BlueStag Posted May 21, 2012 Share Posted May 21, 2012 When you write that you are pretty sure the fuel/induction is correct, you ARE saying that the two pistons in the two carbs are rising and falling freely, with an audible click? You've run the engine with the whole air cleaner assembly off, and witnessed the pistons rise and fall as you blip the throttle? Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 23, 2012 Author Share Posted May 23, 2012 I am pretty good with an SU. I know my floats are not optimal, but they are very close to the measurement. Best I could do with a bit of clear tubing and a re-used 90* measuring piece from an old carb rebuild kit. These carbs are in good shape with the exception of the nozzle on the front carb that sticks IF you use the choke. My choke is not connected in any form and I check to be sure the nozzle does not fall down or something weird all the time. It never has. The slides are in good shape and Ive got a lot of work into those to tune transition period. They are not sticking. If I do have an issue with fuel its gonna be volume as that is the only thing I believe I have missed, but I do not see fuel pressure drop out of 4psi even under load. I have seen the slides in action as of last weekend though. As for the cam, yes I do know how to degree a cam and I can extrapolate pretty closely TDC and determine a lot of other things. I actually have a program that helps if I want to double check or just be lazy. You dont need 'advertised' information to figure out the details. If in doubt substitute .050" measurements, the math will still work out. This is one of the skills I actually did pick up from school(in a class called 'Hot Rod' of all things!) and not from another tech. Its possible Im off, but not by enough to cause this issue. Unfortunately Delta does not post cam cards online. If I had a chance to call them during business hours Im sure I could get it. I cannot find an email for them either. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 23, 2012 Author Share Posted May 23, 2012 You use a dial indicator and profile the cam. From there it's veritable child's play to make your own cam card detailing opening and closing events, determining lobe separation angle, etc... From there there are general rules of thumb regarding opening events of the intake valve, and you can go from there. As for the exhaust -- ray if it's the "new" exhaust with three bolt flanges on it, that is exactly right: t hugs one side of the tunnel. The older exhaust with slip fit pipes apparently was the source of complaints, so they "idiot proofed"" it with the flanges and a relocation of the pipe routing. I no longer use that exhaust, I replicate the earlier one with mandrel bends out of bends and straight tubing now. There are "Windows" for these events that will guide you. Tony, Its the old slip fit style. Someone probably just did not set it up well. It was all one unit from the header to the differential as the PO welded it all up placing it near the driver side of the tunnel the whole way down. I fixed with with a couple of 'S' pipes. I do wish it was not welded. I prefer the slip fit style as long as I can get a precision fit that will seal. I guess thats asking a lot though with 2 pipes and generic assembly line style manufactured pieces on the cheap. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 23, 2012 Author Share Posted May 23, 2012 Maybe Childs play for Tony D, but for an average mechanic - very average like me, basic valve geometry is beyond my ability. Not that I don't understand that timing of the events is crucial, but to dial in a cam without specific details to go by- no way. Maybe Ray can do that and I am under estimating his ability, just thought I would throw it out there. An average mechanic does not need to know a whole lot. A technician however is not an average mechanic. Not to belittle anyone btw. Although I wonder how many of us hybridz'rs are actually technicians former or present. Perhaps my view is skewed though as most of the people I interact with here are also technicians of one kind or another that can relate most or all the information. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 26, 2012 Author Share Posted May 26, 2012 Turns out.... The float bowl filters were plugged with rust. Bowls were staying full for the most part, but they would not support the volume needed above 2500 rpms. I had shut it off multiple times while it acted up and checked out the fuel level and it was good. I moved the mallory 110 pump to the back and deleted the hitachi lift pump and that also helped a little. But the main culprit was those inline banjo filters. Arg! Now the car has a dead spot between 2500 and 4500 where the power is flat, but at 4500rpms or so it picks up and starts pulling the way an L24 should. Im probably making 80hp now! I think I can pull 20hp in tweeking the fuel system some more and mellow out that flat spot. Indeed the fuel system was an issue I just missed that spot that was being a pain. Thanks folks! Ray Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 27, 2012 Share Posted May 27, 2012 Yeah, the old slip fit system allowed you to reverse the piping or turn it so the bends moved the pipe to a more central location. Working with 2+2's allowed some more leeway as you had to add a 13" pipe anyway, so you could turn things even more askew! The new flanged exhaust -- no way, and the flange is the low point, so it SNAGS ON THINGS (which is why my exhaust manifold BROKE---damn flange dragged and caught on something and snapped the manifold! Hence now running noisy headers!) Quote Link to comment Share on other sites More sharing options...
