4.6 stroker build

[goincommando]

ok I'm in the middle of a 4.6 stroker build and it time for pistions and head work. I have no clue what pistons to run should I run the h825cp30 or h802cp30. and for the head do i need a 3 angle valve job??? Need answers thanks

[gradon]

You can run either of those--just make sure you get the metric rings if you go with the 802s or the standard rings if you go with the 825s. Do get a 3-angle valve job, and shave job and maybe even backcut the valves.

[goincommando]

Ok well thanks and what do you mean shave job and back cut the valves?

[gradon]

Basically the head gets shaved some thousandths of an inch to make sure it is flat(nice fresh surface). Backcutting the valves makes the transition from 45* to 30* to allow better low-lift flow. Here's a good article on it:
http://www.chevyhiperformance.com/techa ... index.html

[goincommando]

o ok well thanks and what pistions would you pick to use.

[Biggrnjeep97]

You can run either of those--just make sure you get the metric rings if you go with the 802s or the standard rings if you go with the 825s. Do get a 3-angle valve job, and shave job and maybe even backcut the valves.

Im sure its been said before, but i had a lengthy conversation with federal mogul (maker of 802/825's). There tech line said these two pistons are 100% identical except for the 802's have metric rings and the 825s use standard rings. FYI- the 802's are 20.99/pc and 825's are 29.99/pc from summit. Hope this helps.
-Will

[gradon]

It is true that the metric pistons cost less, but the prem moly metric rings cost more than the prem standard moly rings($70vs$40). Gotta love the logic behind the prices of near identical parts. I paid like $200 for the 825cp30s w/ moly rings(brother's 20% discount at AA).

[Biggrnjeep97]

It is true that the metric pistons cost less, but the prem moly metric rings cost more than the prem standard moly rings($70vs$40). Gotta love the logic behind the prices of near identical parts. I paid like $200 for the 825cp30s w/ moly rings(brother's 20% discount at AA).

True. I believe summit quoted me $40 for rings for the 825s ,cant remember the 802s. If you do the math and convert the ring sizes to standard for the 802s youll find that they are thinner than that of the 825s. I was told by my engine builder that the smaller rings were used more frequently in later model motors,of all makes, to reduce friction. Anyone here have an opinion on whether thicker rings are better than thinner? Or am i hijacking this thread and making a mountian out of a mole hill?
-Will

[goincommando]

ok thanks guys this helped me about alot instead of me beating a haha, AA qoute me about $300 for h802cp30 std rod bearing and std crank bearings with moly rings and thats with a %10 discount not much but it helped, but one more question how much more does the low skrit pistons give you ? and has anyone used them??? thanks guys