Im still debating between quite a few cams. Ive been trying to figure out what kind of valve lift to look for in a cam. My valves are new, pretty sure everything was a basic stock single spring replacement w/ Light re-surface on the heads.

The XE274 Looks nice Extreme Energy #11-246-3
Not sure what kind of idle it has but the valve lift is IN.552/EX.555

Then theres the 286H #11-318-4
.556/.556 "Needs 9.5:1 Compression" Lower Gears, choppy idle. I should be around 9.5 - 10:1 Compression with these heads and pistons.

What exactly happens when there is more and less valve lift? How do I know whats too little or too much? Is "lopey" the same as a "choppy" idle, all these different names and slang people use for idles are throwing me off smile.gif Althrough rough and very rough idle are pretty obvious.

Comon smile.gif

More lift usually means more HP and torque, but there are some times we that isn't true...say if your heads only flow well up to .500", then cam lifts at .600" are kinda wasted. Between the cams you've mentioned, the lift is pretty much the same.

You have too much lift if your valve whacks the piston, really. Other than that, open that valve as far as you can (within reason).

My opinion is, a "lopey" cam is a mild "choppy" cam. The idle quality is basically a function of overlap, although more lift and compression can change the sound of the idle too.

Well if Lopey is mild id probably not be very happy with it smile.gif being what I had before on the small block, mild cam.


The guy I bought my heads from gave me a paper with some stats :

* Single Springs w/Damper
* Force @ 1.900" = 110lb
* Force @ 1.350" = 270lb
* Coil Bind Ok @ 0.550" Lift cam
* All new valves I= 2.065 E= 1.720
* These have also been surfaced, that means a slightly higher compression doesnt it?

My speedpro pistons have a .90 dome and are 30 over

The thing I see that sticks out on this list is the coil bind and lift "ok at 0.550" Is this the lift for a cam they were reccomending? The more I read the more choices and questions I have... smile.gif
Any help would be great, Id like to order my cam today so hope I get some hits here.
Thanks guys.

Would it be ok to go with the XE284H? .574/.578 Rough Idle, 2500+ Stall 9.5 Compression. Too high a lift?

OR smile.gif This one sounds kinda sweet...

MAGNUM 280HR "retro-fit)
566/566
9.5:1
rough idle
street machines
2000+ Stall

One more thing I want to throw in. If I can drive on a cam that requires a higher converter, while im using a stock one that would be cool. I dont want to get a new one because eventually I want to throw in a 4 or 5 speed.

Phil,you know my choice smile.gif

I don't think your springs will follow an extreme energy series cam- to weak for any real rpms. If you go to Comp's site and look at the suggested springs for the cams and compare specs, you'll see those springs are weak in comparison. If you do an aggressive cam make sure to run a spring similar in spec'd pressures to what they suggest. The XE274 is actually a fairly nasty street cam IMO, a friend of mine put one in his LS6 454 and it is impressive- gets rubber in all four, breaks the tires loose at a 45mph roll. You could use your current springs for break in maybe. Bob

Chris

im curious why you recommended the LUN #00026, which is 293/310 advertised. i think its a little large for his comp, dont you???

i think the 280/288 would fit his combo great. and im surprised you didnt reccomend it since you have had such good success with it.

Brandon,my cam would would be perfect.
But just a thought...
The 293/310 is the identical grind to old UD 288/296 231/239 .550/.575 110 LSA,but just an earlier version,with less lift.
A fellow TCer AK69 built a 454 using the 288/296 with 2399's and 049's (heads decked to 9.0-9.5 or so) keep in mind,the 049's had 2.06/1.72 valves,and his motor made 490 HP/525 ft/lbs tq.
So,with my pistons,closed chamber heads,and the 293/310 I think it would be a pretty decent motor.
Phil said he wanted a lopey idle too :D
Mine is pretty smooth,just a hint that something is not stock.

Well its alot easier to shop in a specific comp cams line. I keep going back and fourth through all of them. Im focusing on the MAGNUM line. I think the 280HR would probably be good? What do you think.

