solid roller question
 

Ok, i just got a solid roller cam from a friend. it was a custom ground cam that he used with his super ram setup. the specs are as follows (he lost the cam card, so im going by what is stamped on the rear of the cam):

255/262° @ .050
.575"/.575" int/exh lift with 1.5 rockers
ground on a 114° LSA

i also got an isky valvetrain from him as well (both were used for 1 season). this is going into a street/strip motor with nitrous. the valvetrain consists of:

Isky solid roller lifters (standard .842" dia. no offset, tall kind)
Isky double roller timing chain
Isky Rev kit
Isky pushrods (shortened for use with taller lifters)
Isky titanium retainers matched for springs
Isky valve springs (p/n 9945-RAD)

My MAIN question relates to the spring. If you go to isky's site, there are 2 listings for 9945. the 9945 spring and the 9945 "tool room". the tool room (the one i have) is cheaper, but they dont list the specs for the springs. So i am assuming that they are the same as the regularly listed 9945's? my main concern is that those springs are waaaaay too much pressure for the cam. if you look at the cam that comp offers with the 2 grinds, you will see that comp recommends p/n CCA-977-16, which is a far less "aggressive" spring. i tried calling Comp, but got put on hold forever. so are the Isky springs too much for the cam i listed above, or are the CCA-977-16's in order....

Also, on a side note, under the technical part of the similar cam, it says "....Maximum street effort, racey idle, 3500 stall, low axle ratio, and 10:1 compression." I have no problem with running that combo. But how "low" is low gears?

look at isky's site or catalog and see what spring the recommend. even if the cam is custon ground i bet it's still ground to a cam series they list i nthe catalog. WAG but looking at lunati i'd look into the 74555 spring. i wouldn't run the springs you have not that they may not be good springs but they're used and it's not a wise more to used old springs.

Holy smokes: lunati 74555

p/n: 74555
Installed height: 1.900
Installed Load: 230
Height 2: 1.250
Load 2: 630
Coil Bind: 1.025
O/D: 1.550
I//D: 0.725
Max Lift: 0.815
Damper: Yes

isnt that a bit much?

Your dealing with a billet roller cam here. It can take alot more spring pressure that your average hyd/flat tappet camshafts.
If in doubt CALL isky and talk to a tech. They make some of the
best valve springs in the business.
As for gears, I would say 3.70's would be a good starting place.

If your installing a solid roller cam set-up, you cant have too much spring pressure period. I would reccomend getting new springs regardless so you personally know that they're up to task. My AFR's have a realitively light spring set-up for my roller at 570lbs @1.250 and can only take a .660 lift cam with coil bind.

Ok, kind of reviving this.....

how would that cam live on the street? from all the cams i have seen, that kind of duration is borderline maximum street vs. strip. Then again, they are all ground on 110° or smaller LSA's. Im willing to go out on a limb and say that this cam will pull a better vacuum/idle.

I called Bullet cams since they have a great reputatuion for killer race cams that are consistent, very fast, and yet easy on vavletrain parts. I told them I was gonna freshen up my 355 shortblock and install pistons with around 11.5 compression and I wanted a cam that would make great power, bracets races every weekend both days and sees street miles during the week when time/weather permits-plus is pump gas friendly. Some other info was exchanged but that's in a nutshell. Here is the response I got back from them:

4/7 swap is ok but this is a very small deal 8-10 hp max
we can supply cam for stock distributor gear
11.0 to 11.5 compress is ok
cam grind
CHS280/285 R10
249/254 @ .050
621 lift int & ext w/1.5 rocker
110 L/S
cost is $275

I wondered about getting the 4/7 swap cam core to base the grind off of but again I was told it's not worth the extra money for a small motor. I did want an iron gear so I did'nt have to run the junk, engine eating bronze dis. gear and getting it is not a problem. I was a little taken back by how conservative the cam they reccommended actually was, but I did'nt want to take the motor over 7200rpm either, hence the lower duration. My heads are good to .660 so I may just step up to 1.6 rockers when I order them for a little more grunt. My current cam is ground on a 109* LS 230/230 actual duration292/292 advertised and has enough vaccum to run power brakes, I'm still wondering with this new duration and 110LS if I'll have enough to use the power brakes or not, forgot to ask:doh: But I was assured this would be just fine on the street even though I only drive maybe 1000-2000mi a year if that-just lots and lots of 1/4mi. hard passses. I've read and read and read, now it's time for me to just bite the bullet and try it so I can have some real world facts to tell which this car of mine has been a rolling experiment from day one with different combinations so why stop now. If you want a serious cam give these guys a shout, all they deal with is race cams period-their speality. Everything I've heard from guys running their stuff is positive so I figured these guys are all very successful on the track, why not. Not taking away from Comp, Isky, etc...

Ok, im looking at their site under thier master list. the lift they give, im assuming thats given in lobe lift, not valve lift?

LOL, yeah that's actual cam lobe life, not total. I was going through there trying to find something close to what I wanted, but just said the heck with and contacted them so I could get what's better suited than what I wanted. I was looking at the infamious Lunati 50140 that everybody claims make crazy power in 355-406's but that just wasnt a street cam at all, didnt even get wound up until upper 4000 range.

LOL, ive heard about that cam. But i will take Comp over Lunati, but thats just me. And ive done tons of searching and not finding much. Im finding how a small LSA (106-110°) and fairly large duration (250+ @.050) work together. But im finding very little, on how a 114° LSA would go with 255/262°. I know that larger durations move the powerband up generally (in conjunction with smaller seperation angles) and smaller durations/larger seperations tend to drop the range. I also know that the smaller LSA's make for a racey idle. I'm not too concerned about the racey idle. Im more interested in compatability. I guess im kind of geting confused on how this will all work out then. its got the kind of duration that moves the powerband up (3000+), but yet has the lobe seperation that would drop the range. One of the reasons that I got it was of the minimized valve overlap. Ive read that Nitrous does not like valve overlap. and the Comp nitrous cams have what, 113° LSA? Hmm i guess my real question in all of this is, with the given duration and LSA, im really interested in knowing just how streetable it will be. I think im gonna pop it in and find out:) . Here is my SLOW goal:

-dont know carb size yet
-Victor Jr. with spacer in the form of nitrous plate
-Heads with 200-220cc, running ~10:1 compression (leaning towards the 200cc side, 215 maybe)
-All bolted up to a 355 ZZ4 block
-Hedman long tubes, true duals
-TCI Streetfighter converter/TH350
-3.73 gears, not sure

Thats my slow build up. i have a seperate engine im running while its being built. Feel free to tweak anything you see fit. I DO plan on running a vacuum can or that electric vacuum pump thats offered.

That's almost my combo:) Currently just bought my TH400 w/ T-brake all the goodies-$1K though and I still need a convertor, which is gonna depend on my motor-viscious circle. Have my AFR 210's, ordered my Ford 9" with full spool and 4.33 gear set since I'm going 29x10.5 this year-might be too steep, but I'll have to wait and see. Short block is just gonna be a basic 355 with as close to 11.5 as I can get for compression, victor jr. with 2" Wilson tapered spacer-dyno trick 20hp everytime, 950HP carb, the Bullet cam they recommened, I may call them personally and talk to Bill, I guess he's the go to man, before I actually purchase a cam to see how close he is to the owner of the company. I'm hopin to be mid 11's since the cars already a tank, and the 9" and TH400 are just adding more to the mix:mad: If it's slower I'll be upset, faster well, heck ya baby:)