240ZMan

I'm getting ready to reassemble my '80 L28 block. I had the crank ground .010 undersize and ordered bearings to match. However, when I set the crank in the block the middle journal (#4) that has the special bearing for dealing with thrust is so tight that even before I put the caps on, I can't turn the crank by hand. My suspicion is that the thrust surface of the center bearing is also expecting the crank's surface to have been ground .010, and that the crank shop didn't grind that surface. I called the parts house but they were of no use to tell me if the bearing expects the thrust surface to be ground like the main journal surface. And the shop is closed (Saturday). Anyone know what's customary for grinding cranks? Should the thrust surface be ground down just like the journals?

What type of carbs are those? I've never seen "dual triples" on a Z before.

My use is very similar to yours Jeff. I don't drive it in the rain nor as a daily driver so I only care about dry weather performance. I had the Yoko ES100s on the track for the last day at the end of last season and have to say that I wasn't all that impressed with the grip. I really expected more. I was replacing an all season tire at the end of its life and while the breakaway was much more controllable, the maximum grip wasn't much better. I suspect that all those grooves to help with wet performance work against ultimate grip in the dry. They did tolerate the abuse very well (5 sessions, about 100 miles) with no visible damage except some feathering of the tread in the front. And their price was very good. FWIW, I still have my stock springs/struts in good condition with bigger bars (1 1/8" front, 1" back). Upgrading to the Tokiko package is on my list this summer. I had looked at the Khumo's you mentioned, but they didn't fare well at all in a Car and Driver tire test last year, even ignoring the wet performance. The Falkens weren't included in the test and weren't readily available here in CO last fall so I don't know anything more about them. I read quite a few people complaining that the ES100s become very loud on the highway as they wear. Given how loud my '73 with header is, that didn't matter at all - I doubt I'll be able to hear them But if your car is better insulated, you may want to take that into account. If/when I have to do it again, I think I'll plan to spend a bit more and go with something like the BF Goodrich G-Force T/A KDW ($127 at Tirerack) I think that type of big blocky tread is best for the kind of driving I do.

Good for you Jeff, that's as good a deal as possible I think for new Panasports. Now begins the "rest of the discussion" about tires... so many choices

If it was possible to "dial in" by adjusting a few mm here and there, I suspect that for my car with these tires I could go a few mm positive so I didn't have the rub with the fender lip. But there isn't much clearance between the tire and the spring around the strut, so it couldn't be moved inwards very much. Given that you can't order wheels with that level of granularity for offset, I'd say that zero is the best fit. Of course, I guess you could build some custom wheel spacers ... but I think it would be cheaper and more reliable to trim the fender lip, or go to a narrower (215) tire. I doubt there is much difference in real-world grip between a 215 and 225 tire.

Jeff, I did buy mine from MSA late last fall. They had just begun carrying the gunmetal so I'm surprised they dropped them already. They said they were VERY popular so maybe there's a problem getting them from Panasport. The offset on mine is zero. As I mentioned above, there is minor rub at the top outer edge of the tire against the inside lip of the rear fender over large bumps, otherwise no rubbing. I'm sure that a 215 tire instead of the 225 I have would cure it as well. I'm not a fan of spacers as it's just one more thing that can add to balancing and vibration issues. That's a big part of why I spent the $$$ for the Panasports. Still, I think the Rota Grids do look sharp. They are a bit more "modern" vs. "classic" in style for my taste, but they go nicely with a lowered Z and an airdam. Good luck!

As someone who put an '82 5 speed in his '73, I'll point out that another benefit of the later 5 speeds ('80-'83) is that 3rd is closer (ratio-wise) to 2nd than with the earlier 5 speeds and 4 speeds. This means you won't see your revs drop so much on the 2/3 upshift.

BTW, if you are going to go with 15 x 7, check out the Konig Rewinds. Half the price of Panasports: http://www.zcarparts.com/store/merchant.mvc?Screen=PROD&Product_Code=25-1067&Category_Code=WWC19

I have 16x7 Panasports with 225/50 Yokohama ES100s and have no rubbing except at the top outside edge of the rear tire where it can touch the inside lip of the fender. This only happens when I go over a large dip in my neighborhood, and only at speeds significantly above the speed limit. I do plan to roll the fender lip this summer when I put lower springs on. I doubt you would have any clearance issues. Here's some pictures from when I first put them on: http://www.classiczcars.com/forums/showthread.php?t=19022 BTW, make sure you can find tires that meet your price/performance objectives in 15". I would have gone the 15" route, but there is very little performance rubber still available in 15" unless you let the overall tire diameter shrink more than I was willing. Pretty amazing that 16" is becoming "small"

Thanks Texasz, that's the biggest difference I've seen so far. It looks like the piston and ring set is about $250 vs. just rings at about $60 plus $100 for the block. Also, there's a machine shop fee of about $5 each rod/piston to press out the wrist pins if I switch pistons. So it's definitely cheaper to bore out an L26 block, probably by about $100 - $150. I guess my big question is if that would leave the same amount of material around the cylinders as for an L28 block? The Z specialist recommending this says he's done it several times with no issues. Also, going the L26 route let's me keep my OEM pistons. The replacements I quoted above are from Victoria British and I don't know anything about their quality. I'm pretty sure they are not OEM. So I'm leaning towards going option 2 with the L26 but was hoping someone here might have tried this already and could share their experience.

