Horsepower Rumors

[motormonkey]

Mike F. Im curios on how you got the head flow out of gm ovals for those hp#s and at such a low rpm. Its amazing that that valve size made it without water. Just curios.

[Marty Gras]

I have yet to find "any kind of customer who would spend THAT kind of money on those kind of parts, to make that kind of power". "Hand massaged, one off, triple throw down parts can make power", "who's paying for all this NASA stuff"? Over the last 35 or so years, my customers wanted "overkill for peanuts", and 'oval port' heads were for the BUDGET GUYS. Look, the "pinch down ports" are not new, Arias Hemi heads use that design. Velocity VS Mass flow and you build your motor to what you have. Ford guys will tell you 'velocity' and BB Chevy guys cry 'monster cfm @ low vacuum'. Back in the 1980's our shop could build one of those 330HP jet boat motors up to 508HP @ 5800 RPMs. 461" motor!!! We did use all of the original motor parts, including the oval port heads. We got over 520 lbs of torque, but the motor needed 97 unleaded fuel. We sold this "rebuild" for $4200.00 plus R&R. Guys were crying about the price. So now we talk about much more power from the same heads, and I ask---- HOW MUCH MONEY? Roller cams $$$, monster port work $$$, over 10 to 1 compression $$$, intake?, headers? I love to hear about guys going faster and making more power, but at what cost? Who will purchase your "$mega bux$ oval port motor"?

[YeLLowBoaT]

If it was on ebay... it really makes 350hp...

[SmokinLowriderSS]

If it was on ebay... it really makes 350hp...
But the boat it's in goes 100 mph.

[MikeF]

Mike F. Im curios on how you got the head flow out of gm ovals for those hp#s and at such a low rpm. Its amazing that that valve size made it without water. Just curios.
The engines are not mine, but I believe the #'s as they are printed. The guy that puts this oval port engine together is a great head porter/engine combination builder. There is something to be said about making it all work together!
Granted...they are not a 468's, but I'm sure if you turn more rpm w/a 468 w/ the right combo......you'll see the over 700hp you seek.

[cfm]

What's the most horsepower someone, or anyone has made with Cast Iron OVAL factory heads on a BBC?
My friend's tellin me he makes 700hp out of a 468BBC and stock way ported OVAL heads so I wasn't sure if I should put my BS boots on.
So just wanted to hear some rumors? Anyone?
Good chance he is full of BS, but you never know. Those types of engines / power levels are out there - just not many.
For mega dollar low compression high hp oval port builds look at NHRA SuperStock. I believe thay are over 800hp now, or close too it. Incredible power and speeds for what they are limited to, but you have to have mega pockets and not just any good head porter to get up to that level.
To me, the term 'head porting' is too generic. It gets thrown around way too much. When I here 'ported and polished' I don't listen unless done by a head porter I know of and if the vehicle/boat/etc absoulutely flies. LOL.

[cfm]

Specs=>
4.530" Bore x 4.000" Stroke = 515.8 CID BBC
Brodix #3-Extra CNC'd by Brodix
supposedly 13:1 CR, but only 155 cranking psi
2 1/8 Headers
:
13:1 motor that runs on 87-89 octane. Hmmm. Nope, I wouldn't believe the 13:1 / 155 psi thing either. Oh, the HP doesn't support that either.
Oh well. LOL.

[Sleeper CP]

13:1 motor that runs on 87-89 octane. Hmmm. Nope, I wouldn't believe the 13:1 / 155 psi thing either. Oh, the HP doesn't support that either.
Oh well. LOL.
I'm not sure he claimed that the 13:1 engine ran on 89 octane.The 9.5:1 engine runs on pump gas. Just for reference my old 512 BBF w/FordMotorsport A-460 heads and 10.2:1 comp. made 710 HP at 6,000 and 661 trq. at 5,000. (I know it's a different animal, but just shows what good airflow can do for you with out alot of compression)
700 HP out of a 468 is 1.5 hp/cu.in. Can you get approx. 350 cfm out of those oval port heads? If you can, his dyno numbers aren't out of the question?
I'll ask a couple of guy's I know today what they got out of the stompin 470 BBC they built a few years back. I'll get back to ya.
Sleeper CP

[cfm]

I'm not sure he claimed that the 13:1 engine ran on 89 octane.Sleeper CP
I claimed that. LOL. Based off the 155psi cranking. So, I was going against the 13:1 or the cranking compression or his compression guage. That's all.
Sorry for the sidetrack.

[WannabeRacing]

Possible- yes.
Probable- no.
To do that you have to do some really nice work to the heads and have some great parts and some experience with matching of just the right parts for the combination.