NA engines
- Thread starter futten
- Start date
WarWagon
Caustic Cacophony
- Joined
- Mar 10, 2007
You will be able to get the block and heads milled for increased compression keeping the stock pistons, with thin headgaskets. A Buick 350 piston will swap over into the v6 and increase the compression too, but that requires a rebalance of the rotator assembly.
Which engine are you starting with? If it is a 3.8 the off-the-shelf piston choices are very limited. If you have a 4.1 and don't mind boring it to 4" bore then there are a bunch. Basically, if you want "at least" 10.0 to 1 then probably your best and easiest route would be get a set of pistons made. Doesn't sound like the least expensive route to go but it probably is in the long run. If you do go to 4" I have a set of 13.1:1 pistons for sale. I went with customs in my build. These are not budget build engines by any means but they are unique and fun.
WarWagon
Caustic Cacophony
- Joined
- Mar 10, 2007
If you are indeed running a 3.8L then Federal Mogul Buick 350 piston is the same bore as a stock 3.8L. That piston will net nearly 9.5:1 and if you add shim head gaskets and mill the heads you can get 10:1. Yes a rebalance of the rods pistons and crank will be needed as the pistons are slightly heavier than stock 3.8L pistons with 8:1
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
why waste your time.
275... maybe 300 hp.
we have been over this before.
Erik,
would you care to speak for me?
A.j.
275... maybe 300 hp.
we have been over this before.
Erik,
would you care to speak for me?
A.j.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
as long as you understand the power your going to make.
we get lots of chevy experts that think a buick makes the same kind of NA power. it does not.
as for compression, shoot for the 350 pistons and mill your heads .040 or so.
A.j.
im not expecting huuuge power as you say if i can get 275 300 ill be happy very happy if i wanted more id either go with a chevy 350 or drop a big turbo and fuel injection on the car this is to be a daily driver with some muscle i also want to keep the engine a NA sins the car will have a nascar look/theme too it with upgraded suspension to get better handling sins the car will go around tracks and with the v6 drawn so far backward it gets better weight distribution and also to keep the weight down alittle and ust to be a little differant then just going with a chevy 350 like everyone else i live the rough sound from the na v6 its not that smooth rumble like the v8 is more like a snarling
warwagon: why exactly Federal Mogul pistons? summit racing also has kieth black and can i use the regular once or do i need the Hypereutectic Pistons??
warwagon: why exactly Federal Mogul pistons? summit racing also has kieth black and can i use the regular once or do i need the Hypereutectic Pistons??
CamoDeafie
New Member
- Joined
- Jan 7, 2010
a friend has discovered that L36 series 2 pistions will fit the old blocks, but you need the low friction rings specific for them, and use either stock 3.8 rods or custom rods; apparently it netted him 9.8:1 CR on an LN3 block which has same 3.8 bore and 3.4 stroke; LK9 flat top pistons for a 3.0 will give ya huge compression; but ya might need custom rods though
WarWagon
Caustic Cacophony
- Joined
- Mar 10, 2007
I like the statement too about noise.
I'm just putting a brand out there, does not have to be brand specific.
was is the differance between the engine i have and the stage 1 and 2? im lookin at summit racing and checking out head gaskets the only copper gaskets i see are for stage 1 where can i get copper gaskets for MY engine? and im assuming i need stronger gaskets the stock once
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
there are alot of differences between the stage blocks and the production blocks, notably 14 headbolts vs 8. thicker blocks and priority oiling.
they do make copper gaskets for our motors, but your wasting money and time using copper gaskets for an NA motor. they will leak and power will suffer baddly.
gasket will depend on what year block your using. if its a new 109 then the felpro 9441 is an awesome choice.
if the block is an earlier design with raised deck heights, then you need to use the RJC steel shim gasket to retain that compression your looking for.
depending on what gasket you have, mill the head .040 and have the intake ground to match. this will net a point increase.
as for pistons, hyperutectic are about the best you will find unless you stumble across some rare 350 TRWs, but theres really no need for the forged units at the power your making either. the crappy part, is that there are no pistons that are really good for quench on the NA motor... making the burn lazy and the bottom end feeling flat. be generous on the timing and work your heads as hard as possible.
A.j.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
absolutly, a nice step up would be the turbo 2 dot rods. I have no idea on the strength of the 3 dot NA ones.
yes the steel shim gasket will be your best bet.
A.j.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
H-beams from scat would be a gross over build at your level. even the Stock 3 dot NA rods would probably hold up.
as for 2 dot rods, I have several good used sets or you can get some off of the classifieds. with just a bolt upgrade - 2 dot rods have gone as far as 600 hp
any 4.1 or turbo motor had the 2 dot rods.
A.j.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
Weber racing has reconditioned rods that are as close to new as you will get.
at the power level your at, a heavily abused stock 2 dot would hold just fine. no sense in spending on new, that goes for most of the engine. as most of the factory stock bottom end will hold up to 500 hp. the pistons being the weak link with there weight. as long as the motor is kept under 6000rpm it should hold just fine using the stock guts. all i would upgrade is the rod bolts, and have a premium balance job done.
once you pass the 450 - 500 hp mark then you should consider upgrading the internals.
push your money and time into heads.... thats where the power is at.
A.j.
well the heads are getting bigger valves and beeing ported and stronger springs and possibly a 55 degree valve job roller cam and lifters stock rockers with reinforcement sins i cant find any billet once for the shaft style that those engines have any thing else i can do`?
