i just pulled the motor in my mustang and I am torn between what i want to do. (4.6 2v) Either build an all aluminum shortblock with hi tech cams stock ported heads and full bolt ons. But i have heard that people who built full n/a motors werent very happy with the results. I want it to be around 10.5.1 compression so i can have a lot to tune with. i also have been considering getting the bottom end bored over to a 5.0 so i can have that extra torque and hp since it is staying n/a. My other option is build a low compression motor and put a centrifugal s/c on it i dont want to go roots that way i can keep my existing tb and plenum and everything else. If i do that it will stay under 10 lbs. It is going to be a street car but i definately want some power under it but not ridiculous. Will ported stock heads be enough airflow for either of these options? Now for my next problem. I am looking into an mmr shortblock for either builds. Orbuilding my own aluminum shortblock for either builds. after parts and labor for getting a shop to assemble the blocks what is more cost effective? keep in mind n/a block will need to be bored to 5.0..if i was confusing on anything please let me know hoping to get some answers advice etc. thanks

 

with the first build option you'll hit about 300rwhp. if you want to seriously build a n/a motor you need custom cams, TF heads and a high RPM capable shortblock to make the kind of power i can tell your wanting.

Actually, for a Centri i'd keep it around 9.1 compression wise so your torque is still there and then you could easily run whatever the block is rated for. Actually MMR is having a sale, like $1999 for there MMR600 shortblock. why would you only go 10lbs? you could do that on a stock motor.

stock heads suck for n/a builds plain and simple. but they do alright for F/I builds

 

Boduke is exactly right, that's what you'll end up with if you go that route, about 300rwhp. If you're wanting more than that, you'd want to get the ported Trick Flow heads and some nice stage 3 cams, that'd maybe get you up to 350-375rwhp. But if you're looking for about that much power, you'd almost be better off just putting on a decent blower, pushing 10psi of boost on it and call it a day. Otherwise, if you're getting a shortblock with forged internals and everything, that would be kind of a waste when you'd be able to boost the crap out of it, and be pusing 15+psi and making 500+rwhp.

 

Alright you have me convinced centrifigal s/c is what I want to go with. So if I got the shortblock and ported stock heads. And also the stage 3 hi tech cams I should be good to go?

 

Where can I find that shortblock sale? Mmrs site? Or is it a vendor forum thing?

 

Well how much boost do you plan to run? If you're not doing any more than 10, then I'd just put it right on the block you have now. You can do ported heads and some cams and that would help a bit too. That would prob put you up around 400rwhp and you could keep your current block. Also I'd prob go with something like a Kenne Bell 2.1L over a centrifugal type S/C.

 

I thought 10 would get me a lot more than that. I would like to be somewhere between 500-600. I was leaning towards the centrifugal over te roots style because I have heard of the kenne bell having heat soak problems. If I were to go roots kb would be my preference either way. Another factor would be that you can do a air to air or water to air innercooler and you don't have to tap the oil pan since there is an internally sealed oil system

 

centri all the way but keep compression ratio to 9.5 especially if you aren't planning on running more than 15 psi.

 

Where can I find this mmr block? Mmr still has it on their website for base price

 

Not sure to be honest, the sale might have ended. Got on the website and looks like it ended. http://modularmustangracing.com/

yea 10 psi and under your stock motor should be ok with a good tune,just dont go over 450rwhp. Seems like you wan around 600 though so if i were you. I'd get the MMR streetmod 900 shortblock, some ported PI heads and Blower cams. then a fuel system ( i have no idea there). then to handle the power your going to need a built transmission and rear end.

As for ehich supercharger, i've rode in both and man that Kennebell pulls hard the minute you hit the trottle regardless of what rpm your at. the centri on the other hand is like stock untill about 3 grand and pulls harder up top (IMO) than the KB. Either can make great power.