Bud2

OK, I’m back with another cam choice for you guys to critique. If you remember, I offered one up a few weeks ago that was questioned. This one was recommended by Lunati Cams.
• Advertised Duration (Int/Exh): 284/292
• Duration @ .050 (Int/Exh): 230/238
• Gross Valve Lift (Int/Exh): .530/.530
• LSA/ICL: 110/104
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 2200-6200

The purpose of the cam is for the following: The car is a ’64 Corvette coupe, 4 speed wide ratio transmission. 3125 curb weight. Professionally built differential, using a 373 gear ratio. Long Tube Headers – 1.5 inch Diam. 2.5 inch flow through exhaust (no cats, no crossover and will be changing to 1.75” primaries). 26 inch tall tires.
It’s used on weekends of which 40% of that time is on the drag strip (usually bracket racing on an eighth mile). Not a daily driver. But still needs to be streetable.

Goals:
383ci, 500hp at the crank, shift point @ 6000rpm, limited @ 6500rpm, pump gas (petrol available is 92, 95, or 98 Octane, E10 is 94.). Not a budget build but neither is it an all out heart-stopper.

Will be using 195 AFR, Scatt rotating assembly and Lunati valve train.

Timsride

I think this cam would work well for you but I would also make note that the AFR heads all flow 80% or better. Exhaust compared to Intake. Therfore you dont need a altered intake and exhaust lift. Cams with usually work better with mirrored intake and exhaust. Just my $.02 worth.

larrywalk

That combination should be fun!

Bud2

Trimside, I first was looking at a cam recommended in David Vizzards book, people seemed to think it was too much (Lunati too). This cam is their recommendation. Dropped the rocker ratio from 1.65 to 1.6 as well.

Bud.

cv67

Should run well, like to see a larger header size. 1.5 is a little small.
1-5/8 with a 3"collector would work well all around

Timsride

I think it will be a good combo as well I was just pointing out with lots of messed up sentences after reading it again, that almost all heads benefit from the extended exhaust as they don't breath enough on exhaust side. The AFR's take time to make sure that they do so there is no benefit to extended exhaust. Your combo will hit 500hp with no problem. Don't forget pics as its being built. I miss not seeing new engine combos every day at work, when I used to work in machine shops.

gkull

First of all you are not going to reach 500 hp with a H-flat cam, probably a dual plane, and a 6000 rpm or less peak power.

Vizard is a good reference guide to get you thinking about details. He makes his money selling books, and his statements are flawed. Just like a car rag. Just get a little info and understand that it is not the gospel truth.

I don't believe in bigger duration H-flat cams. The street manners suck and they are more show than go with a radical idle. If you really want 500 hp think about roller cams 236/244 .600 or so lift, small single planes like the Weiand 7531 or what ever the lower rpm model is. and use flat tops with 64 or so cc. It will run fine with 93 octane at sea level

Gordonm

there is no way that combo will hit 500 HP. I have a 383 with a big solid roller cam and AFR 210 heads and 11 to 1 compression and it is just at 500 HP that combo will net you about 430 to 450 hp. A hyd flat tappet cam is old school go with a roller amd make some power.

The Money Pit

Listen to Gkull, and others,...except for the part about more show than go,...
I happen to like my fenders shaking, and 7000 rpms will scare the crap out most guys....but my cam is waaaaay bigger than the one spec'd.

That cam will idle like a stock cam. You need to put some lumps on it.

gkull

Bud2..... If you can muddle through this. It's from my home page. I tried 3 cams in my 383 and two kinds of heads from 2001 - 2005 It's my spare motor in a box and I have used it a time or two over the years when my 427 or 434 small blocks had problems.

