emo-vet

hi guys,
im still looking at which cam to buy to go with my 1991 L98 390 c.i stroker ,8 seprate t/b indiviual runner intake ,afr 195 cc ported comp heads,e/water pump,single mass 22 lb fly wheel, 2.5 " true dual mandrel exhaust with x-pipe,long headers,1.6 ratio roller rockers,6 speed 4.10 ratio diff,faster proms custom chip work, e.c.t

now what is difference between solid roller cam and hydraulic cams please ?

how come the solid roller cams kick in so high rpm ?



what is better please ?

some guys like solid cams,other hydrauilc rollers,im confused now,

some are saying get a cam with lower lobe separtion numbers around the 110-112 e.ct also ?

the cam i was looking at buying is a # 08-468-8 with small base circle of 1.050 " was recomended by com p cam tech staff to suit stroker crank set up !!
here is the specs,
242 intake / 248 exhaust @ .50" duration,
292 intake/ 300 exhaust advanced duration,
584/579 exhaust lift running 1.6 ratio rockers,
113 lobe separtion,
rev range 2,200 rpm- 6,200/6,400 rpm.

i dont want a cam that cuts in to late in the rev range and i like a cam to have agressive idle/lope sound also, thats why i thought i would choose such a cam above.
valve lift has to under .600" lift to suit my new afr comp ported heads as well.

this car is a street car but not a daily driver also so not to fussed on driveabilty at all.

any ideas guys on cam models,brands,prices,cam specs please?
any help would be great thanks guys

thanks alot
cheers
shae

rodj

242 intake / 248 exhaust @ .50" duration,

Those sort of duration # are getting into the not enough vacumn to operate brakes area and a very rough idle.
Solid lifters are better if you are running bigger lift / or higher revs.

emo-vet

hi rodj,
thanks for your reply!
so a solid roller cam will give more hp and power then please ?
so what about a 230/236 duration @.50" hydraulic roller cam then r.e vacuum preasure then ?
so should i go hydraulic roller or sloid roller then ?
thanks
shae

rodj

"so a solid roller cam will give more hp and power then please ?"

Hp is dependent on the lift / duration all else being equal.

A solid and a hyd cam of the same spec will give similar performance.It is just that a solid is BETTER suited to big lift and higher revs because you don't have the problem of the lifters pumping up.

The long duration ( overlap ) not big lift is what gives low vac and rough idle

The cam you mention is a popular one for street use.

Zix

That's not always true. I'm running a 242/252* @.050 duration hydraulic roller cam in my 383 LT4 and it's my daily driver. I have zero problems with the brakes and the idle is lopey, but not rough...though I raised it to 975 RPM to help that.

Also I run the car to 7200 pretty frequently.

I would recommend this can to you, but it likes to make power a bit higher in the rev range than what you're looking for it seems. I'm still making power at 7200 RPM...not sure where the drop off is, and won't know until I put shaft rockers on and get back to the dyno for a 7400 RPM run.

The cam specs are;

242/252* duration @.050
.55x/.56x lift wth 1.6 rockers
110 LSA

Solid cams benefit by being able to have much steeper ramp rates that hyrdraulic cams can handle

BADDUCK

On a car you drive mostly on the street I would stay with hydraulic roller cam. If you are building to be very competitive on the strip at HIGH rpm's go with a solid roller.

conv90

Solid or roller...
...
I like to play with Harley-davidsons engines. Lifters are Hyd.
If you put solid you have the same advantages of automotive .
"Jim's" it's a leader brand in H-D tappets. They made "Hydrosolid".
These lifters are hydraulic under a certain rpm level and they becomes solid over a certain rpm level.
The same is achieved by "S&S" (another leader brand in H-D aftermarket..) by their HL2T kit (It's an hyd. limiter travel kit).
Is there something similar in the automotive field?
-Beppe-

cv67

Rhoads (last I heard) makes a hydraulic roller lifter now, may want to look into it.

