which cam for a 455?
 

I was all set to put my reconditioned #96 heads on my used 73 400. I was planning on installing a Comp XE 262 cam. Everything else on engine will be stock. I got a good deal on rebuilding my original 455 bottom end. My buddy checked out the block and says all looks good. My question- will the XE262 still work well in the 455? I'm looking for good bottom end and a nice sound. Car will never go over 5 grand. Thanks for any help or suggestions.

That would be a good pick for power under 5k in a 455, you should be able to idle it at 750 and the cam`s lift will work with the stock valve train height and springs.

You still running stock springs on those heads with the oil shields? If so, I wouldn`t run that XE262 cam. 470 lift is pushing it and, the XE series is too agressive, to me, for stock springs. Also, I don`t like that cam in a 455. Too short a seat timing and with the `96 heads, will prolly be a detonation machine.

yes, I'm running stock springs. Which cam would you suggest? What about a 068 cam? This was my second choice. I also did a search and see the Summit 2802 works well in the 455 with #96 heads.

I'd probably put a Crower #60243 cam and some #68404-16 springs in it and let it eat.

But that's just me...

JM2¢

Bret P.

I`m with Bret. You need to ditch the stock springs/shields. I was gonna pick the Crower 60916 or the 60242. But depending on how much "sound" you want, the 60243 that Screaming stated will work.

Also, when stepping up to the 60243, I would run headers instead of manifolds.

Insist on keeping the stock springs?

If so then I'd run a stock cam like the 068.

If you are willing to upgrade the springs and are still keeping the stock log manifolds I would choose the Summit 2802, the Crower 60916 or 60242 (60916 & 60242 are nearly identical).

Cam
 

Ran the XE262 Cam in a 9.5 to 1 455 with Q-Jet and Performer intake and 1 inch 4 hole spacer. Awesome throttle response and nice rumble at idle FWIW Rich

did you use stock springs?

Piss poor choice for a 455 with very much compression in it, IMHO. Might be OK for a 7.7 to 1 CR 455 with some 7M5's or bathtub chamber 4X heads, but you are going to leave a BUTT LOAD of power on the table putting a tiny cam like that in a 455 with 9.5 to 1 compression and decent flowing heads on it.....Cliff

now I'm real confused. I have no idea which cam to get. I am running stock valve springs, stock intake and exhaust manifolds.

Read my post above again.

The stock springs, especially used ones, pretty much dictate a low-lift mild cam. The 068 cam is the biggest one I'd consider using.

Personally I wouldn't hesitate to change the springs, it's easily done with the heads off the engine since you're swapping them onto the 455. Then you can run one of the bigger cams that will still run quite well with the stock intake and exhaust manifolds.

Zackly!!!!

Karl

:usa2:

XE262 Cam and Springs
 

I did have new Springs put on the heads ( 7C2 ) I believe. Had the Intake Valve Upgraded to 2.11 and screw in studs installed. This Cam went in 1974 5100 pound 4 door Grandville with 105,00 miles on the original bottom end and pushed that tank to 14.0-14.1 at 97 MPH in 1/4 mile. Pulled great to 4800-5000 Rpm

If you are installing #96 heads on a 455, it will have enough compression to easily manage 224/234/112 sized cams and delivery a smooth idle, great street manners, and broad power curve.

If it's a budget build, get a Summit 2802 cam. It'll make good power to near 5000rpm's, and be pretty user friendly on currently available pump fuel as well.

I have two carb customers in the files who bought engines with around 9.5 to 1 compression with the XE262 cam in them, that absolutely HATE them at every level. I have another customer who opted for the XE268 cam and ended up with a "turd" for 455 street/strip engine. His car should be running high 11's/low 12's, and he's BARELY in the 12's with it in good air.

The owners of 455's with the XE262 cams both claim the idle is "quirky", extremely octane sensitive, and piss-poor power production at every level. One of the engines was "professionally" built by a shop who caters to Pontiac engines, where they were promised strong power to 5500rpm's and great street manners. The owner of that engine is about ready to take a long drive on a short pier with his pride and joy!.....Cliff

Thanks for the info Cliff. Guess I'll stay away from the XE262 and go with the Summit. I'm going down today to pick up the heads. I know I had new stock springs put in. Do you think the Summit 2801 would be too small?

It`s not a matter of the 2801 being too small[ to an extent], it`s if you have the right springs to handle the lift of any given cam. Valve lengths can be an issue also. One must check for coil bind[ spring stacking] and retainer to guide clearance, among other things.

One needs to know how cubic inches and compression affect which "size" of a cam he chooses. Any cam will "act smaller" in a larger engine. So, what`s good for a 350 or 400 can be too small for a 455.

One needs to choose a cam to get the results he wants for his CID, then he needs to make sure it will "fit" in his engine. If the valve will only open so far before it bottoms out on the head or hits a piston, one needs to create enough space to accomodate such a cam.

Also, cams need a spring PRESSURE to go along,or you will "float" the valves. So, when buying a cam, check for spring pressure, coil bind, piston to valve clearance, and retainer to guide clearance at a minimum. The larger the cam, the more important.

This might help.

http://www.fortunecity.com/silversto...build/cams.htm

I'd go with the larger cam. A 2801 works very good in a 400 engine around 9.5 to 1 compression, the larger 455 at the same compression ratio will like about 10 degrees more duration.

We also have to keep in mind here that a larger cam tends to make the engine more pump gas friendly.

