TayGt

Hey can we bore our modular motors? OR is there no enough gain in doing so?

texas_stang02

the stock 4.6 block i believe can be bored up to .030" overbore safely. you don't really gain much power or displacement by boring... the whole idea of boring an engine is to square up the cylinder and get the right clearances when you do a rebuild. the stock bore will have worn a bit, and is most likely not going to be perfectly cylindrical, so you go with something like a .020 overbore piston and have the block bored to the proper tolerances for that piston.

texas_stang02

found this info also (book bySean Hyland)... you can have the bores sleeved, and this will allow you to bore it out to about 3.70 inches (stock is in the neighborhood of 3.55"). a 3.70 inch bore will net you about 305 cubic inches, up from the stock displacement of 281. there will be some power gains if you match all the other components correctly (heads and cams especially) for this setup, but i can't tell you what kind of power you could expect from this setup because i don't personally know anyone who's done it before.

TayGt

OH well i was thinking of stroking it to a 302 for some low end torque. IF i had it bored do you know of a company the sells a rotating assembly to match the bore?

texas_stang02

that's a good question, i'll look around and see if i can find anything, but i don't know any off the top of my head. btw, not sure if you've ever taken a block to a machine shop before, but they're going to want the pistons that are going in the motor so they can machine the bores for the right clearances on those pistons. so make sure you've got the pistons before boring it, rather than boring it and just trying to find pistons to match. the stroker kit might be the way to go if you want more low-end torque. if you were to go the sleeve/bore route to get to 5.0L then your power would come in a little higher in the rpm range than the stroker kit, so it just really depends on how you're going to be driving it and what rpm range you want to run in.

texas_stang02

if you go the stroker route, the pistons will most likely already be an over-size (probably .020" over) so the block can be machined for the right clearances. if you wanted to sleeve/bore it to 3.70" but keep the stock stroke, you could just get a forged crank and rods to go along with the pistons. i'm not real sure if the 3.70" bore is very common though so you might have trouble finding pistons for that application. i'd just go with the stroker, the pistons will already be an over-size.

check with MMR for rotating assemblies... their pistons come in over-bore sizes:

http://www.modularmustangracing.com/

TayGt

wow thanks for that site it gave me some idea like the 5.0 block. What do you think is better cast iron of aluminum block??

texas_stang02

it really depends on the application. the aluminum block will save some weight on the front end, but it can't handle as much horsepower as the cast iron block. but i don't think you will run into any trouble unless you're pushing out more than 800-900 hp, i'm sure the aluminum block can handle pretty much anything you throw at it (within reason of course). most of MMR's shortblocks and longblocks are built with the cast iron block. if you're wanting to build an engine, unless you have experience with engine building (which it sounds like you probably don't) i'd recommend a shortblock (block+ rotating assembly installed) or a longblock (shortblock + cylinder heads installed). MMR even offers their longblocks with ported heads, so that's another option to consider.

TayGt

I do have some experience i plan on doing this all myselfi ask questions to get a better understanding. I am a technician for GM and no one at work really knows bout FORDs

texas_stang02

alright then you should be able to do most of this yourself. there's a book by Sean Hyland called "how to build max-performance 4.6-liter Ford engines", it's a pretty good read because it gives youa good idea of what the stock components can handle, but most of the info on aftermarket parts is pretty outdated because new products and companies have opened up to the 4.6 modular market since then. he doesn't really give a whole lot of into on the actual build process, but there are plenty of good pictures and technical information, as well as information on torque specs for all the engine components and the torque sequences and all that.