another piston question

[bob442]

what is an ideal compression ratio for a N/A motor, and who offers the pistons for that, and what are the other ways to accomplish the ratio.

I've read in posts that someone used camaro head gaskets, but I got confused as to if it was for a iron heads or not, do I want high compression 9:1? or 11:1?, what have some of you guys done to establish some good numbers? and who should I get what internals from, what pistons will hold up the best, and not cost 1000$

I'm starting to get fustraited with reading topics all the time, and not getting the answer I need, so i'm just going to ask, I want to get a cam for mid and high rpm power, possibly getting a no2 kit, wet or dry, I don't even know, I'm rebuilding a whole 3400 motor, and porting and polishing the heads, upper and lower intakes, and possibly getting the 3500 upper intake. are the pistons from summit reasonable for this kind of application? the motor will be going in a beretta with an auto trans and obdii wiring and proper tuning when everything gets to that stage, i'm willing to spend some money, but not dropping more than $2500 on just the motor and internals, i'm doing all the assembally and as much as I can myself with help. someone point me somewhere.
Just name it atleast and i'll source it. thanks.

Bob

[Alxsmt]

camaro 3.4 pistons will gain you 11.5:1 compression from the top of my head (could be wrong) and dohc 3.4 pistons will get you in the 13:1 range (again from the top of my head)

i wanted 10.5:1, wiseco decited they didnt want to make mine even after i sent them a sample of the combustion chamber mounted to a piston like they wanted... ended up going with je. for any custom piston they need every little volume measurement, and size etc. i think mine were in the 850 $900 range with rings and pins

[johnnymossville]

'93/'95 3.4 iron head pistons in a 3400 block with 3500 heads is 11.56:1 which is what I am running. The same pistons with 3400 heads will be a little over 12:1 as the 3400 combustion chamber is a little smaller than tha 3500s. The SpeedPro/Sealed Power pistons from Summit at around $30 a piece are hypereutectic pistons which have a higher silicon content making the suitable for lower boost levels or small nitros shots, and are also the pistons that I am running. The stock rods are forged and good enough for 300+ hp and 7k rpm. I know that a bunch of us have done this. So with my build I run 93 octane Shell gasoline and drove it every day to work and around town no matter what the temp was outside. Can't wait to get my engine in my Monte. Oh yea, I have a set of S&S headers modded to fit that Beretta if your interested.

[bob442]

thank you very much john, now i have anther question, where can i get the factory specs on the internet for the 3400 3500 sfi, and 3.4 camaro motor, and 3.4 dohc motor, so maybe i could figure out something here for a higher compression or is that as high as i could go with ordering from summit...

[bob442]

found it!

Make CHEVROLET
Engine Type V6
Liter 3.4
CID 207
Engine Size 3.4L/207
Beginning Year 1996
Ending Year 2004
Engine Family GM V6
Rod Length 5.700 in.
Stroke 3.310 in.

[sprucegagt]

I wouldn't necessarily trust the information on Summit. Instead just look at the left hand side of this page under "Motor Articles -> Specifications". They are the factory specs.

[bob442]

found more, but for a camaro
L32 3.4 Liter V6 (207 Cu Inch)

60 Degree front Longitudinal, OHV
Bore:92.029 mm
Stroke 84 mm
Cast Iron block
Firing order 1-2-3-4-5-6
L (Front to Back ) 2-4-6
R 1-3-5
Horsepower:160
200 ft/lbs of torque
Knock Sensor Located Right Side Center of Block
Compression Ratio 9.0:1
Fuel: 87 octane
Fuel Tank Capacity= 15.5 Gallons
Total Engine Mass : 452 Lbs (Auto) 492.8 Lbs (Manual)

Sequential Fuel Injection
Computer Controlled Air/Fuel Ratio
Electronic Pulse (injection)
Cast Iron Heads (29 Lbs each)
Aluminum Intake Manifolds
Normal Oil Pressure:50-65 psi

[bob442]

some more info,

http://www.s-series.org/htm/tech/GMPerfParts/144-148.pdf

[johnnymossville]

The pistons I used are for the 3.4L iron head Camaro 1993/95. These produce 11.56:1 cr with the 3500 heads and that is the highest that I wanted to run with 93 octane pump gas. If you use the 3.4 DOHC pistons with the 3500 heads you will end up a little over 12.5:1, and I believe over 13:1 with 3400 heads. On the left side of the screen you will also see the CR Calculator which should give you very accurate numbers.

[bob442]

thank you sir. much appriciated, i'm now looking into how the hell i could use a 3500 crank and 5.9" rods, sourcing all options. these motors are pretty confusing to keep track of everything, i got a note pad going. lol

[bszopi]

For all the internal info (bore, stroke, head chamber size, etc), use the site CR Calculator (on the left sidebar). You'll be able to get everything you need to determine different CR for different combinations.

[bob442]

well i understand that, but, do all the pistons have the same pin size? same rod size?

[bszopi]

Look in the Specifications section of the site (like Andy mentioned a few posts back) and all that info is there.

[ForcedFirebird]

Rods didn't change from the 2.8 iron head up through the 3400, after that they changed to 5.9" and 2.249" big end.

[sprucegagt]

You sure about that? I thought I remembered reading here that they were really 5.827" rods.

As for using true 5.9" rods they can be done, but only with custom pistons.