416 or 427

376" is great for a ported 1.9L.


But I don't care what the science says, there's something really cool about "having a 427." If I buy a crate engine, it's going to be a 427. :😀

I would look at Thompson first, as they seem to be the popular and available option.

Thruwayman90 said:

Well I pulled my heads to throw on some m311…found #7 sleeve cracked.
Trying to decide if I sleeve all 8 on my block and reuse my crank.

thompson ls3 416 or sleeved 427.
Or something from Texas speed or someone else…seems everyone is hit or miss these days, and those 2 are like the “Walmart and target of engines” trying to decide what engine and who to go with.

I don’t plan to go more than my 1.9 jokerz full tilt ported blower, and only beat on the car when I’m running e85 so I figured a stock block bored and forged rotating assmembly would be ok, it’s a street “Mexico” car with limited actual strip time.

Open to suggestions

Click to expand...

A few thoughts. . . .

Since you are going to stay with the 1.9L blower and you already have heads with a 2.165" Intake Valve, it makes sense to go with the smaller 416 inch engine. Unless you're stuck on an engine with a 4" Stroke, you might even consider a 388 CID. But the 416 having the longer stroke, and direct drive roots blower does generate 'big torque' in the lower engine rpm.

Also, instead of sleeving the block, you might want to consider an
aftermarket 'iron block' as they are much, much stronger.

Sleeving an LS3 block for a 427 engine, having a 4.125" bore is a big job!
What type of sleeves are you considering?

Cheers

Got a quote for 2800 to darton sleeve all 8, iron shp block 3k….I’d be all in 6k to fix my Lsa 416 vs 8k dart shp 427 I think the choice is clear

thompson wanted 8700 ls3 416 no sleeves, 5.3 sleeved 427 9200

Thruwayman90 said:

Got a quote for 2800 to darton sleeve all 8, iron shp block 3k….I’d be all in 6k to fix my Lsa 416 vs 8k dart shp 427 I think the choice is clear

thompson wanted 8700 ls3 416 no sleeves, 5.3 sleeved 427 9200

Click to expand...

Dart Machinery engine blocks use high quality & high strength materials.

There is 'No' comparison between an LS3 block having thin cast iron 'sleeves / liners' which is what an LS-3 engine block uses. Also, the LS3 is still an aluminum block. Because it is an aluminum block being used for high HP applications, it must be of a deep 'Y' Block design, which adds strength. However the 'Y' block design suffers from windage issues.

Whereas the Dart Machinery Engine Block uses high strength iron alloy which adds 'rigidity' without the 'Y' block design. Windage then is dramatically reduced! Piston speeds can now also be increased by about another ~500 fpm, without loosing ring seal.

Cheers