[Skip Fix]

OK why don't we look at an UD 288/296 that has similar specs. Bullet and Lunati still can grind them on what ever lobe sep you want, so maybe a good choice too with similar specs. I've got multiple dyno pulls in a 400 and a 455 where it doesn't lay down at 4900! Lee Atkinson's old early Bird ran mid to low 11s with it, that was not a high compression engine. So we can keep the same specs basically (231/239) and have alot of data from lots of guys including the Butlers that used that cam.

One thing I find interesting it seem the cam gets the blame for the rpm limitations and no mention of the head. Almost all the formulas for rpm peak use the head CSA or other numbers for an rpm prediction. We're asking a 215-230 cfm iron head to feed 455-470 ci and wonder why the rpm is limited?? In fact just last night was talking to a well know Pontiac "stocker" that using PORTED D ports on a 455 SS cat they were building was head limited.

FWIW one of our west Texas Pontiac guys has had good luck with the Comp XE 274 and the 284 in some pretty fast Pontiacs, but then his cars go pretty fast regardless of what he has in them.

[slowbird]

We ran 11.8s to 11.9s with the xe274 cam in our street 400. We did put it into our 455 but the lobes went flat before we got it to the track. It seemed to work pretty good in the 455. I know it ran great in the 400.

[Steve C.]

From a old catalog, the discription for the Ultradyne 288/296 hyd flat tappet with 231/239 at .050 and ground with a 110 lobe separation, .485/.507 lift ....

"Hot street/bracket cam, 3000ss converter or 4-speed. No power brakes. Power 3000-6000."

I believe Lee's best with that cam in his first gen bird was 11.46 at 115.4 mph with a 1.53 60-ft. It was later when he switched to the Ultradyne 247/247 at .050 solid flat tappet ground with a 108 lobe separation that he ran 11.27 at 119.61 mph. It was my understanding the "bigger" solid cam was just as driveable as the smaller hyd cam. I wonder what his comment would be about "no power brakes" with the small 231/239 cam ?

Jim Butler stated the Ultradyne 276/284 (243/[email protected]) soilid flat tappet cam ground with a 110 lobe separation was good for 1.2 bhp/cid with 9.5 compression (540 hp /455cid)

[Skip Fix]

My 304/312 FTH UD in a 400 ran my power brakes fine, and even the A/C with a idle solenoid! But was on a 112 LS.

I know we are in the street section but talking to the "stocker" guys they run some BIG cams, as big as alot of race guys rollers, with the stock lift-part of how they go so fast. 400 ci D port early Birds deep in the 10s and well over 120 mph! I'd almost guarantee they aren't worried about that bottom end TQ, they must have enough to launch and get those times as they have to be stock weight.

[Brent Flynn]

I had a .480/280 Crane in my 350Pontiac engine in my Suburban and had great power brakes! But, if it were me, i'd try bout a .500 lift/290ish duration hyd in your engine. Im running this type of cam in both my 455's(they both runnin 11 to 1) and they run like crazy up to 5400rpm. U could always advance 2-4 deg if you runnin tall gear.
Your engine will be done by then anyway no matter what cam you put in it, so you might as well build torque, not horsepower. With these cams you get both. 108LSA is in the ballpark, and these cams are absolutely streetable. Use some good oil(Rotella, Amsoil and the like) and you shouldnt have to worry bout wiped lobes if break-in procedure is good. Just my opinion....

[ponjohn]

Originally Posted by Skip Fix

My 304/312 FTH UD in a 400 ran my power brakes fine, and even the A/C with a idle solenoid! But was on a 112 LS.

I know we are in the street section but talking to the "stocker" guys they run some BIG cams, as big as alot of race guys rollers, with the stock lift-part of how they go so fast. 400 ci D port early Birds deep in the 10s and well over 120 mph! I'd almost guarantee they aren't worried about that bottom end TQ, they must have enough to launch and get those times as they have to be stock weight.

That may be true but the lobes are square....LOL.

