Do you plan to keep the 3.08's? Also, what tranny? The answers would help with cam and head choice.

Also, no secret. I'm no fan of the XE line of cams. Yes, today oils have fewer anti-wear additives, but the failure rate of these cams is unreal. Do a search, "wiped XE lobe" on this site, www.camaros.net, www.chevelles.com, and www.novas.net. You'll be reading for days.

FWIW

 

But flat tappet cams have a higher lobe failure rate anyway. The lifter slides on the cam lobe instead of rolling and must spin in the bore instead of just going up and down. Also the Zinc levels have been reduced for quite a few years with a lot of the average guys not even realizing it. Faster ramp rates compound this problem but also increase power. That is why all the cam companies have their performance line with fast ramp rates. The Voodoo line has similar fast ramp rates. They have to have fast ramp rates to compete in the market based on who makes the most power with a given duration. We buy their product to make more power. They give us what we want, even though it goes beyond what GM engineers determined would live without failure.
Faster ramp rates, higher lifts, stronger springs, less protection in the oil and trying to maintain a given duration to fit a demand all combine to make this an issue. The cam the OP is talking about is not as radical as a lot of the XE flat tappet line and these problems would be less likely. Comp sells a lot more cams than most of the manufacturers if not all the others combined so you do hear of a lot of failures. More so on the XE flat tappet lobes for the above reasons.

 

63Mako, I agree with everything you said. But you help me make my point. You list all the reasons today that conspire against the flat-tappit cam. That's why XE's aggressive ramps make less sense than ever.

If it were me, I'd get one of the old tried and true cams that almost always outlast the engine. Perhaps Comp's older Magnum line or how about Chevy's 151 cam or the 962 (I'm assuming he'll gear the rear). I'm not sure they'd give up much HP to a comparable XE grind with similar duration. 10 HP tops, maybe 12; i.e., 310 HP vs 320 isn't worth the risk. And as you know, if you lose a lobe, you can't just replace the cam. You have to pull the engine,tear it down, and clean out the shrapnel. It's not worth it.

Don't forget, there are some pretty snotty stock eliminator cars, with stock lift cams, running 10's and 11's. SE rules govern lift but not duration.

But with an older grind your valve train would run quieter and the cam is much more likely to survive.

If you haven't already, go to the links mentioned earlier and catch up on some anectdotal evidence regarding the failue rates with the XE. It's overwhelming.

Also, if you're running good heads, headers, and decent exhaust, forget about dual pattern. More here:

http://www.camaros.net/forums/showth...attern+cabbage

FWIW

 

Im running an XE grind. It is a XE 288 HR. The roller cams can handle the fast ramps. The flat tappets with these big ramps have engineered in a greatly increased chance of wiping a lobe. Problem is there are a lot of them running trouble free and most guys going for a performance upgrade on a budget aren't going to spring for $1100 to upgrade to a retro roller. To get the performance he wants with his 3.08 gear he doesn't have a lot of options other than an expensive new build. You can only get so much out of those old grinds and the OEM design performance cams need gears.

 

Decisions! Decisions!
Great reading and info. Thanks everyone, Bruce

 

Thats the reason I decided to go hyd roller on my current 350 build.

I bought and sent back a 268XE after reading about all the breakin problems. Sure, there are plenty of XE cams running fine - you just don't want to be the one with issues. Not worth it.

Look at it this way - if you wipe a lobe you gonna have to tear it down anyway - perfect time for flatops and a roller conversion

 

Your leaving out one factor the hardening treatment available on modern solid cams pro 55 If the cam companies were worth a crap
all there solid cams would have it as standard not have to pay an extra $50.00 for it. Maybe Japan will get into the cam business
there good about making sure there they don't screw there customers
with bad products for sale. Last time I checked GM is bankrupt begging
there goverment to save them lol.

