427ci stroker install for a Pontiac G8
11-02-2012, 05:39 PM
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427ci stroker install for a Pontiac G8 So the car is parked for winter, I'm mid build on it and tossing a few options around. Initially I'd taken the engine apart to do a cam swap and install ported heads. After it was apart, I decided to expand the project a bit..
Current upgrades are:
OTR Cold Air Intake
Ported TB and Intake Manifold
Ported LS3 heads
Doug Thorley 1 3/4" LT headers (non-cated)
Borla catback
Underdrive crank pulley
I was able to come up with an LS3 block, the current plan is to pick up a 427ci stroker kit. Up for recommendations on the internals, but here's what I'm thinking:
Callies Compstar Crank 4.10"
Manley H-Lite Series Rods 6.125"
Wiseco 4.07" Pistons dished, dish size is up in the air right now
Here's where my dilemma comes in. The cam I purchased was bought with the intention of adding a blower down the road (specs are close to 224 duration .581 lift, don't have them in front of me), so I know I'm leaving some HP on the table. Also, considering lowering the compression to 9.5 or 10:1 in anticipation of the SC.
My buddy is trying to convince me to sell the cam I purchased, and go more aggressive now (LG Motorsports G6X3, specs are around 240 duration .630 lift I believe). Then if/when I decide to add a blower, pick up a FI cam at that point. He's also pushing to keep the compression at 11:1 or higher to pick up some additional power.
I know that the fuel system and a stall converter will need to be upgraded as well. Also have upgraded valve springs and pushrods from comp cams.
Has anyone done a build like either of these? The goal is 550hp/550lb-ft at the wheels, I'm thinking either of these setups should get me at least that much. Really trying to avoid any drivability/idle issues. Also need to keep the car calibrated for premium fuel.
Thoughts and opinions are appreciated
Current upgrades are:
OTR Cold Air Intake
Ported TB and Intake Manifold
Ported LS3 heads
Doug Thorley 1 3/4" LT headers (non-cated)
Borla catback
Underdrive crank pulley
I was able to come up with an LS3 block, the current plan is to pick up a 427ci stroker kit. Up for recommendations on the internals, but here's what I'm thinking:
Callies Compstar Crank 4.10"
Manley H-Lite Series Rods 6.125"
Wiseco 4.07" Pistons dished, dish size is up in the air right now
Here's where my dilemma comes in. The cam I purchased was bought with the intention of adding a blower down the road (specs are close to 224 duration .581 lift, don't have them in front of me), so I know I'm leaving some HP on the table. Also, considering lowering the compression to 9.5 or 10:1 in anticipation of the SC.
My buddy is trying to convince me to sell the cam I purchased, and go more aggressive now (LG Motorsports G6X3, specs are around 240 duration .630 lift I believe). Then if/when I decide to add a blower, pick up a FI cam at that point. He's also pushing to keep the compression at 11:1 or higher to pick up some additional power.
I know that the fuel system and a stall converter will need to be upgraded as well. Also have upgraded valve springs and pushrods from comp cams.
Has anyone done a build like either of these? The goal is 550hp/550lb-ft at the wheels, I'm thinking either of these setups should get me at least that much. Really trying to avoid any drivability/idle issues. Also need to keep the car calibrated for premium fuel.
Thoughts and opinions are appreciated
11-02-2012, 08:08 PM
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Personally I would build a 416 with your ls3 block if you plan on going FI in the future. If you planned on staying NA, then I would consider the ls3 based 427 but I would make sure a great engine builder with a good history building the ls3 block based 427 shortblock.
You aren't really saving much money by piecing together your own parts and assembling it yourself, but you are owning a whole bunch of risk. There are more than a few documented oil eating ls3 block 427 engines out there built by "pro's" who made mistakes.
FI is probably your best bet for smooth idle and 550/550 whp & tq.
You aren't really saving much money by piecing together your own parts and assembling it yourself, but you are owning a whole bunch of risk. There are more than a few documented oil eating ls3 block 427 engines out there built by "pro's" who made mistakes.
FI is probably your best bet for smooth idle and 550/550 whp & tq.
Last edited by Stage7; 11-04-2012 at 02:29 PM.
11-08-2012, 08:28 PM
#7
Stay away from the 4.10 inch crank if you're thinking of going FI down the road. Stay with the 4" crank. JMHO
You could build a nice 418 with ~10:1 CR. Raise the cylinder pressure with a tight lsa in the -109-110 range for now. Stay with a small cam or it will be pretty soggy on the bottom. When you're ready for FI change the cam to something more appropriate. No way you can really have your cake and eat it too though.
You could build a nice 418 with ~10:1 CR. Raise the cylinder pressure with a tight lsa in the -109-110 range for now. Stay with a small cam or it will be pretty soggy on the bottom. When you're ready for FI change the cam to something more appropriate. No way you can really have your cake and eat it too though.
Last edited by WKMCD; 11-08-2012 at 08:34 PM.
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11-08-2012, 08:46 PM
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I agree with sticking with a 4" stroke. You also need to mention what type of supercharger you're looking at. If you go with a Procharger you can run a little more cam than you'd want with a Magnuson. Unless you're looking at one of the new i-1's. Not sure how far down the road you're planning on boost.
For reference:
http://www.dragzine.com/features/sem...-supercharger/
For reference:
http://www.dragzine.com/features/sem...-supercharger/
11-09-2012, 09:57 AM
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We have very affordable ERL 427ci Dry Sleeve turbo short block packages available.
Our M1 package will be more than enough for what you initially are doing and will be good for pushing it down the road. Our sleeves are longer than factory sleeves to help with the "oil consumption" issues and our packages are warrantied as well.
5500.00 with you sending us your core for a sleeved, balanced, blueprinted and assembled 427 ci short block is a great price with great parts in them as well like;
Callies
Wiseco
Clevite
ARP
Our M1 package will be more than enough for what you initially are doing and will be good for pushing it down the road. Our sleeves are longer than factory sleeves to help with the "oil consumption" issues and our packages are warrantied as well.
5500.00 with you sending us your core for a sleeved, balanced, blueprinted and assembled 427 ci short block is a great price with great parts in them as well like;
Callies
Wiseco
Clevite
ARP
11-09-2012, 08:42 PM
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I think you should make up your mind on FI before you start buying parts.
If you add the supercharger, you don't need 416 or 427 cubic inches of displacement. Hone your block, stock crank, forged pistons and rods and you are good to go. LS3 sized engine can get you 800+ rwhp without going nuts on boost - some turbo guys are pushing 1000. NA vs FI engines really should be assembled differently from internal parts to cam timing.
If you add the supercharger, you don't need 416 or 427 cubic inches of displacement. Hone your block, stock crank, forged pistons and rods and you are good to go. LS3 sized engine can get you 800+ rwhp without going nuts on boost - some turbo guys are pushing 1000. NA vs FI engines really should be assembled differently from internal parts to cam timing.
