Everybody has got me convinced to yank out the Comp XE284 cam from my 402 big block and go with a solid flat tappet.

Looking at Comp's selections I'm debating on a few:

XS268S 1600-6000 rpm band, .553/.568 lift, 230/236 dur @ .050
XS274S 2000-6400 rpm band, .568/.578 lift, 236/242 dur @ .050

What I'm working with is a 402 with a .030 bore, 290 oval ports with 2.06/1.72 valves, stock deck height with (I think) a .039 gasket, .180 dome Speed Pro pistons, 1.7 rockers, RPM intake with 750 Holley, TH350 with 3000 stall, 4.10's out the back pushing a 3620 lb car (with a 185 lb driver :D) I do have power brakes as well as 1.75 primary headers thru a 2.5 inch exaust.

I'm going to guess the XS268S would be the best cam but what about the XS274S? Would either have enough vacuum for the brakes?

I'd also like to know what type of Lunati solid cams would work?

My car is street and strip use.

Also what kind of power gains are to be had going from a hydraulic to a solid lifter cam?

Take a look at the Lunati 402A2Lun:

New Street/Strip Chevrolet Big Block (1967 – Present) Solid; Fair idle. Very responsive high performance street cam. Needs 2500 RPM stall converter, headers, 9:1–10:1 compression ratio and 3.55 gearing or better.

Advertised Duration IN/EX: 272/282
Duration @.050 IN/EX: 238/248
Gross Valve Lift IN/EX: .550"/.570"
Lobe Sep Angle / Intake Ctr Line: 112/106
Valve Lash IN/EX: .020"/.022"
RPM Range: 2400-6800

Or if you really feeling froggy the 402A3Lun:

New Street/Strip Chevrolet Big Block (1967 – Present) 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 IN/EX: 276/284
Duration @.050 IN/EX: 243/251
Gross Valve Lift IN/EX: .586"/.600"
Lobe Sep Angle / Intake Ctr Line: 110/104
Valve Lash IN/EX: .026"/.030"
RPM Range: 2500-6800

You will make power in all areas of the rpm range with a solid over a hydraulic. Just ensure that you have good poly locks and a stud girdle, that way you don't have to worry about adjustling lash all of the time.

Sorry to sound ignorant but what are polylocks? Those aren't those locking rocker arm holders are they?

Wouldn't either of those two cams be too big for my application? Would either of them provide any good vacuum to run my power brakes?

Also where did you get your solid Lunati from? I just checked Summit and it seems the only solid flat tappet cams they carry for big blocks are by comp and crane.

Dawg...call Lunati and speak with Steve...you can order direct from them, and they will have a much better selection. I would much prefer the Lunati over Comp...but that's just my personal preference. And yes, poly locks are the locking type of rocker nuts...you will need them. I only adjust my solid cam once a season, and it's been right on at that. John

Dawg,

Yes, they are locking rocker arm nuts. Don't skimp out and buy cheap ones, get good ones with a stud girdle in the event a locking nut decides it does not want to stay put. the stud girdle will still keep the nut in place.

You definitly want to order from Lunati, I had to in order to get my 402A7Lun and not wait 2-4 months. ???? Steve's number is 662-892-1526.

Go to the Holley website, www.holley.com . The 402AXXX BBC and 401AXXX SBC is UDHarold's designs from Ultradyne. Lunati incorporated them in their line up while he was there.

No, those cams would not be too big for your application, in my opinion. The seat to seat timing is still conservative, just the .050 timing is out there, but that just means it has fast ramps, creating faster valve movement and creating more swirl in the chamber and more vacuum.

I have a 401A6Lun in my 350 SBC, still runs my power brakes, has an awesome idle, and power all over the place. After you look at the specs, you will ask yourself if it is not too much cam for a 350 and power brakes, but it is not. I would not go any bigger though for my 350.