As of May 2001 I installed a 383 cubic inches which is 3.750 stroke and 4.030 bored 397010 4-bolt block. I only went with a 383 because of time delays to get a high end 3.875 stroker crank. I had blown two 355 ci motors in 3 months and I was in a hurry to get back on the road. I went to great lengths to make this my best high tech motor ever. It is deburred, screened, balanced and blue printed. Ultra lite hollow drilled 40 lbs internally balanced 4340 forged crank, Which was nitrided and treated with oil repellant. SFI 6.25 inch Fluid dampner, Moroso 8 quart road racing pan, Manley 6 inch 685 gram H-beam bushed rods, JE flat top pistons, Lots of Ceramic thermal coated parts. 11.21 C.R. I was afraid of going to big on the cam and ordered the Crane street solid roller 232/240 112 LSA .600 something lift with 1.6 RR's. Race ported Dart Pro1 215 cc aluminum heads with titanium 2.08 intakes 1.625 exhaust valves 64 cc angle plugs 1.55 dual springs with 195 pound closed pressure with rev kit. Ported Weiand Team G. man with Speed Demon 750 CFM twin squirter carb. Hooker 1 3/4 Super Comp headers into 3 inch true duals with 3 inch in out race mufflers. The good power band is from 3500-7500 rpm.

In Feb. 2003. This first 383 started misfiring really bad at a road race at ThunderHill Race track, California. By the time I limped it back to pits it was blowing water out of one pipe. It had a failed lifter roller wheel that took out the cam. Then the motor overheated and took out the copper head gasket. So I decided no more screwing around and lets make some serious power. I decided to go with a custom billet cam and larger heads. The Dart 227cc & Crane custom mech. roller cam 240/248 degrees @.050 .635/.644 112 LSA also ground 4 degreees retarded for more top end. This proved to be too much cam for street use and had a power range of probably 5000 - 8000 rpm. So I bought another billet custom cam with 236/242 112 LSA installed straight up with 1.65 I and 1.6 E roller rockers giving it mid .600 lifts. It is still pretty high strung. It's still making good power at my 7500 rev limiter. I've taken it on some 3000 mile round trips.

MY 4.11 HD rear end from tom's differentials, Art Carr Racing 700r4 with switched lockup 3500-stall 9.5 -inch 3-clutch convertor. Built to handle 850 hp. Full Vette Brakes poly suspension kit 1 1/8 ? sways, 550 fronts and rearched 7 leaf 420 plus inch pound steel rear 17X11 and 17X9 centerline wheels with Goodyear Z-rated F1 steel tires.
Anyway I like the feeling of acceleration and the Torque of a 383 is really something compared to my older 355 ci power plants. Nothing like shifting into 4 at 130 mph and running it on up. It was once a goal of mine to have a verified over 200 mph street legal car. This was the car and motor to do it in. I was able to get it to 7000 rpm with 2.86 overall rear gearing on 28 inch diameter 300 mph Bonneville tires. You can do the math. But it did not pass the tech inspection for 200+ mph cars. I was lacking a fire system/window net, and parachute. What do you expect I only drove it 400 some miles to Bonneville to check out the rules and watch the other racers. It?s also a mid pack finisher in SCCA in the BSP class. It did some 11.70 1/4's on my 10X28 slicks. It's not setup for drag racing. I got burnt out on drag racing from years of sitting in a fire suit in the staging lanes with sweat running down in my eyes watching some person in a 17 second Firebird doing a one wheel burnout. Road racing is my real passion. I just never had enough money to really do it right. I do make a few events and Thunder Hill, California is my favorite track. Our local Reno-Fernley is still dangerous to all the fast cars, but has been expanded out to a full 3.8 miles. The paint scheme is blue-green with purple-gold-silver ghost flames.

April 2005 Even though my 4th version of 383 power plants had only 6-7 months of use I yanked it out and installed a Motown small journal 427 ci small block (4.125 X 4.00 inches) This new 427 uses 350 chevy main journal sizes to keep bearing friction down. It's a fully forged light weight internally ballanced 4 inch stroker crank. As built it was supposed to have @608 hp and I set the rev limiter for a 7000 red line. Now after a few thousand miles of track and road testing I would not build a 383 or 396 ci again. You would have to drive a hot rodded 427 to understand. The quality and strength of these aftermarket blocks is amazing. I enjoy building motors and I only farm out what I can't do like machine work.

