1968 289 Piston recommendation

[dalorzo_f]

Doing a full rebuild of the C code. Need new pistons and am coming to the US so will get a set there (right now you can't find a set of 0.030 over for a 289 anywhere in Australia, some shipping strike/issue)

Going to be a very stock build. Crane 260-H-2 cam, very close to OEM spec, original block @ 0.030 0ver, stock heads, intake/exh manifolds, etc. C4.

Sealed Power flat tops, Mahle, Keith Black, or..??? Looking at cast, coated hypereutectics, don't think the cost of forged is worth it for a 200Hp build... some have 2 reliefs, some 4, slightly lower compression with 4, but a result that is even remotely noticeable?

Recommendations?

 

[robert campbell]

I would go with the coated hypereutectics. Very little more cost than cast pistons with the ability to hold a tighter tolerance as they are not affected by heat expansion as much as the cast.

An old timer in my area told me that the hypereutectics were developed in WWII for our high altitude fighters that experienced the numbing cold of the upper atmosphere. The change in temperature was causing a ton of failures due to the wide operating temperature that these fighters experienced.

Also, they are widely used in new cars for the ability to tighten the piston to bore diameter clearance coupled with reduced piston ring pressure that reduces overall friction and provides a few free "horsey's"!

Certainly the cast has been ok forever and with a car the is driven as little as our toy's one must think. But the cost is so minimal in my mind, why not!

Rob