Dad Posted April 10, 2014 Report Share Posted April 10, 2014 ^^^ Thank's for the ECU info, I'll be following Scotts progress as he seems real knowledable on the control systems. Dad Link to comment Share on other sites More sharing options...
lionbull Posted April 11, 2014 Report Share Posted April 11, 2014 I personally just had my stock cast pistons fail and I'm over 300hp at the wheels. I dynoed at 15 psi and it was 300hp. When the engine failed I was running 23 psi. My head cracked and the ring landings on 2 of the pistons cracked. I'm unsure if it was detonation related or just too much power for the stock internals. where did you get your car tuned?300hp is not "too much power" FYI I can tell you still have the spirit of TBI in you, though you are MPI.Everything we have read about these motors needing piston upgrades needs to be deleted/edited with the appropriate info regarding the benefits of MPI on a stock application. Link to comment Share on other sites More sharing options...
CaliConquestAlex Posted April 12, 2014 Report Share Posted April 12, 2014 (edited) The piston tops, cylinder walls, and combustion chambers in the head all looked fine with no signs of continuous detonation. Nothing looked melted or deformed at all. Here's a few pics... My tune seemed fine all the way up to 23 psi. The car ran excellent. If anything...it was running rich, not lean. http://i1050.photobucket.com/albums/s415/apordes/61C52A60-2EBE-4AFC-B172-22E283C45E4E_zps0v1va2cd.jpg http://i1050.photobucket.com/albums/s415/apordes/4C5973B7-B4A6-4CBD-BF9E-6D5EC9138312_zps8b3uwr4n.jpg http://i1050.photobucket.com/albums/s415/apordes/19BE3831-CD11-4D6A-ACAF-94C92C8BFC65_zpsbpicxtui.jpg http://i1050.photobucket.com/albums/s415/apordes/8EA072FD-DF52-4300-AFFD-57F87A8FC932_zpsnl0riwum.jpg http://i1050.photobucket.com/albums/s415/apordes/IMG_1772_zps794a7465.jpg Here's a few videos of the car running: Car even still ran with the pistons and head cracked... Edited April 12, 2014 by CaliConquestAlex Link to comment Share on other sites More sharing options...
Funky Phil Posted April 12, 2014 Report Share Posted April 12, 2014 (edited) those look like hyperucractics, what ring gap? Edited April 12, 2014 by Funky Phil Link to comment Share on other sites More sharing options...
CaliConquestAlex Posted April 12, 2014 Report Share Posted April 12, 2014 (edited) They're stock replacement cast pistons. Not sure of the ring gap. I'm using wiseco forged for the rebuild. The head was a Clearwater njv unit. Using a Dad's M28 njv head now. Edited April 12, 2014 by CaliConquestAlex Link to comment Share on other sites More sharing options...
Dad Posted April 12, 2014 Report Share Posted April 12, 2014 looks like hypers to me also. got a part # ? Detonation clearly breaks ring lands. http://www.enginebuildermag.com/2001/08/back-to-basics-preventing-piston-problems/ Link to comment Share on other sites More sharing options...
Tim_C. Posted April 12, 2014 Report Share Posted April 12, 2014 Condition of the parts is key. Stock can run very well as many have testified, but it is rare to find a stock bottom end in good shape. the cracks in those pistons could have already started a long time ago, and finally cracked the rest of the way with the added HP. I like to rebuild and go with stronger forged pistons. Worth every cent. They are also lighter. Lighter and stronger is better all the way around. Link to comment Share on other sites More sharing options...
Funky Phil Posted April 12, 2014 Report Share Posted April 12, 2014 hypers dont fall under "stock" block. I reuse OEMs or drop in forged slugs. Those are my only paths. Link to comment Share on other sites More sharing options...
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