FWIW, if I were building the same engine here, it would get a RAIV sized cam, a set of Rhoad's lifters, and high ratio rockers. I'd also be tempted to put one of Ace's Wolverine 5059 clones in it, but since we quit using flat cams here quite some time ago, we haven't tried any of the newer offerings. I'd also cut the heads just a tad and put the compression closer to 10 to 1......Cliff

Interesting, a larger cam will make car more pump gas friendly. I'm going with the 2802. Thanks to everyone for their advise. I'll let you guys know the results when I get it running.

just picked up the heads today. guy installed a new set of Comp 901-16 springs. Told me anything under 500 lift should be fine. I'm going to order the Summit 2802 cam. All I need to get now is a set of lifters and pushrods. I'm assuming I have to get the factory length pushrod. Am I correct? Is there a better brand of lifter? I'm using stock Pontiac studs. I'm not going to use the adjustable Chevy studs. I just want to torque down the rocker nuts and be done.

Sorry, you can't just torque the rocker nuts down and be done with a non-stock cam. You're looking at a very short engine/valvetrain life and a lot of problems.

There is ONLY one right way - straight 7/16" studs and polylock nuts, then learn to adjust the valves.

And it is so easy. I have never in 36 years of working on Pontiac's gone with the factory settings.

It is so easy (and normal to me) to just buy a set of polylocks and adjust the valvetrain. It only takes a second to learn. Even if you stay with the bottleneck studs and use 3/8 polylocks....... The lift of the 2802 does not mandate 7/16 studs but they are cheap insurance. Just a thought. :)

Single w/damper springs... :gag:

Shoulda got the Crower double #68404-16 springs. :-ohwell:

Agree with Bart too,the 2802 cam needs an adjustable valvetrain.

And I never use the OE bottleneck studs either.

But again that's just me I guess?

Seen too many of those bottleneck studs break @ the worst possible times,even with stock cams and valvesprings when run hard enough.

Best of luck with it.

Bret P.

sounds like I should install the 7/16 studs. that's easy enough. How do I make sure I get the right length pushrod?

If your gonna be using the stock length valves for the #96 heads & the OE installed height w/a hydraulic cam & lifters like that 2802,you probably should'nt be too far off from the stock length pushrods,not unless you milled the snot outta those heads and/or the decks or such.

Factory pontiac pushrod length for the '67-'79 pontiac V-8's is typically between 9.130" to 9.170" depending on the source info and such.

Any pushrod around that ^^^^ length should do the trick.

Understand that custom pushrods lengths are typically sold in .050" steps,as there is no need for the lengths to be any closer than that.

So with pushrods,there is no "perfect" length,"close" is good enough.

HTH

Bret P.

+1 on the valve springs. The Crower 68404 springs are the best "drop-in" spring out there for the Pontiac heads with stock components. They don't put killer pressures on the cam/lifters, and have a LOT of room for running larger than stock cams without getting anywhere near coil bind.

We built a set of #46 heads yesterday in the shop and used them. They fit all the stock parts, and with a little seat grinding and valve work very little shimming is required as they are designed to run at 1.600" installed height.......Cliff

You are getting very good advice.

A cam like the 2801 would work if you are looking for a factory-style idle and don't plan on high RPM's. The 2802 is a better choice if you want a little edge to the idle and want to have strong power to 5000 RPM. And it would be more pump-gas friendly. Just don't turn the engine much beyond that if you have stock rods. With the 96 heads you should have plenty enough compression that you don't need the fast ramps built into the XE cams.

Changing the springs is a good idea when going to any aftermarket cam since they always have more lift than factory. If you are on a very tight budget then sometimes you can get away with stock springs (I have in the past) but its really not worth trying. Springs don't cost that much, and more often than not I ended up replacing them down the road due to valve float problems. The 68404 springs being recommended would be my first choice.

If the valvetrain is set up correctly and the springs are not too heavy then bottlenecks should be fine. But the big studs are good insurance. If you stick with the bottlenecks then you can measure and order pushrods the right length, but polylocks are the easiest way to go. I would feel comfortable with any of these options using the 2802 cam and the 68404 springs.

Walt

thanks to all your great advise. I'm going with the polylocks and the 2802 cam.

Thats good. That 2802 cam with it`s 282/292 SEAT timing is WAY better than that XE cam with 262 seat timing on a 455.:pound: I`m not a fan of those 901 springs but you should be able to get by with them.

Like the others said, 7/16 studs and poly locks and you`ll be good to go. If you`re not sure how to adjust valves, Ken has provided a procedure.

http://www.angelfire.com/fl4/pontiac.../valveadj.html

He also sells parts, installs parts, and can answer questions.;)

i had a set of single springs with damper on an engine once. never again. they were the recommended springs with a RA IV clone cam from warrior racing. they were all done in a little over a year/few thousand miles. the engine would nose over after 4k rpm. pretty much ran fine otherwise. changed them out and it was back in buisness. all though you might be just fine with what you have, it will be alot less hassel and money to get good springs now. just a thought.

i had a build close to yours: 73 trans am .030 455,trw flat top pistons, small chamber 4X heads(around 9.2-9.5-1), ra III exhaust manifolds, performer intake, 73 Qjet, 400 turbo, stock style L88 converter, 3.08 gears, with the summit 2802 cam. idled with a little attitude and would biol the 275x60 15 radial TA's any time i wanted from a 20 mph roll. never got it to the track before someone bought it, but it was i nice street driver.

that's what I want to hear. Another quick question, I'm assuming the stock screw in studs for Pontiac were 3/8, not 7/16's. Can I use polylocks on the original 3/8 studs?

yes they make 3/8's poly locks, but i have seen the stock 3/8 stubs break also. while .465-.480 lift isn't huge, the 7/16th studs are cheap insurance. it's been awhile, but studs and poly locks around 50.00?

true, that is cheap and very easy to install.