TimZ

Do a Google search for "HKS Standard Bypass Valve". Looks like Alamo Motorsports still sells the diaphragm.

I heard TonyD say one time that crank scrapers give you an extra 1000 rpm of resonance! My thinking on the LD question was that the damper is a tuned mass mechanical filter, that was tuned to damp some specific range of mechanical vibration frequencies. My mental picture is that it's a notch filter of sorts, with the notch tuned to the resonant frequency of the crank. So when BHJ designed their crank damper, my recollection was that they tuned it to match the characteristics of a fresh OEM damper (my recollection could be faulty on this - open to corrections ). What I don't have a good feel for is the characteristics of the filter - is it relatively narrow band with high attenuation, or does it damp a wider range of frequencies with somewhat less attenuation, or something else? My assumption here is that the damping bandwidth is likely sufficiently wide to cover the variety of cranks that it will likely be attached to, within reason. So then the next thing that occurred to me was that a knife-edged crank might not fall into the "within reason" category if it's resonant peak has been sufficiently altered (again I'm _assuming_ that this is a possibility). Does that make sense or am I off on a tangent? Main thing I was trying to get a warm fuzzy feeling on was how robust should we expect the damper tuning to be to variations in crankshaft selection (say, non-knife edged L24 through LD28). Also TonyD, why do you hate Webers so much? I heard you say one time that they destroy cranks or something...

A harmonic damper - and yes. To address a couple of other items from previous posts - 167hp loss from a 350 sbc is way too high if we are talking about frictional losses and such. This number is almost certainly referring to the energy available in the fuel vs. how much comes out the crank. Unfortunately a great deal of this is due to the thermodynamic efficiency of the Otto combustion cycle itself, and there isn't much you can do about that, aside from relatively small improvements from compression ratio changes or changing to Diesel or Miller cycle, or something similarly impractical. None of them are going to be anywhere near 100% efficient. I concur that a great deal of effort went into the BHJ damper and it is a really good investment so long as you are using the crank(s) it was designed for. Tony - I'm assuming that this was the diesel crank - is that correct? Do you know if the tuning is similar or the same for the Diesel vs the "normal" L28 crank (or L24 for that matter)? To my thinking, Ablesnead did raise a legit question regarding how tight a tuning match is really required between the damper and the crank, and how much does the crank's resonant frequency change if you remove significant mass and possibly stiffness from it by knife-edging it. Offhand, I would think that knife-edged cranks like some I've seen on this forum might have significantly altered resonant frequencies, and it might not be intuitive as to how they were altered. Thoughts?

We really need a "Spittake" emoticon. Just sayin'. <edit> found one...

That's correct and no it's not semantics - they are not the same thing. Take a look through this thread for some discussion on this: http://forums.hybridz.org/topic/15727-l6-dampner-problem-help/page-3?hl=bell&do=findComment&comment=116851

Regarding what switching temperature to use, I think the question you need answered is what temperature is typically measured at the CHTS port when the thermostat housing reads 160, 180, or 195. This should give you better insight as to what switch to use at the CHTS. My N42 head doesn't have a CHTS port so I can't help, but it sounds like somebody (Xnke, perhaps?) must have measured this already...

Do you have a Google Picasa account? It's free and you can upload your pictures there and then just use a link to the pic in your post.

Me too - been using them for several years now, they've worked flawlessly.

So sorry to hear this - all of my dealings with Ross have been 1st-rate. Please give my best to Ross - we are all pulling for him.

Not your rear, PeeWee, your _ear_!

The last several post all have some great advice. On networking - are you on linkedin? You should be.

This will necessitate using a whole 'nother set of problem-solving skills...

While this is generally somewhat true of the democratic party, politicians _all_ love or hate defense spending, depending on which contract you are talking about and which districts have manufacturers in them that are affected by that particular contract. And defense spending is spread around pretty evenly by design. So the notion that Democrats are the "enemy" of defense contractors doesn't really hold much water. I worked at McDonnell-Douglas in the early 90's, and Dick Cheney was the Secretary of Defense when they cancelled the A12 under false pretenses, cancelled the light attack helicopter program and steered the F22 project elsewhere, all of which were key programs for us, and is arguably a major part of the reason that that company is now called "Boeing". Point being that this stuff is more than just R vs D, and who is in office isn't a good indicator of what defense spending on Aerospace is going to look like. That said, it would not be surprising to see defense spending get cut in the near future - hard to say if it will be in Aero or not, though. Probably not that much new spending on traditional air superiority aircraft like the F22, but drones probably won't get hurt, for instance. Also, the emerging commercial space companies look like they would be really exciting to work at, but probably a little risky job security-wise. You would likely end up changing jobs several times as startups come and go. While stressful, it's at least easily explainable on your resume.

