Pop N Wood
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Everything posted by Pop N Wood
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Hard for me to believe such a system would consistently form a tight valve seal without some type of spring/flex system. If the valve is closed by purely mechanical means, then temperature changes alone will require constant adjustment. Maybe the rocker arm itself flexes somewhat?
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It would mean constant heat. The control valves are not the best design and they all seem to leak after many years of use. A new one should last you many years and I don't think they are overly expensive.
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Someone correct me if I am wrong, but I am pretty sure most sanctioning bodies do not allow roll bars with cuts or welds in the main hoop. Maybe not an issue, but something you may want to look into if you plan on participating in any SCCA or NHRA events.
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The bad news is you really need both. If you are going to buy just one, then depending on your use this guys says buy the torch first http://metalshapers.org/tips/fournier/index.htm A torch is also extremely useful for heating stuck bolts or cutting off shock mounts. The "hot wrench". The MIG is the better choice for welding car sheet metal. Torches generate excess heat which warps body panels. I was also told that using a torch on some unibody cars is unsafe because the heat stresses can cause metal fatique leading to catastrophic failures. Since you are looking at rust repair, a good MIG will probably be your #1 choice. For a cage, maybe you can't braze the joints but you can weld them. I have been told a MIG can't be used on chrome moly tubing, but cromoly can be torch welded. In fact, many feel a torch is better than a TIG because it better relieves the heat stresses making less brittle joints. And of course a torch will work with mild steel. And should you ever try shaping aluminum, then a torch is the way to go http://metalshapers.org/tips/white/aluminum-welding/index.htm Either way, follow the advice in some of the other welding threads and buy a quality welder. You don't have to spend a lot of money, but if you buy a cheap one without the needed adjustabilty (or sheilding gas), then you could get so discouraged fighting the machine that it will be just so much wasted money.
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No... but a shorter stroke does. I am afraid I have to disagree with that statement. A shorter stroke may help' date=' but it is far from the determining factor. Valve float and lack of airflow will kill your top end long before the crankshaft geometry becomes an issue. Cut you off mid sentence, but making an engine that turns 9000 RPM is a REAL challange. If your valve train is not up to it, then your bottom end is not going to be the limiting factor. Like someone said above, 300 HP at the rear wheels means 350+ HP at the crank. That is a nice strong 350, but remember you want to give up 48 cubic inches. The 302 in the 1969 Z28 was conservatively rated at only 290 HP, and I think that was gross and not net. With todays better heads it may not be as much of a challange as it was in 1969, but to get that much HP out of a 302 will require a lot of cam. You will also have less bottom end than the 350. All in all, the engine will not be as streetable (and cost considerably more) then a comparable 350. I know where you are coming from. My original goal for my Z was a 302, mainly because I had a buddy in high school with a 302 Z28. That car was awsome. But, since coming here and talking to people like grumpyvette, I became a convert. The only reason people use to build 302's was because class rules limited their displacement. In fact I think that was the only reason Chevy put one in the Camaro in the first place. But if you throw out the Hot Rod magazine recipies for building torque monsters to put in 3600 pound muscle cars, then you can build a large displacement engine that runs well at high RPM yet still retains enough low end torque to make it enjoyable in traffic. If you are dead set on a high reving engine, then you may want to do some homework on what it will take to build one that will live. Like fl327 said, if you want to turn 8000+ RPM, then you had better stick to a forged bottom end. This is a favorite topic of Grumpyvette. Go back and look as some of his posts to see what the challanges are going to be. I still think you will need to forego the junk yard option and get something like a Scat crank.
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Better check with the deck pukes on that one. A carrier has significant sail area, more than any sail powered vessel. A big issue when you want to turn or moor one.
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The 65-70 amps per HP assumes near 100% efficiency. Less efficient motors or figuring in the voltage drop in the cables/batteries will increase this number. Older/slightly discharged batteries will increase the current requirements even more. 2-3 minutes to recharge...don't know about that. Depends how long they were putting out 400+ amps. Batteries are rated in amp-hours. This number goes down drastically as the amperage draw increases. A battery capable of putting out 10 amps for 10 hours (a 100 amp-hour battery) may only put out 100 amps for a few minutes. Thus it is going to take a lot longer at a low current to recharge even a short high current draw. Also keep in mind your car may have a 90 amp alternator, but you are going to need a good portion of that to run the car itself. If the site used the full alternator capacity to recharge the batteries, then that is not accurate. The other thing I thought about is engine management. Too much boost at low RPM could be deadly. With a belt driven blower you have some protection in that the blower speed is locked to the engine speed. With a separate drive system you will need something smart enough to manage the boost.
