LanceM

You guys might be right but that sure is not the right way to do it on a head. None of them are smoothed down, they look like moon craters. The peaks would glow with the engine running I would think causing all kind of problems. It sure couldn't help performance in anyway. Another mystery of life

I was looking at an E-88 head that I was going to get rid of when I noticed something really strange. Around each intake valve there are 4 large punch marks in the head, looks like it was done with a punch and by hand as each chamber has the marks spaced differently. Looks like a good way to create hot spots in the head, anybody have any idea why someone would do this??? Or maybe I have some long lost high tech hi flow supersecret head here

Any washer bottle from 70-78 should work, the differance is the plug for the pump motor. I believe that 510's and 810's used the same bottle also in that time frame.

I'm with Ed, maybe, but bad rings and high compression would cause excessive blow by in my book. A quart in 300 miles is excessive, a leak would be a mess, burning it would look like a smoke bomb I would think! I'm thinking though that this oil use didn't start until putting this new head on right? If it didn't use oil before the head change then the only thing I would be looking at would be the head or head gasket. Compression is good so that would pretty much rule out the gasket in my book, time to look at the head. Yeah, I know all new, but maybe not done right, or seals left off, or seals torn. With bad seals on the exhaust valves you'll burn a lot of oil but not see it on the plugs, bad intake will show on the plugs. The only way to check the seals it to pull them out and look at them, might as well replace them if you look at them...

To pm click on the users name in the thread, one of the choices in the pull down is send " " a privet message, click on that and go! There are other ways but that is the easiest for me. I have a 72 240 about to leave this world that has a good spare tire well if you are interested, don't know if it will replace a 280 well correctly or not though.

I don't have the whole box but I do have a rear plate you can have for shipping. Don't know but maybe the cover for your old box will work with this plate???

Right, laquer over enamel and it will lift the enamel, enamel can go over laquer. Laquer is an old paint and for the most part except for never driven show cars is never used anymore and I don't think is available in Calif. Acryllic enamel is out of date anymore also as a durable automotive finish. Usually only used for repair of a same type paint job or when you want a paint job as cheaply as possible. The current standard is ureathane which is a two part paint, and also two or more stage, a base coat, or several base coats and a clear coat. Alkyd enamel is different from Acryllic enamel, mostly I believe from a durablility stand point. Alkyd is the older of the two.

Check in my gallery, I didn't use one on mine.

Just on a chance I would bring the engine up to temp and retorque the head. You do have some strange symtoms going there. Ed has some good ideas, try them to help narrow things down...

Guides are another "machine shop" do only. You can replace the valve seals with the head on the engine. Here is a link to replacing seals with the head on, it will give you an idea of what is involved. http://www.geocities.com/inlinestroker/seals.html

Thank you very much, a blind man could see the REMOVE button, I must be really blind Latest version posted... Thanks again montoya_fan01

Any idea what the ratios are for an auto? Just plug in the ratios for 1,2,3rd gears on any of the lines and you should have your answers

There are probably a bunch of these out there already but I worked this one out to answer some of my own questions. Should be easy enough to modify if you are using different transmission ratios or want to try a different rear end ratio, just plug in the numbers. Enter in the revs per mile for the tire you are using and the rest is figured. I got the revs info from the data provided at tirerack.com for the tires I am interested in using. The trans ratios I got from zgarage.com. I may have screwed up big time with the caculations but the numbers look right, if you find I made a mistake let me know and I'll fix it Edit: OK, latest and greatest posted, added some shift point data. I really need to get to work on something important Z gear ratios.xls

Thanks for clearing that up, I didn't realize they used soft seats! Changing the seats isn't a backyard job, it will have to be done at a machine shop. The seats are pretty much blanks when installed and then are ground to the correct angles in the head. At this time the valves will also be ground to clean them up (remove any burnt spots/pits) and match them to the seats. There is a spec for minumum valve edge thickness, after grinding any that are below this spec will have to be replaced with new. It isn't unusual to reuse a full set of valves, by the same token it isn't unusual to replace one or two on a valve job. For what you are thinking of doing I would recommend checking shops in your area and find out what a valve job with new seats and guides would cost and let the shop handle the part buying and the work. When you get the head back from them it will be all set up ready to install.

Powder coating looks nice! With things mounted like that I would think you would have increased bump steer, you have changed the geometry of the lower arm and actually moved it up by the thickness of the ball joint. My vote would be to take the time and do it right by the book, the engineers had a reason for doing it the way they did...

Unleaded heads had no seats, it wasn't until after the removeal of lead from gas that heads had hardened seats installed. It's been a long time ago but I seem to remember that by 73 a lot of American cars were unleaded only... When you get the head off it will be easy to see if it has hardened seats in them, there will be a metal ring that is the seat, it probably won't be perfectly flush with the chamber, no seat no ring. Yes the VB catalog shows all of the gaskets/seals required for a head rebuild, including valve seals.

OK, Long list If you pull the head you WILL have to replace the head gasket,they are not (typically, some high performance ones are but not a stock datsun) reuseable . Since you are driving a 280 I would think but I may be wrong but you probably already have hardened valve seats. Valves and valve seats are ground to match so no need replacing valves unless they have already been ground past spec or are worn past spec. If you have the head off valve guide replacement is a good thing. If the springs are originial or don't meet spec replace them, in a normally driven car valve springs last forever, never heard of the 25K thing... When removing the head the best way is to crank the engine to TDC before doing anything else. Be sure to block the cam chain tensioner before removing the cam sproket other wise you will have to pull the front cover to fix it. Best money spent here would be for a FSM, factory service manual, often on ebay, it tells you all you need to know.

Never mind, I found a site with all of the ratios on it and made up a spread sheet, looks like 3.90 is the only way to get what I want... Think I should have kept that 4 speed...

I put an 81 5 speed in my 240 with 3.36 gears, needless to say my low end just isn't what it used to be. I drove the ZX with 3.90 gears and they were too low for my driving/liking. I've got a 3.54 rear and have been thinking of putting it in, but is it worth the trouble? Will it give me the zip of the old 4 speed first gear or will I have to go to a 3.70 or 3.90 and put up with the high rpm cruise?

Yes, but it would be a lot easier with the block out of the car.

I am starting to think you are right.....

I don't know what "support" you were looking for but what he said is true of a stock 70 Z compared to other "sports" cars of the time. Most of them had 10-20 years of racing experience behind them that was poured into the production cars making them better every year. The Z was new, and that experience flowed into later models. You need to relax, it's just a book and one man's opinion, it's not going to change the shape of the world except your's if you let it...

Well if I had been driving a race prep'd 911 and jumped into a stock 70 240Z and threw it around the track once I probably would have said the same thing. The BSR cars were a far cry from stock, and look what everyone does these days just to their street cars... I don't believe that the 240Z of the time was designed to directly compete with say the 911, if it had the price would have been closer to the 911's and the handling and performance would have been too. Just my $.02...

Just my $.02 but it looks in your first post that you want to clean the piston tops as well. My vote there is to leave them as they are, you've little to gain cleaning them and too great of a chance of crud getting between the piston and piston wall that you won't be able to get out, and it would be a sad day if you started it up with all that crud stuck there...

The real only acess to them is pulling the fender and going from the side where they exit the body. Under the cowl their point of exit is almost unreachable but from what I could feel there is a steel tube that enters from the cowl to the under dash area, there a rubber 90 is connected and exits the side under the fender. I suspect Tomo that you have one of 2 problems, either the rubber 90 is cracked as you suspect or you have rust through at one of the seams under the cowl area. I believe with a lot of twisting around on your back you can get to them without removing the dash but it wouldn't be fun.