280HR (11-430-8)
.566/.566
9.5:1
Rough Idle
Lower gears in all apps
Use headers...
2000-5500 RPM Op. Range

http://www.compcams.com/Technical/CurrentCatalog/HTML/172-195.asp

You could use the 280HR, it will work in a 454 motor to produce a lot of mid range power, but that single pattern cam may run out of steam by 5300 - 5400. That is not a bad thing though, you will have a lot of power by 2000 rpm. Set up with the correct gear you will have a fun car to drive. If you decide to go roller I have a brand new set of Comp 854 Hyd Roller lifters for the MkIV blocks that I am not using and can discount considerably.

Hey Chris what was the part number for the lunati and lifters kit through summit?

Phil,the 280HR is a hydraulic roller..we'e talking flat tappet hydraulic.
The part # for the Lunati cam/lifter kit is
LUN-00026LK

..I don't think you'll be disapointed

My springs and everything will handle this cam alright? It sounds nice , I still like the sound of this one.

Your springs will NOT work with a roller if they are meant for a flat tappet.

Well crap, I dont know the difference, and im not sure what kind of springs these are either. I know they arent anything fancy though, and there single springs.

::sigh::

For what you would spend on an HR, a solid will equal or exceed it powerwise imop.

Most people wouldn't rec a 110/270 sping for more than .500 lift.

You might consider a custom 280/286 (230/236) magnum lobe cam if your stuck on CC.

Powerwise an A1,2,3 UD solid will equal or exceed both I think.

If you want a Hyd, I like how the A7 or A8 looks too. I don't know your whole combo or exactly what you want so it's a little hard to pin down a better recom. Personally I like the A3 276/284 solid the best for a mostly street car.

Spring wise, Isky 8005 IIRC will work with all the cams listed. Reason being, there have been a lot of problems with CC retainer/lock QC lately.
Not bad steel, just not assembling to catalog spec and having to F with parts to get the spring at the right height. There are some pro's on here that won't use them anymore because of it.

Phil,I run Crane single springs with my cam..they're good to .580 lift..I forget the open/closed numbers.I think the part # is CRN-13308-1
The 280HR is a roller and the Lunati cam/lifter I mentioned is a non roller.You want a non-roller for what you're doing.

I think that's a spring kit p/n.
I don't recognize it, but I don't look at the kits much. For a 540 ish lift hyd, crane uses the 99893. Don't remember the # for the smaller cams for BBC's since I never look at the small cam page. SBC's I do.
btw, you do know about the rotator eliminators for those heads don't you?

graemlins/waving.gif Chris

Scott,the 99893's are the springs I use,and the part # is for a spring/retainer kit.
And they are good to .580 lift.

btw, graemlins/waving.gif too

..and I don't think 390 closed chamber heads have exhaust rotators smile.gif


..heres a link to the spring/retainer kit:
http://store.summitracing.com/partdetail.asp?part=CRN%2D13308%2D1&N=100&Ntk=PartSearch&Ntt=CRN%2D13308%2D1

I've got 049's on the brain from my last post.

Crane used to list 99893's for their street solid roller. Which go to .63x lift.
Now they list the 99895's. I know because I bought my 781 heads with 99893's for a future SR setup. Not that they will actually work very well that way. I had them set up for a SR and wanted to just pull shims to run a FT. My machinist laughed at me when he found out what I was doing. I use his spring checker to set up my own heads. He said they are ok for .550 lift cams.
And to quote Harold in reference to 99893 springs "Those are small block springs"
Granted that was in a 288/296 thread.
I spent a few hrs on the phone with Wolfplace trying to fix that problem so I can really run a SR when I want to. Isky 8305's at 1.98 and longer valves. As found, my installed ht was 1.73. Or $450 to fix an already overpriced set of 781's.

Not bashing your set up since it obviously works, I just think that you can do better than those springs due to their 390 rate which puts them over 350 lbs on the nose when you get near the .600+ lift range.

Scott, I'm no expert, but the Isky 8305 springs look way too weak for any roller application.

I use the 9005 springs (185# seat, 465# open)for my Isky Street Roller with .602" & .646" lift and have no problems with stock stem length valves on my 049's.

These are the springs that Ron Iskendarian recommended.