I'm getting ready to rebuild my L28 and need some advice from the group... Current setup: Block: from '80 ZX Head: N42 Cam: mild performance grind (will probably upgrade to more agressive this summer) Fuel delivery: Weber DGVs Exhaust: 6:1 header + 2 1/2" pipe Pistons: flat tops from 81-83 ZX Option 1: Bore block to next size and replace pistons Option 2: Use an L26 block and bore it out to stock L28 size and reuse existing pistons. This was recommended to me by a local Z specialist. I can get an L26 block from him for $100. As I see it without having fully priced everything out yet, the differnce in cost between the 2 options is probably not more than $150 with option 2 being the cheaper route. I'm more concerned with what is the best from a reliability and perfromance point of view vs. cost. I'd really like to find an N54 block from a later (81-83) ZX, but around here there aren't any left. Will the L26 bored out to 2.8l be as strong as the L28? That's really my biggest concern. BTW, it's a '73 240 driven hard as weekend car with several track days per year.

I had a vibration on my '73 and had the u-joints replaced by the only shop in Denver that still does that. After installing I still had a vibration, but not as bad. Turns out they couldn't get the good (spicer I think) u-joints so settled for what was available. There was a small amount of play still. I took it back a second time and they ordered the good joints and now all is well. In all fairness to them, they were as surprised as I was. To confirm if you have an issue with the u-joints, get under the car and put one hand on each side of the joint and try to wiggle it. If you can feel ANY play at all on new joints you have an issue and probably should go back to the shop that put them in. Be careful not to confuse this with play in the drive shaft from the tranny and diffy. I found I had to turn the shaft so that it was sort of between the limits of its motion, and then holding it still with that hand try to feel any movement on the other side with the other hand. Also try to move it up and down, not just rotate them. That was the issue with my first set. Good luck! Drive line vibrations are a pain.

I hope I'm not hijacking the thread with this question: Why are you using 240 con rods? What is the advantage in an L28 over the stock con rods?

I'm thinking of doing an engine rebuild on my L28 over the winter which would likely result in a .020" overbore and saw that Victoria British has a piston and ring set for $240. That's a lot less than anyone else so I'm wondering if anyone has any experience these pistons and their quality?

Ahhhhhh. Things are getting back to normal:)

I did too. I'll guess that Mike removed the entire thread. Good riddance to it!

I'm thinking of doing an engine rebuild over the winter which would likely result in a .020" overbore and saw that Victoria British has a piston and ring set for $240. That's a lot less than anyone else so I'm wondering if anyone has any experience these pistons and their quality?

If you're using Outlook like so many do, let your mouse hover over the link for a few seconds. The URL (address) that you will REALLY go to if you click will pop up. Look to see if the domain matches. For example, in this case the domain turned out to be zha.sk. It would have been paypal.com or ebay.com if it was legit. If it's a string of numbers (IP address), don't click either.

Bill, you have a private message from me.

I hate to be thinking bad thoughts for you, but if you started with clean oil, and it's mixing with coolant, it's going to look milky. I don't know anything else that's going to cause a white milky oily substance to come out of the cylinders during a compression test. I know from recent first-hand experince. In my case the culprit in the end was a small hole that developed in the head near one of the valve springs that allowed coolant to leak onto the top of the head and drain back down into the crank case with the oil. I couldn't see the hole until I had the head pressure tested. Then it was obvious What does the oil look like on the dip stick? Is there any sign of milkiness? You could have a pin hole leak somewhere that isn't going to noticeably drop the coolant level in a short period of time but will cause the oil to become milky. Until you're absolutely sure coolant isn't mixing with oil I wouldn't run the engine. Coolant may be slippery, but's no lubricant.

I've got flat top pistons and an N42 head with a very mild cam. I run premium and have no pinging issues. It would be a shame to put dished pistons in an N54

When I still had my L24 in my '73 I had to replace my E88 head. Don't ask why - call it a learning experience I found an E31 that had been freshened up about 10k miles ago. I had read all the good things about E31s so I was hoping for an improvement. I have to say that in the end my butt-o-meter wasn't able to tell any difference between it and the stock E88. I suspect that this improvement, like a lot of others, wont' make any major increases in horsepower unless you do things like a bigger cam to improve breathing. I'm not trying to talk you out of this swap, just suggesting that if your current stock head is in good condition, you might want to spend your $$$ on something else, or wait until you can do a swap to an L28. Now THAT made a difference

http://www.classiczcars.com/forums/showpost.php?p=132080&postcount=13 I found this post by Carl to be helpful in deciding to get a front spook but not the rear.

Were your valves adjusted properly before this all happened? If so, then check your clearances now. If you bent a valve you'll have more clearance than before. If the pistons just tapped a valve you may not see the mark on the piston and you won't be able to see any obvious signs that the valve is bent. A friend of mine with a datsun roadster recently missed a shift at the track and over revved his engine. It had a mild knocking sound at idle afterwards and didn't idle well either. When he pulled the head at first he couldn't see any signs of damage either. But when he looked closely with a lot of light he could just barely see the nick where the piston just touched the valve when the valves floated. His clearances are now a few thousandths greater than before. His valves are bent. Putting new valves in your head isn't too big of a deal. But depending on your head's condition you might want to look for a used one and replace it. All depends on $$$ and what's available in your area. I know a guy I used to work with who is in Melbourne FL and does work on Zs. He used to have a decent stock of used parts. PM me if you're interested and I'll see if I can find his email address. Good luck.

I think that unless you run some ducting from the openings in the spook directly to the brakes that you aren't going to have any more water getting on the discs than if you didn't have a spook at all. The vents are far enough away from the brakes that the air isn't directly aimed at them anyway. My guess, and it's only a guess, is that the spook without brake vents isn't going to cool any worse, at least for "normal" driving on the street. I bought the one with the vents because someday I may want to add the ducting for better cooling on the track.