Pop N Wood

Do a search on the archives. There have been some VERY long threads discussing this one. I lost my old bookmark file or I would give you the link. IMO you really can't go wrong 240 or 260 or 280. They all have their plusses and minuses.

I use to try to defend the quality of domestic cars. Trouble is every time you really get into it you run into someone that had a Chevy or Pontiac that went through more transmissions than spark plugs. I no longer entertain such discussions since you will never convice the former owner of a Pontiac Fiero or Chevy Vega that GM cars are reliable and well engineered. I once talked my sister into buying an 1976 Oldmobile Starfire instead of a brand new Volkswagon Rabbit. I told her to not buy the Rabbit because it was the Rabbit's first year. Needless to say my sister will never take auto advice from me again. That Starfire was such poorly designed and constructed car that as far am I am concerned GM's reputation will never be the same. I guess the Japanese save their experiments for home use and only export proven models. GM has produce more than it's share of lemons. Anyone ever own a Citation? How about a car with the Oldmobile diesel? The Caddilac 4-6-8? But I think my biggest complaint with GM cars is the quality of the interiors. Look at a japanese dash. Everything is nice and tight with simple knobs that stand the test of time. Then look at your basic (fill in the blank) American car. The dashes all rattle and all too often have these goofy switches that break off in your hand. Flame suit on, but when it comes to quality complaints GM deserves a lot of what they get.

An el cheapo sabre saw with a metal cutting blade works perfectly on 18 gauge steel. I think 24 tpi. Or use a sawsall or air powered saw if you have either one.

You definitely want to search the archives. I have seen some very respectable members of this board say they feel coil overs are not suitable for a street car. Obviously to each his own. Would like to second what Dan Baldwin said about "225/50-15s fit without rubbing on 15x7" zero offset wheels". That is exactly the set up I ran for auto X with my 240. In fact, the majority of the people at the trials ran the same. Seems like most of the guys on this board are running some insane wheel/tire set ups, but then again they have considerably more HP than my near stock 240 motor. I have always wondered what wheel spacers and rear tires being a half foot wider than the fronts would do to a Z's handling. I used Datsun "Euro" springs and KYB struts (all from MSA) and had a nice street car. Definietly not the most radical set up (especially compared to some of the guys on this site), but it handled very flat on the on ramps. The 50 series tires were probably the biggest hit to ride comfort. I also replaced all the rubber with urethane. In particular you want to replace the steering coupler with something solid. Overall I had a nice handling car. It tends to push a bit more than I liked, but I think that had something to do with the oversized sway bars. The MSA set up is considerably heavier than what most of the other auto X's were running. If I had it to do over I would probably go with adjustable struts and maybe 16" wheels to better fill out the wheel well (if that is possible). I would have to think about coil overs. Don't know if I would want springs much stiffer than I have. Same for lowering the car. The Euro springs lowered the car just slightly. Any lower and I don't think I would enjoy the Maryland highways.

Some one once posted they used a pressure washer that had a built in heater to remove undercoating. High pressure hot water sure sounds a lot less painful than 5 gallons of solvent and a trash can of solvent soaked rags.

I always thought split fire plugs were based on sound principle. I will never pay $5 for a plug, but still I don't see why a split fire plug wouldn't work. By Gauss's law charge will accumulate at a pointed or sharp edge. Thus the spark is initiated at the edges of the electrode, not the center. There are also people who theorize that spark plugs ignite the mixture because small portions of the plug exectrodes ionize (melt) and are carried along by the arc. Metal along the edge will heat up and melt more easily (since there is less cooling mass) than the center of the electrode. Thus it would make sense that since split fire plugs put more sharp edges in the spark region they should (could? would?) have better spark characteristics. Anyone know for sure?

Does look like a good deal. The ad is a little short on brand names but worth looking into. It has all cast internals, but so does the GM engine. I will do a site search to see if anyone has experience with that company.

I was going to raise the issue of V8 pumps all being cast iron but Lockjaw beat me to it. The oil pump is drawing directly off the sump, so that is probably the coolest oil in the system. If your oil is cooking in the pump then I would hate to see what it is doing inside the crank shaft passages. And yes, copper has a MUCH higher thermal conductivity than aluminum. Look it up in a CRC manual. The only real advantage of aluminum is weight.

Crate engines are pretty common, and routinely discussed, on this board. To try and summarize some of the dialog I have read. For low dollar/moderate performance engines it is hard to beat the price of a crate. When you add up the machining costs and price of a rebuild kits the crate engines are hard to beat. Especially when you consider the cost of potential unknowns (such as a cracked block and/or assembly screw up). The warrantees are a definite plus and several members have spoken highly of them when claims were made (for GM engines at least). When it comes to a higher HP engines, the Grumpyvette contention is you can do better on your own. Make sure you consider all the costs. His example is the ZZ430 knock off (a GM Fast Burn 385 with hot cam, cam kit, 750 carb and some odds and ends pumping out a streetable 430 HP). That engine will quickly add up to $7000 for a true turn key, ready to start package. See scroggins-dixie's web site to see what I mean. Grumpyvette also went on to say the ZZ430 knock off is still too torque oriented for a Z. If you build your own you can select components to move the HP up in RPM. This is a good idea with a light weight Z car. Which brings me to a question for you. Where did you find a420 HP turn key crate engine for 5 grand? That is a very good price. I would be interested in something like that myself. Can you post a link?

