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I know a little about it, but would like more info on exactly what is done and the difference between the two. I can't find relatively definite answers, at least those pertaining to my engine.
I have the 4.6L engine from the S197. I have new sparkplugs and FRPP hot rod cams in. My engine is also running an F/I setup with a Roush M90 blower and Steeda cold-air.
Would it be better for me to stroke my 4.6L? bore? both, neither? etc.
I'm looking for power. How much will each route give me, roughly?

Really need some tech heads/grease monkeys to chime in. Thanks.
 

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IMO huge waste of money if your planning on keeping the M90. You will get minimal gains from stroking or boring alone.
 

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IMO huge waste of money if your planning on keeping the M90. You will get minimal gains from stroking or boring alone.
Increasing cubic inches is always a great way to gain power. Back in the day we used to say there is no substitute for cubic inches. Cost is not that prohibitive if you want to upgrade rotating assembly parts anyways, You have to at least get your blocked honed if your going to put in new pistons.

If you stroke to 3.75 and bore it .020 you will increase engine capacity by about 8%. That is pretty significant. I can't say how much power you will gain but I'm going to guess right around 15-20 at the wheels, but again that's just a guess based upon 30 years of building cars. It might even be a little more since you have a blower. Plus, upgrading your rotating assembly will give you piece of mind now, and for any future power upgrades. Going big bore is the most efficient way to gain power but with our sleeved cylinders I would be wary of going more than .020". Stroking is not as efficient as boring but will aid significantly in how much power you make.
 

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From what I have read stroking will giving you a little extra tq, but don't bore if you don't need to. Boring will thin the cylinder sleeves. I have a stroker kit for sale for over $1000 under new price if you are interested...

http://www.moddedmustangs.com/forums/2005-2010-mustang-parts/276154-fs-engine-build-part-out.html

This is true only because you can gain more displacement by stroking than boring, BUT, cubic inch for cubic inch, the gains from boring is greater than stroking. Because you can not gain as much displacement from boring, the overall gains are not going to be as much.
 

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Increasing cubic inches is always a great way to gain power. Back in the day we used to say there is no substitute for cubic inches,
A.K.A. - There is no replacement for displacement.
 

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Agree with cmg427. Not worth the cost if you are keeping the M90. That little fella will be out of breath before you have to worry about exceeding the stock internals' capacity.
 

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I was debating this for a while.. IMO cost wise it would be better to just run an extra # or 2 of boost then boring it and stroking it. What is the cost of a pulley/spring swap vs boring and stroking?



^based on having a built short block already.



p.s. I would recommend getting a TVS upgrade and sell your m90. It may only cost you a grand or so to get a used TVS with using the money you get for selling the m90. You can pick up a brand new TVS for 2200-2400. Get a built short block and make 600+ RWHP !!!
 

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All the TVS's I have been looking at are only adding 150hp at most. What TVS should I be looking at to make big numbers? 700+?
 

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All the TVS's I have been looking at are only adding 150hp at most. What TVS should I be looking at to make big numbers? 700+?
Roush TVS by itself can put you over 600rwhp with the right pulley. Add supporting mods (cams, longtubes, bigger tb, bigger cai) and you can make 700rwhp. The people that are only getting 150hp is because they are going with a bigger pulley so they dont blow their stock block.
 

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Roush TVS by itself can put you over 600rwhp with the right pulley. Add supporting mods (cams, longtubes, bigger tb, bigger cai) and you can make 700rwhp. The people that are only getting 150hp is because they are going with a bigger pulley so they dont blow their stock block.
Any other root style super charger other then the roush which can supply more than 700? I thought I knew superchargers until I found out there is root, twin screw, centrifugal. **** i have a lot to learn.
 

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If you are aiming for 700+ to the tire then get ready to open up the check book. And if you are going to do it with a PD blower then get the biggest available for the 3 valve. The less you have to lean on the blower the better.
 

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Any other root style super charger other then the roush which can supply more than 700? I thought I knew superchargers until I found out there is root, twin screw, centrifugal. **** i have a lot to learn.


Ohh just to confuse you more, the Roush TVS2300 isn't a twin screw. HAHAHA :facepalm: It is a Twin Vortices Series features new four-lobe rotors and high-flow inlet and outlet ports that greatly enhance thermal efficiency, enabling greater volumetric capacity at higher revolutions per minute (RPM) <-- Copied from Roush cause I couldn't remember what the "TVS" stood for and I didn't want to try to use brain power and think. haha
 

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If you are aiming for 700+ to the tire then get ready to open up the check book. And if you are going to do it with a PD blower then get the biggest available for the 3 valve. The less you have to lean on the blower the better.


