OEM heads need a dual pattern camshaft to make good power. Single patterns have their place but not with OEM heads.

 

cstraub
Would one of these work better than the Howards Cam?

Cam and Lifters, Hydraulic Flat Tappet, Advertised Duration 276/286, Lift .500/.500, Chevy, Big Block, Kit

Part Number: SUM-K1301

Cam and Lifters, Hydraulic Flat Tappet, Advertised Duration 286/296, Lift .540/.540, Chevy, Big Block, Kit

Part Number: SUM-K1302

Cam and Lifters, Hydraulic Flat Tappet, Advertised Duration 296/306, Lift .540/.540, Chevy, Big Block, Kit

Part Number: SUM-K1303

 

Dan, assuming here this will be at best a 8.5/1 motor. I would try to stay with a cam with a 110LSA and run it at 106ICL. The cams you listed are all 114LSA. Yes they will work ; yes you can make a better choice. Will be a few more $$$, but Lunati has several cams that would work well. The VooDoo series are very aggressive, short seat timing, but decent lift to net a lot of area under the curve. Don't know the number but the Lunati 231/239, 110LSA hyd flat tappet would work well. JMHO.

 

Lunati 60203

http://www.lunatipower.com/Product.aspx?id=2151&gid=287 L J

 

Dan you don't give us the Pistons or Static Compression. A stock 454 with the 118cc 781 heads yields approx an 8:1 Static Compression. I've run a 266H-10 with this combo which gives approx a 6.7 DCR. The combo will have loads of torque with them 390's short shifting at 5200rpm. You can't go much above 5500 rpm with the Stock 454 Valve train without Roller Rockers or much above 6G's without a Girdle.

If your running the original flat tops then a Closed Chamber head with approx a 100cc chamber would be raise the Static Compression up to approx 9:1 in which case that 266H-10 will give you a 7.5 DCR with a Bigger Bang.

I would recommend a Domed Piston somewhere around a 25.7 to 28cc dome an use the .019" steel Gasket (keeping the quench at .044") to reach 10:1 Static compression and cam with something like a 274/278 H12 with a .552/556" lift to yield an 8:1 DCR . The 112 LSA will promote the Torque Band and with Roller Rockers you can shift at 6000rpm.

If you can get the Static compression up to around 10 to 10.5:1, and want to run a Hydraulic FT Cam, I recommend the Comp Cams XM278H-12 or perhaps Nostalgic Profile for the LS6 Engine with a similar profile.

 

Dan you don't give us the Pistons or Static Compression. A stock 454 with the 118cc 781 heads yields approx an 8:1 Static Compression. I've run a 266H-10 with this combo which gives approx a 6.7 DCR. The combo will have loads of torque with them 390's short shifting at 5200rpm. You can't go much above 5500 rpm with the Stock 454 Valve train without Roller Rockers or much above 6G's without a Girdle.


If your running the original flat tops then a Closed Chamber head with approx a 100cc chamber would be raise the Static Compression up to approx 9:1 in which case that 266H-10 will give you a 7.5 DCR with a Bigger Bang.

I would recommend a Domed Piston somewhere around a 25.7 to 28cc dome an use the .019" steel Gasket (keeping the quench at .044") to reach 10:1 Static compression and cam with something like a 274/278 H12 with a .552/556" lift to yield an 8:1 DCR . The 112 LSA will promote the Torque Band and with Roller Rockers you can shift at 6000rpm.

Z15
You have some good info in your post:thumbsup:...but some not so good.:sad:
The stock valvetrain will go way above 5000 without roller rockers and way above 6000 without a stud girdle:yes:.....

Limiting the stock 77 engine is a lame cam profile and weak springs....both easily corrected. The pancake intake and emission calibrated Q-Jet didn't help either. Over 7000 rpm, big roller territory....stud girdle time.