madkaw Posted May 27, 2012 Share Posted May 27, 2012 After re reading the thread, it's hard to believe you have had the same issue with two different cams. I'm with the float issue. Insufficient fuel in the bowls with show up under heavy loading, but otherwise drive decent. Maybe time to revisit the floats and bump them up a bit and check out the needles and seat closely Yep! Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 27, 2012 Author Share Posted May 27, 2012 I knew it would be something stupid simple I was overlooking. I think its time to put a few extra filters on the car. 1 is not enough! I picked up some power in the flat spot yesterday. Or so says my butt. Time to take exhaust readings and re-tune these carbs now that Ive messed with them and tweeking them is obviously giving me improvements. Thanks all for putting up with me and being there when I had no place else to bang my head. Quote Link to comment Share on other sites More sharing options...
srgunz Posted May 28, 2012 Share Posted May 28, 2012 You are right. Seems like most of the time its a simple problem overlooked. I had the same issue on my 72. I was running just the factory electric pump in the rear. Stock 240 fuel filter. After a while I learned the fuel pump had an internal fuel filter. Pulled it apart and bingo. Plugged up just like yours. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 29, 2012 Share Posted May 29, 2012 Damn, I GOTTA pull The Blue Turd's screens and check them. I think they have been in for 106,000 miles and at least four regular fuel filters... Whaddya think they're plugged just a bit? Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted May 30, 2012 Author Share Posted May 30, 2012 Damn, I GOTTA pull The Blue Turd's screens and check them. I think they have been in for 106,000 miles and at least four regular fuel filters... Whaddya think they're plugged just a bit? Damn Tony, Well at least your not exibiting problems like mine. My biggest issue was probably poor fuel and many years of sitting. All my fuel lines and the fuel tank have rust. Some day Im going to find a 25' bristle snake that I can fit to my drill that I can run through fuel lines on these cars when I get them. I had a filter at the tank side before the lift pump(and the filter in the hitachi lift pump) and a filter at the fuel pump in the engine bay. Im going to run 2 more at the fuel rail going into the float bowls now. I need to get some miles on this car to flush the system out though. Rust and water in fuel sucks! Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 30, 2012 Share Posted May 30, 2012 Silicone Plug, large syringe of plastic, Hydrochloric Acid Dilute 10% Solution (maybe 20%)... Plug back end of fuel line. Use syringe to fill line. Let line sit, then flush with water, follow with some vanish or other caustic solution from toilet cleaning that you pump through---air dry. If you get pinholes, you needed to replace the line anyway the rust was that close to perforating. Quote Link to comment Share on other sites More sharing options...
rejracer Posted June 1, 2012 Share Posted June 1, 2012 Try evapo-rust to clear the lines. I'm running some in my cooling system now, when I drain it, you can have a quart of the solution. If your coming up to sac in the next 2 weeks give me a holler. Quote Link to comment Share on other sites More sharing options...
stephen closkey Posted July 8, 2012 Share Posted July 8, 2012 have you checked the oil in the su slide top.....too thick...too slow!!!! Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted July 8, 2012 Author Share Posted July 8, 2012 Once I cleaned those screens I have had no further issues. I rechecked them not long ago and found no buildup. Ive installed a few extra filters as well. Carbs are dead on again. Ive verified with my portable universal wideband. Ive got the AFR into low 12s on heavy acceleration so I know the carb oil is where it needs to be. The car has been great since finding those filters and cleaning them. Quote Link to comment Share on other sites More sharing options...
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