I'm pursuing more power from my engine combination and so far, I've been recommended a couple cams from Cam Motion and BTR, as well as a couple cams I've selected that i think might fit the bill. The engine is a factory ls1 block, bored out 3.905, eagle stroker crank, eagle rods 6.125, and Ross -9cc forged pistons with valve reliefs. 2000 Camaro m6, nearly full bolt ons, UDP, Hooker LT 1 5/8 headers, Hooker catback, no cats, fast 90, NW90TB, slp lid, 85mm maf. I'm limited to 91 octane that will have up to 10% ethanol in it because of our wonderful state legislature.

Here's where things get murky. We built this engine in 2006 with a set of used 317 heads from a speedshop out of Florida that were "welded", cnc ported, polished, and milled to a static chamber volume of 50ccs(supposedly). The first time we ran these heads (2005) with a 224/232 112lsa cam, we didn't have enough PTV clearance, which broke some ringlands and necessitated a rebuild, hence the 3.905 and stroker kit. Ferrea 2.055int, 1.6exh stainless valves. The porting looks decent but as far as flow numbers or port volume I have no idea. There's some stampings on it from the machine shop that built the heads, but nothing comes up in the search function. Best I can tell it's a work order number with CNC-T stamped on both of them. The heads will be coming off the car to check deck clearance to see why my machine shop threw a set of .060" graphite headgaskets on it (Shop labelled DC as .007, as in .007 in the hole). The SC is either 11.8:1 OR 12.4:1 depending on deck clearance measurement being above the deck or in the hole.

I have a set of mint, low mile 243 casting heads that I can send off to TSP or FED or TEA depending on what the budget looks like after the holidays.

Anyway, I've been recommended:
Cam Motion Hot Street Stroker 239/247 .621/.604 113 +3
BTR Custom grind 235/250 .629/.629 112.5LSA
And the cams I've arbitrarily picked by skimming a catalog are:
TSP torquer v4
TSP BFD 5.7
TSP Stroker 244/248

I'll also be replacing the lifters while the heads are off, they are EGW stock replacements and I'm pretty sure they won't live long with these high lift high duration cams. If anyone has a recommendation there, I'd appreciate it.

So, option A would be to use the 317 mystery meat heads after CC'ing the chambers, runners and possibly getting someone to benchflow them and pair a recommended cam with it.

Or option B, send the 243 heads off for a full cnc port and valve job and spec a cam to it and have lower static compression (11:1) with a matching cam using good, valid flow data and known good engine combinations.

I'd be thrilled with 450rwhp, but more is always more and ofc better. Strictly a weekend car that might go back to the track once or twice a year when it's done.
What say you?

 

450 whp is very doable with a good set of ported 243's and a reasonable size cam that will drive nice. I'd consider the following.

1) Replace the 1 5/8 Long tube headers and go with a least 1 3/4 primary Long tube headers. I run 1 7/8 on my 383 LS1 stroker

2) Ask whomever ports the heads to recommend a custom matched cam for best results. Sounds like you're considering excellent head porters. I'd add Mamo Motorsports to the list if you can consider aftermarket heads as Tony is top notch. He can set you for a 500whp+ 383 LS1

3) Consider getting the Fast 90 & 90mm TB ported. If you go for 500 whp, sell the 90mm Fast and get Tony to port a new Fast 102 intake and 102 TB for your car.

 

New LTs are definitely up there on the list, just focusing on internals for a minute until I'm squared away. Could go full bore and tuck some 2" headers in there and have to clearance the subframe for them

I don't want to ditch the fast 90 just yet since I just bought the NW90 TB to get rid of the paperweight Fast 90TB, that thing was downright dangerous. Maybe i can catch a 102 on sale somewhere.

I'll see what cam the shop I pick recommends and go that direction, do you think it's worth the time to send out the 317s to get any data out of them or should I just sell them as is? I hate wasting good parts, but it just won't work on my short block due to several issues.

 

Since limited to 91 octane, I would do 243s. Ported or even a good hand port will do. I wouldn't mess with milled ported 317s.

As for cam, some in 235-237 intake duration would work nicely. LSA would depend on driveability and if NOS might be used. I'd go a 113 LSA.

1 7/8 headers definitely.

Port and smooth out any rough edges in Fast 90 yourself with sanding rolls and drill.

Good luck with your build.