Advertised Duration IN/EX: 276/284
Duration @.050 IN/EX: 243/251
Gross Valve Lift IN/EX: .518"/.530"
Lobe Sep Angle / Intake Ctr Line: 110/104
Valve Lash IN/EX: .026"/.026"
RPM Range: 2500-6800

Cool, thanx I will look into that....one thing though....if I run a stud girldle would I need the tall valve convers for clearance?

I don't suppose Lunaiti makes any of the Voo Doo cams in a solid flat tappet do they?

Also they say the power range on those cams starts at 2400/2500, yet they tell you to have a 2500 stall....technicly if the power range starts at 2500 wouldn't they normally tell you to run a converter that stalls 500 rpms "inside" the range? Or do they figure big blocks make so much torque a 2500 stall would most likely act as a 3000 stall?

Yes you will need the tall valve covers for clearance.

HERE (http://www.holley.com/types/Chevy_Voodoo_Cams.asp) is the link to the Voodoo line of Lunati. You will see the solid ft at the end of the list.

Those recommendations are actually that, general suggestions. If you are not on the money with your specs, don't sweat it.

My cam for my SBC says 10:1 compression and 2500 stall, I only have 9.6:1 and 2200 stall (have new 2400-2800 converter on the way), and it still runs awesome. It has been run on an SBC 350 with as low as 9.2-1 making 430 BHP at 6200. So I would not worry about it. This info I got from Harold directly.

Hhhmmm......all of the solid lifter cams listed on that page were rollers and not flat tappets....unless it's worth the hassle and $$ to go solid roller.

The tall valve cover thing might be a bit of an issue...I tried running a set of tall valve covers once before (for looks) and the master cylinder interfered with me getting the driver side cover on.

Perhapsn I can run just the poly locks and skip the girdles? Or is that a bad idea?

Hey Dawg
you can also go with a smaller master
I had to do that and the vac is still very good

Sorry, I missed the flat tappet request. Just go with the 402AxLun series. As you can see from the specs, they have aggressive ramps themselves, still designed by Harold himself.

I went with a 9" booster to clear the tallest valve covers. My tall cheapo valve covers cleared the standard 11" booster no problem, but I do not know if they will clear a girdle. You can run the poly locks by themselves if you would like, it is just extra insurance with the girdle that is all. THESE (http://cgi.ebay.com/ebaymotors/BB-CHEVY-TALL-CHROME-VALVE-COVERS-BBC-IMPALA-CHEVELLE_W0QQitemZ120033585467QQihZ002QQcategoryZ3 4202QQrdZ1QQcmdZViewItem) covers clear the poly locks and I was able to keep my standard 11" booster.

This is on a 69 Chevelle SS.

Have you got the flow numbers on the heads? What is your max rpm you want to turn?

No flow numbers off the heads, though I did see somewhere the heads I have flow past .600 lift. Everyone has informed me to keep the lift around the .550 mark. As far as RPM's I was thinking 6000-6500 max. At min I'd say 1800-2000.

Not sure what size brake booster you have....mine is the stock one that came with the car....which used to be a 4 wheel drum set up.

I put some more thought into it this morning....and I'm now considering a roller solid lifter cam......any thoughts/inputs on this? :D

I thru out my comp cam (flat power range)
I like my crane cam.

and I'm now considering a roller solid lifter cam.:hurray: :hurray: You can still stay with Lunati....they have a very nice line of solid rollers...or do what I did. Harold custom ground a solid roller for me. Im extremely happy with it. Give him a call at 662-301-1245. John

I run a comp solid roller in my 410 BBC.
Open chamber truck ovals with 2.19/1.72 valves
10/1 compression, airgap rpm, 750 dp.
Grind #CB 4873B/4875B R 113

Specs:
at .015 273/285
at .050 236/248
lift .640/.654
LSA 113
ICA 108

I have a 700R4 with 2400 stall Idles with 12"hg in gear at 700 RPM.
Should run your brakes.
Made 390 to the wheels, ET/MPH in the sig.

