240260280z

Stephen, now you need a 510!!!!

I'd like to surface harden but I'm not sure how much or how to. Some sort of eddy current device would be nice. I am guessing the inserted pad in the rocker is of a special alloy that helps. What ever was on the small surface was worn off or compressed at least 0.002" btw thanks for saying nice work... from you that means a lot for machined stuff!

I'm sending you all three

Some pics of cleaning up a rocker. Here is what a "good" used rocker looks like. It has had a lot of quality time with the cam and polished to shine with smooth undulations in the surface. Not much surface for holding oil when so shiny like chrome. Here are the 3 best rockers out of a used set of 12. I refreshed the worst of the 3 by using a flat slab of marble and sand paper. I measured variance to be 0.001" across the surface's peak. The front (engine side) is where the drop off is. It was interesting that simply placing the rocker on the flat surface gave the results; so it seems the machining surfaces are parallel (see below) and registered off the bottom of the rocker. Pulling the rocker towards me with 500, 600 then 800 grit accomplished the following: I did the same for the lash pad side. I took off the ridge and the surface's peak was measured to be less than a thou. across the surface. The ridge (the silver square is actually indented) took a while at 500 grit to remove. To finish, I washed thoroughly with detergent to remove all abrasive then coated with Clevite 77 break-in lube.

is fuel level measured from the ledge or from the bottom of the fuel bowl? if the back carb is 31mm down from the ledge then the fuel level has to come UP to 29mm. If this is the case then your observation of the last carb spitting is right and is probably due to it being leaner. However all your plugs looked rich so if spark and fuel is ok then you should change jets.

I have a batch of very weak nitric acid to be used for a final dip to brighten the part. I have not started plating yet but I did a lot of reading and it seemed to be a useful final step. I did crude plating a few years back and it worked fine but the finish was dull.

Has anyone tried VW seats in a Z? I'm looking for something comfortable, adjustable and modern for the trek to Memphis. I was impressed with my friends VW seats. Thx

Is your last name Leno?

I think the oer gauge registers from the ledge where the main jet assembly screws in. For a tube/straw alternate method, you may wish to put a mark or ring on the straw so that it registers from the ledge......or just bottom it out and ensure all three are the same level. The fuel level from the ledge should be 31mm to 27mm down. It is something you can adjust to tune. Just make sure all 3 carbs have the same level. Repeat the measurement a few times so that the straw measurement is accurate enough for your liking. Take pics to make a tach tip for all when you nail it.

I drank the Kool aid and wasted a lot of time because of following his guessing. I expected more based on his writing and credentials but was let down and had to dig out of the hole I jumped in.

fuel level adjuster How to measure fuel level with oer tool (a pipette may work the same if you bottom it the same in all carbs. http://www.classiczcars.com/topic/47089-sk-racing-carbs/?p=432407 how to measure with caliper (ignore the 25mm bs from Keith Franke that I stupidly parroted):

Your timing seems ok. For SK's there is a screw for lowering the fuel. There is a gauge like an eye dropper you can experiment with. A pipette may do the trick. You could probably dip a stick or the end of a caliper to measure fuel depth. The carbs should not leak.

Flush with canned carb cleaner to improve flow. Use the straw to spay into holes. After it is clean, inspect for cracks/ failures of the joints.

Yeah I measured 45 seconds on my 280z after it sat for the winter in storage. You can change rockers as long as the surface is smooth, the curve is normal, the alignment of the cam interface is parallel with the lash pad interface AND both are in line. It is best to use Nissan rockers rather than after market ones.

You can dial back the idle enrichment screws to get a good a/f at idle and have clean plugs when idling. But if the fuel level is too high or the jets are too big then once off idle, the car will still be rich. Try a few plug cuts at different loads to see what plugs (a/f) is off idle: 1. Cruising 2. Accelerating up a long hill at WOT. As the guys mentioned above, if your distributor is not advancing, the fuel will burn later as it is leaving the exhaust. I don't think this will blacken the plugs though... but your exhaust will be very hot and may glow at night.

There is a restriction in the oil passage at the top of the block that limits oil to the head. The oil in the head just oils the cam bearings and the rockers. You will just take a little from the cams by enlarging. I can send you a rocker if you want to replace that one.

Yup: http://forums.hybridz.org/topic/58658-pistiondeck-height-misinformation/?p=536534

Help. For a stock L28 engine, the piston pops out of the block but the AtlanticZ and OzDat engine planning tools do not match!! I looked at my FSM's to double check all numbers: Connecting Rod Length: L28 connecting Rods c-c 130.35mm in FSM's Honsowetz, Monroe, and on-line engine calcs give 130.20mm (so this is an error but not enough to make the model fit the real world.) Piston Compression Height: Not in FSM's but it is 38.1mm everywhere Crank Stroke: 79.0mm in FSM Still, with the con rod adjustment I get a piston above deck at 0.08mm and OzDat tool gives 0.06mm using the shorter rod data. Real world for L28 is ~ 0.584mm protrusion of piston above block (nearly 1 order of magnitude higher!!!) See picture at top. It seems to point to this question: Is the block height correct at 207.85mm /207.87mm /207.90mm? It would seem that the block height needs to be ~207.37.... did someone write a "3" and read an "8"? The only source I can trace so far, for this value is 207.85mm in Tom Monroe's book however he has the rod length that is shorter than the FSM..... help

Your problem seems to be too much fuel. 4 & 5 seem less rich. Do you or a friend have an air-fuel measuring device? Quick and dirty first step would be to lower fuel level if you do not have leaner jets. You could also get hotter plugs (5) rather than (6) heat rating.

Yup! The firing ring.

Looks like we will have a new member in our club soon. What a nice guy! Even more impressive is that he has driven his Z across North America many times over East West and North South and diagonally! Looking forward to seeing your Z!

Check for VIN in this list: https://web.archive.org/web/20120920004831/http://www.editgrid.com/user/mlwilliams/Z_Car_Registry

The carbs seem to have an issue. If you could take a photo of all plugs together, we could see if it is just one carb or all 3. Check fuel levels in carbs too.

Can folks please add accurate HG compressed and diameter measurements to this thread. I have scoured the net for many data points but there is a lot of variance so Id like to start again in this thread to improve the accuracy. Here is what I have collected: MFGR_____COMP_____dia NISMO____0.60mm___??? Ishino___1.00mm___??? Nissan__ 1.14mm___??? Nissan___1.20mm___??? Nissan___1.25mm___??? Felpro___?.??mm___88.9mm Felpro___1.10mm___??? Felpro___1.15mm___??? Felpro___1.20mm___??? HKS______1.00mm___91.0mm HKS______2.00mm___91.0mm Tomei____1.00mm___90.5mm Tomei____1.20mm___90.5mm I measured the 88.9mm Felpro on a spare I have. Most state 89mm. _____________________________________________________________________________________________ Some oval shaped early L24/L26 gaskets are also mentioned but I omitted these as the volume would be difficult to calculate without knowing more details. FYI: part number 11044-N4221. Stamped with the Nissan logo with the code NRZ 46F. NRZ stands for Nippon-Reinz made in Japan. oval ring measures 89.5mm x 87mm features the same water passage holes that original (1971 E31 240z) head gasket had.

Exhaust popping is usually too rich or retarded timing. First verify timing marks: Check piston 1 top dead centre with the mark on the damper pulley. Also have a look at exhaust and see if it is spitting soot or stinky like rich fuel burn.