Marine240z

Zed, the piston bore hole in the gasket extended slightly into the hole, the gasket itself was 3 mm thicker than the stock. I have not seen the "How to Rebuild" manual and was unaware the tolerances for skirts were addressed. This is my first rebuild so maybe I am being a little anal. If I was not so concerned about keeping all the components matching stock original, I would have just purchased a pre-made crate 24L and been done with it. Much simpler but not as satisfying. Keep your inputs coming. I post some more pics later this evening. Also check out the Silv-o-lite section in the catalogs on the uem home page. It has a ton of great info and calculators. Lon

I really feel that the pistons were just Chinese or Taiwan poorly made copies. The kit itself was junk as well and should never be sold by a reputable z supplier. These items should be sourced from American, Japanese, or European suppliers who work with exact detailed measurements from Nissan. Madkaw, I read your rebuild thread, and am surprised that after all the issues you had that your suggestion the skirts are usually wider than the bore was made seriously. The piston should be perfectly sized from top to bottom. The expansion will be determined by the alloy make up and silicon content. According to Silv-o-lite the skirt should only exceed the diameter of the head if the skirt is coated with a dry film lubricant and then it will only be .001. Good cast pistons ( forged is a whole other topic and expense) should be uniform in measurement and weight and the copies from Asian producers are crap and should not be sold by any reputable supplier especially when you are dealing with investments such as ours. There are really only two good suppliers for cast pistons in the US. UEM and Birmingham Machine. Ring sets should come from Hastings, or Mahle or possibly other "American" manufacturers. Our original pistons were hypereutectic and contained an average 12-14 percent silicon. I was amazed at the overall good condition of mine which is a testament to the build quality of these great cars.

Hi everyone, I am in the final stages of a complete rebuild of my 72 Z. 133 thousand miles on the odo. Transmission is complete, head done with a midly agressive cam, block refinished and bored to .030, crank polished, ground and balanced. I had ordered a "complete" engine kit including fuel, oil water pump, all gaskets pistons, rings. This kit was ordered from a well known z car parts supplier. I received the kit and a thourough inspection by me and my trusted mechanic exposed the following issues: 1. Head gasket was too thick and did not fit correctly. 2. Pistons were ITM make and skirts ( bottom) was 0.5-1mm wider than the piston head. They were also 26-30 grams heavier than the stock ones I removed. ( I know, the were 83.75 vs 83.00). Two of pistons weighed 1.5 grams more than the others, and one weighed 2.1 gram more. 487 grams was the base weight. 3. oil pump did not rotate completly 4. Timing chain guides had 1 small air bubble underneath the rubber coating 5. Timing chain was thin and not as robust as the stock one removed. After an exhaustive internet search, the following corrective action(s) were taken: 1. Felpro oem gasket ordered ( $56.00) vs $22.00 kit Fits perfectly. 2. New " Silv-O-Lite pistons ordered from United Engine & Machine Company, Carson, Nevada. They have been in business since 1922. I also ordered new " perfect circle" rings from Mahle sizes 2mm 2mm 4mm. The web site for the pistons is: uempistons.com 2-5. New oil pump and timing chain kit from Beck Arnley The pistons and rings should arrive Friday so I will update at that time. Attached are a few picks I will also downloads more soon, and document rebuild as much as possible. Also am replacing the stock exhaust with a new 35 year old original "new old stock" ABARTH. See attached ad from the August 1973 Road & Track magazine. Lon

I agree, original 240 Z's from 1970-1972 are the only way to fly! They set the standard that everyone else aspired to...

VERY cool, I hate those liberal obama loving jackasses at Google so will not sign up for an account. ( use bing for search). You said stock 4 speed tranny, what about the clutch. That video put me in the drivers seat, and got my pulse racing. Looks like a great time, I also own a front engine Porsche ( 87 S-4 ) and love to see the rear engine souped up VW engines in the 911's get their asses handed to them...

Thanks for all the super feedback, I think that any aftermarket item that was approved for the Z in the 70's adds value. The exhaust system is such a key component to proper engine maintenance and tuning I can only believe that this Z inspired design will not only look and sound good, but will contribute to it's overall performance. I believe that the person running the booth is the same person that I purchased the system from. I remember him saying something about attending a show. Being a new contributor and 240z owner I am slowly getting up to speed on all the national Z events. Will keep you posted on my thoughts on this system once it is up and running. Lon Dan your right the over/under tail looks really great! Are you running stock tubing or larger diameter?

Chas, Yes this is new old stock NOS, I found an old ad in a 1973 Car and Driver magazine on this system, supposedly it was designed as a free flowing system used in racing applications. The French swear by them and the ad claims to increase h.p. as well. I am going to order it and will keep you guys posted. Thanks for your comments. Lon

http://www.abarth-exhausts.com/datsun/ Does anyone have any experience with these. I am in the middle of complete engine rebuild, and am increasing the piston 2mm. Am also upgrading the head with mild performance cam, port/polish etc. Higher performance will necessitate a better breathing exhaust system. The system was designed available specifically for the 240Z ( 70-73) by Abarth, as an aftermarket add on. It is a bolt on, no modification needed. This particular exhaust is a new, 35 year old NOS that is still in the original wrapping. All comments or suggestions appreciated, I want to stay with OE/original period aftermarket parts rather than a modified modern muffler system if possible. Marine240z