I buy my rotating kits from www.flatlanderracing.com To just purchase your own 427 through 454 small block just call the guys at:

scottyp99

The thing about roller cams is that the lobe shape that is allowed by the use of roller lifters makes the valve "jump" off of the valve seat, open very quickly, stay fully open longer, and then very quickly close the valve. A flat tappet cam, because the cam is sliding against the face of the flat tappet, must open the valve relatively slowly, and then, just as it is open all the way, it is time to slowly start closing the valve again. Comparing a flat tappet cam and a roller cam with the same lift and duration specs on paper, the flat tappet cam will let the valve spend more time at lower valve lift, because of the slow opening and closing rate, whereas the roller will let the valve spend more of it's "off the seat" time in a relatively fully open state. Even tho the valves are off the seat for the same length of time with both cams, the roller allows the valve to spend more time at a height where the port will flow alot better. So, a roller cam will give you the benefits of a long duration flat tappet cam, without the down side of a long duration cam. Retro-fit roller cams and the required hardware needed are kinda pricey, but when you really sit down and look at all the advantages, you will have to agree that it is money well spent.


Scott

Bud2

This is a full roller setup!

More research.

Bud.

scottyp99

I had to go back and re-read the thread to make sure, but you never mentioned it being a roller cam, and I guess we all just assumed. OK, now that we have that all cleared up, on with the show!!!!

Scott

Bud2

So we think it will do the job?

Bud.

cv67

Dont think youll hit 500 even ifs a HR. should make mid 4xx easily with outstanding torque where you want it though. Probably be done by 6k +-
Try not to focus so much on that peak hp # it will be less fun to drive.



one day Ill practice what I preach. 26x@.050 cams on the street

gkull

I found it!

http://www.lunatipower.com/Product.aspx?id=1858&gid=264

It is a mild roller for a 383. Like my first crane grind. You will have detonation problems with over 10.5 c/r

I thought it was a Voodoo H-flat

bluedawg

Afr has several dynoed combos on there web site using similar cams with 383 cubic inches and hitting 500 horse. I also know that they are in the head selling business. But their claim to fame and all that is great is that with great flowing heads and mild camshaft comes gigantic torque and horse power. If you go with a two piece timing cover you can always change the cam up later for a bigger camshaft if you are not satisfied. Good luck with your project.

Rick_V

I ran a similar Lunati cam in a 86 Z-28 that was Strip only car weighed right around 2800 lbs. It was a beast off the line but was totally finished at 6000 rpm. I originally had 1 5/8 headers with collectors and open pipes and talked to a head guy about porting my Dart heads. He looked at my headers and said he would port them but not expect to much improvement with those headers. He said 383s need to breathe on the exhaust side and recommended at minimum 1 7/8 but said 2" inch would be optimum. I put 2"ers on it and he was right. Car went from mid 11's to mid 10l's.

540 RAT

That will be a rather mild cam, not quite reaching the "street performance" category. Its pretty much a good running "ordinary street" cam. And it will have a WAY mild idle. No shaking the fenders with this one. I would think this one would be way too mild for a true Hotrodder and part time Racer. I didn't see it, but maybe Vizard's cam recommendation was a much better choice.

Bud2

Lunati Cam #DV294-06HRH. Hydraulic Roller. Duration 294/243. Lobe lift 0.373. Lift –0.615”.
Or
Lunati Cam #DV290-06HRH. Hydraulic Roller. Duration 290/239. Lobe lift 0.367 – 0.605.

The tech guy at Lunati said the above cams would be 'peaky' on the power curve and somewhat hard on the valve train.

He also said a possiblility would be the 501A6LUN grind. These are the specs.
•Advertised Duration (Int/Exh): 288/296
•Duration @ .050 (Int/Exh): 234/242
•Gross Valve Lift (Int/Exh): .530/.530
•LSA/ICL: 110/104
•Valve Lash (Int/Exh): Hyd/Hyd
•RPM Range: 2500-6500

(Why is selecting a cam such a difficult process!!)

No offense but I just wanna stay with a 383.

Bud.