 

I don't know if you have concidered it but roller cams sure are nice. Cost more also. I had a cam wipe out and now just don't trust flat tappet or solid lift anymore. sure run oil additives or a specific brand of oil but most oil companys are now making oil for roller cams due to almost all factory set ups are roller now. mark

 

Dans54,

I put some 1968 closed chamber heads on my 1977 shortblock, have 8.8:1 CR.
I run a modest Crane 282H-08, now a Summit grind. 226/226* .533/.533" 108 LSA.
800DP, vintage Eddy C396QJ intake, HEI w/MSD, 3000 B&M..whopping 3.42 gears. Shifting at 5100 rpms for the best times... 1.70 60' 8.03 1/8 12.7 1/4 @ nearly 106 mph. More possible this year but I have a better engine coming together. A lot of the performance was due to the DRs and getting the car to launch and figuring out the shift points. Think I made 7 strip outings in 2009 when it was a new combo. This is a daily driver mild combo...just a tad too expensive to drive daily.

I would not go too aggressive on the duration due to the mild compression (probably 7.9 to 8.1:1 CR). Thing is your 3.90 gears are kinda demanding a bit more duration...

Chris mr 4 speed has a pal running bottom 13s. His engine is much like yours in a 69 Chevelle, with the 238/248 Summit cam. Waiting for some passes with his new torque converter for a more Apples to Apples performance comparison. 3.42 gearing.

Going from a 2500 stall to the B&M 3000 cut an instant 2/10s off my Elky's times so expect something like this from that Chevelle. My 2500 didn't quite deliver 2500 and my 3000 converter flashes to 3400!!!! So an extra 1000 rpm at the launch is a huge torque output and multiplication difference! Get to know a tire distributor.

Some other guys run pretty strong with 'stock 1977' engines with cam and basic bolt ons. Just remember, huge gains in performance if in a lighter vehicle.

 

The stock valvetrain will go way above 5000 without roller rockers and way above 6000 without a stud girdle

Did I say anything different - Yes it can go a tad over 6000rpm with the Stock Valve train providing you have quality Roller Rockers; other words, you are taking chance to on Braking Rockers, Studs, Springs throwing lifters. Been there did that. If your so inclined but better keep a spare assembly in the Glove Box to change valve train components out between lights; but you're going to do what your going to do anyway ;o)

I recommend a Girdle for anything above 6300rpm in a BBC as at that point you're into Fast Ramp SR with .660" lifts on the street and might hit 7000rpm which cost considerable more - which I don't think Dan is prepared to spend.

Note that George and I, have similar recommendations for a Cheap FUN and dependable 454 that you can bolt on a 750Dp/Edelbrock RPM and blast around in forever in a day.

If he's going to run the Stock 8:1 Static run a 266 or 268H-10 HFT. If he ups the Static to 10:1 run a 278H-12 - it's not that complicated.

I was pointing out the significance of Static Compression Vs DCR Vs Cam Selection within a realistic RPM Range that a Stock 454 can CONSERVATIVELY handle.

Siish! My 10.25 Static 460ci SR MK IV will hit 7000rpm putting out over 600Hp on Pump Gas but I got considerable more money tied up in the mill but I really can't say that it is all that more fun to drive that 425Hp 8:1 with the 266H-10 Combo, which had considerably more torque off idle. Both engines put out MAX power within the same 4000 RPM limits - one from 1800 to 5800rpm and the other between say 2800 to 6800rpm.

I did not say to short shift at 5000rpm. I said 5200rpm and by the time you shift the tech will hit 5500rpm and lucky to get it in by 6000rpm after which it's touch and go with the stock Valve Train.

 

Yes it can go a tad over 6000rpm with the Stock Valve train providing you have quality Roller Rockers; other words, you are taking chance to on Braking Rockers, Studs, Springs throwing lifters. Been there did that. If you so inclined better keep a spare assembly in the Glove Box. If you don't mind changing Valve train components out between lights do what your going to do ;o)

I recommend a Std Girdle for anything above 6300rpm in a BBC.

