Cam specs for Ported Heads

[tpepmeie]

Originally Posted by Pete

PS
I would also like to know the best cam specs.
I know we could get 500rwhp from a 350ci the question is how much driveability will we have to give up.
If ported LT5 heads have 255cc intake port and 340cfm what would be the right cam for max power anybody have a cam/head caculator.
I would like to try a bigger intake cams maybe in the future when money starts to grow on trees,it gets a bit pricey, unless i find a low priced SGC Stage III intakes or maybe borow a set.
Man i would love to get another 15-20hp and hit 130+mph :-).

Pete, I'll hazard a guess. For a 350 with peak power around 7000 rpm, maybe like 284 seat duration (which could be anywhere from 239-244 @0.050"), and .430 lift. Exhaust 10 to 15 degrees smaller duration and .400-.420 lift.

Corey did a 372 for Bonneville with Stage 3 cams, and maximum porting stock valves. Made great power for its size.

Todd

[XfireZ51]

Originally Posted by Pete

Here's my take.

I doubt it but, if Todd were to loose any low end power with his cam choice he will make up with C.I.'s.

Basicly if Todd makes for example 650RWHP @ 7k RPM i'm pretty sure he won't be making zero power at 2k or 3k RPM.
I can't wait to see how it turns out.

Pete

Pete,

Todd is taking a methodical/quantitative approach. I'm looking at a similar approach but for a motor configuration that more of us are likely to do.
Your approach, btw, has also been very methodical. I'd like to use some other tools to point toward what the right combo should be.

[tpepmeie]

Originally Posted by ALZR1

650RWHP @ 7k RPM I'd love to see that one.
AL.

Yeah, 650 rwhp is a little optimisitc. Fingers crossed for 600, though!

Todd

[XfireZ51]

Originally Posted by tpepmeie

Yeah, 650 rwhp is a little optimisitc. Fingers crossed for 600, though!

Todd

Todd,

What are you using to develop camshaft and valve timing specs?

[XfireZ51]

Here's a great article courtesy of our DOHC cousins at SVTPerformance.

http://www.svtperformance.com/forums...01-beyond.html

[Pete]

Guys emphases on "EXAMPLE".

I know bigger cam could make a lil more power.
Horsepower costs money and i'm a little short at this time.

.239 might not be worth the gains/money over my .236
.242 or .244 could be worth the few ponies
If a set of SGC Stage III intakes come up for sale for the right price i'll be all over them like a cheap suit.
It's on my to do list for the near future.

Pete

[tpepmeie]

Originally Posted by XfireZ51

Todd,

What are you using to develop camshaft and valve timing specs?

I just write the checks, Dom, and let the professionals do it. Finding someone you trust to do the cam design is half the battle. I have a simple formula using stroke length and RPM I use to get ballpark duration, which is where I pulled Pete's numbers from. Lift is a function of valve size to cylinder size and RPM.

I told my guy that he might sell 6-8 sets a year if these billets work, and if he offered a range of designs. I think the price point would have to be sub-3000 to get that much volume. The cams really need to be tailored to your airflow and hp targets, but a few "off the shelf" designs would satisfy most owners.

[Bob G]

Dom heres some ford cam specs
http://www.crowcams.com.au/media/cat...FORD%20BA8.pdf

[XfireZ51]

Todd,

Thanks for that.

Bob,

I'd actually seen similar charts on some of the Ford sites I visited yesterday as I searched for info. I'll see if I can find them again. Of course we are talking about a smaller displacement motor but it helps provide some perspective.

[scholtmj]

Originally Posted by Pete

ported LT5 heads have 255cc intake port and 340cfm

.

What lift is this at?