OK, I'm sure we can all agree that WD's car isn't running right and a gear change will make only a slight change. You didn't mention spin off the line but I seriously doubt there is a problem there. Examples of faster cars with less equipment don't really help other than to illustrate that WD is way down on the MPH. I would agree that this car really needs a higher stall converter to optimize ET and the mph would still be lousy with no other changes. WD is actually running a decent ET for the MPH showing. The converter would make that a great ET for MPH. I'd also like to add that unless you are planning to add N2O the converter may be tighter that even indicated. N2O converters are usually built tight so when the N2O hits it will flash to the right stall and not flash way high. As far as the MPH goes I'd be looking into major tuning/mechanical problems. I would think you are off in the range of 6-10 mph. There is something way off in one or more of the systems. As has been suggested look into problems with plugs wires and such. I don't think compression is a real problem even if it is 8.5:1. It may make the car slower if it is too low but it shouldn't cripple it. I'd be running closer to 11:1 with that setup but that wouldn't be worth more than a few mph. When everything is right and you still need a some more power go that way. The first thing I'd be doing is popping the valve covers off and watch each rocker arm to make sure all valves are opening while cranking or running. If one or more look like they are off you may have some flat lobes. You can have a flat lobe and be way down on power but the engine still idles/drives decent because the lobe is opening up slightly. Still with the cam I'd make sure the cam was degreed in correctly. Potentially it could be off enough to take the life out of the engine especially if retarded. Something else to note with that cam and heads your shift point would have to be above 5500 rpm to really make use of them. I'd get rid of that digital ignition system and just install a regular distributer with a good recurve and a hot ignition box just to be able to say that isn't it. Next would be a carb swapout to eliminate that. Your wideband should be able to tell you if the carb is running rich/lean. I don't think this is a situation where you have a fuel delivery problem because that would show it if you are very lean on a run. I'll assume that you can say the trans is shifting right with no apparent slippage. Like I said IMO there is one or more major system problems going on that need tracking down.
thank you to reply I think the real problem is tuning To much timing (36' total) or/and carb tuning (13:1 wot) You say I need a 3000 converter I think I have one somewhere I plan i cam change for the cold season (TA_288-92H,TA_290H,TA_298H) I will buy a set of roller rocker I think I really need one What do you think ?? I'm not the only one with that kind of trouble
I don't see any reason to change the cam. Your current choice looks like a great match for your build.
Shoot for about 11.5:1 air/fuel ratio at WOT Set the timing to about 32-34 degrees total all in by 2200 RPM abd use 8 degrees if vacuum advance on top of that. I would not swap the cam
If I am reading correctly, this car is naturally aspirated Sean. So, if he is at 13:1, he is in the ball park. Most guys I talk to have the best luck between 12.7:1 and 13.2:1. My car is no exception.
I am, and that's why I thought my fuel pump was adequate as it can maintain 12:1 AFR at WOT here, but my 12.95 run at 108mph is at sea level (don't recall the DA though) and it was coming up short. Considering average day here is 20% less air (80kpa vs 101.3kpa), you can see how marginally acceptable here can become quite inadequate, LOL. I was shooting for a 13.2 AFR on my car, but was leaning out higher than that starting around 4,000rpm and was in the low 14's by the time I shifted. No bueno. I had the EFI keep opening the injectors for longer and longer, but the AFR's were doing the same thing each run, telling me the fuel pump was giving it's all and it wasn't enough.
