The more I read about cams, the dizzier I get! If you do go with roller rockers, the cam should be designed to work with them.....Some cams, like the Comp extreme energy series, have very fast opening/closing rates that would be amplified by using the high-ratio roller rockers.... That can be hard on the valvetrain unless very good valve springs and lighter components are used to keep them in control. TA has roller cams, but some have voiced concerns on the weight and valve spring issues. It's a tough subject as there haven't been any published cam-comparison tests done.
For a 4500 lb Riviera you want monster torque from 2000 to 5000 rpm. This is also the range best suited for the stock intake manifold. In order to accomplish a very wide power band the cam profile needs to be a moderate duration with high lift. Because of the higher ramp rate, a roller cam would be best. The head port work determines the effective maximum valve lift but expect a lift around .500" If the car is going to see mainly street miles then I wouldn't go past .500 for the sake of longevity. For a wide power band it would be good to keep a 10 degree spread between intake and exhaust durations. This helps scavenge the exhaust at higher rpm and extends the power on the upper end. The intake duration should be around 220 degrees and the exhaust around 230. A 110 degree LSA will support the low to midrange end of the power band and with the above durations the overlap is 5 degrees for a moderate idle, plenty of manifold vacuum for power brakes and reasonable gas mileage. If the advertised duration ends up being around 280 degrees and the cam is installed 4 degrees advanced, the dynamic compression will be under 7.5:1 if you have a 9:1 static compression ratio. No problems with pump gas. I hope this helps as you work your way through the many threads on camshafts. Paul This is a case where the engine is just begging for a few pounds of boost from turbo or a supercharger.
I think Paul has spec'd out a very good cam for you. The Nailhead likes a split duration grind, presumably because of the poor flowing heads. Something close to what he suggested would work really well.
I just got this cam, will be installing it in the summer maybe. I have to buy some more stuff to make it all at once...... Oh and dyno test before changes:3gears:
Paul, thats real close to my 218 xfi intake 230 extreme energy exhaust on a 110 LSA with 108 centerline [2 degrees advanced]. shifting at 5300 rpm[you dont need to rev high to make power and at 5300 rpms the engine should last forever] with a 2 speed and 323 gears gave me a 12.8 et at 107 mph. but thats with a 425 ci and a skylark. yes you have the 3- speed to help off the line.but you will have a 401 ci and 800-900 lbs more weight. heres one 216 xfi intake 224 extreme energy on a 110 LSA if you want a little more vacuum go with a 111 LSA. keep it at least 9.5 and no more than 9.75 comp ratio.
Quick update to my plan... I have been reading up on cam selection and been discussing options with CompCams tech support. I was feeding CompCams with some of the information I was finding on this site which included providing them with the specs for Joe's (GSGTX) cam. Interestingly, they recommended I run the same cam. After further discussion about the differences between my car and Joe's (weight, cubic inches, trans and converter) they concluded that this cam would still be their recommendation. So, it looks like I will be running the following cam: duaration 218 intake - 230 exhaust @ .050" duaration 262 intake - 280 exhaust @ .006" lift 504 intake - 490 exhaust with 1.6 ratio rockers 110 LSA (108 intake centerline) Now, I just need to get over my block issues (sleeve and a couple of thin spots in the cylinder walls; see my other thread: http://www.v8buick.com/showthread.php?240889-Block-Inspection/page2) and I can get going with this build Thanks
That cam will work really well for your car If you keep the compression ratio right at 9:1, the dynamic compression ratio will be at 7.5:1 and you will not have a problem with pump gas. Paul
i never said not too.where did you read that? 9.5-9.75 is good. in a lighter skylark you can go 9.75- 10
Paul, with a nailhead you can you can run higher comp. because of the heads, and they dont need a lot of timing. thats what the guys[old timers on the forum lol] always say. there were right never had any pinging.9.8 with the old engine and 10.1 with the new engine with a little bigger cam 224 at .050 on the intake. on high test gas 92
HI. This is Alan in Los Angeles. I am not a mechanic, but this is what I did to my '63 Riviera, 401 Rebuild. Forged Pistons by Ross. '65 Crankshaft. Stock Rods. ARP bolts. Rotating Assembly Balanced. Roller Cam/Roller Lifters/Roller Rockers from TA. Heads Ported & Polished by Mike Lewis at Protech in Fresno. (rec: by Russ Martin in Grass Valley,CA.) $2000 for Heads. '65 Factory Dual Quad Intake. 2 Edelbrock 650 cfm Thunder Series Carbs. I left stock Exhaust Manifolds but Intake & Exhaust are Port Matched. '65 Switch Pitch st400 Tranny rebuilt with Shift Kit. Car is non A/C. 3.23 Gears. 2 1/2 " Exhaust. Magnaflow Muffler. The performance is wonderful. Better than I expected. Its a Hot Rod Riviera but thats what I wanted. I did have some Cooling problems sitting in Traffic so added a Pusher Electric Fan, and that solved it. Larry Daisey, Russel Martin, Tom Telesco, Mike Lewis all very helpful and I'm very grateful to them. Good Luck !
Trying to get going again on my build. The block is at the machine shop getting a sleeve installed in one cylinder. I put together a plan with all of the parts and machining (see attached). I added a column for part costs (kinda sorry I did) just to see how bad it would look. Still need to find some prices on a few items and I need a recommended source for the following: 1) Screw in oil galley plugs - looking for ones that won't interfere with oil flow 2) Head bolts - hoping to find new bolts to match the originals with the extra thread to mount the accessory brackets 3) Pushrods - any upgraded pushrods available? Anyone know the length of to stock pushrod? Do I need to gather up all my parts and measure before I order pushrods? The rockers I will be using are adjustable, so I assume I can set geometry with the rocker instead of adjustable pushrod I also printed out the custom piston order forms for both JE and Diamond to see what information I need to have the pistons manufactured. Looks like I will need some assistance on this. I know some of the information I will need to wait for the machine shop (i.e. deck height), but some of the information is above my understanding (previously I have only used off the shelf pistons). I will take a pass through both forms and post up later for assistance. I have heard good recommendations for both vendors, so my plan is to get quotes from both a pick the cheapest. Thanks Doug
you need your deck height and your head cc to get the right pin height. and also to tell them the right dome cc for your comp.also the pushrods have to be measured at last. the rocker arms do not make up for the geomerty
Kinda late to comment on the cam but thought I might comment anyway. Iam now driveing the cam you are getting. I have Joes short block. It has plenty of TQ. Pulls strong. I am still doing some tuneing but as of right now, Joe is right its a very good street cam. Also I put power disc brakes on my car and it stops on a dime while idleing through a parking lot.
if you know how much the pistons were down in the hole before you tore it down you can do your deck .height. there about .050-.058 in the hole to start with
Bob, thanks for the comments on the cam. I am actually buying the heads from that short block you bought, from Joe. Quick update.... Looks like my build will be delayed for a while, as I need to find a new block. We needed to sleeve one cylinder in the block. Spoke to the machine shop this morning and they let me know that the bottom of the cylinder broke as they were installing the sleeve. Since my goal to keep the numbers matching engine is no longer possible, I am going to see if I can find a buildable 425 block, to gain a few extra inches. Good news is that I the only parts I have purchased at this point are a set of heads and the cam and lifters, which I can use on the next block. Anyone know of a rebuildable 425 block for sale;preferably something that has not already been bored and doesn't need a sleeve.
