dolf

I have a 383 that is going in my 68 camaro. I have most of the parts already but need help with a cam and proper valtrain components. This is my DD so reliability is a must. With that said I don't mind a decent sized cam. I do autocross so a broad curve would be nice. Here is what I have already.


Forged bottom 383 4 bolt
AFR 195 El. street port. 65cc. (shooting for 11.25 comp ratio after milling)
Edelbrock air gap (will prob port and match to the heads)
Pro systems carb. (will be custom made for the car once cam is figured out)
Dougs 1 3/4 to 3" x pipe and 3" borla xr-1's

The car also has a t56 and a 12 bolt with 3:73 posi.


Now should I go solid roller or hyd roller? What cam would you guys suggest as well as valvetrain components? Thanks

kenSS

iTrader: (1)

i would go hydraulic roller for DD. A set comp pro magnums rockers and possibly a gridle should be fine.

ZONES89RS

iTrader: (25)

Depends, you want to have a rough cold start or easy? I see most solid cams have a harder time starting when cold. The hyd arnt bad. If you arent going for max power, hyd roller is the best way to go.

Something with what you want would be a custom grind. Call comp and see what they recommend.

dolf

I was recommended the comp xr288hr. 236/242 110... What would the manners be with that cam in a 383? I'm hoping with the 3:73's and t56 the bigger cam will be easier to drive at lower speeds. ANy one have an idea on what ratio rockers would work best? I know the AFR's like lift so I was thinking a 1.6. Any ideas?

HotRod H269

I would go with 1.6,be sure you check piston to valve clearence.

ZONES89RS

iTrader: (25)

Here is what my 383 sounded like with the same cam:



I was happy with it, drove verry nice and with my BS heads i was killing head and cam LS1 cars.

Shifted at 6200 RPM, i had 2.73 gears and 9.7 to 1 compression and it still killed most cars i ran across.

Oldsmobility85

iTrader: (1)

If I may add my two cents I think that you are on the right track with your build. A hydraulic roller daily driver is a very nice luxury compared to a sollid roller. A mid 230s duration camshaft @50 should suit very well with a cylinder head of that style. I also think that 1.6 rocker arms are a nice touch to street engines with lower lift camshafts (lower lift being low 500s) if you put 1.6s on a 530ish lift camshaft your overall lift will still fall short of 600 wich makes things real easy on the valve springs but the faster valve lift speeds really force the heads to start working sooner wich is good. I think you will like that setup. And with having a few more cubes helps the engines manors for street driving as well.

DeltaT

iTrader: (5)

I am a proponent of modern solid roller cams. I have one in my current 383 and it will rev easily to 7000rpm, although the cam itself runs out of steam around 6400.

With a stick, I would do something like a 236/242@.050 on a 110lsa. If you don't want to spin it that high I would drop down to a 230/236 and keep it below ~6300rpm.

You can have it all with a good roller: high vacuum, smooth idle, killer midrange and a top-end that seems endless. Add in the very low maintenance on these modern rollers (Check every year and adjust IF needed - most of the time they don't need it) and you are golden.

Jim

dolf

How would the 230/236 power curve be compared to the 236/242? I'm thinking it might be a better route since I do autocross. I may even drop the comp down a bit to run lower octane gas seeing as it's a DD.

dolf

A 230/236 110 with higher lift and fast ramp rates would be a tq monster right? Anyone know any custom cam guys here that can help with lobe selection and what not?

DeltaT

iTrader: (5)

A solid roller 230/236 will idle like a 222/227 hyd. roller and will be a definite torque monster with those heads. And it will have awesome mid and top end. I like Comp's Extreme Energy Street Rollers, and their P/N for that cam on a 110LSA is 12-769-8.

With your heads I would set it up with 1.6 roller rockers and let 'er feed!

Jim

ZONES89RS

iTrader: (25)

In reality, it would please you, but you will end up wishing you had the 288HR. Trust me lol.

swv

http://compcams.com/camquest/default.asp

BOWTIE

Not sure if you can still get Crane grinds anymore, but there PowerMax hyd rollers were very strong. In fact I will stop short of claiming GM is using Crane Cams in their crate motors, but if you check out the published specs for the cam in the GM Performance Parts ZZ383 that is supposed to make 425 HP/460 TQ, it is identical to the Crane Powermax 222/230 .509/.528. That cam should make power to 6000 maybe more with a set of 1.6 rockers. The next one up is 230/238 .539/.558 (.575/.595 with 1.6 rockers). I have the 222/230 in a 355 with an old set of Dart cast iron heads that was built in 1995 that made 425 hp on an engine dyno and is still running strong to this day.

ssdeuce74

iTrader: (2)

most these guys are on target but do you need vacum for acessories if not low 230 duration lift at or under 550 110 is good for sbc most run better with that then 108 give you the mid range for carvin up the corners road course is not all top end just my opinion but i do run nothin but sbc my nova has a 250 duration 555 lift 108 ceterline powerband 3k -6600 and its really to big but it was free.

jj62

I also autocross.
Are you slow speed under 80mph or high speed over 80mph?.

First off you have a great set up except for a DD with 11:25.1 compression you'll
rattle the motor to death on pump gas. Now days with all the new parts and tech available no more then 10:00.1 is needed. Even better 9:5.1 as the gas gets worse all the time. If you stick with the high compression you'll need overlap to bleed some compression off and will that affect your DD driveabilty.

As for a cam on a low speed A/C you'll want one that comes in off idle with tons of
torque. To pull you threw the corners and turns w/o a lot of shifting. So I would recomemened between 500-525 lift, 222-232@50 duration and a 106 lobe center angle. More duration if your doing hi speed A/C on a larger track.

If you can afford a $1000.00 for the ISKY 9000 series solid roller lifters go with them.
But don't use cheaper set with needle bearings for autocrossing. They wouldn't get enough oil while your in slow turns and will come apart on you. I had it happend and it cost me a block.
So either a hyd roller which is fine or a solid flat tappet lifter.


62 vette, 383 stroker, 469hp, 453lb torque, 4speed,373gears.....

RedGut86

iTrader: (1)

As a fellow autocrosser, my only concern is low RPM vacuum here. This can apply to both the hydraulic and solid cams though. Make sure, especially with that compression that you have enough overlap to prevent knock but also good vacuum, you don't want to be fighting rpm as you slam on the brakes approaching the finish/grid.

I keep hearing more and more from people like DeltaT that with polylocks solids are not bad at all, it is a huge PITA for me to take off the valve covers...so I don't know yet. It sure can be tempting though.

Let us know how it works out, I'm interested to know.

P.S. I've yet to hear someone be upset with the 288 but I'd like to hear more about the xfi series (268,280,292).