Yes 300-450 isn't too expensive, but 450-600 is, and 600-700 EVEN more.. Think about all the stress you will be putting everything under.. You will basically have to build a new car! Suspension, Engine, Fuel system, MAF, Clutch, Tranny, Tires, electronics (gauges, msd ect.) I don't know if Turbo would be cheaper or not. Might be easier to sell your GT, but a used GT500 for 30K or under and just swap a blower too get 650 RWHP with tune, blower, and injectors. ALSO have you ever daily driving 500/600/700RWHP cars? IMO anything over 575/600RWHP is pretty useless on the street.. Pavement just sucks and you can't hook up. You really can't just get into it. 500-575 RWHP is really I think street friendly. Later it just gets too expensive to be able to not fully appreciated it on a daily basis other then a "properly" prepped track.
 

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Thanks for the good info. I am in the 400 range currently on the bottle. I already can't hook on the street on street tires (20's aren't helping no sidewall), I have always wanted to build a motor however.

It will probably be a long time, but I'd like to start piecing together a forged motor on a engine stand. Just something I can piece together over time as money allows. Just basically trying to figure out my road map on what setup to choose. I'm happy with my car currently and am in no huge hurry. The bottle is a lot of fun.

My end goal is to get a forged motor built (Injectors, Ported Heads, Cams, Valve Springs, MAF), have the Super Charger, Transmission, and Long Tubes pre installed ready for quick up and in. Also have the long tubes bunged for gauges and wiring done for the most part.

I'd knock the fuel pump, UCA's,LCA's out on the current setup.

Overall I think it would be cheaper to just build this car how I want it, than to trade it for a GT500.

I figured I could do everything for under 15k over time, waiting out for used Parts/deals/sales. I could even deal with some extended down time as I have an explorer I can beat on for daily travels.

If you think about it, its almost like spending $15-$20k for a bad ass new car which is a good deal in my book lol.

As for Super Charger I am leaning towards the Kenne Bell Mammoth 2.3L which should take me as far as I would ever want to go lol. Seems to be the biggest S/C on the market. Since I am a newb to S/Cs, how long do they generally last before you have to replace them? After looking at some dyno graph comparisons it looks like the Twin Screws give the best power band.
 

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Thats a good question. Id like to know the life expectancy of a s/c too
 

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Lots of people getting 450rwhp to 500rwhp with the DOB kit for as little as $3500. That is the limit the engine will take without forging the bottom. The next level of performance is many times more expensive.
 

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I just chose to stroke my build due to the goal (600) and the, as stated, strength of the cyl wall would be thicker/safer. I have beat the crap out of my car for 5 years and the blower has been up top the whole time... I have only had the KB 2.6l but it has been flawless for 5 years/400 passes at the strip making 500+ hp.. the only thing I did that was a complete waste of money was the head porting... the stock heads could be "cleaned up" a little but a full porting is expensive and can actually reduce boost. I did have my block ported and cleaned up because the weak point on them seem to be where the thickness of the cast varies.. dbl keyed crank is another thing that isn't done very often. when we looked at the crank key from my 450hp build it was showing signs of failure.. haven't had it apart since we built it the last time but three years and no issues..
In Jan I am going to pull the power train and go thru everything.. I am going to finally do the Stage two blower cams (stockers still in there now) and the vct lockouts... check the compression and repair/replace whatever is needed to get it where it needs to be..most likely rings and a good honing will be in order.. replace all the valve stem seals and maybe upgrade the springs,again.. the seals ar bad for sure already because every time I start the car after it has sat for a few days I make a cloud of burned oil.. a big cloud... still runs like a bat out of hell but the oil leak down is not tolerable and the driving factor in working on it this winter.
Most S/c's can be rebuilt so the life expectancy is unlimited for the most part... just depends on how many miles/runs you put on it
 

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the only thing I did that was a complete waste of money was the head porting... the stock heads could be "cleaned up" a little but a full porting is expensive and can actually reduce boost.

replace all the valve stem seals and maybe upgrade the springs,again.. the seals ar bad for sure already because every time I start the car after it has sat for a few days I make a cloud of burned oil.. a big cloud...
Out of curiosity, whose heads do you have?
 

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Stock w/600 bucks worth of machine work.. 2mm oversized exhaust valves
 
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