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turbo
04-29-2001, 06:58 PM
hay fellas, does any one know about hypereutectic pistons, are they suitable for turbo engine. because they recomended by local machine shop. now with hour running time on new engine 2 pistons are missing half the top where valve relief is about 1/4 by half inch. 7psi boost 8.5 comp pump gas with octane boost.

Jetmugg
04-30-2001, 04:33 PM
Sorry to hear about the tops of your pistons coming apart. First off - I would definitely recommend forged pistons for any boosted application (turbo or supercharged). They are simply stronger than any cast piston can be, due to the grain structure imparted by the forging operation. (Hypereutectic pistons are cast from a higher silicon alloy than standard OEM type cast pistons, but they are castings, all the same). I think the Hypereutectics are OK for most naturally aspirated engines, and possibly a light load of nitrous once in a while, but stick with the forged slugs for the heavy duty work.
BUY THE BEST, AND ONLY CRY ONCE !!!!
Steve M (metallurgical engineer).

spectras only
04-30-2001, 05:40 PM
Turbo, Jetmugg is right.The Hypereutectics are fine for natural asp. engines,but I would definately recommend forged pistons for turbo or supercharged engines.Case in point;one of our customers has a new Donzi that he wanted to supercharge, so he went to a reputable engine builder[ won't mention names]who replaced his higher compression ratio [forged] pistons with low compression hypereutectic ones. What happened next, the factory adjusted fuelpump regulator was a little bit lean and after one fast wide open throttle run 6 out of 8 pistons had a meltdown.I know a lean condition could kill any engine ,but I still wouldn't put hypereutectics in a S/C engine.
[This message has been edited by spectras only (edited April 30, 2001).]
[This message has been edited by spectras only (edited April 30, 2001).]

squirt
04-30-2001, 06:12 PM
jetmugg has hit the nail on the head. Gotta go with the forged jugs. Pay the freight up front or risk the chance of nibbling the tops of the pistons.

turbo
04-30-2001, 07:02 PM
Thanks jetmugg for the advice. orignally I wanted to use trw but the guy talked me out of them, the engine is a 351 cleveland thats right I am an oddball.it ran 4400 with an A imp.for 8 years trouble free. I figured I could squeez a little more out of this thing. have any ideas where to get forged .020 over pistons for this application.

spectras only
04-30-2001, 09:29 PM
turbo, you can get forged pistons for your 351 anywhere, ie; Summit Racing, Jeg, or any speedshop.Also at http://ford.com/us/motorsport/parts.html ph; 800-444-4503
[This message has been edited by spectras only (edited April 30, 2001).]