zdude1967

My car smokes a blue fuel smelling exhaust. I am thinking of buying the z therapy rebuilt kit and trying my hand at doing it myself. Has anybody used this kit and what was your level of success.Is it easy to use and does it cover how to adjust the floats Thanks Glenn

KTM...Thanks. Short delay due to family matters. I hope to do the compression test by the weekend. I will post the numbers then. Thanks for your help Glenn

I am heading to Harbor Freight now for the compression tester. If I do find it is a bent valve should I have concerns about any damage to the bottom end. If so is there a way to check it for damage. I am not sure how many miles are even on this engine, it did run weel prior to the over rev. Glenn

The number 4 intake and both # 5 were loose. I guess what I was/am hoping for is some issue in the head that can be corrected with the head on...bound springs or something. The lash pads seem fine, the rockers do not seem to be bent, I would have to remove them to make sure. My understanding is the leak down test will determine where the compression is going, exhaust, intake or rings/piston. My goal at this point is to hopefully determine the cause to be in the head and able to repair without head removal.Can these engines make piston to valve contact without snapping the timing chain. Glenn

Good job the car looks great Glenn

The rockers are on... two were very loose and the lock nut was loose as well. Seems like the lash pads are in and correct. The retaining spring (not the valve spring) seems ok as well. Any suggestions Thanks Glenn

The other day I had my 260 out and the pedal got stuck under the floor mat. In any case it revved pretty high before I could release it. Now I have a loud valve tap and the # 5 cylinder seems to have lost compression. I did not do a compression test but rather a simple finger over the spark plug hole. Could I have bent a valve? It over revved for maybe 20 to 30 seconds. Can these Z engines typically have piston to valve contact. The head was rebuilt 500 miles ago, timing chain etc all new. Any ideas or suggestions would be appreciated Thanks Glenn

Thanks everyone for your suggestions. The Etc. was referring to a high capacity oil pump, new fuel pump, new hoses etc. I have done a lift test on the carb piston; it falls smooth and at what seems to be a reasonable pace. I will smell the oil shortly thanks for the suggestion. I put some Marvel Mystery oil in last night and took out for a hard drive. I discovered something that may help determine the issue. On hard acceleration, pedal to the floor very aggressive acceralation the car began to sputter, backfire from the exhaust, and generally run like crap. Ease off the pedal, give it a second or two and it stops and you can accelerate at a non-aggressive level and the car is fine. This happens over and over with the pedal to the floor acceralation. I hope this issue is the cause of the smoke as well. Anybody know what this is.... I guess this problem is either fuel or electrical but not mechanical such as worn rings are. Anyone??? Thanks Glenn

Thanks to all for your help. I certainly would prefer a rich mixture to needing rings however I think I adjusted the carb as much as possible. I have the round dome Hitachi HGJ46W carbs. The mixture screw underneath is screwed in completely. I used a flow meter and matched everything. They lift at the same time etc. This is what is leading me to think rings as it blows a boatload of blue smoke on hard acceleration.However the exhaust can make your eyes burn. Am I missing something with the carbs? I understand that the head was shot, when I had it rebuilt, original brass parts etc. Is it possible that the former owner put a smaller needle in to improve performance due to the worn heads? Anyway I appreciate the help, put a lot of effort into getting it back together...my first time. The thought of having to break it all back down kinda sucks. Glenn

John How can I detect if the oil rings are wiped. All the spark plugs are carbonized...black

how do you do a leak down test. the head was rebuilt by a local engine shop. all guides etc were replaced. they said the original brass seal weere in it. in any case it did not blow blue smoke before the rebuild. it blows alot of smoke on acceralation. is it possible that it is fuel. I have adjjusted the carbs and the mixture nut is about a 1/2 turn from being screwed all the way in. I pulled the plugs and all 6 are black carbon. 6 bad cylinder rings is that possible. the bottom end is original as far as I know. You can see the crosshair grind in the cylinder bores so I assumed it was in ggod shape. any input / ideas / suggestions would be appreciated Glenn