Not sure what you were running, individual results vary....but you are being very conservative. Magazine articles pump equipment to get people to buy the latest gee whiz stuff....guys adding a buncha crap they don't need to go fast or last a long time. Roller rockers do have their benefits, especially in the more extreme applications....far above what you are talking about.

Run the right spring, long slot rockers, right clearances....I must have been lucky the last 15 summers with my 427 and 6500+. This is sane. I recall many times north of 7000 rpm in my pal's LS-7 powered Chevelle. My 68 Nova with the L-88 valvetrain saw 7000 lots of times....think NOTHING at all of the L-88 road Race Vettes....all afternoon abusing the engines...Stamped Rockers, factory HD stuff.

For the purpose of the original poster's build, way unnecessary to bring stud girdles up. The roller rockers would be 'luxury items' here. JMHO

 

Dan: I can say I've had a stock 283 at 8G; but it doesn't mean it lived long.

One thing important is the condition of them 781's relative to Guides, Valves and Seats, which is expensive considering to days machining cost. I would consider 5/16" guides over the 3/8's to lighten the assembly and put in 2.19/1.9 valves as it is easier for the machinists to install the larger Valves at the OEM Specs into worn seats.

New Springs are essential. The CC 924-16's are a good choice installed at the STK 1.88" height for HFT Cams and use the Crane Exhaust Rotator Eliminator. The CC 10 degree Steel Retainers and Keepers are excellent and about the most reasonable priced items on the market. Lash Caps will keep the end of the Valve tips from mushrooming and suggest either the CC Pro Mag or Harland Sharp Roller Rockers with ARP Studs and Poly Locks. With this setup and say the 268H-10 in an 8:1 Static 454 you will have no problems if you accidentally over-rev and can use the advantage to blow by those claiming the STK Valve train is dependable over 6000rpm ;o)

You should have no issues pushing 6500rpm with 2 Bolt Mains, Cast Crank, Stock Rods and Hyper-Pistons but would not keep it there. Besides that 268H-10 will run out by then but if you ever decide to up the Static with Domed Pistons them 781's will do the job with a XM278H-12 HFT cam. A Holley 750Dp/Edelbrock RPM will handle either.

All I can do is suggest something based on my experience whether you take the advice is up to you providing you can afford it. In the long run it's all about FUN and appreciating the sport.

 

The combo will have loads of torque with them 390's short shifting at 5200rpm. You can't go much above 5500 rpm with the Stock 454 Valve train without Roller Rockers or much above 6G's without a Girdle.

I have never had valve train issues following your guidelines. Heaven forbid I turn 7k without a stud girdle 4 yrs later, 1100 passes on Crower lifters, 2 yrs with .708 lift cam, no stud girdle.....when will this valve train quit on me?

 

I have never had valve train issues following your guidelines.

Apparently you're more into the Drag Strip where the engine runs for a couple of minutes and perhaps no more then 11 seconds under WOT as I'm into Road Racing where the engine is keep at Hi-Revs and in the Power Band for extended periods. My ride is also my Daily Driver and would never consider more then a .660 lift considering the mileage I put on the engine.

I would say it depends what you want - Do you want a Strip TOY or a Car for Transportation?

I use figures approx 500rpm below what I consider safe for a Stock OEM 8:1 Cast Crank 454. The BBC revs FAST and by the time you shift that 500rpm is long gone.

 

Street legal strip toy to you

 

Hey Bob: Using STK Rockers with that .702 lift and Hi-Spring Pressure with your SR, I bet you can't pull the Valves out of the Guides without filing off mushroomed tips and have pity on the guides. You must be running +.100" Valves.

