jmortensen

I think those are all Roadster parts. Part number 1152 is for a U20 engine not an L series engine.

You mean it should allow the motor to rev higher not faster, right? Because the engine with more hp will rev faster, and the 2.8L version of the L6 is bound to have more hp than a 2L. The car will make more hp with the 2.8 block and a 2.8 crank. It might have a higher rpm limit with a 2L, but it will be at the expense of hp.

I think you'd have to try it and see if the longer bolts are long enough. The cam towers only get torqued to something like 12 ft/lbs so it's not like you really need to crank down on them, but if only the first 2 threads engage, then you'll need longer bolts.

I think you should just run the shims. The only hiccup you might find is the need to run longer bolts. A lot of people do a mod to the P heads where they shave .080 and run 5 sets of shims stacked up, and it causes no problems. Here's a writeup on that: http://www.geocities.com/zgarage2001/head.html Just stack em, get some longer bolts, and call it good.

I've seen a couple cages built that way, but I tend to agree with Zsaint. The weak part of the Z isn't the rear of the subframe, it's the strut tower. So it would be better structurally to tie the strut tower to the hoop instead of the back of the subframe. Most people put a plate on the trapezoidal area behind the strut itself and then have a tube coming off the hoop hit that plate. No reason not to add another bar to hit the strut towers.

Just make sure that when you're all done adjusting that you still have 1/8" to 3/16" free play in the pedal before it starts to depress the master cylinder. Otherwise you'll have problems.

That seems to be the going price from what I've seen. Not only do they fix your timing, but they also pull the chain tighter. Loose chain is a bad thing, and the stock tensioner is not up to the job of tightening a chain when the head has been shaved a lot. The end result of shaving the head and not shimming the cam towers is that the chain will chew up the bottom of the slack side chain guide.

That's not the answer? I was feeling pretty sure...

You want NO slack? Take a look at the Kameari tensioner. That's about as close as you're going to get, but even there you have some amount of chain stretch to deal with. The sad fact is that the L series doesn't keep EXACT time, and the tensioner doesn't take up ALL the slack, especially when you rev up the engine and then abruptly let off the gas. Here's a good thread about the Kameari tensioner setup from hybridz: http://forums.hybridz.org/showthread.php?t=102066

You've got two forces resisting you when you turn the engine by hand. The compression and the valvetrain. It seems pretty clear to me that you a point in the valvetrain where it wants to move forward, and the crank doesn't. No big mystery. FWIW, you might want to move the slack side guide to take up as much of that slack as possible, keeping the angle so that the chain hits the bottom of the chain guide as smoothly (tangentially) as possible.

Like I said, I haven't done it myself, but this thread has a part number. BTW, its a Timesert, not a helicoil. Same thing, different manufacturer I guess. http://forums.hybridz.org/showthread.php?t=105025

Mikunis are pretty easy, and everyone seems to run the OA jet block / emulsion tube, so that variable is pretty much removed from the tuning equation. So really you have pilots (VERY important), mains, airs, and last the pump nozzles (not nearly as important) and that's it. Get an O2 sensor in the exhaust, then you'll know for sure instead of trying to read the plugs or smell the exhaust. I used a narrowband one wire O2 sensor and read it with a $6 Harbor Freight voltmeter. The Japanese P90a came with solid lifters. There is another way to convert them to manual adjustment, which I haven't done, but it sounds REALLY easy. You pull out the posts on the hydraulic head first. Now the normal ones don't fit, because the hydraulic head's posts are a different larger thread pitch. Someone on hybridz.org figured out that there is a helicoil that threads into the P90a head that fits the regular manual adjust posts. So that's all you need to do. Not sure if the rockers are the same, and you'd need some lash pads I'm sure, but the rest is just bolt in with those helicoils. Sorry Arne for jacking your thread.

If it's cheaper to fix than to total it, they should pay to fix it. If they decided it's too expensive and total your car, you can buy back the salvage usually for 10% of the amount they pay you for the car. But IIRC then the car has a salvage title, even if it really wasn't "totalled" in the first place. Maybe a big deal to you, maybe not. Were you planning to drive it into the ground or did you want to sell it in a year? That's where it becomes a big deal.

Have you been over to www.hybridz.org? That site is particularly about engine swaps in Z's. Lots of good chassis and suspension info over there too.

