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Piston Choices Help


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The parts I bought came with standard bore pistons, DOH! I knew it going in and was hopeful the block was in good condition. Apparently there was enough rust on a couple of cyl's that caused a re-bore :( Oh well, now I need some help on piston choice. I don't need the most killer pistons with this set up so I thought I'd get some input from you guys.

 

Specs:

355 (.03 overbore) chevy

Alum Edelbrock Performer Heads w/ 2.02/1.6 valves and a 64 cc chamber

Edelbrock Performer 400 Cam .442 lift / 214 Deg Duration

Shorty Square port headers, 2.5" exhaust w/ Dynomax

 

I want lots of streetability, low cost, etc., etc. I see summit has some piston sets, anyone have any luck with them? Also and specific ring suggestions as well. This is going to be a mild street engine, on a mostly daily driver.

 

Thanks for the input guys. I'm excited!

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I'd say go with Hyperutetic (?sp) and go with 9.8:1 or higher compression ratio. It does mean you will have to run a higher octane than the low but I don't believe premium. I've used Speed-Pro pistons on both my rebuilds with 10:1 compression ratio on both, one is in my truck with 20k on the motor and no problems. IMO I think it would give you a really well rounded mild street engine. Just my $.02.

 

Tyson

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He has alum head,

so 10-10.5 is not a problem on pump gas. He could run 10-1 on 87 octane..

 

DCR is a product of the intake valve closing and with a mild cam he probably has a wide LSA, therefore later intake valve closing, lower DCR.

 

I'm not a fan of the Edelbrock cams, they are very old lobe profiles. Like 60's era profiles.

 

I use Delta Camshaft in Tacoma for many of my builds. Very reasonable prices and they can do whatever you want.

I just ordered a solid flat tappet for a 408 I'm doing. Small base circle, custom grind, tight lash profile for $55+shipping...

 

I would run a cast flat-top piston.

In a 355 with a rebuilder flat-top, you'll be luckt to see 9.75-1 with a normal deck height, gasket, and 64 cc chambers.

 

 

If you use that cam, get 1.6 rockers to put the heads to better use...

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Thanks for the input fella's!

 

I took my flywheel and flexplate to the machine shop this morn for ballancing and picked up the pistons I purchased with all the other parts i got in my 'deal'. Tom, my machinist, said it was a SHAME i couldn't return the KB hypers for a larger diameter. I agree, any one know who'd do that w/ out a receipt?

 

Also, any word on the SUUMMIT Brand Pistons and rings? Their price is definitly reasonable and this engine isn't going to see NO2 or pressure so I figure their ok. My machinist also said 10CR is probably the max i'd want to use for a daily motor but I am considering all options. I was hoping to see GRUMPY to chime in but I haven't seen him on here for a while.

 

Guess he's too busy playing in his big *** garage ;)

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These are what I'm looking at right now. If you all don't have any negative things to say about them, I'll probably order them tomorrow so I can have them by the weekend. The are Summit's Hyper Alum pistons, with my heads (64cc chambers per spec sheet) they will give a 9.6:1 ratio. Right in the middle of all the discussions. Looking at the Street performance chromemoly rings to go with.

 

Pistons

http://store.summitracing.com/default.asp?Ntt=pistons&searchinresults=false&Ntk=KeywordSearch&DDS=1&N=115&target=egnsearch.asp

 

Rings

http://store.summitracing.com/default.asp?Ntt=pistons&searchinresults=false&Ntk=KeywordSearch&DDS=1&N=115&target=egnsearch.asp

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Summit doesn't make anything themselves... They are probably a Sealed Power piston.

9.6-1 is a good compression ratio and with the aluminum heads you will probably be able to run 87 octane without issue.

Any good moly ring will work.

 

You might check out Northern Auto Parts, they have pretty good deals on rebuild kits...

 

You will have a fun motor... I would bump up the cam size a bit...

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I wouldn't mind doing that jake but it seems like I'm replacing everything that I bought in my deal. I'll stick with it for now and if it's not enough, I can chance it out later right?

 

I'll order the pistons today, and maybe a set of Summits 1.6 rockers, do you know if I can use standard length push rods with them or do I need to measure and get something to length?

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You should be OK with stock length pushrods, but you shoudl always check the geometry, especially when you start using aftermarket heads.

 

The smaller cam will make your combo very responsive, it will be snappy. Should be fun.

I personally have a tendency to undercam and for your motor, you are definitely on the smallish side but it will run good.

 

Also,

This is my opinion but I'm not a huge fan of hyperuetectic pistons. They are still JUST a cast piston. They are also more brittle. Harder material, but when they have issues, usually the whole piston ends up in the oil pan.

They work fine, but to me they are not usually worth any extra money.

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I got my Summit pistons, the look decent, not quite as nice as the KB's but at almost a 3rd of price, they'll do right?

 

I have been looking online for some good prices on a Harmonic Ballancer, HEI or other Distributor Coil, water pump, alt, and pully's that i'll need to button up this engine. I don't need NEW parts, I don't want cheap parts, but I don't want to spend a ton on them eh! I did grab a deal on a fairly new Eddy carb on Ebay last week, but they are low on the other stuff. :)

 

Got any ideas? I am looking for good quality but low price new parts or any place that has lots of used but good items. I wish I had an engine to start with but I didn't so I need to gather up all this stuff and I don't want it killing the rest of my budget...

 

Thanks!

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