3.0 max bore

[98soupercab]

Just curious, what the safest bore size these things can handle?

I've got a '98, but I'd probably cut a boneyard specimen first.

Please allow me to edit my grammar.

What is the largest bore these can safely handle?

Clearly stock would be the safest, hence my edit.

Science/theory project ideas, that all.

 

[rurouni20xx]

ive seen .040 in some books as max overbore (bored to) and ive seen some where you an go 1.00 mm oversize. if your looking for cylinder to piston clearance consult your haynes or chilton manual, i could tell you but mine is not handy.

 

[fastpakr]

ive seen .040 in some books as max overbore (bored to) and ive seen some where you an go 1.00 mm oversize. if your looking for cylinder to piston clearance consult your haynes or chilton manual, i could tell you but mine is not handy.

1.00mm and .040 inches are the same bore.

 

[rurouni20xx]

1.00 is .03895, .040 is a lil off but in a sense yes they are the same, best to order the piston and measure it, then bore to that size as they are a lil off.

 

[fastpakr]

1mm is .0394 - barely half a thousandth off. The machining equipment can't even manage that difference. For all engine building purposes, .25mm is .010 over, .5 is .020, .75 is .030, and 1mm is .040. There's no 'bore to that size' to it - it's the same thing.

 

[98soupercab]

Thank you. I wasn't sure how far I could go without jacket issues.

 

[rurouni20xx]

i agree w/ that, our (motorcycle style small bore) precision hones and bores go from 45 to 100 mm and do metric sizes at work. ive done sae machining w/ these and used sae scales in college, along w/ sae smallbore hones that would go (and i did measure on occasion based on piston diameter) to .0001 inches. the 883 to 1200 sportster conversion we did the pistons were 3.4993 on the front and the rear was 3.4994. i bored it to to 3.485 and honed it to 3.4995 on both. there were others i did this close but i cant recall them. that was one of the sweetest motors ive ever built. hope my trk does that good when im thru...

 

[Beef52751]

performance shops do consider .001 a big difference. I would have the block sonic checked to be safe, as not all blocks are exactly the same. some may be able to be bored bigger than others.
Beef

 

[rurouni20xx]

very true beef, the only problem is custom pistons that go over .040 are pricey...then again anything thats actually forged is too.

 

[Gotta_gofast]

On a 3.0L 0.020 inch is recommended but I wouldn't suggest pushing more than 0.030 inch overbore. The walls are not very thick, if you need to bore/hone your engine over 0.030 inch than you might want to consider a new block.

 

[NiTrO JoKeR]

what if the engine was also sleeved what could the max bore be then its just curiosity I was told that the sleeves are stronger than the original but I'm pretty new to this

 

[pjtoledo]

sleeves may work, but they should be less than 7 years old. (like this thread is)

 

[92Ranger3.0]

Just curious, what the safest bore size these things can handle?

I've got a '98, but I'd probably cut a boneyard specimen first.

Please allow me to edit my grammar.

What is the largest bore these can safely handle?

Clearly stock would be the safest, hence my edit.

Science/theory project ideas, that all.

Hello, ihave a 92 3.0 Vulcan I had my Vulcan motor bored over to the 1.00mm I believe if I remember correctly the piston size was 3.543. I do however need to advance the timing slightly from 10 degrees to about 12 to get it to run smoother. I think with this big of a bore it would be better to upgrade to a programmed performance ECU.