You're right Arne they're all pretty much the same. Even a stock engine can do a little better and make a bit more power with a bigger cam IME.

Here you go: http://www.atlanticz.ca/zclub/techtips/cam/index.htm Looks like the early cam is ever so slighty more aggressive.

The external oiling system is superior in regards to lubrication when everything is functioning as it should, but either works fine unless you're really really pushing it. If one has a cam timing advantage I'd definitely go for that one. With stock I would think the one that is more retarded would be the one to have. The spray bar is more prone to trouble though, like the soldered joints in the bar coming loose.

Well, OK. Let's break it down as best we can, which admittedly probably isn't going to be very good. In order to accurately break it down you'd need two identical engines with the only variable being displacement to be dynoed on the same dyno on the same day back to back. Not going to happen. But I'll do my best... ;-) Brian the guy with the ~310 bhp 3.2L Rebello motor figured out his hp by trap speed and figured it at 278whp. When I do the same calculation on my 2.8 that I built in my garage I come up with 239whp. His 3.2 is 12.5% larger than my 2.8. 239 x 1.125 = 268. So if you calculate up then I'm 10 hp off of Rebello's motor size for size. I'm going to say that the extra 10hp comes from Dave Rebello being a better engine builder than me, I'm sure he knows tricks that I don't to free up hp. But, to my credit, I have tuned the carbs quite a bit since then, and I'm now running a higher compression shortblock, so who knows where it is now... BTW--I'm not sure that I buy the ET hp calculator, and I'm not sure that dynos are much good either since Brian dynoed his car on one dyno and got 225whp after Rebello had dynoed it at 300+ on their engine dyno (http://forums.hybridz.org/showthread.php?t=99611), so this all may be peeing into a headwind. It is really impossible to compare unless you have the same dyno on the same day. But here's how we're attempting to make a comparison: My car's weight was 2650 with me and a friend in it, trap speed according to an old Gtech was 108. I've been told that the old Gtech doesn't average the last xxx feet, so you need to knock it down 3 mph. So assume a weight of 2650 and a trap speed of 105. Here's the calculator: http://www.4lo.com/calc/dynocalc.htm If you use the trap speed of 108 it comes out to 261 hp, but "corrected" its 239. Now for Dave's bit: "If you don't know how to correct the R/S ratio and don't think the bigger bore and proper cam selection will inhance air flow and therefore greatly improve torque and HP then yes there is only a minimal improvement." Using a LD28 crank and a 240 rod yields a rod ratio of 1.60. Stock L28 is 1.648. So the r/s ratio IS better with a stock L28. If I were smarter and had used L24 rods, I could have had 1.68 r/s ratio. Maybe he's using some custom rod and piston, but to my knowledge he uses the LD28 crank and L24 rod like everyone else. Cam selection helps both engines, so this is not an advantage for a stroker. I unshrouded the valves and notched the block on my build, so that might take some of the advantage away from the larger bore being further from the valve, but that's a couple hp you're talking about there. "But the fact is when built properly the longer stroke and bigger bore allows for cylinder head improvements that can't be accomplished on the smaller engine." Such as??? And how come it doesn't show up on Brian's motor? "We see more rear wheel HP with our big engines than a street 2.8 can accomplish at the flywheel. With our long rod 3.2L we are approaching 330 HP & over 300 ft lbs torque (flywheel) with a 7600 RPM redline, (on pump gas)." My garage built engine put out 85.36 hp/liter. That 3.2 Rebello stroker put out 86.88 hp per liter according to the drag racing calculator. So I'd have to disagree with this statement. Looks to me like it's worth 1.5 hp/liter, IF everything else were exactly the same, which again, it admittedly isn't. "Further more it should only cost slightly more to build a full blown (3.1 or whatever) than a 2.8 as the engines in question still need all the same parts, pistons, cam, bore, bearings, porting, valve trane, etc. Sounds like you read a one sided article. Why should it cost $3000 more for the bigger engine. The way we build them about the only difference is the cost of the crank." The only difference is the cost of the crank? I was under the impression that you have to do a lot more machine work, sonic test the block to bore to 3.2, probably a good idea on 3.1 too, get ahold of the crank, rods, pistons, etc. Yeah, I did reuse a lot of parts in my build, because I'm poor. I used an L28 block, had everything balanced, cast pistons, E31 head, 280 valves, did all my own porting and polishing, cc'd the heads, deburred the block, notched the block, unshrouded the valves, etc. etc. etc. I spent about $2500 in machine work, did a lot of it myself and got 239whp (according to the calculator). If I'm wrong on the cost of building a stroker vs building a 2.8, then so be it. If it only costs $250 more to make it a stroker (seems to be about the going rate for the crank) then it's DEFINITELY worth it. 10% increase for $250 is CHEAP. If you're buying a motor from Rebello, and he's only charging $250 more for the stroker that's one thing. But if you're putting it together yourself, maybe that's another. Here's a writeup on strokers I think is pretty useful: http://zhome.com/rnt/3.1HanveyProject.htm

