Im building a 427BBC for a friend and figure there will be some good cam knowledge here.

Weekend only street car may see strip occasionally. 3.5 rear TH400 3500 stall.

Motor is 30 over with small dome srp pistions giving only 10.0 with 118 OC heads. He has 990 heads, I'll get him to try and take a bit off the face to get chamber size down a bit but understand not much can easily be gained here. Dot rods, ARP bolts and pressed pins.
He has an 850 Holley and an older Edelbrock C427X manifold. It had the divider removed. These items are all fixed.

Has some short 1&3/4 headers but we can probably look at something with a longer primary. I think a 2" primary might be too big. He has parts for a 3" system.

Im thinking that running a cam with a narrower lobe separation angle, I can crutch the low compression a bit, but its only a thought. I will recommend lifters with the oiling hole, Ive used Isky versions with success.

I think he can tolerate a rough idle, he already has a race car and a 55 cruiser so this will fit in between these.

 

There are other choices, and it might not be as much cam as you'd prefer, but with "only" ~10:1 CR you might want to take a good look at Comp's Nostalgia Plus N+LS6S Solid FT grind. IMCO, even with this cam, theoretical DCR would look a bit better if you could raise CR to ~10.25:1 (2-3 less cc's)...

"Outstanding power and modern
tight lash with the sound of the GM LS6 cam."
1800 to 6500 RPM
276°/283° adv.
239°/246° @ .050"
.544"/.539"
112° LSA

If you want a more aggressive cam with narrower LSA there's the Nostalgia Plus N+ZL-1, tho I'd recommend getting nearer to ~10.5:1 CR (~5 cc's less chamber)...

"Nostalgia Plus™ version of legendary
ZL-1 camshaft. Modern lobe design makes
this cam better than the original."
3500 to 7000 RPM
299°/309° adv.
262°/272° @ .050"
.581"/.622"
110° LSA

elle88 chose the latter for his recent 427 build, which despite a lowish theoretical DCR still turned out to have a very stout mid-range and top end. Either ought to run OK on pump gas (assuming good carb and ignition tune).

FWIW, every C3 I've owned has had a 427 BB of one sort or another under the hood, including my NOM '78. Have a solid roller, alum head, long-rod one in the works for the SA as we speak.

Bottom line: I'm no expert, but hope that's worth $.02


TSW

 

The cam I run in my 427 is somewhere between the 2 that TheSkunkWorks listed. My torque converter isn't quite as loose as your friend's but it still works great with this cam. Low end torque is plentiful and the power comes on hard from mid-range on up. A good shift point is 6500-6800 RPMs if that helps. It likes to idle at 850 RPMs and that idle grabs plenty of attention when I arrive at local car events. I went with the same lifters you're talking about but mine have the Crower brand on them if I remember right- I think they're all pretty much the same though. Also, I run Hedman headers w/ 2" primary tubes and, as I said before, there's an abundance of torque. If you want the specs that I haven't listed in my sig let me know. The cam should be available through Lunati at this point if you're interested.

 

A real friend does not even think of using anything less than a roller cam

I have owned/driven/built a variety of FT cams over the years and they just don't have the pleasure and drivability of a roller.

Those big nasty solid FT cams are for people wanting all show and no go. They don't run well and the peaky narrow power band just sucks.

You have to remember that you only have 431 or so ci and TQ is what moves the car not some high peak HP figure. My 434 ci motor is a pleasure to drive and it won't be beat by sub 600 hp motors

 

Mornin' George,
We're getting some good snow here at only about 2100 ft. so I'm guessing you're gonna be knee deep in it there before this storm is done.

As for cam choice, not everybody feels that it's worth the extra $$$ to go with a roller cam and that may be the case with his friend- in any case that's a personal choice. His goals aren't clearly stated but given his choice of heads it doesn't look like creating mega power is critical to him.

Only you know what you mean when you talk about big nasty solid FT cams. For me the 2nd cam listed by The SkunkWorks would fall into that category due to the duration numbers and I'm not sure that would be a good choice for street use. However, I mentioned my cam to the OP because his friend's gearing and trans are the same as mine, so I felt I had something to offer. With that overall gearing I can shift my car at 2000 RPMs from 1-2 and 2-3 under light throttle and pull effortlessly to 60 MPH in a few seconds from a stop, or I can nail it and pray for traction even with drag radials out back. I'm not sure I'd call that all show and no go and the powerband is far from peaky or narrow. I have no doubt that, with good hook off the line, it's comfortably an 11 second car in the 1/4 mile.

That being said, if money is not an issue a roller cam with similar specs would create more power for obvious reasons. I'll be interested to hear what the OP has to say.

 

I ran the comp 294 s was a great cam in a similar combo

 

Here is one that makes a good street / strip cam -
Lunati 402A3LUN
Solid, fair idle. Excellent street/bracket racing cam with very strong mid-range and top end torque and horsepower.
Needs 2500 RPM stall converter, 9.5:1 compression ratio and 3.73 gearing.
Advertised Duration (Int/Exh): 276/284
Duration @ .050 (Int/Exh): 243/251
Gross Valve Lift (Int/Exh): .586/.600
LSA/ICL: 110/104
Valve Lash (Int/Exh): .026/.030
RPM Range: 2500-6800
http://www.lunatipower.com/Product.aspx?id=2135&gid=284

 

That's Lunati's iteration of my cam. They got the profile from Harold Brookshire, who owned Ultradyne Cams when I bought it from him. That was right before he had to close his doors and then went to work for Lunati. He told me that his nickname for the cam was "Sleeper" because, although it has a noticeable idle, it runs even harder than the idle would lead you to believe.The only difference I can see without digging out my cam card is that my lash is .026 on both sides.

