400hp 305sbc. Is this true or what

There are other articles on how to build 305's up to 370 + hp,like this one;
http://www.popularhotrodding.com/en.../0667_phrs_305_chevy_engine_blocks/index.html
One thing about the article you show is that it makes it's peak hp at 7200 rpm,which sounds a bit high for a stock bottom end.But there should be lots of 305's around,and small block Chevy parts are easy to get.If it's all I had,I would be looking for higher hp levels.
Guy

Just recently, a frequent poster here on this forum cited a 500 HP 305 that uses 416 heads, IIRC. No details were given (nor asked for- lol) but I'm going to go out on a limb here, and say that he will post something in regards to it, here in this thread (how 'bout it, ap) .

AFA the build linked to in post #1, just be aware that the heads are the old-style fulie's decked to 59 cc's (for a CR over 10.5:1), the cam, headers and intake are all sized for big peak numbers- not for good driveability in a street scenario.

Not too good for a DD unless steep gears, loose converter, and the loss of vacuum for P/B, etc. are OK w/you- and this is just the 400 HP level- the power peak was actually 402 HP. At 7200 RPM and a not-so-stellar 355 ft/lb torque, at a high 5500 RPM. And all this w/stock rods, rod bolts, and crank. Makes me shudder just to type it!

I'm wondering what amount of voodoo (and how big of a cam) it takes to surpass 500 HP- w/416's. And at what RPM...

the basics- 7100rpm power peak, launched on a 6000 stall (I think, may be a few hundred RPM off), 10:1 compression, a big solid roller cam (in the 260's) with a narrow LSA (around 102 i think). Ran high 10's in a car that weighed around 2900lbs.

the heads had stock size valves and runner volume (super stock rules).

Those were stock castings keep in mind, with aftermarket stuff you could go well beyond that, but I don't know that a 305 is worth the expense in most applications (rules permitting).

ap72 said:

the basics- 7100rpm power peak, launched on a 6000 stall (I think, may be a few hundred RPM off), 10:1 compression, a big solid roller cam (in the 260's) with a narrow LSA (around 102 i think). Ran high 10's in a car that weighed around 2900lbs.

the heads had stock size valves and runner volume (super stock rules).

Those were stock castings keep in mind, with aftermarket stuff you could go well beyond that, but I don't know that a 305 is worth the expense in most applications (rules permitting).

Click to expand...

Thanks. What do you make of the engine that the OP linked to? Power peak @ 7200 w/ a much smaller cam. Prob. a big difference in porting and/or dyno numbers/calibration/correction factors, but there seems to be more discrepancy than that would indicate.

I would take the engine from post #2 over the one from the link in post #1- any day- unless I was only going to take it to the track. What a total dog it would be on the street.

well on the cam, smaller at .050", but probably bigger at the seat, you have to also keep in mind the engine I posted was severly limited by the heads so it took a longer duration, the 165cc runner and stock valves are hard to work around, once you get the valve up high enough the valve makes less of a difference- but that's w here the solid roller setup makes a big difference. Plus the engine I had was running only 10:1 compression- basically a stret engine and i believe the superstock rules also restrict the intake manifold, the 400hp enigne could ahve used a vic witha lot of work done to it.

Rules really eat away at a super stock engine.


another thing to do is forget the durations, look at the timing events themselves and the heads that they were ran with, then it really gets interesting.

A few more. > http://www.hioutput.com/tech/343hp/343hp.html > http://www.hioutput.com/tech/290hp/290hp.html

SSedan64 said:

A few more.

Click to expand...

The Lunati build: “343 corrected horsepower at 6250 rpm was observed. The peak torque output of 356.2 lb-ft occurred at 4250 rpm. The engine made over 1 hp/cubic inch from 4500 through 6500 rpm, the highest rpm tested. It made over 300 lb-ft of torque from 3000 rpm (the lowest test point) through 5750 rpm.” Is a good one for a 305. Peaky, but OK w/gears and converter or stick tranny.

The RHS build- for being computer compliant w/a stock chip, and 290 HP- ain’t too shabby, either. The L30 Vortec 5000 (5.0L) was only like 230 HP.