Cam selection
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
You'd likely have a big fan base here though:
http://forums.corvetteforum.com/engine-mods-7/
Melting Slicks
Joined: Apr 2005
Posts: 2,777
Likes: 105
Sorry to break it to you the L88 cam is not a radical camshaft. The opening and closing ramps are very slow compared to newer camshafts thus allowing the use of lighter valve springs which in turn puts less stress on the camshaft itself. Do a little research and look at the old Chiltons manuals what the specs are on the valve springs that were used back then. They are in the 80-100 lb range at the installed height. Heck the 69 427 430 hp motor has only 116 lbs of spring pressure on the factory dual springs.
In 1967, was the L88 cam not considered to be a radical camshaft?? Zora and The General 
certainly did. .... And for the genre for a 67 BB, it still is.Also, did I say anything about factory springs???
Here are my spring specs that I installed 30+ years ago:
Valve Springs, Triple, 1.550 in. Outside Diameter, 482 lbs./in. Rate.
Do these seem "light" to you?
You are certainly are entitled to your opinion, so please lets not
And again - "The Choice is Yours for Both"
Last edited by babbah; Oct 17, 2013 at 10:23 PM.
Instructor
Joined: Mar 2009
Posts: 156
Likes: 1
That's right, it has more lift, reasonable duration, its a hydraulic roller, and 10.2:1 compression, so it will run on pump gas. It pulls through the entire RPM range to 6200 without slacking up. Even with the stock 390hp cast iron intake and oval port heads, id put this 66 up against an original spec 425hp in the 1/4 mile any day of the week. rpm was around 850 in the video. i can tone it down to 650 and make it shake all over the place without it stalling and i dont have to worry about oil flow to the lobes. 
Just because it makes a big choppy hackity hack sound doesn't mean its got enough power to pull a wet string out of a cat's ****.
Wiped lobes are usually the result of not replacing the cam bearings, poor oil pressure at idle, or one of those comp cam cores that were known for taking dumps at random. Zinc in oil? Not so much, but it's good for conspiracy theories.
That sealed power replacement or crane suggestion would be just fine. If the OP wanted some extra umph, then he ought to say so.
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
The cam in my 66, 427 / 425 hp has wiped a lobe.
The car has been finished for 16 years. I was unaware of the zinc removal issue for some time after the rebuild.
Need some help deciding on a replacement cam. Roller or stock replacement with the proper oil. I here roller solid cams have lifter issued. Tough to tell fact from fiction.
Any help would be apperciated.
The car has been finished for 16 years. I was unaware of the zinc removal issue for some time after the rebuild.
Need some help deciding on a replacement cam. Roller or stock replacement with the proper oil. I here roller solid cams have lifter issued. Tough to tell fact from fiction.
Any help would be apperciated.
Safety Car
Joined: Mar 2009
Posts: 4,191
Likes: 951
From: Corpus Christi, TX
OP:
Yes, solid rollers have lifter issues. If you check with CF members like Hotrod427, the advice is to consider solid lifters to be maintenance items like oil filters. Plan to replace em away every couple of years.
With stock, unported heads, and factory exhaust manifolds, you might get an extra 20 hp out of a decent hydraulic roller cam (which do not have lifter issues). Without better heads and exhaust, more cam isn't going to do a lot of good. You wanna spend close to a grand for a proper roller cam conversion, that's your call. I'm not sure the benefit justifies the cost.
And yeah, for any flat tappet cam other than a 250 HP base model you probably do need oil with ZDDP to avoid wiping cam lobes. This has been well documented. Check "Engine Builder" magazine among other publications.
Lastly, the factory engineers knew what they were doing. Comp Cams among others grind cams with way too close a lobe separation angle for the motor to have decent street manners. Chevy goes the other way: wide LSA for good idle, good low end throttle response and decent top end HP. A blueprint replacement L72 cam will be just fine if everything else under the hood is close to stock.
Yes, solid rollers have lifter issues. If you check with CF members like Hotrod427, the advice is to consider solid lifters to be maintenance items like oil filters. Plan to replace em away every couple of years.
With stock, unported heads, and factory exhaust manifolds, you might get an extra 20 hp out of a decent hydraulic roller cam (which do not have lifter issues). Without better heads and exhaust, more cam isn't going to do a lot of good. You wanna spend close to a grand for a proper roller cam conversion, that's your call. I'm not sure the benefit justifies the cost.
And yeah, for any flat tappet cam other than a 250 HP base model you probably do need oil with ZDDP to avoid wiping cam lobes. This has been well documented. Check "Engine Builder" magazine among other publications.
Lastly, the factory engineers knew what they were doing. Comp Cams among others grind cams with way too close a lobe separation angle for the motor to have decent street manners. Chevy goes the other way: wide LSA for good idle, good low end throttle response and decent top end HP. A blueprint replacement L72 cam will be just fine if everything else under the hood is close to stock.
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
Going hyd roller for for a person who wants max performance and minimal maintenance is the way to go. I have re-cammed many 60's vintage engines that the customer wants that old school sound but the reliability of today.
A mild hyd roller will net you more power under the curve and give you 10's of thousands of worry free driving miles.
A mild hyd roller will net you more power under the curve and give you 10's of thousands of worry free driving miles.
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
OP:
With stock, unported heads, and factory exhaust manifolds, you might get an extra 20 hp out of a decent hydraulic roller cam (which do not have lifter issues). Without better heads and exhaust, more cam isn't going to do a lot of good. You wanna spend close to a grand for a proper roller cam conversion, that's your call. I'm not sure the benefit justifies the cost.
Lastly, the factory engineers knew what they were doing. Comp Cams among others grind cams with way too close a lobe separation angle for the motor to have decent street manners. Chevy goes the other way: wide LSA for good idle, good low end throttle response and decent top end HP. A blueprint replacement L72 cam will be just fine if everything else under the hood is close to stock.
With stock, unported heads, and factory exhaust manifolds, you might get an extra 20 hp out of a decent hydraulic roller cam (which do not have lifter issues). Without better heads and exhaust, more cam isn't going to do a lot of good. You wanna spend close to a grand for a proper roller cam conversion, that's your call. I'm not sure the benefit justifies the cost.
Lastly, the factory engineers knew what they were doing. Comp Cams among others grind cams with way too close a lobe separation angle for the motor to have decent street manners. Chevy goes the other way: wide LSA for good idle, good low end throttle response and decent top end HP. A blueprint replacement L72 cam will be just fine if everything else under the hood is close to stock.
I wondered how much actual power increase a "modern" roller cam provides on an otherwise antique engine architecture. If it's 20, plus/minus a little, that's a believable number to me and not worth the expense to install it.
Of course, you can always spring for the big bucks and go for the whole "system" and get new, modern heads and matching pistons to get the whole package to get the most out of your new "modern" roller profile camshaft. How much does that cost and is it really worth it? On a street driver, more cubes ='s more bang for the buck.