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No offense, but this whole thread doesn't make a lot of sense to me. All people can do is offer advice and information. What you do with it is up to you. No one is going to try to "convince" you of anything. If you want to put a 4 banger out of a pinto in your Z it is no concern of ours. Like a couple of other guys have said, you need to figure out what you want. By destroking a 350 to get a 302 you are telling me that 1) you don't care about cost and 2) you really don't care about performance because you are willing to pay more money to get less engine. Also you need to figure out wheter you want a supercharger or not before you build. The optimum CR and cam for a blower engine is different than a NA one. BTW, why are you even considering a blower if you aren't into performance? Just because an engine has a smaller displacement doesn't make it any more capable of reving. My dad had a Caprice with a 265 engine. This is an encono engine for old men. I doubt the bottom end wil support much "reving" and like you said, the small bore will make heads flow restrictive. If you want to rev, then you are going to have to invest money in some serious valve train components for starters. A solid bottom end with lightweight components is next. And if you want the engine to live you had better pay attention to the oiling system. That kind of stuf is going to be more expensive to come by if you pick an odd ball engine. If you really want a 302 then do it right. Scat still sells 302 rotating assemblies. Not cheap, but I think you almost have to go this route if you want "300 HP at the rear wheels" from a 302, let alone the numbers you will get out of a blown motor.
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I got thinking about this some more. The site said the blower is driven with 3 DC motors putting out a total of 18 HP. With a 12 volt system it will take 65-70 amps per HP. Thus driving all three motors off one big ass battery will draw over 1200 amps. No way. If you use 3 separate batteries (one for each motor) you will still draw over 400 amps/battery. That is like running a separate starter motor per battery. No way will a car alternator charge up 3 full sized batteries in a hurry. In fact, you had better put some type of smart battery charging circuit to keep from overloading the alternator and/or causing an excessive voltage drop.
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Consumer Reports ratings... not sure about this
Pop N Wood replied to JKDGabe's topic in Non Tech Board
I stopped paying attention to consumer reports when they gave an "unsafe, do not buy" rating to the Dodge Omni/Plymouth Horizon. Their "test" to prove it unsafe was to run the car up to 50 MPH, turn the steering wheel a quarter turn and then let go. They said the car started swerving back and forth until the driver grabbed hold of the steering wheel again. Something I would lay awake at night worrying about. -
Summit racing has Griffin aluminum radiators for less than half the MSA unit. May have to make some mount ala JTR but the Griffin unit is very popular for Z's. Do a search to see what size. Also I have read posts that claim the 4 row brass radiator doesn't cool as well as a typical 3 row unit. Can't say why for sure but it could be more restrictive of air flow and/or a poor 4 row design. Which brings up another point. What type of fan are you running and how good is the shroud? Also does your car heat up when idling or at speed? If you heat up at idle, you may need a better fan or fan shrouding. If you heat up at speed, then you may need to add a chin pan to smooth out air flow or seal air gaps between the radiator and from bulkhead. Air flow is really more important than radiator size. This topic gets discussed a lot, so a search should give you plenty of options.
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Why not hook a small gas turbine engine to the blower? That way your engine develops beaucoup HP without no power loss to drive the blower. Or if you only want 15 seconds of boost, connect a solid rocket motor to a turbo. Use the stored energy in the rocket to as a consumable power source (instead of the batteries this system uses). 18 HP of DC motor isn't going to move too much air. Don't typical blower assemblies consume hundreds of HP from the motor? The big question I have is what type of bypass assembly does this system have? You wouldn't want to be drawing air through the blower when it isn't engaged. Thus you need some type of damper/valve system to shut off the normal intake track when the blower is on. Also you will need to switch back to the normal intake path when the blower runs out of CFM. The thing says it is rated at 405 CFM @ 5.5PSI. This isn't going to supply even a Honda engine at high RPM. How in the hell could you produce 425 HP with only 405 CFM of air flow? Putting flow restictors in the intake tract will have a big impact on the NA performance of the engine. He doesn't mention how to do this in his ad.