Yes they are..
But they need an approximately 1.98 installed ht to work on a solid FT on the street.
And 9315's use a 2.0 ht.
And they fit my rot. elim. w/o cutting OD down.
My heads were fubar'd sort of. Stock length valves had a 1.75 installed ht.
Everybody I talked to said "don't sink the valves to fix it". So, since my supposed SS valve are magnetic..., I needed .100 longer valve to get any normal BBC spring to fit. And if I go with .250 longer, I get a 2.0 installed ht. Perfect spring wise or a SR with .650 lift .
UDH said 210/520 for a spring.
To bad my 8305's came in 15 lbs high....

Phil

i told you in one of your previous posts you might have to change springs. its not a big deal, and while your machinist is doing it he can check the condition of the seats/guides. its a win win situation.

now i see why Chris suggested the lun-00026, it will give a more aggressive idle, but i have to say i wouldnt get to concerned with having that wild choppy idle.

big cams and daily driving dont exactly go hand in hand. besides, even a stock BB with headers and duals sounds healthy.

stay in the 280 advertised range and pick a cam that has a 110 lobe separation, like the comp magnum 280H. the tight LSA will give more of a noticable idle.

if you want to go a little larger you might look at the Comp magnum 286H. its 286/286 236/236@.050 and .556/.556 lift.

or you could have UDharold make you a 280/288 cut on a 110 lsa!

Yeah I think those are 2 good choices, the guy said coil bind ok at .550 so that basically means they perform up to 550 lift? I could change the springs but id like to just leave them alone, there new and I cant really afford it on my parts list right now.

i know what its like to be on a tight budget. but if there is something that needs to be done, im not willing to skimp on it. id rather the car sit than have problems later.

im no expert, and i have my machinist set up my springs. but there is more to worry about than coil bind, if you dont have enough spring pressure to control the valves then you will run into valve float. which will limit the rpms the engine can turn.

please save yourself some trouble and go with the springs reccommended by the cam manufacturer. the springs that are on your heads do not have enough spring pressure for any of the cams that have been mentioned.

Originally posted by RatONaStick:
Phil

big cams and daily driving dont exactly go hand in hand. besides, even a stock BB with headers and duals sounds healthy.

or you could have UDharold make you a 280/288 cut on a 110 lsa! Big cams and daily driving don't work well unless you have a tanker truck of gas in your yard either :D Unless I played around with my carb in a nitwit fashion (which would be typical of me), I lost on the order of 4mpg going from a smallish duration (230 @ .050), high lift hyd roller to a big duration (256/260 @ .050) SR with comparable lift. 10-11mpg to what feels like gallons per mile..

Matt

Phil,if you can..just grab the Crane spring/retainer kit I mentioned..its $99 at Summit part # is CRN-13308-1 and they'll be good to .580 lift..same springs I run.You probably have stock springs that are shimmed up.
And while you're at it,order up the Lunati cam I mentioned ;) ..so $250 total.For a balancer,grab a stock or Pioneer brand replacement.

Another $250, I could never afford it! smile.gif I think I'll take a head in and have my guy check the springs for me and then just go from there. Whats coil bind? Is that the max lift of a spring?

Originally posted by pnutkemist:
Whats coil bind? Is that the max lift of a spring? Coil bind is when the spring "coils" are compressed completely. All the coils are in contact with each other. I hope that your machinist is assembling this motor and can check things like coil bind and piston to valve clearance. These are some fundamental things, and if you have to ask this kind of question(no offense meant) you should think about having the shop completely assemble the entire motor. Just my advice ;)

Phil,if you do have stock springs,and funds are limited for the spring/reatiner kit I mentioned,then you'd be better off staying with a cam that is no more .520 lift

I am using the xe274 in my 454 and yes it has a definte choppy idle. Like one of the earlier post about this cam in an Ls6 it is a rather nasty, but very powerful street cam. If I was not to lazy to change it I would go with xe268 or one of Harolds grinds, just a tad smaller. Since you are on a budget you could go with a crane energizer. If coil bind is any concern I would use the correct springs, even if I had to wait a month to get the right parts. Years ago wrong valve springs, float and coil bind cost me an engine. Now we both know better Mark