hi guys,
ok now after finding out that small base circle cams arent as strong as standard base cams i am sending back my #08-000-8 ,230/236 duartion @.50"
with 280/288 advanced duration with 112 lobe seperation and .541/.537 lift @1.6 ratio back too comp cam for another cam.
ok well as alot of you guys now bye now i am builing up a forged light weight 388 c.i race motor with the full works/mods done and all top quality components to go with my indivdual cross ram (8) x 50 mm diameter throttle body intake with 6 speed and after market programble/tuneable Haltech ecm configuration.
this car is not a daily driver,just a hobby/toy and want to build it pretty sick!!
so im thinking i might just go a bit larger now more than the cam mentioned above.
here is what im looking at now,
# 12-468-8 or 08-468-8 comp cam hydraulic roller cam
not sure what the diffreence is between the two # though ??
here is the cams specs,
242 int,
248 exh @ .50 " duration
292 int,
300 exh @ advanced duration
with .584 " lift int
.579 " lift exh @ 1.6 ratio
has 113 lobe separtion and rev range is 2,200 rpm-6,200 rpm.
but i will see if i can order the cam with 112 lobe seperation though.
so what do you think guys please of this cams specs please ??
will it be a good performance cam with a nice lumpy idle im after ??
as thats what im after.
also i am only interested in hyd roller cam cams,not solid roller cams!!
hope to hear some help and comments please guys
cheers
shae

 

If your cam was a billet version, you sent it back for nothing. Although small base circle cast iron cams fail from time to time, I have seen stock cams break as well. Cam breakage on a street driven car is quite rare.

 

hi pete,
thanks for your reply!
so my cam isnt a billet one,but would i still be able to retun the cam for another cam do you reackon?
also what do you think of the larger cam i mentioned above please??

also does a particular cam have to be " computer compatible ' ???
thanks
shae
p.s if some other guys could chime also would be great!

 

with Pete, I don't see it as a problem unless you're running high spring pressures and high RPM, which you wouldn't do anyway with Hyd Rollers. I think that might be a problem for solid lifters and 7000+ motors. I think the 230/236 cam is avaliable in a higher lift (.600+) version, which would be some improvement. The second cam is getting pretty radical, and would be harder to tune. Less bottom-mid range power.

 

hi curveit,
how are ya!
thanks for the reply.
would this larger cam be easier to tune with this after market real time tuneable Haltech ecm though compared to the stanrd 730 ecm with chip burned/programmed ?
how much lumpier would the larger cam be over the 230/236 cam ?
cheers
shae

 

It only has to be computer compatible if you have no plans of retuning it. You "should" be able to tune either of those cams. 242 @.050 is quite a bit of duration @ .050 on the intake lobe.At least for my tastes. You will have a lumpy idle, that is certain.

 

hi pete,
thanks for the extra info.
it would be nice to find a comp cam hydraulic roller cam in the specs of 236 degrees range intake @ .50" duration and 240 exhaust ,
with about just under .600" thou lift running 1.6 roller rockers and 290 advanced duration and 112lobe seperation
any ideas or part #,s ?
thanks
shae

 

I always have comp cams do my custom grinds. I simply pick a lobe for the intake, and one for the exhaust. Tell them what type of core, base circle, and lobe seperation, and they grind it up.
I do not know any part numbers because I use custom grinds every time.
Check their website for a full list of all cam lobe profiles.

 

ok pete,
i will check there website!
cheers
shae
*happy new year to all *

 

emo-vet,

I'm pretty sure that you are on a very self-destructive path!

The first cam you talked about was kinda small. The cam now is VERY big. I think you got yourself into Cam selecting with no real PRO advice.
You should call Comp cams and talk with them about what you have got and what you want it to do! They will be exceptionally helpfull. You will be very happy if you listen to them and quit trying to pick the cam that you (and others(with NO real details of your motor)) try to pick for you.
I know I have probably offended some folks but they WILL get over it. I have been selecting cams for over twenty years and WE ALL have a tendency to select a cam that is 'too-big'.
I will be selecting the proper cam for my 383 with high-flow TPI parts and bigger heads...I WILL USE Comp Cams CAM HELP!
I know a lot about motors but I, Like MOST don't have the dynos and test-time to know the cams like the manufacturers do! I also agree with you about using a Comp Cams grind. They are the best Camshaft maker that I am aware of. As far as custom grinds go, They will make them but most of Us don't 'really' know what we need.

I hope this information/My opinion is helpful. I also hope you listen to at least some of this post. Regardless of if you want a 'driveable' cam or a 'racing' cam...the manufacturer knows them best. The specs on the last cam you named sounded like a big 'Drag-Cam'. That would be great for a drag-only car. I think you need to decide on that 'drag' thing though. That cam wants a high=riser intake and big Carb, Not Tuned Port Injection.