[silver68]

Remember it is not just the engine you will be trying to put into the elevens, it's the whole car. If elevens are your goal you must look at the whole picture. Before even considering a cam the car must be weighed. Lots of people on the internet seem give opinions on cams without considering weight, suspension mods, gearing (rear & trans), clutch or torque convertor, and tire size & compound. A well planned car can make a hero out of a pump gas street driver without having to have gobs of horsepower. That is the reason some 455s with a xe274 run elevens and others run high thirteens. Another very important consideration is the altitude above sea level of the dragstrip you will be racing at. Big difference between sea level tracks and those at 2000 ft. With a four speed car espescially you will find more e.t. gains with rear suspension upgrades than a cam change. For early birds, calvert racing split mono springs, caltracs, and dual adjustable shocks are the only way to go. That being said, get a custom ground hyd. roller, you will be much happier.

[Brent Flynn]

Originally Posted by silver68

Remember it is not just the engine you will be trying to put into the elevens, it's the whole car. If elevens are your goal you must look at the whole picture. Before even considering a cam the car must be weighed. Lots of people on the internet seem give opinions on cams without considering weight, suspension mods, gearing (rear & trans), clutch or torque convertor, and tire size & compound. A well planned car can make a hero out of a pump gas street driver without having to have gobs of horsepower. That is the reason some 455s with a xe274 run elevens and others run high thirteens. Another very important consideration is the altitude above sea level of the dragstrip you will be racing at. Big difference between sea level tracks and those at 2000 ft. With a four speed car espescially you will find more e.t. gains with rear suspension upgrades than a cam change. For early birds, calvert racing split mono springs, caltracs, and dual adjustable shocks are the only way to go. That being said, get a custom ground hyd. roller, you will be much happier.

I agree...thats why guys should give as much info as possible. If he has everything else right( gear. coverter, suspension, exhaust, carb-intake, etc) the cam ideas will work without spending the cash for the hyd-roller. This stuff has to be in the ballpark no matter what cam he uses. Although, cam selection depends on all this info. Dont know how much gear he is running, tires, anything. My 68 bird runs 11.63/113 with a 25yr old Engle .503lift shelf cam. It would run even better if i'd go to a taller gear. I run a 4.10 with 30'' tire and go thru at 5600. Stock heads, intake and carb. It isnt that hard to go 11's in a 67-8 bird even with 3.36 gears. I ran 11.88/113.5 back in 1994 wiith 3.36 gears, 29.5 tire, 3600conv, driving power steering, fuel pump, alternator with almost the same engine. Had .540 CC solid in the car then. It Prob woulda ran better with the little Engle tho. Drove it everywhere with that combo at 10mpg.

[GF79TA462]

I have a .030 over 455, just in a 400 block, and with the xe274 and 1.65s it has gone 12.17 in my bird that weighed in at 3425 right after that pass. Thats with 6x-4s that had the bowls flowed and the egr junk removed from the exhaust ports. No actual porting was done to the heads. It makes power to about 5300 rpm and idles at about 900 in gear with a decent lopey/choppy sound. Ive always ran 93 octane in it and never had a problem, it should be right at 9.5:1. The car can do a 1.69 60 ft. time but usually goes 1.74 or so on a poorly prepped track. However i have run 111+mph so I'm thinking if the car was capable of launching better the motor could pull the car into the 11s or at least 12.0s. With fully ported heads i would think going to the xe284 would be a better match for the combo mentioned along with a taller gear than a 3.55

[Skip Fix]

"Remember it is not just the engine you will be trying to put into the elevens, it's the whole car."

Which is what alot of folks can't figure out, and why those stockers fly! Most guys have a shelf full of cams, convertors and multiple carbs. Tri Ys are even making a comeback!

[old66tiger]

I have an XE274 in my 455 with ported 6X heads, slightly massaged RA manifolds running into 2.5" X-pipe exhaust with Pypes pro-V mufflers and a home built (Cliff Ruggles designed) Q-Jet carb. My car managed 326 RWHP and 439 RW Torque. Nothing to write home about but for the weekend cruiser, I suppose it is OK. FWIW, I was expecting much bigger numbers but it may be the RA manifolds or the mufflers that are hindering some of the performance.

