CID/RPM/CFM/HP

[F-BIRD'88]

You avoided the question... With a lot of ( ^^%&&) what did the car run ? ET MPH.... no correction.

Going from 660ft actual elevation to sea level at a sea level track or the equal of (density)... will not result in 2 tenths ET.

The MPH is what tells the tale and you will never run at "sea level" at 60F and no Humidity...

Your trouble is your analysis is way off reality. if you actually want o reach a car performance goal
without making it a race car.

What did the 3650 # car actually run? ET ad MPH

[skinny z]

I haven't avoided the question. I've ignored it because that is NOT the question.

Are you able to tell me if heads that flow 255 CFM @ .500-.550" lift will support 385 CID and 500 HP? If not 500 HP then what is a reasonable number? Naturally aspirated.
If you can't answer THAT question that's OK. But THAT is the question.

[F-BIRD'88]

Yes **you *** Someone can make a real dyno tested 500 HP on a 385 CID SBC with a 255cfm head but you will need to seriously STEP on that 385
to get there.. It will want to rev up.... It will be near "unstreetable" and not well suited to a 3650 # street cruiser. If you want it to actually go fast.
Is this a Ported GM vortec head?

[skinny z]

Someone can make a real dyno tested 500 HP on a 385 CID SBC with a 255cfm head but you will need to seriously STEP on that 385
to get there.. It will want to rev up....

That was my suspicion.
Now that said, 1.2 HP/CID is a reachable and streetable target wouldn't you agree? Maybe even 1.3 HP/CID? That's 426-460 out of 355. For the record, "our" circle track engines were dynoed at 440 HP at 6200. Those are Vortec headed engines. (And those ARE dyno numbers, NOT as it would sit in your chassis).
At 1.2 HP/CID we're at 460 out of 385 cubes. At 1.3 HP/CID we're smack on 500 HP. I can see that peak HP might have to be approaching 6500. I'll agree with you that an engine that's making peak power that high in the rev range would not be my definition of streetable.
Thanks for the input.

Is this a Ported GM vortec head?

No, it is not.

[mag2555]

You need to think along other lines too in regards to better performance, as in Aluminum Rods and maybe lighter wrist pins.

They don't show any greater power on a stationary dyno , buy they sure as heck allow a motor to rev faster and that translates directly into faster ETs!

Also in terms of better power / performance while being street friendly your better off attaining it by means of better flowing heads then by means of a bigger Cam.

[skinny z]

You need to think along other lines too in regards to better performance, as in Aluminum Rods...

Durability, as in plenty of miles, is of prime concern. Aluminium isn't much for fatigue resistance.

Also in terms of better power / performance while being street friendly your better off attaining it by means of better flowing heads then by means of a bigger Cam.

Sadly, this is something I've come to realize. The current 355 is a compromise at best seeing as the cam is entirely unsuited.
My hope, with an impending shortblock rebuild or replacement in the works, is to make the most of these heads and let the performance fall where it may. A properly spec'd cam for the 355, with these heads, would most certainly make a difference in horsepower as well as "streetability". I'm just loathe to move sideways in a build (as in re-ring and re-bearing) as I've done so many times in the past without benefit of a measurable performance gain. A cam would help in that regard but again, there's the 385 CID question as posted.

[Krooser]

Get a real cam grinder to spec a cam for you...Mike Jones, Chad Spier and others are on here to help.

[lefty o]

depending on compr, and cam, i think youll be starting to run out of air but youll get close to your 500hp mark.

[randy331]

I've ignored it

That would be my suggestion for most of the advise posted on this thread.

Randy

[mag2555]

Myself and many many others have used Bill Miller Aluminum Rods which are treated to T6 spec in street builds run up over 20,000 miles without issue and with strokes far longer then in your 385!

[randy331]

Yes **you *** Someone can make a real dyno tested 500 HP on a 385 CID SBC with a 255cfm head but you will need to seriously STEP on that 385
to get there.. It will want to rev up.... It will be near "unstreetable" and not well suited to a 3650 # street cruiser. If you want it to actually go fast.

Not true at all.

Randy

[steve316]

Have a few builds with 421 sbc that range from 550 hp to 631 hp that are very street friendly. One has over 30,000 miles on it. A 500 horse 385 would be like taking a walk in the park, very relaxing.

[skinny z]

[quote=steve316 post_id=695262 time=1509202186 user_id=3883]
A 500 horse 385 would be like taking a walk in the park.
[/quote]
Of that I have no doubt given a fresh sheet of paper to build a spec.
But back to the original question, could you pull it off with the heads mentioned?

[skinny z]

[quote=Krooser post_id=695164 time=1509156230 user_id=21749]
Get a real cam grinder to spec a cam for you...Mike Jones, Chad Spier and others are on here to help.
[/quote]

Is it Jones who's in a partnership with Vizard?
I had contacted them regarding a 355 I had posted about here and DV chimed in.
Of course, given the heads in question, the cam will make or break the deal.

[skinny z]

.