pros&cons 427 ls3
07-02-2010, 08:49 AM
#3
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Well a lot of shops don't recommend running a 4.1" stroke crank on power adder builds. This is do to the piston design. You need the 4.1 stoke on the stock bore to get a 427. On NA builds most shops are ok with the 4.1.
The other way is to have the block resleeved and run the 4.0" stroke crank.
The 427 should make a little more power and torque compared to the 414's and 416's. Both builds will require new pistons for valve clearence. The stock rods are ok with new bolts. I would buy new rods.
The other way is to have the block resleeved and run the 4.0" stroke crank.
The 427 should make a little more power and torque compared to the 414's and 416's. Both builds will require new pistons for valve clearence. The stock rods are ok with new bolts. I would buy new rods.
07-03-2010, 10:08 AM
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My 416 LS3 = 504whp 4.0 stroke
My 427 LS3 = 560whp 4.0 stroke (sleeved)
Numbers are through an A4, 3.91s and built tranny.
Only changes were cubes, different cam and some hand work on the heads. If you go the extra step to resleeve go 427. If not then stay with a 416.
My 427 LS3 = 560whp 4.0 stroke (sleeved)
Numbers are through an A4, 3.91s and built tranny.
Only changes were cubes, different cam and some hand work on the heads. If you go the extra step to resleeve go 427. If not then stay with a 416.
07-03-2010, 09:50 PM
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Unfortunately the best way to build a 427 is with a large bore - like GM did with LS7 (LS) or the old style BBC 427's running 4.25 bore. If you really want 7 liters - consider sleeves for your block. Not cheap but will make a very solid combo for either FI or N20 in the future too.
Larger bore will breath better and shorter stroke will limit piston velocity. Take a look at flow numbers from many head suppliers - 4.125 bore flows better than 4.0x.
Good luck,
Larger bore will breath better and shorter stroke will limit piston velocity. Take a look at flow numbers from many head suppliers - 4.125 bore flows better than 4.0x.
Good luck,
07-04-2010, 12:15 AM
#7
LS3 block The LS3 block is stronger than the LS7 block as a base for sleeving. The center bulkhead, thrust bulkhead, has a considerably larger fillet on the LS2 and LS3 blocks than does the LS7 casting. Also, the LS3 block has a larger fillet between the bottom of the bore casting and the main webs, larger than on the LS2 and much larger than on the LS7.
The LS7 block does have doweled steel main caps, but the powdered metal caps on the other blocks have held over a thousand to the wheels. I have a system in place to dowel the powdered metal caps to keep them from shifting around at high power levels for those who need it.
A stock LS7 block is hit and miss on whether it will hold up with nitrous. I have repaired many with cracked sleeves - blocks out of stock unmodified Z06 Vettes.
Steve
The LS7 block does have doweled steel main caps, but the powdered metal caps on the other blocks have held over a thousand to the wheels. I have a system in place to dowel the powdered metal caps to keep them from shifting around at high power levels for those who need it.
A stock LS7 block is hit and miss on whether it will hold up with nitrous. I have repaired many with cracked sleeves - blocks out of stock unmodified Z06 Vettes.
Steve
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Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
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07-04-2010, 08:44 AM
#8
The LS3 block is stronger than the LS7 block as a base for sleeving. The center bulkhead, thrust bulkhead, has a considerably larger fillet on the LS2 and LS3 blocks than does the LS7 casting. Also, the LS3 block has a larger fillet between the bottom of the bore casting and the main webs, larger than on the LS2 and much larger than on the LS7.
The LS7 block does have doweled steel main caps, but the powdered metal caps on the other blocks have held over a thousand to the wheels. I have a system in place to dowel the powdered metal caps to keep them from shifting around at high power levels for those who need it.
A stock LS7 block is hit and miss on whether it will hold up with nitrous. I have repaired many with cracked sleeves - blocks out of stock unmodified Z06 Vettes.
Steve
The LS7 block does have doweled steel main caps, but the powdered metal caps on the other blocks have held over a thousand to the wheels. I have a system in place to dowel the powdered metal caps to keep them from shifting around at high power levels for those who need it.
A stock LS7 block is hit and miss on whether it will hold up with nitrous. I have repaired many with cracked sleeves - blocks out of stock unmodified Z06 Vettes.
Steve
07-04-2010, 06:50 PM
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The LS3 block is stronger than the LS7 block as a base for sleeving. The center bulkhead, thrust bulkhead, has a considerably larger fillet on the LS2 and LS3 blocks than does the LS7 casting. Also, the LS3 block has a larger fillet between the bottom of the bore casting and the main webs, larger than on the LS2 and much larger than on the LS7.
The LS7 block does have doweled steel main caps, but the powdered metal caps on the other blocks have held over a thousand to the wheels. I have a system in place to dowel the powdered metal caps to keep them from shifting around at high power levels for those who need it.
A stock LS7 block is hit and miss on whether it will hold up with nitrous. I have repaired many with cracked sleeves - blocks out of stock unmodified Z06 Vettes.
Steve
The LS7 block does have doweled steel main caps, but the powdered metal caps on the other blocks have held over a thousand to the wheels. I have a system in place to dowel the powdered metal caps to keep them from shifting around at high power levels for those who need it.
A stock LS7 block is hit and miss on whether it will hold up with nitrous. I have repaired many with cracked sleeves - blocks out of stock unmodified Z06 Vettes.
Steve
How would a LS1 block with Darton MID compare with the LS3 block for strength?