That aside, my biggest complaint and annoyance with this cam is the crappy idle. The idle is not rhythmic like you would expect. There are times where the starts to lope harder and there is a small stutter - kind of like a harmonic resonance that creeps up and then goes away. There is a new MSD distributor, new wires, plugs, etc on this motor. I have played with the idle set screws on this carb and there isn't any magic answer. I seriously think it is the cam itself that lends to the crummy idle. I am running unported vacuum with the timing set at 13 initial.

My next cam will be a Hydraulic Roller. I want better vacuum for the brakes and everyone that I know who is running a HR say that they will never go back to a flat tappet cam ever again. Piece of insurance.

[Cliff R]

"One thing I find interesting it seem the cam gets the blame for the rpm limitations and no mention of the head. Almost all the formulas for rpm peak use the head CSA or other numbers for an rpm prediction. We're asking a 215-230 cfm iron head to feed 455-470 ci and wonder why the rpm is limited??"

Skip, my smoothed over 6X-4 heads that only flowed 232cfm made peak power on KRE's dyno at 5600rpm's on a 455 engine. The cam sported 304/314 duration, and we saw no shortage in power anyplace in the rpm range, or power falling off around 5000rpm, etc.

When we installed the KRE heads peak power was still made at 5600rpm's.

When you mention Ultradyne cams in comparison to the XE lobes, keep in mind that I have NEVER mentioned that Ultradyne or any other line of camshafts experienced valve train stability issues which limited engine power production to around 4900-5200rpm's.

This is a problems specific to the XE lobes, not any one elses lobes that I know of.

The problem is DIRECTLY related to the seating velocity of the valves, which can and will cause "lifter crash" at high rpm's. The relatively heavy weight of the Pontiac valvetrain is part of the problem.

We have a few customers who do NOT have this problem, one in particular is running quite well with an XE274 camshaft in a 455 engine using stamped steel rockers and thick wall pushrods, combined with relativley light valve train components. The valvetrain geometry is also perfect. He just happened to be setting up his combo for pure stock racing, so he didn't use heavy roller rocker arms, and used stronger/lighter valvetrain components and a bit more spring pressure than is normally used with those cams.

He made excellent dyno numbers and backed them up with pretty decent track runs, FWIW. This confirms that the lobes have plenty of "area under the curve", and the lack of off seat valve timing is not holding them back as much as I have always thought.

The loss of stability in the valvetrain is the real culprit here, but we only see a snap-shot of this as most folks don't turn their 455's much past 5000rpm's with those cams anyhow, and the vast majority don't dyno the engines, or have the cars set up to run all that well at the track either.

If you are just blasting around town spinning tires when you leave the Dairy Queen, or doing burnouts once in a while from a stoplight, leaving a car show, or making nice U-Tube video's road racing around the countryside, etc, you would never know their is a problem right to start with....FWIW....Cliff

[goat2789]

check out my chasis dyno results with the xe274 cam. expected much better numbers because the cars runs very strong. at the strip the best i ran was 13.5 @104 due to posi not working so no traction.

[PONTIAC LARRY]

Billy, I think you are safe with Crower 60919 camshaft. Cliff's hard work and sharing of his findings are appreciated by many including myself. It is enough cam to go deep in the 11's and not have issues as being the "wrong cam", put it in advanced 4 degrees.. The XE CC lobes have issues..run away run away...

[ponjohn]

Originally Posted by PONTIAC LARRY

Billy, I think you are safe with Crower 60919 camshaft. Cliff's hard work and sharing of his findings are appreciated by many including myself. It is enough cam to go deep in the 11's and not have issues as being the "wrong cam", put it in advanced 4 degrees.. The XE CC lobes have issues..run away run away...

Do you think this holds true across the product line including rollers?

