Who has bored out their 4.6

[mpentico]

Gee I hope this has not been hashed out on this forum already.....
I did do a quick search, but no specific info.

I am considering building a new motor for my 05 GT. (more HP)
Installing the typical P&P heads, cams, springs, headers, etc.

It is the block and bottom end I'm having difficulty with.

FYI, I'll be staying normally aspirated. No S/C or turbos for me.

From what I've read, stroking the 4.6 is not a good idea. I like torque, but do not want to lose top end HP or revs. So if I just bore out the aluminum block, how large can I go and what will the final displacement be using stock size rods?

Using balanced internals and strong valve springs, what will the red line be?

Can I go with larger bore size with a cast iron block? If so, how much more?

Any help appreciated. Partial answers accepted, but not with full credit.

 

[TGJ]

I have a 5.0 Big-Bore in my 96 TBird, that is a 4.6L Bored to a 3.7" Bore.

If you intend to use the stock sleeves, the max over-bore I would go is a .030 over which would still displace 4.6L, but would be 284 Cubic Inches( CI ) instead of the stock 281 CI.

You can have the stock block bored out and resleeved to 3.7", stock bore is 3.55". Using the stock crank this displaces 304 CI or 5.0L.

A cast block is capable of having a Big-bore done to it but it is more costly than the aluminum block.

With the parts you are suggesting for a RPM red-line, 7000 - 7500 RPM would be easily attainable if the cams/heads combo can make power that high.

With the right set of parts, you should easily exceed 400 RWHP N/A going with a Big-Bore. I would say about 380 RWHP N/A with the right set of parts, using a 4.6L.

 

[mpentico]

Great info.... I appreciate the specs.
My target is 5 liters displacement.

Anyone else have input on this?????

 

[Hoboattacker]

Don't let people convince you to go with a different block just because you are getting internals. I haven't heard of our blocks failing yet. I've only heard of people throwing a connecting rod through the block...and not matter what block you have if you throw a connecting rod, it's going to leave a nice hole.

 

[BlackRod]

Saleen stroked our motor to a 5.0. Maybe that's worth looking into. Also, DSS has a 5.0 stroker kit.