What rpm do you shift at? That setup should pull smooth to 6000 rpm. Maybe it won't be pulling that hard at that point but it should get there with no fuss. What do you have your lifter preload set to? Should only be a small amount, .010"-.030". What track do you race at to figure the elevation? NO cam change X100 unless you confirm you have a lobe wiped. Adding 9 of cam timing would only be worth .1/1mph. There is no "magic" cam that will add gobs of power. Rockers would be a waste of time at this point and would just add another variable. Check the lobes. If you aren't sure what to look for get somebody that would. If we were at the track I would have told you to get the valve covers off while we were standing there. I can tell you how to do a rudimentary check on the cam timing if you have or can get somebody with a dial indicator and a magnetic base and you/they know how to use it. That is all you would need. Under an hour of time with very minimal teardown. Nothing fancy and it will see if you are in the ballpark. I would add I'd do a quick compression test on all cylinders just to see how they are doing. This would be a good time to check the "0" mark on your damper for true TDC. Maybe the ring has slipped affecting your timing start point. Unless you can find 5 or 6 small adjustments to make on various systems you won't be going anywhere. 2 of ignition timing isn't going to do it. That is why I suggested swapping the whole ignition setup. With your compression, aluminum heads, and cam timing a few extra degrees would probably help. The little stuff can pick up power big time when you add it all up but check the mechanical stuff first and go from there.
Before you edited your post you said you were burning the tires in all the gears. I'm assuming that includes out of the hole. I repeat you need to address traction issues and make sure you have enough stall, at least as much as the converter you have advertises. Also 1000 cfm is a lot of carburetor for the cam you are running. There probably isn't much wrong with your car otherwise. Good Luck. Bob H.
i agree with no lift, that mph is horrible for that combo. i would start with degreeing that cam and see where it is. if it a schnider cam it will be way off. my 286-08h was 7* off and i think that will have an affect on it. the mph will tell you a lot about what's going on. also how is the fuel supply? it may be running out up top. your car is on the heavy side but should be faster than it is. what is your rpm's through the traps? once you get the tune figured out that's how i would figure out what gear is needed. check that cam though, the degree and any round lobes. if the 310 is wiped out i have a 308s cam in the box that is about 10 years old that was intended for a stage 2 headed set up that i will sell. you could also run it on a chassis dyno and that will tell you a lot.
As I said in my earlier reply all you have to do is carefully watch your rockers as they move either cranking or running to make sure they all move about the same amount. As you watch them for a short while you will pick out if something isn't working right. If the car is running be ready for oil to start flying. You can only do it for a short time before you have a flood.Just rotating the engine by hand won't really do it because the lifters need oil to pump up and they may collapse. Do 1 side at a time and reinstall valve cover. That will minimize spash. Do the compression check. So you are saying you installed the cam by just aligning the "0" marks on the gears? What timing chain set did you use? That is very important. To get the most power out of the cam you should be DEGREEING the cam in to make sure it is in right. Unfortunately things aren't always manufactured as they should be and degreeing in the cam assures you that it is right. Correct way to degree cam but you don't have to get as "fancy" with the equipment: http://www.v8buick.com/showthread.php?220945-Camshaft-degreeing-101 Like I said if you can get a dial indicator setup we can see if you are in the ballpark.
I agree with you on the cam timing. If you are using a Rollmaster timing set, then cam timing needs to be advanced 4 degrees from the "straight up" marks. The MPH should be at least 4 mph higher with your mods.
When I install the cam I check the spec with the degree wheel and is alright You say we need to put it 4 degree advance for best result is it true mine was in spec when i put it in ( 3 year from now) I have a cloye double timing chain with the 3 keyway sproket
the basics. compression test and a leakdown test. if your cranking pressure is around 100 or so then there is a problem.
I agree IF the card has the timing specs listed with the usual 4 advance. Some of the TA cards come with no advance in their specs. WD do you have the specs off the timing card that you can list? Maybe somebody here has the card if not. One of the main reasons to advance your cam a few degrees is to make up for chain stretch as the miles rack up. Most chains will stretch slightly after a few miles. So if you are truely "straight up" per the cam card then your cam is probably retarded slightly. The other reason is to perk up the low end and build some cylinder pressure. In your case you can use it even more because of the less than optimum compression ratio and the aluminum heads which tap off heat. At the very least it will perk things up a bit if what I said in the first paragraph is true. You can advance it if the lobe check and compression check work out. Did you ever say what rpm you are shifting at?
