Kenny Bee 194
Member
Here’s a summary of my Chevy 408 ci small block crate engine that I had built a while back. It started out as a 350 GM block clearanced for a 4 in. stroker crank making 628 HP and 527 ft-lb torque. Well, after I put it in my 71 Nova street car and warmed it up then pulled the valve covers to adjust the valves, I noticed a lot of condensation on the top end.
I drained the oil and found water in the oil. So, I pulled the pan and found a crack in one of the areas that was machined for stroker clearance.
So back went the engine and after talking to the engine builder, I decided to replace the GM block with a Dart Little M block to make sure there would not be any more leaks. I also had a Comp Cams belt drive installed so the builder could try a few different cams. He gave the me the block and belt drive at his cost and did all the machine work, assembly, and dyno testing at no further cost to me.
After testing three different cams, he settled on a Lunati cam with 0.669” lift and 309 / 317° advertised duration on a 114° LSA. This engine dynoed at 644 HP and 561 ft-lb torque. The engine made significantly power more down low (as much as 75 ft-lbs.) which the builder attributed to the much stiffer Dart block resulting in less bore flex and better piston ring sealing.
I installed it in my 71 Nova street car where it went a best of 11:33 @ 120.9 mph.
I next installed the 408 in a 69 Nova drag car and went a best of 10.24 @ 126 mph.
Here are the details on this engine build:
Kenny Bee
I drained the oil and found water in the oil. So, I pulled the pan and found a crack in one of the areas that was machined for stroker clearance.
So back went the engine and after talking to the engine builder, I decided to replace the GM block with a Dart Little M block to make sure there would not be any more leaks. I also had a Comp Cams belt drive installed so the builder could try a few different cams. He gave the me the block and belt drive at his cost and did all the machine work, assembly, and dyno testing at no further cost to me.
After testing three different cams, he settled on a Lunati cam with 0.669” lift and 309 / 317° advertised duration on a 114° LSA. This engine dynoed at 644 HP and 561 ft-lb torque. The engine made significantly power more down low (as much as 75 ft-lbs.) which the builder attributed to the much stiffer Dart block resulting in less bore flex and better piston ring sealing.
I installed it in my 71 Nova street car where it went a best of 11:33 @ 120.9 mph.
I next installed the 408 in a 69 Nova drag car and went a best of 10.24 @ 126 mph.
Here are the details on this engine build:
PN | Description |
#31151111 | Dart "Little M" 4 bolt main block with 4.030" bore |
4" stroke 4340 forged steel crankshaft | |
6.0" stroker H beam 4340 connecting rods w/ARP 8740 bolts | |
#PT110H3 | Wiseco 13.5:1 compression Pro Tru Series 2618 flat top pistons |
Total Seal plasma moly rings | |
#10711140P | Dart Iron Eagle 230cc heads w/49cc combustion chambers |
#22440 | Manley chrome silicon 1.550" double valve springs (250 lb seat / 680 lb open) |
#245-C5245-027 | Cometic MLS 0.027" thk. head gaskets |
50199ALUN | Lunati 0.669" lift, 309/317° advertised duration, 114° LSA 4/7 Swap Solid Roller Cam |
#818-16 | Comp Cams EndureX Extreme Duty vertical bar mech. roller lifters |
#6100 | Comp Cams Camshaft Belt Drive System |
7/16" stud aluminum 1.5:1 roller Rockers | |
#52030 | Port matched aluminum single plane high rise intake manifold |
#Q-950 | QFT 950 cfm carb w/2" Spacer |
#20196 | Moroso 7qt. oil pan |
#22171 | Moroso billet aluminum racing oil pump |
#60000 | Moroso Crank Trigger Ignition System |
Kenny Bee