Solid roller for a street driven car I would consider the following:

Pressure fed roller lifters. Idling around town is a killer on roller lifters. The pressure fed design puts oil directly to the needle bearings helping to cushion the pounding they take at low rpm.

Cast gear compatiable core. This way you can run your distributor gear you have and not go to a bronze gear.

Competition Cams Xtreme solid roller cam XR274R(236/242 @.050, .639/.646 lift, 108 LSA), and Crane vertical bar lifters. Make sure to have it custom ground on a billet core as the off the shelf grinds are on cast cores. And tell them you want it on a core that will allow you to use your stock distributer gear. No biggy though if you have to swap out the gear with a bronze gear.

I have the exact same combo that you have as far as pistons, intake, carb, and compression. This cam gives 13-14" of vacuum at idle around 1000 rpm's. I have never messed with power brakes so I have no idea what you need as far as vacuum goes for that.

The good thing about these comp xtreme rollers are you can go bigger and keep good vacuum since the ramp profiles are more aggressive.

Forget about the stud girdle. Waste of money and a big hastle for no reason with this cam/spring pressure/RPM level. Run the right spring and poly locks and you will be fine.

chvl71402- What pistons are you running with those open chamber heads?

Forget about the stud girdle. Waste of money and a big hastle for no reason with this cam/spring pressure/RPM level. Run the right spring and poly locks and you will be fine.

Chad,

What springs (specs) are you running?

I'm considering on my next rebuild to try the Comp XR286 (on a billet core) and was wondering what kind of specs these XE cams need.

I originally ran the Comp 939 spring which is 161 lbs at 1.90" and 418 lbs at 1.350" and a 468 rate. I ran that spring for 2 years. I then stepped up to the Comp 933 spring which is 176 lbs at 1.95" and 494 at 1.30" with a 490 rate. These have been on for 2 years now as well, and will likely be replaced this winter with 933's again.

Hey! I was taking a look at the Lunaiti Voo Doo solid roller cams for big blocks, and here's a couple I'd like to inquire about:

-----------------------------------------------------------------------

Part #: 60230

Solid Roller; Lopey idle, Good high performance street cam with good mid range torque and horsepower in smaller 396–402 cubic inch engines. Needs 2500 RPM stall converter, headers, 9.1 compression ratio and 3.55 rear gears ratio.

Advertised Duration IN/EX: 261/267
Duration @ .050 IN/EX: 231/237
Gross Valve Lift IN/EX: .629"/.639"
LSA / ICL: 110/106
Valve Lash IN/EX: 018/018
RPM Range: 2500-6400

Part #: 60231

Solid Roller; Rough idle, Good cam for high performance street or mild strip applications. Needs 2500–2800 RPM stall speed converter, headers, 9.5:1 compression ratio and 3.73 rear gears. Great cam for powertouring applications.

Advertised Duration IN/EX: 267/273
Duration @ .050 IN/EX: 237/243
Gross Valve Lift IN/EX: .639"/.655"
LSA / ICL: 110/106
Valve Lash IN/EX: 018/018
RPM Range: 2500-6600


Part #: 60232

Solid Roller; Rough idle, Good cam for street/strip applications in 396–427 cubic inch engines. Excellent mid range torque and horsepower. Needs 2800–3000 RPM stall speed converter, 10.1 compression ratio, headers and 3.90 rear gears.

Advertised Duration IN/EX: 273/279
Duration @ .050 IN/EX: 243/249
Gross Valve Lift IN/EX: .655"/.663"
LSA / ICL: 110/106
Valve Lash IN/EX: 018/018
RPM Range: 2600-6800-----------------------------------------------------------------------

Now I am new to the solid roller world....a little experienced in the hyd. flat tappet world....and as a hyd. flat tappet most of those cams would be rather large....but I am wondering if on a roller cam if numbers like mentioned above would be considered rather tame?

