Camshaft lift question.

[Daytona100]

How do you know if you have enough camshaft lift for your application. How much is to much and how much is to little. Does too little lift limit rpm. Whats a happy medium as far as lift goes. I understand duration but is valve lift as important. Is .500 lift enough to feed a 550 to 575 hp big block chevy with 5lbs boost. Any input appreciated.

[TIMINATOR]

We need to know: displacement, head type and flow,boost, intended use, compression, carb(s), exhaust type, octane, and anything else you can tell us. Then we can help. TIMINATOR

[Daytona100]

Timinator here are some specs. 454.030 Flattop pistons 088 square port heads 2.19 intake 1.88 exhaust weiand 177 5lbs Boost 950 Holley blower carb. Flow # on the heads are .050 32in 24ex .100 69in 53ex .200 125in 103ex .300 183in 140ex .400 233in 176ex .500 264in 198 ex .600 292in 204ex. Previous cam Crane 134561 236in 246ex .050 553in 576ex. Boat ran like shit couldnt spin my 28 prop. New cam yet to be installed Blue racer part# wg1130k 218in 228ex .050 .500 lift intake and exhaust. Stainless marine exhaust 91 octane pump gas. Thanks for any help.http://www.***boat.com/image_center/data/500/1542engine_shot_002.jpg

[Moneypitt]

Any input appreciated.[/QUOTE]
First thing to do is to reduce the size of your post so that it can be read on the screen without having to scroll back and forth. Myself, along with others, that may have good info for you may pass because of this "wide" screen hassle........MP

[SmokinLowriderSS]

If I got everything plugged into DD right, and the head flow numbers I dug out are close enough, the new cam is looking like it's worth about 60 HP usable for ya from 4,000 to 6,000 RPM, and a similar torque figure. I'll let the guys who know a good deal more than me work on it further, but that old cam put a lot of your HP WAY up high in the RPM scale. IMO, the long duration was doing your torque absolutely zero good trying to twist that prop. The new plan looks like a definite improvement.

[Daytona100]

If I got everything plugged into DD right, and the head flow numbers I dug out are close enough, the new cam is looking like it's worth about 60 HP usable for ya from 4,000 to 6,000 RPM, and a similar torque figure. I'll let the guys who know a good deal more than me work on it further, but that old cam put a lot of your HP WAY up high in the RPM scale. IMO, the long duration was doing your torque absolutely zero good trying to twist that prop. The new plan looks like a definite improvement.
Thanks for the input. What do you think about 1.8 rockers on the intake?

[Daytona100]

Any input appreciated.
First thing to do is to reduce the size of your post so that it can be read on the screen without having to scroll back and forth. Myself, along with others, that may have good info for you may pass because of this "wide" screen hassle........MP[/QUOTE]
Sorry about the wide post. Fits on my screen. Is that all the good info that you have. If so Thank you!!!!!!!!

[junkyardhunter]

it not really a good idea to guess on what cam you should run. You should talk to someone that knows there SH#T like george @ CLAYSMITH CAMS. he was a very big help for me

[SmokinLowriderSS]

Thanks for the input. What do you think about 1.8 rockers on the intake?
Well, modifying your DD engine file, the 1.8 rockers turn the .500" lift cam into a .528"er, and I don't see how they would alter duratrion, soi all you get is .020 (aprox) more lift, worth about 12 to 15 pounds torque and about 10 HP.
In My Opinion, leave the 1.8 rockers alone and save ya money.

[steelcomp]

Well, modifying your DD engine file, the 1.8 rockers turn the .500" lift cam into a .528"er, and I don't see how they would alter duratrion, soi all you get is .020 (aprox) more lift, worth about 12 to 15 pounds torque and about 10 HP.
In My Opinion, leave the 1.8 rockers alone and save ya money.
The 1.8's will also increase duration. NOt from zero to zero, but it will increase .05 numbers on up, and create more area under the curve, essentially opening the valve faster, and holding it open longer, at higher lifts.
Don't know if DTD takes this into consideration.
I agree about "guessing" at a cam. It's not necessary. Another source for good cam info is right here on the boards. CStraub69 is the best in the business. You can PM him directly.

[Daytona100]

The 1.8's will also increase duration. NOt from zero to zero, but it will increase .05 numbers on up, and create more area under the curve, essentially opening the valve faster, and holding it open longer, at higher lifts.
Don't know if DTD takes this into consideration.
I agree about "guessing" at a cam. It's not necessary. Another source for good cam info is right here on the boards. CStraub69 is the best in the business. You can PM him directly.
Thanks for the help. I have talked to Chris and hes the one who gave me the cam recommendation. I would love to have Chris grind me a cam but really cant afford it right now. So I took his recommendation from our conversation and found a cam with similar specs and close to what I ran in my last motor and thats the cam I came up with. The boat ran really good with a gm 2611 roller 211 intake .050 & 230 exhaust. Im running a little less compression this time and bigger heads. Iv just got to get off my butt and start working on the boat again.