As zguitar says, keep the compression 10:1 or under and you should be able to run pump gas. The other thing that helps is a big cam. The more duration on the cam, the more compression you can run without detonation. I built my last engine too hot for street gas. About 11:1 compression, and with my .490/280 cam I need about 95 octane to prevent detonation at 35 degrees advance. You'll find people who back off the timing to run high compression, again this is just my opinion, but I think that is a big waste. There is a lot of power in the timing, and I'd rather have 9.5:1 with the proper ignition advance than 11:1 with the timing cranked down. I could probably get a cam with a duration over 300 degrees and be marginally able to run pump gas without detonation and keep my advance, and I've considered doing that but I've got too many other things going on right now. I'd suggest a cam similar to mine if you're going to run compression in the 9's. If you go for more compression then get something bigger. Back to your octane question. I get the 95 octane my engine needs 2 ways, one is to mix my own octane booster. There are threads here about it I think, but you can mix 5 galons of 91 octane up to 95 octane with a gallon of octane booster at a cost of about $10. So that is expensive. The other option I've used is AVgas, which is aviation fuel. It comes in 100 octane "low lead" which is illegal for street use, but when you cut it 50/50 with 91 octane you get 95.5 octane. Not very convenient, the AVgas is relatively expensive, and this is an option for me since I don't drive my Z on the street anymore. As far as carbs go I estimate that swapping from SU's to Mikunis gained me ~40 hp. It was a huge difference. This was on a 2.8L also. I would consider running the bored SU's on a stroker for a street engine, or 44 Mikunis or 45 Webers. The bigger triples will be able to fully utilize the cam and give your car more top end at the expense of low and mid range power. I'd forget about stock SU's or 40 triple carbs. You could get the car running on the stock SU's then do something else down the line, but if you're building an engine to make lots of power the SU's are going to be a serious limitation IMO.

39:11=3.54545454

No, I got an interior panel off of a 72 I think. Hammers and plastic trim pieces don't mix...

I beat on the metal tank with a BFH until it no longer hit the quarter panel, you'll also need the interior panel for the metal tank, since the tank is larger the interior panel has a bigger bulge. Problem that I was having is cracking the plastic tanks. I have a hunch it was a result of autoxing, but I broke 3 of them (try to find 3 plastic tanks!!!) before I switched to the metal tank.

My #4396, 5/70 had one at one time... ;-)

I kinda like having vents to open and close, but that fits the bill as far as specs go. If it doesn't fit, you must acquit... uh, I mean, if it doesn't fit, send it back and buy something else.

The advantage that a 3.1L has over a 2.8L is simple... 10%. If the two are built to the same specs, you do the same port work, same induction, all that, you'll see a 10% gain. So the question is how much is that extra say 25 or 30 whp on a pretty aggressively built barely streetable engine worth? If your answer is $2500 or $3000, then the stroker is for you. $100/hp is a little steep for me. Above and beyond the displacement the stroker has no advantages compared to the 2.8L, and has some disadvantages in rod/stroke ratio. Potential redline is NOT really compromised, as Dan Baldwin has shown in some previous threads. Piston speed goes up something like 50 fps between the 2.8 and the 3.1 at 7000 rpm, but the r/s ratio should mean that the 3.1 would be more detonation prone than the 2.8. Quantitatively how much of a difference does that make, I really don't know. Might be the difference between 93 and 94 octane, couldn't really say, but it is a disadvantage.