I just rebuilt the top end of my 260 engine. Head redone, headers etc. It is now making blue smoke. If I let it run in my garage the smoke actually burns your eyes. It seems to be gas rich? In any case I am getting some feeddback that maybe my rings are gone. I am going to look at doing a compression test. But two questions: Does this sound like rings. If I have to replave the rings can it be done through the bottom end with the engine in the car. Can I pull the oil pan and go in that way. I hope so my wife just got the garage back from doing the top end. Hate to see the look on her face if she sees an engine on a stand where her parking space in the garage used to be Glenn

Hello I just rebuilt my top end and have a good amount of blue smoke. It did not smoke prior to the top end rebuild. I installed a high capicity oil pump when I rebuilt adds about 15 to 20% more oil. Could this be the cause of the blue smoke. Am I flooding the engine with too much oil. The engine is stock. Thanks Glenn

The build date is 11/74. The colors are yellow, cream, and two greens. Any ideas Glenn

Bruce, I will actually be calling your place tomorrow for a manifold hose. The SAE 30 weight is no problem then, what is the best way to go, what have you used? Thanks Glenn

I looked up the oil for the cabs in the Haynes repair manual it stated to use SAE 30 oil however some post here said to use SAE 20 like a 3 in 1 brand. Which should I go with and how much does it need. What happens if you overfill it- would that lead to head in hands regret?

SteveJ How do I find the build date. Glenn

The engine is all back together however I last the diagram on the path of these hose. Can anyone help? They come around the back of the L26 from the engine side (passenger) of the engine..

Could anyone tell me what this is on a 260z. If you also know how it is wired you rock!

I just completed a bunch of work on my 260. Rebuilt cylinder head, timing chain, gear, headers etc. In any case I don’t know if the oil pump has ever been changed, I saw a high capacity oil pump on the motorsports website. They of course have the standard one as well. The high capacity one claims a 10 to 15 % increase in volume. Would this be beneficial in a basically stock engine, could it be harmful, or it just doesn’t matter Anyone?

I bought used headers for my 260z and they seem to line up. The head is square exhaust ports so are the headers. The problem is the intake manafold is 1/2 inch thick and the headers are 1/4 inch thick. How does this work with the circle piece that holds both of these down and together.

Thanks for the info. Being that the edges of the pistons are not clean do you think that suggests the rings are OK. I did notice the valve stem of the #1 cylinder was caked with damp looking oil build up. I did not really notice the other stems. ZDUDE

I just pulled the head from my 260. The piston tops seemed to have what I called non-carbonized oil. In English this would be oil that can by wiped off to expose the piston top below. As in the photos. My concerns are do the pistons tell a story that rings are worn because the oil is not burnt onto the pistons to the degree that it cannot be wiped clean with a dry rag. I have read that if the pistons have a clean ring around the perimeter that mean s the oil is slipping by the rings and coming over the top of the piston. My photos do not seem to indicate this...however the car has been sitting in a hot Arizona garage not running for 6 months. Does this matter. In any case I would prefer not to have to pull the block and get it rebuilt. Do the photos look like a healthy engine??? Any insight, anyone Thanks zdude

I had asked other shops and their EST on time was less. This shop is the only one I know in my area. However, I am asking now to what I would consider a well informed group with similar interests (ZEDS) and no reason to be anything but truthful. If $300.00 is the average cost for something like this thats cool. I am just wondering if I am getting a little love tug (jerked). ZDUDE

I just sent a head out to have two broken exhaust studs removed by an EDM tech. One of the studs has a broken EZ-out in it. In any case the shop called me and left a message it was done and the cost is $300.00. I do not think I am a cheapskate but $300.00 seems out of line. I thought maybe $120.00 to at most $180.00. Has anyone any experience with getting broken bolts removed by and EDM machine and if so what was the cost. Am I correct in my guess that removing broken studs at a standard machine shop and doing a Heli-coil would probably cost maybe $150.00 tops. Thanks Z-Dude1967