The next power levels for a stock cid n/a motor?

[rkreigh]

Originally Posted by tpepmeie

It would take about 20 more hp to truly get 600 brake hp, at STP conditions (as is normal for engine dynos). By my calculations, Pete is pushing 13.3 BMEP @ 6800 peak power speed. That is a specific output on par with the very best Tuner 415's out there (abt 560 SAE rwhp for a 415, for example).

To get much beyond that would take either 1) a further improvement in charging efficiency - breathing, or 2) drastically reduced frictional losses.

#1 would likely require something like an individual throttle tuned-length intake and more aggressive cams. #2 maybe a dry sump, low friction rings, and smaller bearing diameters.

FWIW, the Lotus GT1 race engine, unrestricted, gave about 13.5-13.6 BMEP @ 7000 RPM.

Todd

P.S., well done Pete!

man I need more porting! my 390 makes about 508 at the wheels, 617 on the "friendly" LPE engine dyno. getting that HP out of a stock block is very impressive

we talked about going with a "mini stroker" crank, with ground down rod journals to get the 396 displacement without the high billet crank cost, a much lighter rod with smaller (lower drag) bearings

I also love the individual runner idea. remember the old BB chevy "crab cross ram" lemans intakes. long tubes that gave a very straight shot at the head port. get real tricky and use a slider throttle valve for very low restriction.

doesn't make much low end torq, but screams upstairs

Pete

you have done a phenomenal job squeezing power out of the stock block

congrats on the many long hours of r&d

your heads are awesome!