You Take Care and Be Safe, -John

 

hi john,
how are ya!
thanks for the reply back.
well i just got of the comp cams website from helpful advise from pete k and had a good search for cams.
so what i have found is that this time i will order the cam in standard base cirlce not small base circle.
then i will order the cam in steel billet for strength as my engine parts i have ordered and brought are all forged steel.
then i will order the cam with a lobe sep of between 110-112 lobe seperation.
in the xfi hydarulic roller series cams there was tow cams with a duration @ .50" of 236 intake size which is between 230 and 242 size i was intially looking at buying.
lift @ 1.6 ratio comes in at .571 " ,so the new afr comp heads are good for up too.600" lift so that should be ok.
but i will ring comp cams tech staff tonight my time and see what they reackon,but i tell ya,its a long wait on the phone to the tech guys @ comp cam.
some times waiting for up too 15 minutes or more just to be able to get to talk to them.
any way thanks for your advise john.
cheers
shae

 

Hi Shae
How are you... If you're building a stroker, a small base circle cam is often required to clear the rods. Some rods will clear, and some you have to grind. With a small base cam, you can be pretty sure they will clear. You'll know on assembly. This is what I've always heard; perhaps someone else has a different opinion. If you still wish to get a bigger cam, I would keep the LS at 112* and go for .600" lift with an intake no larger than 236*, with an exhaust 4-6* more. The 230/236 will still have more bottom-mid range power.

 

hi again curveit,
r.e the rods mate, i brought are esp eagle forged 3d feather weight H beam rods that have arp 12 point bolts.
yeah i was hoping for a cam of 236 intake plus 240 exhaust and yep as you said keep lobe sep @ 112 !
now that i know that the small base circle cam is much weaker than the standrd base circle cam i will get the standard base circle but also i will get the forged steel cam shaft this time.
thanks mate
cheers
shae

 

I wouldn't say a small circle base cam is much weaker..... Sure they break in some race engines but you have to remember that in these engines we are running springs with 250+ lbs of seat and over 800lbs open pressure. Not to mention they occasionally get spiked to 9000+ RPM out on the track. Since you're looking at Hydraulics that can't have a seat pressure anywhere near what a solid runs not to even get into open pressures, why are you betting on breaking that cam? One more thing, the biggest cam you picked is not a "big drag" cam; that cam would be right at home in a 427+ cid street engine.... For reference, one of the cams we are running now in a fast street car has 276/284 @ 0.050; and this is being run in a 355cid. Sure this is a totally different animal than what you're dealing with and probably want; but the point is, seek out a builder that you trust! Whether it's on here or locally, talk with them and make sure they know exactly what you think is acceptable street manners and things like this. They will be able to talk you through how these parts will work together and how this engine will behave. It's just my opinion but a person that builds 100's of engines a year for all different racing classes will know a lot more about parts working together than the comp cams tech line....

 

hi deakins,
how are ya!
thanks for the info.
i wasnt hoping to break the cam its just another guy posted on here with a picture of a broken cam that was a small base circle cam so i thought that there no good.
so you dont seem to mind very large cams in street engines hey,i like the idea of a big cam engine actually too.
but not as big as you mentioned,proberely around the 236/242 intake mark with 240/248 exhaust mark with 110-112 lobe sep and around the just under .600 " lift mark.
but i will get billet cam this time along standard base circle.
any way thnaks for your info and input mate!
cheers
shae

 

The cam you have will do fine and won't break with hydraulic spring pressure loads as long your spring pressure and lifter preload is right and the lifters are not banging on the cam,,, or that there's not enough core shift to put a wierd load on the cam. Also must note that a good dampner is necessary for any engine,,, a crap dampner can cause all sorts of havoc.

These are the lobe #'s from the e-mail I sent you back in October recommending it on a 111 spread. It was what I thought to be the best compromise for you.

3017 286 236 159 .362 .090 .075 .543 .579 .615

3038 294 242 163 .360 .102 .087 .540 .576 .612

You went a little smaller,,, and typically that's beter than going too big. Still,,, there probably isn't 15 peak horses between the one you have now over the 236/242. Average power from 2500 - 6500 would be about the same, trading a little up top for a little down low. If you're going to be cruising around in it,,, you'll be extremely happy with the the 230/236 you have now.

If you just have to go with another cam, I'd ay skip right up to the 242 lobes on the intake and the exhaust on a 112 spread. That'll be worth about 20 peak horses,, again making about the same average power,, trading low end for top end. Considering the AFR heads E/I ratio and your true duals w/o cats,,,, adding 6-degrees to the exhaust won't give you much and the single pattern cam will pull a little more vacuum,, making it a little easier to "tame"

 

hi kevin,
how are ya mate!
hope you had a good x-mas day buddy!!!!
glad to catch up with ya again.
im sorry i didnt come too you and mention cams again mate, but i feel that asking you too many questions is pushing my luck.
but i do value and appreiate your expierence and good advise very much mate!
im thinking to get another cam any way but in forged this time to match the rest of the forged internals even though not neccesary and go for more lift than the one iv got plus go a little larger than what iv got.
for me i like fairly lumply idle cams.
so yep those two cams you mentioned are exactly whats in my mind.
you know how you wrote those cam numbers what you have posted now,well back in october in the email,i think the problem back there was i didnt really under stand what they all meant but do now.
so that where i stuffed up last time mate.
any way im thinking i might just take the plunge and buy the 242/248 cam in billet with standard base circle and 112 lobe seperation.
so thanks again for your help kevin.
i will catch ya soon no doubt.
cheers
shae