To Fill Or Not To Fill

Would you recommend filling or partially a block (460) that is going to be bored .030 over??. The engine is either going to be a 501 or 521 stroker in a drag car.

What hp level? You have to weigh whether or not an aftermarket block is more practical for future upgrades.

Barney wrote:What hp level? You have to weigh whether or not an aftermarket block is more practical for future upgrades.

700ish... not really looking to upgrade anytime soon.. but crazier things have happen..lol

You dont need to fill it at that level. I wouldn't worry in the least.

Barney wrote:You dont need to fill it at that level. I wouldn't worry in the least.

Thats what I thought.. But a local engine builder was telling me it should be..

1faststang wrote:

Barney wrote:You dont need to fill it at that level. I wouldn't worry in the least.

Thats what I thought.. But a local engine builder was telling me it should be..

It's not a Chevy. Sounds like the local guy needs a lesson.

Barney wrote:

1faststang wrote:

Barney wrote:You dont need to fill it at that level. I wouldn't worry in the least.

Thats what I thought.. But a local engine builder was telling me it should be..

It's not a Chevy. Sounds like the local guy needs a lesson.

I was about to post the samething.. They don't know their Fords..lol

Oil temps will be higher with a block fill, and you also have to remember that cylinder pressure is highest when the piston is within an inch of the top of the bore and falling fast as the piston drops in the bore. A fill to the pUmp holes wont even get you there.

On a .030 bore, I don't do it. Sonic check your bore and it will be fine. I have ran 15:1 at over 850 hp on a .080 over bore with out a fill.

I think it rates right up there with a main girdle, just helps hold the parts together after the engine blows up.

JMHO

IDT-572 wrote:Oil temps will be higher with a block fill, and you also have to remember that cylinder pressure is highest when the piston is within an inch of the top of the bore and falling fast as the piston drops in the bore. A fill to the pUmp holes wont even get you there.

On a .030 bore, I don't do it. Sonic check your bore and it will be fine. I have ran 15:1 at over 850 hp on a .080 over bore with out a fill.

I think it rates right up there with a main girdle, just helps hold the parts together after the engine blows up.

JMHO

Great Info!.. Thanks!

mine is .080 and not filled.

The fill helps ring seal IMO, iits worth doing in high hp stuff. But At 700 you can get away without it.

dfree383 wrote:The fill helps ring seal IMO, iits worth doing in high hp stuff. But At 700 you can get away without it.

I just feel that if you are making the kind of hp that would flex the cylinder wall, maybe it's time to rethink your build and step up to an aftermarket block. Unless rules dictate an oem block, then I would back up to a .030 bore.

Thanks for all the helpful info!

In a build as you describe it is an absolute waste of time, money, adds weight, increases oil temps, and does nothing for power gains relative to the performance losses resulting from my aformentioned downsides. I know people running unfilled 385 Series blocks with double the horspower you are targeting.

Paul

dfree383 wrote:The fill helps ring seal IMO, iits worth doing in high hp stuff. But At 700 you can get away without it.

Agreed, in a build such as described here the power gains from ring seal are about as worthy of discussion as the difference between a 6.7 & 6.8 rod. In other words, NIL.

Paul Kane wrote:In a build as you describe it is an absolute waste of time, money, adds weight, increases oil temps, and does nothing for power gains relative to the performance losses resulting from my aformentioned downsides. I know people running unfilled 385 Series blocks with double the horspower you are targeting.

Paul

Thanks Paul.. Glad to hear opinions from all the experts on here!!.. I'm learning lots!!.