How high can I rev it?

My post on the "other" site:

Dyno yesterday. 472 very lean(14.5-15.2). Only went to 5800. Made low 400's hp and trq. at the rear wheels. Peaked at 52-5300. Here's what I know:

Cam specs: Camresearch with .642/.642 lift; 300/304 adv. dur.;260/264 at .050;108LSA;104ICL. Solid cam with Scorpion roller rockers and matching valve springs

Victor intake with Demon 825 carb

Edelbrock heads 75cc pop up pistons 12.5-13:1 compression right out of the box. No prep.

MSD goodies with 36 deg. total timing

Block is a dove with h beam rods. Pistons are forged. Crank is stock.

I'm running VP 110 fuel.

I'm going up 8 jet sizes to try and get to 12.5 afr. My question is with these cam specs. how high can I safely rev the engine once the jetting is close? Who wants to make a prediction of how much power it will make once tuned? What jetting should I start with?

Thanks in advance for your answers.

You said that you have "matching springs" and we need for you to be more specific. Can you give the seat pressure and open pressure,,,,or can you give the valve spring part numbers? Next question, do you have titanium retainers or steel retainers. Seeing as how they are Edelbrock heads, I'm going to assume steel retainers.

Next, your 825 cfm Demon carb is most likely too small. If you can borrow a bigger carb, such as a 950 cfm carb, I think the engine will rev higher.

As too the rpm, I'd hope it would go to 6,500 rpm or so, but it depends on things like springs, retainers, and the engines ability too breathe.

Charlie Evans

Thanks Charlie, you're up late too. The springs were matched to the cam so I'll find out Monday what the pressures are. You got a 950 I can borrow? The car is at Greg's in Owensboro and I'll be there next Friday to tune and dyno some more. Also, I have a set of Dove C's I need freshened up. Talk later. Thanks, Frank.

Anyone else care to chime in here? Where do you think it will end up hp/trq wise once tuned? Thanks, Frank.

What carb model number would work best? I.E. Holley part#?, Demon part#?, etc...Thanks, Frank.

Open the victor up to a 4500 flg and put a 1050 on it if your looking for power.

Found a custom 900 that's supposed to flow 1000. Will be at Speedy Dyno in Owensboro, Ky on 3/22 to give it a try. Will post results. Camresearch says, should make power to 6800 or so.

Any idea on initial jetting? Thx.

dfree383 wrote:Open the victor up to a 4500 flg and put a 1050 on it if your looking for power.

Dave I personally think if you are wanting to build and make power from a 460 a Dominator is the only carb, if it is a street engine (very mild) 850 minimum...

I know you see lots of Chevy guy's run with a 4150, 850 and run good, But these are not Chevies and for some reason these BBF love bigger carbs....


JMHO
Randy

I have a very close cam to yours from cam reaserch in my 429 made peak power @ 6600 w/ 850 dp. .258/260-.640/640

Just thinking..I may have the same cam, i lost my catd and going off memory. when Jon degreed it for me we didnt have to do anything installed straight up, using a motorsport timing chain.

Cheatham, what's your carb setup? Jetting, adjustments, etc... Thanks, Frank.

My carb is an 850 holley dp when we first started the dyno runs it had 80's front and rear, it was fat up high so we jeted 75 front 76 rear turned out better and made 17 more hp. best I could do was 357 @ 6500-6600 at the wheels.

How do 'Ya know when a carb is too big

Correct me if I'm wrong. I go by a rule of the shift point should be 500 rpm's below the maximum rpm on the power curve of the cam. Then 250 rpm's below the max will be the max you want to rev it for a longer period of time. A quick rev wont do damage if its not way over the limit.

511Fox wrote:How do 'Ya know when a carb is too big

Usually CIDx2+50=minimum carb CFM. Too big of a carb is totally subjective

UPDATE:

Bolted on the 900/1000 4150 and picked up 18HP. Way too fat at 84/84 both power valves blocked. Dropped the exhaust with open headers and picked up 35 more HP. Car still falls off above 53-5400 RPM. The headers are 1 7/8". Way too small. Will be trying some Hooker Super Comp.'s(if they fit. if not, custom 2 1/8" headers). Peak power so far is 459.5 at the wheels at 5400.

I bought both comp and super comp for my cougar and the cop ones were total crap. The super comp gave us a ton of problems as well, but I think that was because of the different heads on it.