When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So I am pulling the motor soon and have been looking at cam options, I would like to say I am not the most experienced when it comes to cams.
I came across the Lunati BareBones Hydraulic Roller Retro-Fit Camshaft Complete Kit Chevy Small Block Non-Roller Lift: .503" /.503".
The specs are
Lift: .503''/.503''
Duration: 276 Deg / 286 Deg
LSA: 112 Deg
RPM Range: 1800-5800
I want to know if this will fit my 1976 Corvette, and what do I need to expect when it comes to horsepower.
The kit has springs, valve seals, retainer clips, rollers, and timing chain and a sprocket.
My next question is, would this be a good driver cam?
Are you changing anything else with the motor?
heads or pistons?
really to get the best bang for your buck for camshafts the whole combo has to work together.
stock heads are 76cc if I remember right, and the pistons are dished. In actuality probably less than the advertised 8.5:1 CR.
I was planning on keeping it a lower budget build. The plan was fix all seals and do a cam and put it back in the car but do you recommend changing heads?
You could replace all seals and install a cam without ever pulling the engine out of the car.
but you wish to pull it out anyway.
Your car.
New cam with dished pistons and horrible stock heads = mild cam.
Flat top pistons and 64cc heads will bring you into 10 - 1 compression territory. Now you can add some cam. You will need to recurve your distributor and rejet your carb.
budget build??
Put on some headers, recurve your distributor and skip the cam. ALL gaskets and seals can be replaced without removing the engine.
Comp 268H Cam and Lifter set, 9-1100 Cloyes Timing chain, Comp Magnum roller tip rockers, one piece pushrods, 2101 Edelbrock Performer, Fel Pro 1204 Intake Gaskets, Q-Jet electric choke conversion, Long Tube headers, dual 2.5" exhaust......and a good curve in the distributor with proper performance timing settings.......you cannot do much more until you buy heads....
Stock compression on my 77 worked out to 7.6:1 to 7.8:1 CR. You just can't get much cam with that compression.
Here is the dyno for that cam. https://www.compcams.com/xe262h
You will NOT get those results due to your heads and CR currently. However that cam will retain some of your low end and midrange torque for good street operation. Don't fall into the trap of top end power numbers unless you plan on being there all the time. Street driving is likely what you're looking for.
For under $1000 you could find some vortec heads and a compatible performance intake, use a steel shim head gasket, and get 9-9.5 to 1 compression. the vortec heads flow well for street use and would go well with the recommended 268H cam.
From: At my Bar drinking and wrenching in Lafayette Colorado
The problem with most of the CompCams cams is that they are ground on a very tight LSA (110 degrees). This tends to produce poor idle vacuum and idle tuning capabilities in a low compression engine, and is more intended to induce that "cammed engine sound" with little benefit to performance in the low-flow, low compression engine. If you note, all the factory performance cams run LSA up around 114 degrees, for good reason.
For comparison, the factory L82 cam is actually a very good unit. It's the same as the 350-horse L46 cam. Its specs are as follows:
Duration @ .050: 222/222
Lift: .450/.460
LSA: 114 degrees
The CompCams 268H specs out as follows:
Duration @ .050: 218/218
Lift: .469/.469
LSA: 110 degrees
You can see that these cams are very close to the factory L82/L46 cam specs, but have the disadvantage of the 110 LSA. If I were you, on your otherwise stock, low-flow, low compression engine, I'd seriously consider running the factory-spec L82 cam. You will have good performance (that cam produced 350 hp in the L46), ease of carb & timing tuning, and good manifold vacuum for your power brakes. The 110 LSA can work on a higher compression engine, but on a low comp engine, it's going to bleed off what precious little compression you have... so I'd keep that angle wide if I were you.
Lars
The 110 LSA can work on a higher compression engine, but on a low comp engine, it's going to bleed off what precious little compression you have... so I'd keep that angle wide if I were you.
I think you have that backwards Lars.... The Narrow LSA cams usually have an intake centerline of around 104-106 which is a few degrees earlier than the wider LSA cams. This allows the intake valve to close sooner which builds compression earlier in the cycle. The wider LSA's close it later so they are at a disadvantage for building compression.
Most all GM engines with wide LSA cams have compressions ranging from 9.0 to 11.0 and this compensates for the later closing intake valve.
I was able to get cranking my 350's compression up to 180 PSI using vortec heads, steel shim head gaskets, 106 LSA with a short 235@50 cam. This was a short track car not a street car...
From: At my Bar drinking and wrenching in Lafayette Colorado
As you note, narrow-LSA cams work great for short-track race cars and some racing applications. Not much so for the street in a mild near-stock engine. The Thump-Yo-***** cams are a perfect example of that. I have a lot of dyno data to back that up, as does Cliff Ruggles. But to each his own...
Lars
What is the advertised duration on the stock 222/222 L-82 cam? I'd bet it's a lot more than 270*. I've read it's in the range of 292*-288*. Can't confirm it, but sounds likely given the era.
I followed what Lars and SWCDUKE have stated and recommend on the forum for my original numbers matching 1970 L46 rebuild. The motor produces 17” of vacuum at 750 rpm’s, while pulling strong to 6K redline. The motor produced 410 lb ft of torque on an engine dyno, I know after the dyno results, I had Henry Olsen tuned the motor in the car and that tuneup definitely added some more numbers in the torque beyond the dyno results.
This is the cam card from a Speed Pro L46 camshaft.
Camming the 76
