANTS TO GET THIS THING RUNNING RIGHT. AND I GOT ALL THE GOOD ROD AND MAIN BOLTS IN IT.
A few thoughts........ Adding more compression will reduce the amount of nitrous you'll be able to use with iron heads. It's kinda like boost. THe more compression the less nitrous you'll be able to use on the same motor combination. YOu can actually make more power with less compression since the more will take a little more nitrous. I'm not talking a big difference, but you will pick up on "motor only" hp with more compression. For example, if you max out at 700 hp on your old more with nitrous, you may only get 670 hp with a high compression setup. Are the rockers your using stamp steel? I can't believe those stock rockers are surviving the abuse of those stiff springs with that cam. If your building another short block at least put tappered pins in the pistons instead of the light weight thin pins. Even though you might not have a thick deck on the pistons, losing a ring land to nitrous is nothing compared to losing a pin. I know your looking to beat that motor a bit with the juice so I'm just looking out for you. Instead of building another short block, just buy a set of 1.60 roller rockers. What are you running for a nitrous set up? Fuel system? Lines? Electronics? Are you running 2" headers? Its sounds like you have a good setup but there's either something out of tune or a bottle neck somewhere. On the plugs, Lean it out 2 jet sizes on the front and back to see if it picks up any. If it does keep going until it stops going faster. As you go leaner, when it stop picking up mph go back to the last jet sizes that you ran the same mph with. Its better to be a hair rich than lean but only a hair.
WELL AS FOR THE FUEL PUMP I HAVE A HOLLEY BLUE RUNNING THE NITROUS AND ANOTHER HIGH PERFORMANCE PUMP RUNNING THE MOTOR, FOR NITROUS SYSTEMS I HAVE A BIG SHOT 400, AND THE FUEL LINES ARE 1/2 INCH COPPER TUBING INTO TWO HOLLEY FUEL PRESSURE REGULATORS, I HAVE BIG TUBE HEADERS ON IT. THE ELECTRONICS INCLUDE A DIGITAL 6PLUS, ELECTRIC SHIFTER TO GET ME OUT OF LOW GEAR, ELECTRIC WATER PUMP, ALTERNATOR, ELECTRIC FAN. WHAT DO U THINK THIS MOTOR SHOULD RUN ON MOTOR PROPERLY TUNED.
I have just tore the front bowls off of the carb and to my discovery there were 85's in the front with a power valve. I have blocked the power valve off and then cranked it up. It seems to respond better with the power valve pluged but how much must I jet it up with the power valve pluged.
Go up 8-10 jet sizes. I would start off with 93' s. Your front and rear should match with your power valve plugged since the metering plates and air bleed should be the same. If you go with 93's or 95's in the front put the same in the back. Whats your fuel system setup? it can't be bad if you didn't blow it up when you sprayed it unless your running a safety cut off switch. ..........You do run a fuel pressure cut off switch on your nitrous, Right? Your running a Big Shot NOS plate kit? Stay away from cheep regulator on the nitrous. They are too restrictive and the pressure does not stay consistant and they do not respond fast enough.
I currently am running a holley blue for the NOS and a Comp Pro fuel pump for the carb. I have 1/2 inch copper tubing from the fuel cell to the front. I wants to take it to the track in Fayettville and test and tune it. I really need to get it timed and see exactly where it will go. And how much retard should I run for 225 horses of NOS.
That'll work That will work. 1/2" will be fine for the motor. But what exactly the gph on the Comp pump? The Blue pump should be plenty on the nitrous side. DO YOU Have the fuel safety cut off switch yet? It will mount off the nitrous fuel regulator and shut off that nitrous it the fuel pressure drops off for any reason. For $40 its more than worth it. On the 225 shot, take out 8 degrees. That should put you at 28 degrees total timing. Thats just a starting point, you can go as little as 6 or as much as 12. It depends on how your combination responds to it. Make sure to run 110 octane to keep things together. I would start with 5.5 psi of fuel pressure on the nitrous for a NOS nitrous kit with the recommened jetting. But you should be able "square" the jetting as you get things in tune which is running the same size nitrous and fuel jet. If you get aggresive and go straight for the "square" setup at least run 6 psi for fuel pressure before trying 5.5psi. 1 psi makes a big difference on nitrous kits so it very important to have stable fuel pressure from the launch to the finish. Get a good gauge and set the fuel pressure with it flowing through the plate. You can put the plate over a bucket or put a clean towel in the intake. Just don't load up the engine with raw fuel. If for any reason nitrous gets sprayed in the motor while its not running DO NOT try to start it OR even turn the key on UNLESS you unplug the ignition. YOu will need to crank the engine over for about 5 seconds to purge it from the motor.