It was also brought to my attention on engines such as mine(which is fitted with Speed Pro .180 domes) that I can't run over a .500 lift....of course that can't be true seeing my current cam has a .574/.578 lift with stamped Summit 1.7 rockers....and I do have closed chambered heads....there's no danger of pistons kissing valves if I went with a bigger cam is there?

Do you normally have to replace the distributor gear with a bronze gear? Why or why not? What's wrong with cast cores? What's special about billet cores? Are you saying I'd be better off not buying an off shelf cam?

I've also gotten some info on running beehive springs.....what's the big deal with those?

Piston to valve clearance is a major consideration to check. With the short stroke you might not have the room for a cam that size.

As I mentioned earlier those are the exact pistons I run. My deck height is at the stock height with a .039 gasket. I have however had my heads cut roughly .035. My piston to valve with the 274 comp solid roller is .095 on the intake side and .125 on the exhaust side. This is measured with a dial indicator and real springs. With the checker springs it is more like .075 and .105. This is a touch tight but with the right/good springs is not an issue. I have been as tight as .060 on the intake side with checker springs with this same cam before having the heads redone and getting all the valve heights set the same. This is also with a 108 LSA cam vs. the Lunati's you are listing at 110. The 110 LSA cam will help your P-V issues a little.

I'd say the first 2 cams are the better choice and should not give you too many problems with P-V clearance. The 3rd choice is getting a little large. P-V is all going to depend on if your heads have been cut any, and where your valves are sitting in the head. Also lift isn't as much the issue as is duration and LSA when talking about P-V issues. As always you must check P-V clearance with any cam change. Do not go with any of us telling you it will be fine:p ;) :) .

Yes in the solid roller world these cams as well as mine are rather tame. Duration is still in the 270-280 advertised range. Lift is much more than their flat tappet counterparts because roller ramps can be much more aggressive than can a flat tappet cam.

Do not buy a solid roller ground on a cast core. Been there done that. You will start wearing a groove in the lobes in short order. That is exactly what happened to mine, and all comps shelf grinds in the extreme line are on cast cores. A shelf cam is fine as long as it is on the billet core. A billet core cam will eat the cast gear up and thus the need to go with a bronze distributer gear which are made of higher strength alloy materials. Likewise a bronze gear will eat the cast cam gear up thus the need for going back to a cast distributer gear with a cast core cam.

Heads are not cut, valves I believe sit in the original spot.

Chad are your heads the 290 oval ports as well?

I'm really inexperienced on the piston to valve clearance, using the dial indicator and the mathematical formulas of .095, .125, etc you posted....:( .....perhaps I'd be better off having it done by an expert?

Or maybe I should copy off of you? :waving:

My heads are the 390 castings. Not much difference though. Yours may be the ones that was GM's "semi open" design. They just had the quench area around the spark plug hole moved back some.

To check intake P-V:

For a quick check degree in the cam using checker springs and then set intake valve lash on the valve you plan to check. Bring the piston up to TDC with the intake valve just begining to open. On the intake side the valve will be opening while the piston is running away from the valve thus the reason you can run less P-V on the intake side. Continue to turn the engine to 10* ATDC and stop. This is usually the point that P-V is the closest. TO be more precise check in 2-3* increments from TDC to 15* ATDC. To check place a dial indicator mounted in a magnetic base on the head. Place point of dial indicator on the spring retainer making sure it is parallel with the valve in both directions, and making sure the dial indicator is compressed aound .150 for travel and set to 0. Then, push rocker arm down to compress checker spring until you feel the valve hit the top of the piston. This is your P-V clearance.

Do the same for the exhaust valve except the exhaust valve will be closest at 10* BTDC with valve closing.

You must check all valves if you are on the tight side as valve heights could be off as much as .020 or more depending on previous head damage, valve jobs, etc. I like to do final checks with real springs and heads fully assembled. That goes for degreeing work as well since a sloppy chain could put you a couple degrees retarded with the engine loaded. Real springs will give you as much as .020-.030 extra P-V clearance due to valve train deflection.