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Yeah, what John said. The pressure drop across a heat exchanger is referred to as head loss. The system pressure John refers to is the average pressure throughout the entire cooling system. This is one of those things that it is hard to speculate on. You have to work the numbers, or better yet conduct a test to see what works. The amount of heat a radiator dissipates can be computed from the temperature drop across it times the mass flow rate through it. The specific heat capacity of the coolant and radiator surface area also comes into play, but they could be the same for both radiator types. Thus keeping the coolant in the radiator longer will most likely lower the output temperature, but if the flow rate is reduced more than the temperature drop, you will lose cooling capacity. Think thermostat. A thermostat restricts the water flow through the radiator to reducing cooling (raise temperature) and opens up to increase cooling. Also most people don’t realize what a poor heat conductor water is. If water isn’t moving it is actually more of an insulator. Thus smaller coolant passages and higher flow rates will generally improve cooling capacity, up to a point. The last item to consider in a double pass radiator is the air cooling the second pass (or first pass depending upon the configuration) will be preheated by the other pass. This obviously affects cooling capacity and is why intercoolers are put in front of radiators. Raising the overall system pressure (by using say a 20 pound radiator cap instead of a 15 pound cap) really doesn't increase the cooling capacity of the system. The heat capacity of water doesn't change much with temperature, especially at the low systems pressure in a car cooling system. What it does do is raise the temperature at which the coolant will boil. You need to make the system pressure high enough to avoid boiling at the lowest pressure point (or hottest point) in the system. If the pressure inside the water pump drops too much, then steam bubble form inside the pump (called cavitation). This greatly reduces the flow of water through the pump. Also hot spots (say in the heads) can be significantly hotter than the rest of the system. If these points go above the boiling point for the given system pressure, then steam bubbles can form in the heads, and steam doesn't cool as well as water. So if you go to a more restrictive double pass radiator, the water pump will have to produce more head to drive the same water flow rate. This may require a higher system pressure to avoid cavitation. Interesting discussion. But go with what is known to work. Keep in mind that street cars don’t seem the same level of maintenance that a race car does and also in many ways see a wider range of driving conditions. So you probably want more margin (i.e. excess capacity) for a street car than a race car.
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brake upgrade -- worth the price????
Pop N Wood replied to Poundz9oh9's topic in Brakes, Wheels, Suspension and Chassis
What is inaccurate in his description? There are two different versions of the Toyota 4x4 calipers, one that works with the stock rotors and one that works with the vented rotors. The calipers are not interchangeable. "Caliper upgrade" says brake upgrade to me. Also if you look at other 4x4 sources, his prices are high but not totally out of line http://fonebooth.com/brakes_zcar.html I use to have a link for a JY selling used calipers mail order for $85 delivered. Now if you want to talk about a rip off, check out MSA's price on the 4x4 brake upgrade http://www.zcarparts.com/store/merchant.mvc?Screen=CTGY&Category_Code=PBC07 There is quite a bit of dissention about the worthiness of the 4x4 calipers. Do a search, but seems like the guys who have done the calipers only love them, while many others (who may or may not have done the upgrade) don’t consider it an “upgrade†without vented rotors. The big issue with upgrading brakes is shedding heat. Obviously increasing the mass of the rotors helps shed heat. One thing is for sure, the 4x4 calipers are HEAVY. Not the ultimate racing set up, but probably cost effective for the street. -
MSA use to carry that book. I have a copy, pretty good book. But geared more toward the 510 than a Z. There is a section on reinforcing the Z, but it is not very detailed. You can get better advice by searching the archives on this site.
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When I buy tools I normally believe you get what you pay for. But I bought a Ryobi sawsall at Home Depot on sale for $49. Extremely happy with it. Variable speed, about half the weight of the $100 units, fits my hands well and it gets the job done. If I worked construction/demolition where I was using it daily, then I would pony up and buy a Millwalkee or Porter Cable. But for me the Ryobi is perfect. The only thing better might be a cordless unit. Very usefull for clearing sheet metal in the junk yard.