By the way I run CROWER HIPPO's too, 2.19/1.9 Manley Sever Duty Valves, Pro Mag Rockers, Jomar Gridle and Donovan Cam Gear Drive, NASCAR Holley 830 Dp/RPM Air Gap over 781's. After 6 years on the road the Lash has remained stable and I can't count the number of times I've been over 6G' or hitting 7. I've run the AR288-10 CAST Core no issues with 933 Springs in that period but looking forward to running the LUN-502A1LUN to broaden my torque for this summer. M21 to 3:31's. I find the 288AR a little too late coming on and a somewhat explosive - Plus - I will feel a more secure with the Billet and likely run a little more Spring - LOL

 

I've run the AR288-10 CAST Core no issues with 933 Springs in that period but looking forward to running the LUN-502A1LUN to broaden my torque for this summer. M21 to 3:31's. I find the 288AR a little too late coming on and a somewhat explosive - Plus - I will feel a more secure with the Billet and likely run a little more Spring - LOL

Wondering what your combo is with the 288AR?

 

From my experience the 288AR-10 is an excellent Street Strip Cam for a Mid Cubic Inch BBC with Static Compression between 9.5 to 10.5 even with 3.08's (Lower Gears obviously better for the Street /Strip application) with either a M20 or Automatic; however, I run the M21 to 3:31's and that tall 1st gear is a little doggy around town and to launched below 30mph you really have to feather and light up if you want to move out. It is probably more suitable for 3.42's and lower gears. I love the M21/3.31's when it comes to HWY and Road Race Performance. The 288AR-10 just doesn't seem to have the low end I'm looking for (late coming on) and doesn't have the constant torque I require to make smooth shifts on a Road Course (too explosive in a drift). I believe the LUN-502A1LUN with the shorter Intake and Longer Exhaust Duration and with that 112LSA will broaden the Torque Curve and give the throttle response I'm after for my application.

The 288AR Grind can be ordered on a Billet but I see no problem with the Cast Core as long as you don't go under 170 Lbs on the seat and don't push the 200/500 lb limit (Hence the 933's installed at the 1.88" stock height). I believe CC originally recommended the 929 Springs with 148lb on the Seat for the 288AR which in my opinion was too low and responsible for the flaking reports. The cam likes to rev and very easy on the valve train. Obviously you can run Higher then 200/500 on the Billet and not think twice approaching 7G's.

I ran the XM278H-12 with 925 Springs and really liked that cam - tons of torque and great throttle response right through the RPM Scale and makes me wonder why I went SR. I got to say that Extreme Marine Grind had to have one of the Best Sounding Exhaust Notes I've heard - Just Down Right MEAN - LOL.

 

I have that cam on a billet core. Was just wondering about your experiences with it. What size engine did you run it in? 454?

 

Rich: 454+.030" = 460. If you read my previous posting in this thread I think you will get the drift of what I believe the 288AR performs like in a Strong Engine - Great Cam in my opinion for 9.5 to 10.5 Static M20 or Auto with 3.42 and lower gears. I would imagine 3.73's and a M20 or Auto (Possibly 4:10's with a M21) would be about ideal for the Strip running 250/550 springs on the Billet.

It will cruise at between 2200 to 2500 rpm without complaining and doesn't seem to cork all the way to 7G with 2.19/1.9 781 heads. I just find there's not enough torque on the low end and it's a little too squirrel in the mid range for my application running the M21 and 3.31's through a Road Course; other words, explosive and more suited for Street/Strip application.

 

Interesting observation on the 288AR single pattern cam. Basically, what ISKY has to say.

 

Well for one thing, for my application, the 288AR-10 likes WOT at the expense of Road Manners and Traction.

Did I mention that I run BF T/A P295 N50 15's on the rear which is a 28" Tire through a M21 to 3:31 12 Bolt Posi powered by a 7000rpm 600Hp SR 460ci MK IV LS4.

Here's my ride, a 70Z Chassis:

Not a Drag Racer or Trailer Queen but an 11 sec Cambrian Shield Road Warrior.