Quoted from an article written by David Reher of Reher-Morrison:

First, put away your clay and your light-tension checking springs.....

You must use the same components when checking valve clearance that you intend to use when you assemble the engine. This includes the same lifters, the same pushrods, the same rocker arms, and the same valve springs. Light-tension checking springs simply can’t duplicate the load and deflection that the valvetrain experiences with stiff race springs. The difference in actual valve clearance between checking springs and race springs is typically .020 to .030-inch. If you set up your engine with checking springs with .075-inch intake valve clearance, the actual clearance with race springs will be closer to .100-inch.

The XS274S Comp Cam would be a nice fit. Had that same cam in my 427 it just gave up too early in the rpm range. I would think it would work well in a 396/402 BBC.

I had pretty much the same set up,with a Comp 294S cam (248* @ .050"),idle vacuum for the power brakes is fair,occaisionally had to blip the throttle for extra vaccum to the booster.Not for everybody.Hope this gives you an idea when the brakes start becoming an issue.

Junkyard Dawg,

Several weeks ago Uncle Jack had a post about his 496 with the VooDoo 60232 in it. He had excellent bottom end torque. When we dynoed the 60232 in a ZZ502 with 310 Canfields, we had 565 ftlbs at 2500......
The 60230 and the 60231 have identical ramps, same opening rates, same closing rates, as the other VooDoo solid rollers, so the 60230/60231 would have great torque around 2500 in 396/402 engines.
As far as my old UltraDyne solids are concerned, back in the 80s we had a 3200lb 402 run 10.68s with the 296/304F8, now the 402B1LUN. This is 296/304 at .020, 263/271 at .050, .630"/.630" valve lift, and 108 LSA. A little radical for a street car, but the 296 has gone 100,000 miles in street cars as the exhaust of the 299/296F10. These are the same ramps as the 276/284F10, everyone's favorite street cam, and a good hard hitter for a 396/402. Lunati calls this the 402A3LUN, and about their best seller of the old UD cams.
The rollers make more power than the solids, certainly the 60231 vs the 402A3......

UDHarold

As a comparison, I had a hyd roller in the 402 .030 motor that worked real well. Was a Comp NX276HR [ 276/294, 230/242, 113LSA/108ICL]. This pulled about 12" vac at 800 idle and would pull to about 6200 in the 402. May have rev'd higher but that's all I spun it to. For comparison, add about 8* to hyd duration due to lash, this puts you at 238/250 for a comparable solid. Of course it will rev higher due to the solid lifters and higher spring pressure.

GRN69CHEV what heads were you running? You had the same pistons and valves as I did?

Just out of curiosity how much vacuum is required to operate the power brake booster?

Harold thanx for the info and if my engine can handle it w/o any mods I think the top cam will be my pick.

For those who don't know I'm in the middle east fighting a war on terroism. I just called my wife and told her what I wanted to do and she gave me the green light to do it.

I know I need to check piston to valve clearance but a quick question here....the 60230 cam has a 231/237 duration and the 60231 cam has a 237/243 duration.

My current cam has a 240/246 duration.

I'm being told duration dictates piston to valve clrarance more than lift does.

Yet both of those solid mrollers have over .600 lift whereas my cam has a .574/.578 lift, all of this with stamped 1.7 rockers...

If what I'm hearing is ture I don't suppose the Voo Doo solid rollers i just mentioned would most likely work now would they?

I emailed Chad a while back and talked to him about his motor. I`ll try to get this right. What I understood was that the lower duration cams had more p/v clearance than the higher duration cams. I know he told me why but I can`t remember. I think the 60231 would be a great cam for your motor. I think that even though it`s got less duration than your current cam, it will build more cylinder pressure and will have more "seat of the pants" feel and should run better then what you have. You should definately check your clearances but you could always notch your pistons if it`s close, I would`nt take too much out of them. I think you`ll be ok though.

By the way, Thank you for your service. We do apprecieate it.