Just got a reply back from Comp Cams to my question of upgrading. Here's what they recommended: duration @ .050 of 242/248 with valve lift of .576/.599 on a 112 LSA.

Current setup is 6" rod 383 w/ AFR 190's PN 1018, HSR, 52mm TB, 3.70 9-bolt, 2800 stall; car weighed in at 3340 w/out driver. Comp Cams dur@.050 230/236 with valve lift of .544/.555 112(+4). Dyno'ed at 383 RWHP and best of 11.78 at track with ET Streets. RPM peaks at 5850 and I shift at 5950.

Going to upgrade to the AFR 195 Eliminators w/Comp Port, raise the stall to 3400, swap in my 58mm TB.

How does the new cam sound? Is it street-able for a sunny Saturday drive?
I asked about vacuum and shift points but haven't heard back yet.

 

What is the SCR??. Which pistons??.

 

SCR is 10.82:1, pistons are flattop -5cc valve reliefs, block is zero decked, align honed.

 

So reply from CC stated I'll get approx 8in vac at 1k idle with cam above. Wow...I'm thinking this will be a tad bit too aggressive.

What do you guys think about a 236/242 dur., .584/.579 lift with either 112 or 113 LS and 108 or 109 ICL?

Really just looking to gain a few more hundred RPM and use some of the flow potential of the new heads to gain more power. Thoughts?

 

Id use more stall
Get a vacuum canister your brakes will be fine
Id think youd pull a little more vacuum than that at 1000

 

what cam lobes they recommending? looks like xe, with a 1.6. I run a slightly bigger 246/252 .640 hyd roller based on comp magnum high lift lobes i believe, in a 401" sbc and its pretty aggressive. Mines a turbo cam on a wider 113.5 lsa. I get 10" cold and 12"-13" warm with a ton of timing advance and 950-1000 rpm.

Brakes work but multiple braking sessions does lose power quickly. You will want to run a vacuum canister or vacuum pump or go hydroboost like i am.

Its a driveable cam with a tune on my low comp 401, but that cam in a smaller 383 will be aggressive. 8" vacuum sounds right. You may get 10" with alot of timing and playing with air fuel.

All depends what you want out of the combo. Its making real strong power with those heads esp at the low peak rpm of 5850. Afr 195's are gonna make an easy 20-30 hp more and shift power up another 200-300 rpm with same cam as long as intake supports it, and i know it will with alittle porting clean up. Match it to afr 195 port and taper it into the runner.

For the 242 cam in a 383 i rather see you run 210cc afr's and shift at 6800-7000 rpm. It will flat out haul the mail but intake needs opened to 1206 gasket which usually requires welded up ports on the hsr base unless you got a good late year casting that already has material built up on the flange.

The 236/242 is a better grind for the 195 heads. It will be abit more driveable with alot more vacuum. By the lift numbers it also looks like xfi lobes. They are nice but hard on valve train. Def need upgrade to afr's 8019 spring and i would shim them to 1.78" install height, roughly 165 lbs seat pressure. That cam will also spin up near 6800 shifts and peak 6400-6500 rpm. Heads should flat line out by that rpm. For more i would go 210 heads.

Also if you want better track times you will need 3600 minimum stall speed.

Lastly you can copy my 383 hsr cam. Very driveable yet powerful and nasty lopey idle. Brakes worked fine, but never measured vacuum. Car peaked at 6250 rpm, held flat line to 6600, and i shifted 6600-6800. Afr 195's with 8019's shimmed to 1.775-1.780, 160-170 lbs seat pressure. It was comp magnum high lift, 230/245 .603/.613 109 lsa. 400whp on hot pull and 11.47 at 118-119 at 3450 lbs. 1.55 60's with 3600 stall and 3.42's. daily summer driver

 

Thanks for the input. Above lobes are from the XFI line. I'm thinking I'll just swap the heads and raise the stall by a few hundred and see how that turns out. I love the 230/236 setup I have now other than it nosedives at 5850.

Any idea what the 280XFI would do in my setup? It's pretty much the same as mine but with more lift and 113 LS vice 112 and 109 ICL vice 108. Would this compliment the 195's better and add more RPM/Power or....? I'd like to keep lift under .600 and RPM's at or below peak of 62-6400 shifting at 6500 max.

Orr - That last cam you mention with 230/245 is a huge duration split. I've read with the good flowing exhaust ports, I need to keep the split at 6-8 deg duration for best power. That one sounds like it was designed for a power adder of some sort.

 

You need more lift to get more rpm out of the current cam imo. Heads will help like said, but more lift will pull more rpm.