 

Ouch, on the Japan comment! I did neglect to bring that up. Even those mild factory grinds had the wiped lobe issue. In the late 70's early 80's there were a lot of short lived, soft OEM cams shipped out in the new cars. Improper heat treatment. If I was contemplating using a new hydraulic flat tappet I would probably look at Crower. Great reputation, never heard them slammed on quality. One thing that is also not brought up much is a lot of these budget cam buyers are installing a new cam period. Some of these are installed with existing lifters, Improper valvetrain geometry, dirty oil still in the engine, no cam lube, No break in additive, improper valvetrain adjustment, 1.6 rocker putting additional pressure on the lobe, Stock springs not changed out or improper spring setup, installed height, pressure or coil bind.no break in. Installation and break in error is more common than you would think. Guy on a budget with little mechanical knowledge want's power, buys a cam, makes one of the above errors installing. Then, after it wipes a lobe they get on the internet and bash the cam supplier for selling them a junk cam..............

 

I planned to do something similar several years ago to my 72...basic top end package. Did a leak down on the engine and had two weak cylinders. If you've not already do a leak down/cranking compression to make sure your engine is in good shape for a top end package.

With that said, I'd go with the Comp Cams 262 XE or very similar for your L48.

 

I put the Lunati Voodoo 262/268 on the list for my "Dream 383 Build". Those and a set of AFR 195 Eliminators will be HOT!!!

 

Attitude of the american car builders is completely different then japan its been that way the last 50 yrs. Make the car look good get it off the showroom floor, make sure the parts only last so long cheapest cost for the parts get those suckers back in here for another car. Dealers attitude same thing we don't make much on the sale of the car screw the customer out there money back in our shop.

I bought 4 new chevy cars one new chevy pickup from 1969 to 1979 three of the 4 cars the dealers had to repaint the cars before I took them home and i'm not going to talk about all the other problems.

Bought a new 92 ford ranger it had 6500 miles put on it in three yrs,
the bed had never had anything put in it. Went out to start it would not start checked the wires no fire to the plugs, screw it its under warranty had the dealer come get it out of the garage with a wrecker went to get it me knowing there was no fire to the plugs they give me a bunch of crap about the fuel system clogged up $600.00 dollar bill on it I blew up called them everything but a whiteman.

Heres Japan and its dealers for you, next door on the east side of my house 20 yrs ago neigbor he bought a new honda accord it had a few small problems dealer fixed it, he wrote a letter complaing about it to honda, they sent him a check for $1000.00. next door neighbor on the west side of my house moved in he had a used 280 Z, car was three yrs past the rust through warranty he had some rust back behind the rear wheels he took it to the dealer they repaired the rust problem repainted the entire car charged him not one dime.

Never had anything but chevy ford or lincolns. There has never been any company or companies that have truely worked at deserving bankruptcy the way GM, Ford, Chrysler deserve it.

Back to tech cam companies have a process to make all there cams
better have a good reputation for there company instead they put out cams that are questionable as to will they last, but for $50.00 more we can sell you one that most likely will. Probably take Japans competition to make them give you a good product up front or they can go under to. Maybe the tax payer will be screwed over to bail them out.

 

Brother 63Mako,..I agree install errors are to blame in a percentage of wiped lobes. But how do you explain professional engine builders who are wiping lobes?

Again, do a search on these sites, "wiped XE lobe". You'll wonder why that line is still on the market and why a class action suit hasn't been filed against Comp. Comp obviously didn't spend enough on R&D.

Here's one thing that amuses me. Most lobes are wiped during break-in. Comp would have us believe today's oils are the reason. I say bull. Guess who provides the break-in lube which should have plenty of the anti-wear supplements? Or if Comp's lube doesn't have the needed supplements, why aren't they providing it with every flat-tap cam they sell?

Again, I contend the XE lobes' break the rules of duration vs. lift for a flat-tappit cam.

But agree, roller is the answer here. Spend the extra jack. You'll get better performance and peace of mind.

Good discussion.

 

100% And it is not just Comp Cams but most of the manufacturers that are breaking these rules. They do it because the market wants that extra power cheap and easy. Look at the bottom of a flat tappet lifter and how it contacts the lobe. Looks like the edge of the lifter could contact the cam lobe with a fast ramp especially at high rpm. Then look at the bottom of a roller lifter and how it contacts the lobe. Also it rolls instead of sliding. If you want the performace boost of more lift common sense says go roller. But a lot of times the budget says otherwise.

 

Good read here on avoiding flat tappet lobe falures by David Vizard.
http://www.enginebuildermag.com/Arti...r_failure.aspx