 

Put a L72 cam in the sucker which is the same for the L71`s and L89...plus a great cam for a turbo 400 and a nice converter......

 

for a solid FT and only 431 ci Crane cams

Good mid range torque and HP, fair idle, moderate
performance usage, bracket racing, auto trans
w/2500+ converter, good w/plate or manifold nitrous
system, 3600-4000 cruise RPM, 10.75 to 12.0 compression
ratio advised.
F-244/3454-2S-14 3400-
6800
131121* 99250-16 244 @.050 114 12 52 .026 .587
252 @.050 64 8 .026 .608

 

Running the same cam, with a 454. 3000rpm converter, 4.56 gear and radial slicks. 7.3X @ 94.X MPH in the 1/8th. Same 990 heads as you are running. Those heads are huge, ever thought of AFR 265 or maybe 290's. The 265 would be awesome on your engine. Ron B.

 

Thanks for all the recommendations.

Yes I know the 990 heads are far from ideal but they came with the engine so will have to make do with them. Smaller port factory heads aren't widely available in Australia, the big heads are what made me think of not going too big on exhaust.

Owner also spoke of a solid roller, to which I said if he had the money he should have spent it on a half inch more stroke. Besides I think his money is a bit tighter at present. Im also a bit loath to recommend a solid roller cam and find he doesn't maintain/watch it.

The Lunatic cam sounds pretty much on the mark, should make decent mid range torque. Plenty of lift and the big spread in intake to exhaust duration should work with factory head.

 

Valid case for solid FT's if your buddy isn't likely to adequaqtely look after the solid roller lifters. FWIW, since my first reply I went back thru Comp's lobe library, and found there are ones available in the Nost+ series which fall between the N+LS6S and N+ZL-1 grinds, with 284* I and 291* E advertised (still likely a bit much with only ~10:1 tho).

The exhaust ports aren't so much the problem, so I'd hesitate to restrict them and go ahead and size headers (as much as is possible) according to the RPMpt curve you'd prefer. IMOE a good way to help make rectangle ports better suited to street duty (read, "maintain higher average port velocity") is to have a quick opening intake lobe profile which doesn't require long duration to put a lot of area under the curve. Lift is your friend.

 

Stay within the boundries of what you have you dont need a big cam, you have no compression and no cylinder head to speak of, your not going to make a lot of HP there anyway, so dont overcam it. .245/.255 at .050 is max with what you have there. that may be too big as well.

 

+1....


You guys need to hit up 427Hotrod on this topic. He has ran and dyno tested a lot of SFTs and knows what makes power.

I think the Lunati that was linked above would be a good suggestion....but y'all need more compression, and an intake that will allow that sucker to spin to 7000 to get the power out...

 

An open chamber oval port head is a good head and can be made to work and make power to 7000 rpm but they need some help. If you had a 781 head head that would be a good place to start.

 

Those heads and those gears/converter aren't going to like each other on a 427. I ran a 427 for 20+ years with oval ports, square ports, closed chamber, open chamber etc etc. Ovals are definitely a plus. I ran the same times with the squares as I did with the ovals *eventually* but it took a move from 4.10's to 4.56's and shifts moving from 6500 to 7500 rpm to make it do it.

The dual plane is a good idea to help those heads and I'd consider adding the divider back in.

That Lunati would do well but I'd consider putting it on a 108 LSA to help those heads. It's not big enough to be too ratty on the street with a tight LSA. It's relatively small overall.

I ran at least 20 of the *old school* cams through it over the years. Probably the best overal flat tappet I ever used in the 427 was the old Crane 256/266 with .580/.600" lift on a 110 LSA. It drove well and never hurt parts. Would rev all day if you wanted to. It's definitely not as aggressive looking on paper....but like many of Crane's cams....it just flat runs well!

Another great cam in it was the old Comp 288 street roller. It was 244/244@.050 with .623/.623 lift on a 110 LSA. It was super nice to drive and made great power. It peaked HP at 5850 but at 7000 rpm was only down like 6 HP. Also held about 14" of vacuum. I know Harold Brookshire has a flat tappet version of it if you call him.

Definitely get the edm lifters to get some oil on the lobes.

JIM

 

Your best bet is to have one custom ground on your specs, with all the info you can give the grinder about your combo. It is only a little more money, and well worth it if swapping a cam anyway. +1 on the EDM lifters, and why not use a 1.8 rocker to get max lift with the .842 lifter or go to a .875 lifter with accompanying ramp rates, if machine work is not done yet.....
Any way you can yank the valves open higher faster is going to help those heads and the compression issue.

 

Jim knows his stuff.. He helped me out picking out the 288AR cam for my BB. I couldn't be much happier with the cam!

Thanks again Jim!

 

You're reminding me of the old mushroom cams I used to run in BB Buicks. You could run some outrageous ramps with those things. Hmmmm. Still have the tool for clearancing the block for them...