What do you guys think? I dont hear too much about filling our blocks. The weak link is the lifter valley right? Maybe thats why? A short fill wouldnt do anything for that. Well I'm gonna be creeping up on 800-850hp with my roller block and I really dont want to upgrade.

Would a short fill add any strength?

With E85 would the engine overheat with a full fill? Driven on the street here and there. Right now the motor only runs at 160 on gas. Kick a$$ radiator and stock water pump. Making about 650-700 right now.

 

short fill would help, but the time to do it is BEFORE machine work. So if the motor is together, too late. Yes a full fill will overheat on the street regardless of gas being burned.

 

Why before machine work? The expansion? I was reading up on some fills and they state that its got the same expansion characteristics as the cast iron. Would it still be a problem?

You think it'd still overheat...darn. I know some of the guys running meth with no radiators, no water pump, sometimes have problems keeping the engine warm enough.

But perhaps the cooling properties of methanol vs ethanol are greater than Im guessing....

 

Looks like it needs to be honed afterwards, and a fill up to the bottom of the freeze plugs is all you really need. That leaves an inch or two of the top of the cylinder to be cooled. Supposedly some guys run this way on the street and dont get above 210 degrees.

Running E85 and no thermostat (or a restrictor type), I think its possible I could stay well below that.

Perhaps an oil cooler would help too.....

 

Batass, I run a SC 383 with a "street fill". The block is filled with moroso block filler up to the bottom of the freeze plugs. We should be good.

 

It may have the same density as iron, but you’re filling a space that didn’t have iron in it, the whole point is for it to change how that part of the block behaves.

Most serious engines that see street use and have block fill also run an auxiliary oil cooler to make up for some of the loss of cooling capacity.

As far as the lifter valley being the weak point… what do you base that statement on?

 

I was thinking about using an oil cooler.....

Lifter valley? Thats just what I've heard and its what my engine builder said when I was considering blocks. He said the roller blocks are weaker there because of the changes for the lifters.

What would you say the weak point is? Im asking about the fill because I think I'm going to be very close to 800hp, maybe more, when I change to e85. The other thing I'm worried about is the built th350.....

 

Ford 5.0 engines are lightened versions of the older 302 blocks which some refer to as “cast iron balloons,” and when you push too much power through them they tend to crack right down the middle of the lifter valley. I’ve never seen an SBC do that.

Usually SBC’s start showing signs of crank walk and mangling bearings when you put too much power through them, and some of the factory 400 and 4 bolt blocks will crack around where the mains bolt in. Usually something inside the block lets go first and causes a bunch of damage trying to find its way outside.

 

I heard that too, once you notice your oil pressure dropping, its a good sign that the crank is moving around and the bearings are getting chewed.