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ok i'm not sure if this is stupid or not, but what i was thinking is if i do a pi swap i would do all forged internals. my idea though is to use the stock rod size of the newer engine and ished piston heads to lower the compression back down. that way i would be able to put a super charger safely on it. i figured it wouldn't be any problem because they use the same block. my birthday is coming up and i thought it would be good to ask for like rod bearings and stuff to kinda get it started.
 

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ok i'm not sure if this is stupid or not, but what i was thinking is if i do a pi swap i would do all forged internals. my idea though is to use the stock rod size of the newer engine and ished piston heads to lower the compression back down. that way i would be able to put a super charger safely on it. i figured it wouldn't be any problem because they use the same block. my birthday is coming up and i thought it would be good to ask for like rod bearings and stuff to kinda get it started.
yeah if you are planning a super charger making some serious HP in the future a forged bottom end isnt a bad idea...but id say get ready to spend some coin on the build though!
 

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oh yeah i know went pricing on summit. it's gonna be around 3500 if i buy brand new heads if i can get some used for cheap then i can take a grand of that. i wish the crank was cheaper its 9xx for the crank alone. but i thought hell might as well do something i was going to do the supercharger but then i need a new intake manifold and if i need a new one im going to get a pi one because i want to eventually o the swap then i need heads and then i can run a s/c on pi swap with a 10.5:1 compression on stock parts so then its down to forging up everything. hopefully i can get some nice xmas gifts like rods and piston heads and then that'll give me an excelent start
 

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i would just leave the compression up. all depending on what kind opf blower you are using however you want the comp to be at least 9.0:1
 

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Not completely true. If you plan on running alot of boost and not wanting to run race fuel all the time. 8.5 is a good number. I think that's what the aluminator comes out to for supercharged applications.
 

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I'm running 9.3:1 CR with 9 lbs of boost on 92 octane pump gas. Going as low as 8.5:1 costs you fuel efficiency and off-boost response.

Also, a forged crank is only needed if your going to spin your engine to very high RPMs. I'm running a cast crank with a 6500 RPM rev limiter and no issues.
 

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im with guitar maestro. Upping the compression on a non forged block and then adding a supercharger and still running pump gas seems like a good recipe for disaster in my opinion. Either that or you are going to need a methanol injection system.
 

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You need to plan ahead to what kind of supercharger you want. If you are going with a roots style, lower compression like 8.5:1 is ok. If you are going with a centrifugal or turbo, you want at least 9.0:1 because it will be a dog down low when the supercharger/turbo isn't spinning and building boost yet.
 

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im gonna go out on a limb and say that you dont have the 6-8k to build just the motor.

you'd be safe on that limb....he's expecting mommy and daddy to buy him rods and pistons and such for Xmas...lol
 

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Baby Huey
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you'd be safe on that limb....he's expecting mommy and daddy to buy him rods and pistons and such for Xmas...lol
So what did Santa bring you Timmy?

He brought me Rods and Pistons and bearings and a crank and a blower. Can I have cookies now?


Lol :tongue:
 

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Discussion Starter #14
what i was saying stock parts as in stock pi size parts but all forged parts. i'm not that dumb to run 10.5 cr and a blower on stocker parts. but hey if i can get a few parts for xmas and my birthday why not. if not i'll buy part here and there.
 

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there have been plenty of completly stock Pi motors forced with 9 psi that have held up fine with a good tune. The factory comp ratio for a Pi is 9.7:1 i belive. correct me if im wrong. Ive already shoved 8psi at low rpms for many quick little burts untuned with no issues (knocks on wood)
 

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I see all this back and fourth about compression so here is my $.02 about it.....

I have 10.5:1 compression or better in my car and I'm planning on a possible SC install. I'm not going with a roots blower because I feel my compression is to high for that. But you can get away with that kind of compression with a centrifical blower and a good tune. And that is even going up to 12LBS of boost!! I personally won't go that high....I plan on running 6-8lbs. All you need is a GOOD air cooler system such as a big intercooler. A lot of guys I know will run a Meth kit to cool the air....and again, a good tune.


FYI...Vettes have had 11:1 compression out of the factory for a few years now and there are SC and turbo kits on the market for those
 

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I see all this back and fourth about compression so here is my $.02 about it.....

I have 10.5:1 compression or better in my car and I'm planning on a possible SC install. I'm not going with a roots blower because I feel my compression is to high for that. But you can get away with that kind of compression with a centrifical blower and a good tune. And that is even going up to 12LBS of boost!! I personally won't go that high....I plan on running 6-8lbs. All you need is a GOOD air cooler system such as a big intercooler. A lot of guys I know will run a Meth kit to cool the air....and again, a good tune.


FYI...Vettes have had 11:1 compression out of the factory for a few years now and there are SC and turbo kits on the market for those
i dont care what a vette has, these arent corvettes. Your compression is too high for any large air pump, period.
 
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