Xfi 280 cam works good and is tame in a 383. Its not a huge step up on your setup however but works in your rpm range. I would be tempted to try a magnum high lift lobe in the .600" range and 230-236 range as well. Or run the 236/242 based xfi lobes. Should really come on strong, esp with a shift of 6500 rpm.
I do like alittle tighter lsa, 109-111.

My cam turned out abit different than most and i did run some nitrous through it, but its not a nitrous cam. The large duration split did help carry peak hp beyond its rpm peak and towards redline. Consider it a broad power curve road race type setup.

 

You can get away with 4-6 deg split but what matters more is the opening/closing events thats important. You can run a single or wide split and get away with it depending on timing events and have a winner...or not so great depending. At the end of the day almost splitting hairs but nothing wrong with doing homework.

 

Here's the response from Comp Cams regarding the 236/242 options:
Ok, this is our options for the 236 242. First one has valve lift of .579 .584 and a little bit more aggressive lobes would be lift of .602 .611 and I say we go with the 112 LSA and 108 CL. It will give the cam a little better responsiveness. Which one sounds better?

I'm guessing the smaller lift of the two will be sufficient for my goals of 6200 RPM and shifting at/before 6500. Would the higher lift require any thing other than different springs? I'm guessing piston to valve clearance will be very close with the higher lift cam. Would the higher lift cam be worth that much more power?
I'm leaning towards the .579/.584 lift, what do you guys think?

 

Higher lift will be harder on valvetrain. I dont think you need to go that high for 6200 rpms. If it was a 230 lobe then yes .600 would be better. The extra 6 deg will make up for it.

Should be strong either way.

 

Bought the cam 236/242 .579/.584 lift, 112 LSA and 108 CL. Next question is the Throttle Body. Right now I have a 52mm Holley but I have a 58mm Holley sitting on my shelf. Going with this cam and my new heads AFR Eliminator COMP Ported 195's, when does the TB become a restriction? Should I swap out the 52 for the 58 while I'm into it? Also sending the convertor off to have re-stalled to 3800 RPM. This thing should move... Thoughts?

 

If you have the 58 i would run it to ensure no restriction at the intake. Certainly wouldnt buy a new one if you had a 52 already but since both are available i would go 58. Definately will move when tuned. Should pull to 7k shifts if you want to go that high

 

iv seen cams just like that pull 15" of vac. they are just being conservative.
nexed they will tell you you cant run a mech roller with EFI

 

Right on. I'll swap to the 58mm then and plan for more tuning! This should be a fun winter upgrade...pull motor, swap cam and heads, re-stall converter, swap k-member and a-arms, along with some other lightening mods. Hope to pull some sweet 1/4 mile times next spring!

 

Orr.On your combo,where you swapping out valve springs every season??.

 

Agreed. 260/268@050 solid roller 81 deg overlap 383
I have 8 in at 1000
His will be much better

 

My 383 only saw 1 season of racing before selling shortblock for turbo build. Springs seemed fine and should get 10-15k miles easily. Put same ones on the turbo cam 233/233 .564 for 2 more seasons no issues

 

Doesn't anyone find this a bit odd? Even at 383 cubes, this cam should pull past 6000 rpm.

 

Well I'm sure I could hold it to 62-6300 RPM but the chassis dyno showed it dropping off at 5850. I figured it was a combination of the smaller 190cc heads, single 3" exhaust and since I built the motor myself, I didn't want to push it. But this combo is neck-snapping responsive.

 

Did it drop like a rock or taper off? Was curve wavey? That cam could pull alittle higher in a better head

 

that first set of parts list.. falling off at 58/5900 is about right..

the cam and other parts are at the top end of there power band.
spring prshr/52mm TB. cam size... on the small side. and in a 383 it's even smaller...
most of the time you would see 5500 rpm max. then falling on its face.

exampl..take a 421/427 sbc street eng 11 to 1 cpr 220 afr elntr heads cam @50 say 248/250..620 lift =6500 rpm
and 15" of vac at 950rpm idle..= sreet car

now put that in a 383 and not so much....
in a 350...forget it....

the more cubes the larger cam feels soft...and runs the same..

 

If all is right with the valvetrain could be about right
Those 190s are a torque head the csa cant really make big just the way they are. Should rip your head off with the torque they make though. Nice pieces working on a set now.

A 210 comp port head would carry the power much further

 

Orr, No it tapers off nicely. 5850 was 383.72hp, 6000 = 370, 6100 = 352, 6200 = 344. Rev limiter kicked in at 62xx so I never recorded higher, but it was already done.

 

You are going to gain a lot of area under the curve from 5800-6500 with that new cam and 195 heads. Should be night and day, the 195's are a good 30-40hp more over the 190's on the right setup