I'm thinking about rebuilding my bottom end so i can be in the rang of 500hp one day. I read that its possible to make the 4.6 a 5.0 liter with a bore kit. I also heard that stroker kits are not as good as bore kits for our modular engines. But i only see stroker kits online, Were can i find a bore kit that is good to 500hp, I don't need a kit that is capable of 600+ 500hp is my peak. Anyone rebuild there bottom end, if so what did you buy and how do you like it? Was there a hp increase over stock?
rebuilding bottom end
- Thread starter mat82284
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So the pistons are the only things holding back the engine right now? i heard the rods are the reason which i believe are holding the pistons. Do you have a link to the Mid sleeves? whats a good set of pistons?
02nightmaregt
To hell with your Mustang, I want to see your HOG!
BurningRubber
10 Year Member
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By the time you spend the money on the big bore kit and sleeving the motor, you could probaly build a .020 or .030 bored over 4.6 and invest in some head/cam work. That would be money well spent in my opinion rather than a big bore motor with stock heads/cams.
You can get away with using the stock crankshaft, but you will NEED forged rods and pistons to support 5-600hp.
You can get away with using the stock crankshaft, but you will NEED forged rods and pistons to support 5-600hp.
i'm still new to this whole engine work stuff, so bare with me. whats the difference between a big bore kit and a .20 or .30 over? does .30 make it a 5.0? Would you suggest this kit or another? i would like to spend a little less than 1500 but i also dont want a cheap kit.
MMR Street Mod 600 Forged Rotating assembly (96-04 2 valve only)
This is everything you need except a block to assemble a complete forged shortblock, this kit has the same parts as the MMR Street Mod 600 shortblock but in a do it yourself kit. Available in all piston oversizes for 1996-2009 2V or 3V Specify 6 or 8 bolt crankshaft
its here for $1500
Modular Mustang Racing
twogts4us
15 Year Member
You really need to find a local engine builder with mod motor experience...and lots of it. Ask him (or her) what (s)he uses, recommends, etc. Personally, I'd go with some Manley rods, a cobra crank and decent pistons...many to choose from... Which leads me back to the first part. Talk to someone locally who works on these motors all the time. He'll know what works, what doesn't, what he has experience with... And you might run into trouble if you buy your own parts and then deliver them to him with your car. What if you buy the wrong parts...or overpay, overbuy, etc?
04YELLOWGT
Active Member
You don't need to bore or stroke the car out. A stock bore and stroke 4.6 can take you to 500rwhp. Im making along the lines of 500rwhp through an auto at that. There are also many others on here that have put down close to 600rwhp on a 4.6, jivepepper being one.
I'm not saying you wouldn't benifit from it but if your goal is only 500-600 rwhp that can easily be done with a built motor on boost and maybe a set of cams.
BurningRubber
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Boring a 4.6 (281 cubic inches) over .020 would turn it into a 286 CI engine, rounding up. Boring it .030 over would be a 289 CI engine, rounding up.
MMR makes some great products. It may include everything you need, but you also need to clean up your block and crankshaft (if the kit does not include a new crank) before you assmeble the motor.
IF and only if the engine does not need to be bored to acheive fresh and even cylinders, you will at the least need to re-hone the cylinder walls. If you need to bore it over, you will need correct sized pistons to fit the cylinders. MMR sells the kit with the option of oversized pistons, depending on how much you have bored the cylinders.
The crankshaft needs to be inspected and turned if needed to acheive a fresh surface for the bearings if you are using a stock crankshaft. When ordering a rotating assembly, you will need to specify what work has been done to the crankshaft (if it was needed) in order to receive the correct sized rod and main bearings. If the crankshaft is included in the kit, everything is pre-measured and fit.
Add ontop of the price for the kit for assembly and removal/installation of the engine if you are not doing it yourself. If you don't have experience pulling and dis-assembling/re-assembling an engine don't try it yourself without someone who is experienced in doing so. Just 1 little mistake can ruin a fresh engine. Plus you will need to purchase tools to do the job.
Shops charge a good amount of money for removal, assembly, and installation.