Used their hydraulic flat tappet lifters in a few engines, I was very pleased with them. THey bleed off a little at idle/low rpm making a large cam act/sound a little smaller and more driveable. At around 3k on up they "act as a solid would".

emo-vet

hi guys,
thanks for your replys so far,
i heard that with a solid roller cam you have to adjust the rockers more often than the hydraulic roller do you ?

any way i just wrang comp cam tech department,
the tech guy gave me another cam spec which is a custom grind

# 08-000-8-3016-3037 hr-112,
specs are 230/236 duration,
280/288 advance duration
577/572 lift @ 1.6 ratio rockers
112 lobe seperation
2,000-6,200 rpm range.

i gave him my mods /specs and this is what he came up with.
what do you think about the cam just mentioned guys please?
and also the rhoads lifters may be the way to go actually as you mentioned cuisinartvette
thanks
shae

pr0zac

i think i have mentioned to you before about the 08-476-8. its a love hate. being that you have an auto you might like it more. rpm isn't everything. ramming the biggest cam off the shelf isn't the answer either. unless you have a big stall and some 4.10's or better you aren't going to like a big cam.. its not exactly fun driving with a 4000 rpm stall around town and just wait till it locks up with that big cam. i hope you have the greatest tune out and there is no shudder or surging. i know you are trying to design a high revver but you are going to have to make up for things in other areas where a "real" custom cam would probably get you closer to what you want.. i am sure whatever comp has isn't going to make you as happy as you could be. i have run big cams and small cams in my cars, and while the big cams are fun when you are flooring it what you give up by having it isn't always worth it. if this is a street car you really aren't going to get the chance too often to stretch out past 7000 rpm's, i know at any point other than first gear my car is revving over 6k i am breaking the speed limit to the point where i could be put in jail so i don't really see how its even worth it to want your power band up much further past that.

pr0zac

btw don't even bother with rhoad's lifters.. i have yet to hear someone that actually says they work worth a crap or anything positive for that matter..

cv67

Ive used them in 3 different motors, 2 big blocks, (460, 396) 1 small block (350) with 0 issue.Made a big flat tappet cam driveable.
Also with solid rollers you dont need to check lash all the time, just use the best rocker arm you can get. Old school flat tappet cams with the stock nylon (POS) locknut/rocker arms, yes you had to adjust them all the time.

pr0zac

that whole idea makes no sense.. its like driving a really fast car with flat tires. if you don't want to deal with the cam...... DONT PUT A BIG CAM IN YOUR CAR..

cv67

Depending how you look at it, you ca nhave your cake and eat it too, especially with the sensitivity of EFI . To each their own

emo-vet

hi prozac,
thanks for the info.
btw, im running a 6 speed manual,not auto.
r.e the cam number you mentioned 08-476-8 did you mean # 08-467-8 did you mate ?
i am thinking of running either 3.90 or 4.10 rear gears also.
the largest cam i was thinking of buying 242/248 duration,292/300 advance duration with 584/579 lift ,with 113 lobe seperation,kicks in at 2,200 rpm and is good for up too 6,200 rpm, and not 7,000 rpm
so what does a lower lobe seperation do for performance say like 112 compared to 113 lobe sep please ?
thanks to you other guys for your help and talk on this cam matter.
cheers
shae

conv90

It the SAME custom Grind I have. Me and Pete K we requested this custom gring. (Billet core with pressed gear on a 87-later roller cam)
Comp cams said it was the first one they made with this configuration (Billet core with pressed gear on a 87-later roller cam).
Ask for a discount
-Beppe-

conv90

I don't thing it's like this..
For what I understand, the Rhoads allow to bleed more at lower rpm (decreasing lift and duration and raising vacuum at idle..) and acting as a NORMAL hyd. at high rpm (where it follow the advertised duratio/lift specs).
-Beppe-

emo-vet

hi beppe,
are you happy with the way your cam sounds ?

does it sound quite lumpy at all ?

is there any improvements you can think of with the cam such as smaller lobe seperation or may ne more duartion or adv duration may be ?,o r may be a little more lift ?, if i was to order it in another configuration grind ???

and how about performance, does it kick in nice and not to late in the rev range ?

how about does it also give you some nice revs gain ?

thanks
shae

pr0zac

the 110 lsa is going to push your power band up higher.. the 113 will make it a broader curve.. yes i got the numbers backwards.. i have a 355 lt4, that cam(230/236 .576/.571 113), comp pro mag 1.6's, crane 10308's, 4.10's, 12lb single mass with a stage 3 clutch, shorties, gutted cats 3 in duals with slp mufflers.. if i were to do it again i would get a little heavier FW more compression and maybe a custom BRE cam.. that cam doesn't make as much as i would have wanted and even though its on a 113 its still mostly up top.

emo-vet

hi prozac,
thanks again for the reply and info mate!
whats a custom BRE CAM ?
so really the 230/236 cam you have is not really big enough for your liking isnt it ?
i think i will just take the plunge and buy the 242/248 duration, 292/300advance duration, with 584/579 lift running 1.6,2,200-6,200 rpm.
cheers
shae