I also agree the idle is somewhat confusing at times. It sounds like it loading up, then turns rythmic.

[PONTIAC LARRY]

Originally Posted by ponjohn

Do you think this holds true across the product line including rollers?

No , I am just talking about the hydraulic variety.. I would not discount a Solid Roller Comp Grind but I would shy away from the Hyd roller XE's too..

The fact Billy has a 4 spd car... he does not need a cam the will spin the tires even more but with no topend....= SLOW... Hello! The Crower 112 LSA version of the RAIV would be a great match for a 455 4-spd with 3.55's and 240 cfm 9.3:1..broad power band

[Cliff R]

I would like to point out once again, that it is NOT my objective here to bad mouth a particular brand of parts. I've been following the flat XE hydraulic lobes and the results of them for many years. I even tried one quite some time ago in a 400 engine using well prepared #16 heads. I chose the XE268 cam, and was somewhat disappointed in the results. At that time, I had no idea why the power just quit around 4800rpm's. The cam idled quite well for the .050" numbers and "tight" LSA, and made decent mid-range power. The power did however, end sharply at apprx 4800rpm's. The very similiar Crower 60916 and 60243 cams we had been using pulled well past 5000rpm's in nearly identical engines.

I started following the dyno and track results with the XE cams, and noticed that with few exceptions they didn't pull well past apprx 5000rpm's, even the larger varieties.

I just sort of sat on the information for quite a while, then got some DIRECT information from another engine builder, a cam design expert, and a dyno operator who does a LOT of high performance engines.

The other engine builder built an engine using the XE flat hydraulic lobes, and it would NOT make power past apprx 5000rpms. The dyno shop he used made him aware of the fact that he sees LOTS of very similiar results with these cams. They labeled it specifically "lifter crash". I contacted a cam designer, who told me specifically that the seating velocity is simply too fast, and can and will cause troubles at high rpm's.

We continue to see dyno charts posted from folks who show us very simliar results, few make good power in the high rpms with these cams, and quite a few of their engines show sharp drops in power up around 4900-5000rpm's.

Of course there are a few exceptions to this, as I mentioned in a previous thread, so it's not 100 percent for all applications. In any case, the percentage is high enough, that we avoid these camshafts and do not recomend them.

I will also say, that for years I blamed the poor results I was seeing on the short seat timing events, or advertised seat to seat duration. I was wrong, the problems are more specifically related to instability in the valvetrain/valve bounce/lifter crash (or whatever you choose to call it), rather that the basic design of the lobes (modern/fast ramp).

I felt compelled to release the information above, although I knew the first time I did so it was NOT going to be very well recieved. We're just seeing enough problems associated with these parts that someone has to point them out. Now go ahead and shoot the messenger, if you feel the need?.......Cliff

[PONTIAC LARRY]

Cliff,

I don't see that you knock a brand specifically.. I see that you are refering to just a certain product line within a brand.. I will say I was shocked when I first saw a SBC roller cam and it was ground on a cast iron core rather than billet steel...that scared the heck out of me...
PS: I still love Mellings, Summit and PAW , etc Generic cams

[ponjohn]

Cliff-

Is the 60919 a direct replacement for the XE hft (is the base circle the same)?

John

[Cliff R]

John, don't know the answer to that, never checked an XE cam to see what the base circle was?

I know that the Crower 60919 cam is very, very close to the original RAIV camshaft. Crower juggles the specs slightly, showing it to have 304/314 instead of 308/320 advertised. It shows the same .470" lift as the RAIV cam. The list the .050" duration at 231/240, and the cam card says is on a 113LSA, not 112 as listed on their website.

It's a very good choice for the 455 engine. I like to see 10 to 1 SCR with it, but it will work fine at lower compression ratios.

Our 455 engine made 455.4 hp with it using 232cfm 6X heads, iron intake, q-jet and stock HEI distributor. With the KRE heads it made 494hp, both engines made peak power at 5600rpm's.

At the track we went as quick as 11.64 with that cam, at 3760lbs race weight......Cliff