all with bored blocks, strokers, come in...

[Tony01GT]

I'm sorry if I sound stupid but I do not know much about motor work. Can you bore out your block and then just bolt in a stroker kit say a 4.6-5.0 or a 4.6-5.1 without any other modifications? Would you need bigger pistons due to the larger cylinder size, thus needing different ones than the ones that come with the stroker kit? And what stroker kits do you suggest and what size and/or specs would you bore your block out to?
~Tony
thanks!!

 

[Tony01GT]

I know not many people have the strokers and bored blocks but even if you have information about them I would appreciate it very much.

 

[bdcardinal]

yes, you can put a stroker kit in an overbored block. the only thing thats different are the pistons. i personally think the stroke of the 4.6 motor is long enough and would never build a stroker motor. i would just go with a big bore(3.70").

 

[Tony01GT]

yes, you can put a stroker kit in an overbored block. the only thing thats different are the pistons. i personally think the stroke of the 4.6 motor is long enough and would never build a stroker motor. i would just go with a big bore(3.70").

so you are saying to just bore it out 3.70" over and add forged internals and the appropriate sized pistons?

 

[Tony01GT]

oh and with that done, I take it you would need larger fuel injecters, tune, etc?

 

[FallenPhoenix]

one of the problems with our engines is that the borexstroke is almost square, not the best situation for a performance engine. Another problem is that the bore is so narrow that the valves are partially shrouded, upsetting smooth entry of the air fuel mixture and hurting power. The 4v heads see dramatic flow improvement with a big bore, the 2v can also benefit from this.

 

[Tony01GT]

one of the problems with our engines is that the borexstroke is almost square, not the best situation for a performance engine. Another problem is that the bore is so narrow that the valves are partially shrouded, upsetting smooth entry of the air fuel mixture and hurting power. The 4v heads see dramatic flow improvement with a big bore, the 2v can also benefit from this.

what kind of power gains are normally seen with big bore applications?

 

[bdcardinal]

i honestly have never seen a back to back comparison of a standard vs big bore modular motor test.

 

[Tony01GT]

i honestly have never seen a back to back comparison of a standard vs big bore modular motor test.

yea I know, I'm sure a lot of people would be interested in seeing that

 

[FallenPhoenix]

i honestly have never seen a back to back comparison of a standard vs big bore modular motor test.

same here, a big bore is usually part of a whole build up. If you think about it though, it would be kind of a pain in the ass to get all the work done to a stock engine, then put it back in and run it on a dyno, then take it back out to finish the work, then put it back.

 

[johnnyvista]

well, there's the old addage that 'there's no replacement for displacement'. i can't say exactly how much power i got from the stroker motor by itself because i had some other work done at the same time. however, i can say that my car is a WHOLE lot faster than it was before the swap.

 

[99Roush]

Look at this

There is some good data on this thread.

http://forums.modulardepot.com/showthread.php?s=&threadid=31577

 

[Tony01GT]

well, there's the old addage that 'there's no replacement for displacement'. i can't say exactly how much power i got from the stroker motor by itself because i had some other work done at the same time. however, i can say that my car is a WHOLE lot faster than it was before the swap.

Did you bore out your block when you got the stroker kit?

 

[Tony01GT]

or is it neccesary to bore your block when you stroke it?

 

[bdcardinal]

it is not necessary to bore a block unless there is an obvious ring ridge or scoring on the cylinder walls. although it is normal to do a .010" or .020" overbore on a motor. you dont relaly get power that way, because the gain in size is so miniscule. a big bore is when you bore .25" over stock and that requires a different sleeve to be installed into the block thats strong enough to make up for the less metal present.

 

[johnnyvista]

bdcardinal's right. but i haven't seen anyone doing a serious big bore setup on a 4.6 though. i'd love to see how it comes out.

i put in a new block with a .020 overbore. i figured it was a LOT easier to do it that way than to try and bore the block myself (or have a machine shop do it).

i've never seen anyone do a side by side comparison with a 4.6 - 5.0 or 5.1 stroker. i'd really like to see some numbers.

 

[Tony01GT]

bdcardinal's right. but i haven't seen anyone doing a serious big bore setup on a 4.6 though. i'd love to see how it comes out.

i put in a new block with a .020 overbore. i figured it was a LOT easier to do it that way than to try and bore the block myself (or have a machine shop do it).

i've never seen anyone do a side by side comparison with a 4.6 - 5.0 or 5.1 stroker. i'd really like to see some numbers.

well i'll let you guys know how it turns out i think i'm going to do a big bore .25" over and put a 5.1 stroker in it this winter or spring. and i think i'm going to have fox lake P&P my heads and get a big cam too

 

[99Roush]

bdcardinal's right. but i haven't seen anyone doing a serious big bore setup on a 4.6 though. i'd love to see how it comes out.

Mike Tymensky Big Bore 305" makes in excess of 500 rwhp and his new 358" (big bore 5.4L aluminum block) makes almost 600 rwhp. Both are NA. His is serious.

 

[01MustangGT]

well i'll let you guys know how it turns out i think i'm going to do a big bore .25" over and put a 5.1 stroker in it this winter or spring. and i think i'm going to have fox lake P&P my heads and get a big cam too

i have CHP 5.1L stroker kit. here is the auto machine shop put on my receipt: bore 0.16 and hone 0.20 to plate. i dont even know wat the heck it is mean.
and i have a KB 9psi too. i'll let u guys know wat my power output comparing to MM&FF CHP 4.9L stroker with the Votech