 

The 239/247 Cammotion cam has 17° overlap.
the 235/250 BTR cam has 17.5° overlap.
Almost a toss up. Personally, I'd go with the Cammotion cam. My HO......

 

I’ve got a Tony Mamo custom specced cam that he specced for my 383 LS1 with MMS220 heads, it is sitting on the shelf not being used. I ran it for about 800 miles before I decided to go turbo. Car made 490ish on a mustang dyno with his heads, ported fast 102, and a s60 rear. Shoot me a PM for specs

 

Before you buy a cam you need to let them know that you live in co and what the average DA is if you are racing it. Higher altitudes require 3 things to get a car to perform. Compression, gear and converter. You need more of these 3 then a sea level car. Typically at 6000 DA you are loosing about 15% of your power from the reduction of oxygen molecules. So you need to squeeze it more to make power. This also lowers your dynamic compression substantially. Talk to Bobby at cam motion and tell him what you got and where you live and go from there.

 

Also the strokers need to breathe. A fast 90 won't cut it. I would get a 102 and have ws6store port it, or mamo if you have the coin but I haven't seen a comparison to determine value. Texas speed 1 7/8 headers bare minimum. Check your piston to deck height and get the right gasket on there. You want around
.040 quench. You cluld go tighter but you need to be dead on for measurements and know exactly what you got. And a 50cc 317 sounds like trouble to me. That's a lot of material removed. I would verify that as well and ask some shops here If that's even ok. Too much milling can cause big problems.

 

Inb4nawsssss

 

look up the richard holdener 600hp video on youtube

i'll save you the trouble, but long story short he runs the comp 54-459-11 in a 383 iron stroker (5.3 bored/stroked)

if i recall, that build had TEA ported 243s and a fast 102.

 

As mentioned 1 7/8 headers,

any head milled that much will have trouble sealing up the intake.

the fast 90 will work, but yes get in there and smooth up the rough edges. wouldn’t go further than this if you don’t know what you are doing though.

cam is subjective, but I’d shoot for a hair smaller on a 383 than you were looking at.

a borescope thru a plug hole should let you get a look at the piston height.

 

Been there done that lmao, different car tho.

Thanks for all the suggestions so far, Bobby at Cam motion is now recommending the Titan V, 232/238 113lsa+4 with the 243 heads using FED's flow numbers and a slight mill to achieve 11:1 SCR. I need to call FED and ask them a couple questions, but I'm pretty set on them, their midlift numbers rival some very high-end aftermarket heads that aren't going to be available for quite some time.

 

Maybe try prc 237s?

 

OP, The Cammotion cam you are looking at is designed for rec port heads....not ideal for your heads. I would look more at the Cammotion Torquey Stroker cam for your application as it says 383-418 motors. 235/242 621/604 on a 114. 10.5 degrees of overlap is gonna behave nicely on the street. I would also send those 243s to TEA for a quality cnc job. lastly, add a fast 102/102 combo.

 

Richard Holdener has proven repeatedly that there are no "cathedral cams"or "rec-port cams" . Many of one kind work quite well in the other situation.

 

Bobby at Cam Motion says the same thing, the first cam he recommended was a rec port cam in their catalog. More about timing events than anything related to Port design.

 

Yes, you are correct, he's running TEAs in that motor. That comp cam is 239/247 with ~ .625 lift, pretty much the same as that cam motion.

I run this comp cam with AI ported 243 heads in my 403" LS2. I'm happy with it, its extremely torquey from 3600rpm in my setup. (11.8 static comp, works out to around 8.5-8.7 DCR, I Think. I run 92 and have no issues) I pull to about 6800-7000 rpm. I run a FAST 102 and a 102 TB, and 1-7/8 headers.

 

for what its worth i am also building up a 383 LS1 and plan to use the summit pro ls 8708R1 camshaft. it is similar in specs to the comp 54-459-11.

 

I’ve watched Holdners vids and know that either cam will work in any application, but why not look for a cam more designed for a specific head? Why do cam manufacturers even bother listing cams as a rec port design or cathedral design? IMO, if someone is building a motor, may as well optimize it by using parts designed specifically for a certain application....less of a crap shoot.

 

I think it's more about port flow and velocity. Wouldn't a cathedral port flowing 300cfm @.500lift and rec port doing the exact same thing at the same velocity require the same cam?