Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. izzmus

    red hot valve springs

    I'm not so sure that there is durability involved with any top-tier drag racing valve springs. I haven't paid attention in years, but at the time, valvespring life was measured in numbers of passes, and the number was barely into the double digits.
  2. izzmus

    Designing Helmholtz or 1/4 wave resonator for an exhaust system

    Here's an installation in a 928 Porsche, with before and after sound readings, and an explanation of the rationale. http://www.corner-carvers.com/forums/showpost.php?p=931366&postcount=111
  3. izzmus

    Stand alone engine 150+ HP

    If you're converting to a carburetor and distributor, the sky's the limit. I've seen one enterprising individual stick a distributor on the timing case of a 32v Ford, driving directly off of the end of one of the cams.
  4. izzmus

    Stand alone engine 150+ HP

    I seem to recall some newer vehicles with the engine controller mounted to the engine itself. The only hurdle there is CAN. Assuming that the application is a vehicle and not a stationary application, GM V6s in the cheaper cars did not go full CAN until (relatively) recently, require only the...
  5. izzmus

    Exhaust Manifold Primary Diameter Sizing

    Pontiac tried aluminum exhaust manifolds in the early 60's in a homologation model. The racers would qualify with iron manifolds and only put the aluminum ones on for the actual races, as erosion was a problem. This is manifolds bulky enough that the weight savings was on the order of 50-80lb...
  6. izzmus

    Definition of OEM "hand-built" engine?

    I can't find the link right now, but one of the major motorcycle manufacturers (Yamaha?) has the ability to manufacture engines with 100% automation.
  7. izzmus

    Use of MoS2 in a rotary engine.

    Speaking as someone who does not have to worry about catalyst life, a half-ounce of decent two-stroke oil per gallon of fuel will go a long way towards seal life. Power, too. In an engine that did not have the metering pump, I noted power gains at up to 3 ounces per gallon of fuel, at which...
  8. izzmus

    'Normal' oil consumption

    Apparently, late model Accords are having oil consumption problems. Problem, in this case, being that even when new they use one or two quarts of oil between oil changes, and the people who bought Accords want a hands-off transport appliance without any of that bothersome looking-after. (My...
  9. izzmus

    Centre differentials with uneven torque split (planetary)

    Torque is independent of motion, and a differential under normal circumstances will see no internal relative motion. Maybe that is where you're getting tripped up? Under normal circumstances, the gears aren't moving, so they become little more than odd-looking levers.
  10. izzmus

    diesel vs gas

    Greg, that is interesting, VW didn't seem to change much. What problems did you encounter?
  11. izzmus

    Side by side fuel injectors in open manifold.

    As an aside, Subaru made TBI engines for years with a similar intake layout. One throttle, one injector, two necessarily long runners to each cylinder head, which had a single port runner for each cylinder pair. Being a boxer four, each cylinder pair had two intake strokes in a row. It worked...
  12. izzmus

    700hp 300ci pushrod V8 race engines how do they do it?

    One of the things Larry Widmer has constantly pointed out is the piston top is the bottom of the chamber and shouldn't be ignored. With that in mind, a flat top piston makes about as much sense as a flat combustion chamber.
  13. izzmus

    700hp 300ci pushrod V8 race engines how do they do it?

    Pat, that's exactly what I'm talking about. First you make the power, then you figure how to make the power more usable and durable, and with tighter constraints. Modern engine blocks are far less flexible than the junk that was around then, which helps reliability. I don't know what engines...
  14. izzmus

    700hp 300ci pushrod V8 race engines how do they do it?

    Drag engines were in this vicinity ~40 years ago, with fewer restrictions but also 40 fewer years of refinement and the attendant technology updates along the way. What fuel are they required/allowed to run? "Pump fuel" is somewhat nebulous. Amazing things you can find coming out of the pump...
  15. izzmus

    Why do you need long shocks on long travel suspension ?

    There is an interesting thread on the Special Stage forum regarding the restoration of a Toyota factory stadium racing truck. While there were three shocks at each corner, in the rear the shocks were attached to a somewhat bizarre hockey-stick shaped link that attached to the rearend housing...
  16. izzmus

    Unusual brake rotor wear/metal falling off in chunks

    That looks depressingly normal for certain types of brake pad in certain climates. The pad material transfers to the rotors, and the rotor will rust beneath this layer of pad material, at which point it starts to flake off and the brakes judder horribly.
  17. izzmus

    Fuel Pressure Relating To Hose Size

    My personal car has an unbaffled tank and EFI. (RX-7 converted from carburetion) Fuel pump is a Bosch unit intended for an older turbo Subaru. The world has failed to end in the four years since the installation. The only problem is that, when the fuel is down to the last two or three...
  18. izzmus

    chevy v8 of the 70s thrust bearing load/time adequacy

    It is not uncommon for the torque converter to apply excessive load on the thrust bearing and destroy in in a short period of time, usually right after transmission overhaul. That said, aside from the excessive wear on the thrust bearing, throwout bearings aren't meant to handle the high duty...
  19. izzmus

    Electric Handbrake / Emergency brake - Why?

    The only one I have direct experience with used an electric motor to pull on the standard cable. It engaged any time the ignition was cycled off. Reason? Besides the why-not factor, it means there is one less hole in the body, that much less to do on the assembly line, no pedal or lever to...
  20. izzmus

    Do new GDI engines have throttle plate?

    I never paid much attention to that concept, but I always figured that the supercharger was mainly there as a checkvalve to prevent the airflow sensor from getting an irregular signal.

Part and Inventory Search