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Bushings-OEM, Urethane, both?
Pop N Wood replied to a topic in Brakes, Wheels, Suspension and Chassis
I have all urethane bushings on my Z and they are fine for a daily driver. The TC rod failure will not be an issue if you get the MSA/G-Machine TC kits that have the ball and socket joint. My Z has the Nissan Euro springs and KYB struts, so stiffer than stock but still reasonable. I also have the MSA front and rear sway bars, which I think are too large for my set up. The lower control arm bushings have been replaced with the camber adjusting units. These are essentially solid units. But even with all the suspension upgrades, the ride is fine on long drives. IMO the most important factor in a rough ride are the wheels and tires. Low profile, wide tires are what transmit every bump and pebble. For the daily driver I have 60 series tires on stock 14 inch wheels (I think 205 wide). When I switch to auto cross tires (225-50-15), the ride gets noticeable more rough. I can't imagine what a 40 or 35 series tire on 16+ inch rims would be like. -
Save yourself the search on Aicha. Here is probably the best explanation. The boy is getting quite famous. http://www.xanga.com/home.aspx?user=Aicha
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Sorry. Got well off topic. As you can tell I am not a big fan of stock Vega's. But I guess I should have added that they make great dragsters. Nice light shell with a suspension just begging to be cut out and replaced, yet enough people have done them that you won't be hurting for resouces. A tubbed rear end with 15 inch slicks gives them a nice rake that looks killer, especially if the driver is sitting in the back seat while the engine is in the front. When you look back, in the 60's and early 70's there really weren't a lot of super small cars that you could make such a sleeper out of. Personally I think they make a better starting point for an all out drag vehicle than a Z car, especially when you get to the point of needing a solid rear axle. One word of warning. My brother's vega has some serious incidences with front end pieces coming apart. Make sure you look over the ball joints, wheel bearings and tie rod ends. Brakes will be another issue. The cars simply were not built with high performance in mind.
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Maybe more than you want to spend, but I have been interested in the G-Force T5 upgrade as an alternative to the heavy t56. http://www.g-forcetransmissions.com/tran_gt-5.asp
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You are the first person I have ever heard describe a stock vega as being anything but some slow ass POS econo box. The biggest problem with the Vega, other that it was designed to be nothing more than a cheap grocery getter built for losers who couldn't afford a better car, was the aluminum block. I have had spark plugs last longer than the typical Vega engine. Click and Clack once did a poll on the 5 worst cars ever built. I think the Vega was #3 on the list (behind the Yugo and Volkswagen Microbus). My brother had a Vega for years. When he would tell people he had over 70K miles on the original engine they use to threaten to beat him up. No one believed him. If your Dad's car has never cracked the block dumping a crankcase full of oil onto the driveway, then consider it the exception rather than the rule. I have personally known people in the 70's who had the engine replaced 3 times before the warranty ran out. I guess you could call it a car that was ahead of it's time, because it is only in the last decade or so that GM has learned how to make aluminum blocks.
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The average starting salary for Electrical Engineers right out of school is about $20K higher than an ME. EE's with a master's degree are starting at right around $70K, with no experience. The job market is fat for EE's. Has been for the last 10 years. The military is behind the curve when it comes to cutting edge computer technology. Probably will be for the foreseeable future. Unmanned air vehicles, satellite guided weapons, advanced radars, space sensors, anti-missile missiles. The list goes on. And now with homeland security it will only get fatter. And none of the above begins to address the information revolution. But you had better like math. It is usually the math (and calculus based physics) courses that make the first and second year EE students change their majors.
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Having watched Nebraska lose to Miami in the 2002 Rose Bowl I can tell you the crowd only goes so far. Over 3/4 of that stadium was dresssed in red, but it was the other 1/4 of the fans that felt like hanging around when the game was over. As a USC graduate I can say the current bowl picture is the best possible bowl alignment. Split national championship, no need to travel, and to top it off most PAC10 players grow up dreaming of winning a championship in the Rose Bowl. And no matter who they put in the Sugar bowl, someone was going to scream about getting ripped. This is the best they could do short of a playoff. Only one thing left to do. Michigan is not coming to watch history but to make it. That game is no gimmie. Perry has my vote for the Heisman.