It really adds up to be alot of money.
Thanks for the tips, That kit did include the crank too for $1500. I was reading online that i probably dont need to replace my crank, what do you think? Is there any benafit to swapping cranks, will the stock crank hold to about 600hp? As for the install, my friend who does this for a living is going to do it all for me for $600 I was also thinking of getting my heads ported by them, and buying some blower cams. I definitely want cams, but maybe porting the heads ill just skip. I'm going to see if i can fine a used kenne bell setup if not ill either buy it new or go with a tork tech kit. And if i can get to 500-600hp without head work, then it'll save me money since i dont want to go past that.
BurningRubber
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Thats a fair price for that kit, including the crank.
You could probaly get away using the stock crank, but people say its limit is around 600rwhp. I don't have any truth to back that though, but it is cheap insurance.
If you port the heads, you will be able to produce more power with less boost. For example, if you are making 500hp at 14psi on un-ported heads, with ported heads you could make 500hp and 12psi of boost. Thats just an example, not neccasarily what real world numbers would related to.
Less boost is less stress on the engine and the supercharger.
I was thinking of just using the stock crank because in reality i really don't think ill ever need more than 600hp, if your at 550hp or less you are already running 11's right? Can anyone confirm if the crank can hold up to about 600hp? What crank is the stock crank?
BurningRubber
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550hp is good for way more than 11's if set up right.
HP isn't the only factor for good track times. Gearing, wieght, and suspension are critical also.
I'll let someone else chime in about the crank ratings.
I'm already running 3.73's for gearing, but How fast would 550hp make me? 10's?
BurningRubber
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It depends. Thats enough power to get you to the 10's, but if your car isn't set up to put the power to the ground, or it is packing some un-needed wieght you could be stuck in the 11's.
Its really hard to pin down a 1/4 mile time accuratly with just HP numbers...
It depends. Thats enough power to get you to the 10's, but if your car isn't set up to put the power to the ground, or it is packing some un-needed wieght you could be stuck in the 11's.
Its really hard to pin down a 1/4 mile time accuratly with just HP numbers...
ahh ok, well i was only aiming for high 11's and if i can do 10's then wow. The only weight i have in the car is 150lbs worth of stereo equipment and a spare tire. I plan on doing a full suspension upgrade after the engine upgrade, but not for a little while. I plan to have a couple tunes, one with 6-10psi pushing 425hp and one pushing 550hp, and one pushing 600+ if its capable of getting there. I'm thinking of getting a kenne bell which supports 750hp but I'm not 100% sure if im going that route or not because 5k will break the bank and then some. A used kit would be best, ive also been thinking about a vortech but i dont like how the boost rises with rpms, thats why roots is my favorite choice. What do you think?
04YELLOWGT
Active Member
Are you talking power at the crank or the wheels.
My car makes around 500rwhp and I ran 10.85 @ 128. That was on bone stock suspension 60' 1.69 with 3/4 tank of gas.
Honestly if you get your car geared right (4.10s) a centri car builds boost VERY fast. I know my car sees about 10lbs instantly and climbs to 15lb pretty fast.
ok cool, i was under the impression that i needed 500 for 11's but 10's would be nice. i was talking about hp to the wheels as well. i know at the track they require a roll cage, but im not sure when they when you have to? does anyone know?
04YELLOWGT
Active Member
500rwhp isn't guaranteed you will get into the 10s it really depends on your gearing, weight of the car, driver mod, how you launch and other factors. My buddy in his 03 Cobra made around 525rwhp and the fastest he ever went was 11.1 but averaged 11.3-11.4. I have a stalled auto with 4.10s so I 60' low 1.7s - high 1.6s and my trans shifts hard and fast. If you have a manual you could run high 11s or high 10s it just depends on what you can do. (Hence the reason I like my auto.)
Its 11.49 you need a cage. I've been booted twice now and I'm pretty much done racing at the track because of that. I live to far away from a track to make 1-2 runs and get kicked out. A $100+ dollar for 2 runs really isn't worth it IMO.
