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My first time.

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ok, so i bought my first 240Z a few weeks ago, and it was running really sluggishly, so was looking around, and i saw that the hose to the advance was missing, so i fixed that and it gave it more power, but still not close to what it should have, so i checked the spark plugs, and number 4 was wet. I took the compression, and all the others were around 145-130, #4 was 0. so i took the valve cover off, and there was a rocker missing! so i got a new one, and as i was putting it on, i noticed that the valve spring was sitting much lower than any of the others, just wouldn't come up. so i just took the head off, which was fun for my first time taking one off, and thank god for the shop manual or the chain would have slipped down for sure. so i take it off and it seems that the admission valve seat has come loose and its stuck between the valve and the head. so i was calling around to find someone to rebuild it, and i got some qoutes saying anywhere from $125+parts to $250, new head and valves. to $1300 for a valve job. My question is how much should i be willing to spend, and for what?

sorry for the long account, i'm just excited about my first project.

$1300 for a valve job?...Well, if the head is that damaged, you may be better off going down to the junkyard and finding a head a decent condition or by a used head from somebody for $100. Sounds like the head you have is not worth rebuilding.

byuniqe is right, $1300 is way out of line. I believe you could probably buy a completely rebuilt head and pay the core charge since yours may not be accepted and only pay in the neighborhood of $600. Take a look in the For Sale Forum and you should be able to pick up and an E-88 pretty cheap, then you could always use it as a core to turn in for a rebuilt head. I believe MSA has rebuilt heads fro around $450 plus a $150 core charge (old catalog price). You may be able to find them even cheaper.

Another thought is to check with ATK engines, look in the links section for their web-site. I believe they sell rebuilt heads as well as rebuilt engines. I would be a little leary of junkyard heads as you never know if they are warped or if they are full of corrosion etc. but they would be a good alternative to use as a core when if you can find a place to buy a rebuilt one.

  • 3 weeks later...

Wow 1300$ thats too much , a new head will cost you 449.95 plus core at Motorsport Auto and Im talking about with everything new , Valves , Roker Arms , seal , everything . Tell that guy who told you 1300 $ that he's crazy , I dont think nobody will pay that much for a head , but anyways here the web page for Motorspor Auto , I hope you can solve your problem . take care...http://www.zcarparts.com/

PS. You can request a catalog at no cost at the web page

  • Author

Alrighty, so i got it rebuilt for about $300, good deal i thought, thats with all the seals and gaskets and stuff. so i've put it on, and it turns out that the engine is now running on the last three cylinders, no joke. i checked the compression of them all, 145 across. i checked that they were sparking, yep, shocked the hell out of me. i took a look at the carbuerators, when i give it some gas, sure enough, it opens and sucks air, the fuel pump is obviously working as the 6-5-4 are working beautifully. i put all brand new hoses, so i doubt that there is a clog somewhere. help me out guys, i'm dead tired and at a loss as to what to do.

S
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It sound to me like the car is not in time , check if the piston # 1 is at TDC and the valves are close , and the ignition is pointing to the piston # 1 , Also ( does the car smoke ? )

  • Author

No smoke. I'm kinda fuzzy on this: how could 1/2 of the timing be off? the last three work fine. oh yeah, maybe this would help: when i took out the 123 spark plugs, they were dry and did not smell of gas. the other three did indeed smell of combustion.

As I read your post, the 1-2-3 cylinders have good compression, strong spark, dry plugs with no smell of gasoline. That all sounds like no fuel is getting to the cylinders. Air flow through the front carb doesn't necessarily mean there is also fuel flow.

That the 4-5-6 cylinders are running well says the timing probably isn't the major culprit. I suggest checking the fuel lines to the front carb and the carb itself.

  • Author

alrighty, i checked the fuel lines, no prob there. i checkd the carb as well as i know how. the jet needle is fine, the hole where it goes puts out gas when the reservoir is full, the float works fine, there is plenty of oil, what else should i check?

  • Author

ok, scratch that, i got all the cylinders working by adjusting the fuel/air mixture knob. now i'd like to know how to adjust the carbs, theres a huge difference in how much air they take in.

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