All good advice, and as someone who also hires engineers, I'd say that it's all applicable, regardless of the type of engineering degree you are pursuing You might be surprised how much "cross breeding" goes on once you are in an actual job - you'll likely be expected to do more than just strictly "Aerospace" Engineering. On not mentioning your parent's divorce, I agree, and in fact as an interviewer such questions are off-limits. You should never be asked to divulge such information - even questions like "do you have kids?" are not allowed. Given this, there is no reason to volunteer any kind of personal information like this - the _best_ result you can expect from volunteering personal information is for it to have no effect, it'll more likely do harm. LOL - "I'm a PEOPLE-PERSON, DAMNIT!!! WHAT THE F*CK IS WRONG WITH YOU PEOPLE?????" Any self-respecting engineer should know what movie that came from...

I'll reiterate what others have already alluded to - I think your idea of what goes on in a "lab" at an engineering firm might be a little off. You'd be "designing a bolt" at your desk, probably in an office cubicle. The lab is where you would create, test and verify that design. For most of us in engineering, that's where you get your hands dirty and deal with actual physical things. (I'm an automotive engineer, so my "lab" is a test track ) If you tell me you don't want to be "stuck in the lab" in an interview, I'm going to make some assumptions about you that would sound more like this: ...what I hear is that you'd prefer to sit in your cubicle and run a CAD program or simulation, and are not interested in understanding how things really physically function. Perhaps you think that work is beneath you and you just want work on climbing the corporate ladder. I'm guessing that's not what you really intended for me to think.

(couldn't find an emoticon doing a spittake)

Do you know what kind of dyno it is? If its a Mustang then you might be trying tuning individual load points. If its a DynoJet, then you'll likely just do full-throttle pulls in 4th, which is still useful, but requires you to do part-throttle load points on your own. I'm assuming that if you intend to do tuning that you will be logging engine controller data during each run, as well as the dyno data, correct? Do you already have a wideband O2 sensor that you can log? If you do end up doing load points, then its especially important to keep air temps consistent as I mentioned before, both during each load point and from load point to load point, as well as watching coolant temps. Also, pay attention to the actual intake air temperature for the session and if you find that the engine runs differently once you are on the street, check see if there is a difference in the air temps causing it.

Try to make sure you have a constant supply of cool air to the intake, and if you can, monitor the intake air temp and make sure that it's stabilized and as close to the same temperature as possible at the beginning of each run. That last part is probably more applicable for turbos but in general should apply for naturally aspirated as well. If your intake air temps are not consistent run to run you can really start chasing your tail trying to make adjustments. If the dyno is indoors make sure it's well ventillated - you don't want to start diluting your intake air with exhaust fumes!

Right idea, but I think your math is a little off. It appears that you were assuming 20% driveline loss for your 400hp to the wheels number, which would require a boost _ratio_ of 400/175 =~2.75. So, you would need 1.75 atmospheres (not bar) of boost to reach 400rwhp on your otherwise 175hp engine. 1atm = 14.7psi 1bar = 14.5psi ...so somewhere around 26psi of boost.

http://forums.hybridz.org/topic/46043-using-a-degree-wheel-to-degree-in-your-l-series-cam%E2%80%A6/

My N42 block has the gauge port on the main galley - _after_ the filter. Seems to me that blocking the filter bypass could _only_ make the main galley pressure the same or lower.

Sorry I'm a bit late to the party, but I'm not getting how we were expecting this to help. How was plugging the filter bypass valve supposed to increase oil pressure?

What Tony said. For future reference, they do make a Sta-Bil product for ethanol now, btw. If you've already got water condensed into your fuel, I don't think that will help at this point, though. Also, E85 is reactive with organic compounds, but is barely acidic at all - actually less acidic than water. If you have brass or non-anodized aluminum in your fuel system or the original rubber hoses it can be a problem, but modern hoses can usually deal with it, especially if you only had ~18% ethanol content. Do you know how much gasoline was in the tank when you added the 2 gal of E85?

Agreed, but my recollection was that the pulley holes were 6mm, not 1/4". Wouldn't hurt to check this first.