Simmo

Im retiring a 454 and moving up to a 533.

Its just a fun, reliable street car, not planning to race it. I need to have enough vacume to operate lights. Specs are:
10.3/1 compression
2" headers into 3"
320cc rec port heads
Tit retainers
C454 dual plane manifold 1050 dominator carb
3.7 rear, TKO600

I have the hyd roller from the 454, its only got 500 miles on it and worked a treat on that motor but the new motor is bigger so perhaps I need a bigger cam.

Old cam is 238/244@050 on 112 Lobe sep. .586/.585"

Cams Im thinking about include:
Lunati Voodoo 60623 241/249@050 on 110 Lobe sep .625"
Lunati 54874LUN 245/250@050 on 112 Lobe sep .612"
Crower 01405 245/253@050 on 110 Lobe sep .612/636"

The first Lunati cam looks like it has mostly more mid range than my old cam with a choppier idle.
The second Lunati cam will have a better idle, slightly more top end and be softer on the valvetrain (important).
Crower looks like better mid range/ top end but roughest idle.

Now bearing in mind the freight cost for the cam to Australia is nearly as much as the cam, the benefit over my old cam needs to be substantial to justify replacing it.

Does my dual plane manifold tend to allow a narrower lobe sep angle?

Are the Lunati hyd roller cams ground on a cast core or are they billet with press on cast gear?

SteveG75

The 533 will calm any of those cams down so they will be milder than your old cam in the 454. Big cubes need big cams.

Post your question over at Speedtalk.
http://speedtalk.com/forum/viewforum.php?f=1

There are real cam designers hanging out on that forum. You will get a much better answer there.

C3 Stroker

You are adding about 80 cubic inches.....adding 10 degrees of duration will give you about the same characteristics as the cam on the 454. Big cubes tame a larger cam.

Little Mouse

I sure don't see the first cam making enough difference to warrant all the expense including the shipping.

Your right about the manifold overlap has more negative effects on single planes.

LFZ

the second cam looks like a good fit...thats the one I would go with anyways. Should still make good power, especially for the street.

427Hotrod

We just did a 555" with several cam swaps for an upcoming Corvette Enthusiast article. SR, HR and solid flat tappet.

Not sure what heads those are...so that will make a difference. Likely you could stand a lot more lift.

We also tested a C-454 intake (stock-untouched) and it did very well.

The HR I used was a 254/258 on a 112 LSA. 1.8 rockers on intake side got it to .720/.680 lift. Peaked HP at 6100-6200 rpm and pulled clean to 6500 with HR lifters. Solid roller lifters on the HR cam got RPM up higher and picked up some HP.

Do a search on *Snowman* here for some links to dyno run videos and some insight. I don't want to give away everything about the motor until magazine hits....but you can use a lot more cam and do well. Check the videos of the in car camera while we had it at the track to hear how it sounds and revs. That track day had the HR cam in it.


JIM

BB72

I have the 60623 in my 496 and it wasn't radical at all on the dyno. I had stock ported oval ports so HP was limited. It did sound really nice. It though might not be enough for your bigger cube motors and this may be too tame.

Dr L-88

Simmo................you have a PM

Simmo

Thanks Jim. I plan to try a trick with the C454 manifold where I make the plenum variable via a sliding divider plate plate. While driving on the primaries, the spring loaded divider plate is all the way up, giving a strong signal to the carb. when the secondary throttle opens, the divider plate is pushed down by the 4500 secondaries mechanism, exposing more plenum. Just an idea at this stage.

427Hotrod

That sounds interesting....but with 533 cubes and a dual plane intake and 320 cc heads......driveabilty isn't going to be an issue if the carb is tuned well.

Which 1050 do you have??

JIM

gkull

I used to buy parts for a Vette friend in northern EU. To beat the tariffs on the custom sheets they would be declared as birthday presents. Would that work for Australia?

I'd forget a trick spring manifold. I use a 4 hole wood spacer on a big single plane. You need the plenum volume.

Simmo

Jim the C454 has a section of the divider removed and for more top end I'd like to remove more. But if I can raise the divider at cruise it might allow me to pop it in 4th or 5th at 1800 rpm or less. It should help fuel economy on a long run as well as help vacume for accessories.

I bought an 8082-1 on your recommendation. Had planned to get the 3 circuit but you said it gave too much fuel at cruise.

Id run a spacer but expect I'll run out of room with a conventional L88 hood.