No, really. What is her name and number?

You should post her name and number on the Internet...

A flat crank 10 cylinder would be a whole different animal. To reduce vibration you want a power stoke at regular intervals, say every yeah many degrees of crank shaft rotation. That is why, as one magazine put it, the V8 came off God's own drawing board. They have a nice regular beat. That is also why a V6 is a tougher engine to get smooth. A 90 degree V doesn't lend itself to a regular firing interval (unless you do like GM did and with their even fire V6 and use split journal cranks). A 60 degree V gets you closer, but is still not perfect. But my guess the reason to go with a flat crank V8 is expense. Most forged V8 cranks start out as flat cranks then get twisted into the natural alignment. This is the easier way to forge them, but has some compromises in strength. I know a few years ago the car magazines wrote many articles about no twist cranks and how they were stronger for flat out racing applications.

A big fat wide one that spew noxious fumes... Opps, you meant on the Z...

You need to measure your actual compression ratio and see if it is in bounds. Maybe you ended up with a much higher ratio than you thought. I am not experienced enough to tell you how to do it or exactly how to interpret what you see. But it sounds to me like you have tried everything else. If you bought the car used then there is no telling what you have in terms of former head work and pistons.

Damn. That must be one fast tow vehicle you have there to do 23,000 miles in only 3 days. Matter of fact, that is not a bad average for a Cessna!

Not sure why people are recommending 110V units over 220V units. 220 is far superior to 110 volts for practically any power tool. For any given load they draw less than half the line current. Lower line current means less internal heating. As a result 220 volt welders generally have a higher max welding amperage and won't dim your lights as badly. Having said all that, if all you have is 110V then that is what you need to buy. Also the 110V units tend to be cheaper, but only because they tend to be less capable. For sheet metal and most light welding a 110V unit will be fine. But I will bet you a dollar JohnC's Tig and plasma cutter are not 110v And as said over and over on this site, be sure to get a unit with sheilding gas. Flux core wire smokes like hell and typically produces welds that aren't as pretty.

Want to comment on an earlier remark about the red line of an inline 6 and same displacement V8. The in line 6 has a much longer crank. Thus the idea that a 6 will have a higher red line, "all else being equal", doesn't hold up. A 240 motor has a nice red line in part because of the short stroke. In agreement with what was said above. My 2 cents.

Talk about vibration..

The early Z's had the nice, high compression pre-smog heads. Beyond that it is not worth as much as I might have hoped (having a late 70 myself). For any kind of performance you get more for your money with a 280 block and bottom end, Have seen complete, running Z car engine and transmissions go for $500. Might get more if you find the right buyer.

Pretty car. Very clean looking set up! Sounds like an excellent daily dirver. You didn't say whether the engine was in the JTR, MSA or Scarab position. Also the question about rust makes a huge difference (in my mind anyway) about price. Good call leaving the suspension as is. This is something even a beginning mechanic can do for themselves on weekends. You have done all the hard stuff... V8 and paint. Wish I could give you a price but kind of hard from just one pic.

Chevy's LS1 motor is all aluminum. Has been for a number of years. I know I have seen racing magazines with aluminum blocks from people like Kieth Black etc. Don't know about Ford blocks.

Killing the fuel pump won't solve your problems because the idle circuit will still draw fuel from the carb bowls. Also I wasn't proposing a fuel cut off solenoid as a potential solution. Maybe it is possible but my guess it would be an impossible mod to the carbs. Just throwing out ideas and past experiences. Now if you wanted to go to fuel injection....

Whatever you do don't use heater hose. It won't hold up to the gas for long. The Nissan hoses are expensive but probably your best bet for curing the problem. I have read previous posts from guys who have capped off the vent lines. You have to have some type of vent, but I would think it could be much less elaborate than all the hoses the stock Z uses.

One of the true marvels of the early Z cars was they were one of the first Japanese imports with a decent heater. Should blow plenty hot. First make sure your radiator is full. Seems obvious but a common cause. Then check the thermostat valve under the dash. One of the weak links in a Z car, these things tend to corrode into the closed position.

Usually dieseling is a result of excessive compression and low octane gas. On an older car it can be caused by carbon build up in the combustion chambers. The carbon both increases the compression ratio and heats up adding to the premature ignition. But since you have just had the head done I guess we can rule out carbon build up. My guess is when the heads were done you somehow bumped up the compression ratio. Did you have the head milled/resurfaced? Did you use the correct thickness head gasket? Maybe someone else on the board can tell you a way to determine your compression ratio and whether it might be excessive. If it is too high then your solution might be something as simple as a thicker head gasket or seating the valves further into the head. Solutions? Try race gas. Obviously not a long term solution for a street car but might be interesting to see whether a tank or two will make the problem go away. Water injection? Fuel cut off. Killing the spark will not help a dieseling problem since the fuel is self igniting. My Ford Fiesta had a carb with a solenoid attached to the idle circuit. Turning off the ignition cut off the idle circuit in the carb so no fuel would flow. Absolutely sure fire way to stop dieseling. Fuel injection will do the same thing. The curious thing to me anyway is that you are not experiencing detonation. If it is an excessive compression problem like I am speculating then it would seem like you would get some detonation under heavy acceleration.