Well the nitrous fuel pressure is about 7 pounds with the fuel jet on the 400 horse pill instead of the 300 horse pill. i like a little more fuel. the comp pump flows 140 gph. I am wondering where the timing needs to be set at for horsepower on this motor. I will take it to a track on wednesday and then back to fayeteville on friday night for test an tuning of the car. do u think that it will run 6 anything on its own?
Hmmm... 400HP? A 400 HP shot will break your top ring land of a non-nitrous piston if its in tune. what does it run on the 200hp or 300hp shot? Your putting 200-300 hp of nitrous in the motor so whats happening? If you haven't got at least a 6.60 out of the 200hp shot it wont do any better with the 400hp shot( going off your 7.20's you ran earlier) but you should be able to go in the area of 6.40's on a 200hp shot. On a tuned 200 hp shot you should at least get 200 HP or more because there is 200 HP worth of nitrous going in the motor. If your not seeing it in the et somethings not right and going bigger wont help. Your 408 cam should be able to move over 250 HP of nitrous but its on 108 LC and thats not good for alot of nitrous even more so if your exhaust isn't flowing good. the exhaust valve is open long enough to get the additional volume out but the LC angle of the cam puts the exhaust valve events in the wrong spot and gives too much overlap. The exhaust is opening too late and closing too late. Nitrous causes the combustion process to happen faster ( since it burns faster) which is why you take out more timing for more nitrous but it also means you can open the exhaust earlier without a power penilty. With the valve opening sooner you can close it sooner keeping the same duration reducing the amount of overlap ruducing the amount of nitrous you waste out the exhaust. With Wider LC on a nitrous cam, such as yours, to keep the intake events close to a motor cam (about 104 degrees) and get the exhaust to open and close ealier you would have to install a cam with 110 or 112 lobe seperation ,say, 6-8 degrees advance instead of 4 to get the exhaust to open and close earlier but keeping the intake events the same so not to shift the power curve any higher. I figure I'd through this in here since you seemed to be in that motor alot and might try a different cam. Whatever you do don't go smaller. you should be close with the cam you have. THe problem with the NOS kits it they are rich! Rich, rich, rich! On a small 150 shot the overall mixture of the motor evens out ok and it doesn't really cause a problem but when you go to a larger HP shot your making more HP out of the nitrous so you go from a little rich to too rich, the point where you actually slow down with a larger shot. YOur motor wont be able to move a 1000hp worth of air. You may be able to get it in because its a dense pure oxygen mixture but when it goes to go out the exhaust its trying to move 900-1000hp of air and it can't so it feeds back into the intake as soon as the intake valve opens and BOOM especially with a large overlap cam as the 408s cam on 108 LC! (With wider Lobe Seperation you can get away with more.) It will ignite the incoming mixture since you lost your scavage effect from the exhaust to help bring the intake charge. YOur intake charge and exhaust charge have momenum which all work together helping bring air in and out of the motor but when you start to get reversion and can't get the burning charge out of the combustion chamber and the intake charge can not over come the pressure from the exhaust still in the camber, you'll get an explosion back through your intake. Thats why when you can't tune a larger Nitrous shot to work it a sign to stop. On your setup a 250-300 shot should be all it needs. Put the same jets in the fuel and nitrous sides of the plate leaving your 7psi of fuel pressure and work your way to 5 1/2 psi of fuel pressure. If you go with the stock jetting and 7 psi it will be a DOG if the system holds that 7 psi for the whole run. If you haven't got the results from that 300hp shot and you insist on more you would get MORE from leaning it out than from going to a larger jet. I went from just picking the front tire up and carrying them through the 60 ft to putting my car on the bumper just by leaning my 150 shot from 6 3/4 psi to 5 1/4 psi with the stock jetting. If you haven't burned a plug tip yet you haven't leaned it out too far. The NGK race plugs run softer tips that burns off easier and lets you know when your too lean. Autolites and AC Delcos use harder metel that takes more heat to burn off the tip but by then it may be too late. By the way THIS SUCKS tring to explain all this crap on a computer. I hate typing on top of it. So hurry up and get that beast flyin'. I want to hear you get a good et out of it. And keep it together until I get back. I want to see it run. YOur representing while I'm gone so don't do me wrong. :TU: :Brow:
