Engine: 357 cid 4-bolt main 1pc rear
Crank: STEEL GM crank #14088532, cut .010" under w/ Clevite H bearings
Camshaft: Comp Cams CC-306 (230/244, .510/.540, 112lsa 110ctr)
Pistons: SRP-139629 reverse dome, -16cc dish
Rods: SCAT H-BEAM 5.850"
Heads: TrickFlow TFS 23* alum, milled to 55cc
Manifold: TPIS Miniram, 58MM BBK Throttle body
Exhaust: Hooker 2149 long tube headers, carsound cat, dual exhaust
Compression: 10.14:1

Whatcha guys think on power / torque?

-- Joe

 

Looks like you got me beat!

 

heh. no guess on power?

-- Joe

 

No reason that combo can't make 400hp or more at the crank.

 

I'm going to guess about 480hp and close to that tq wise. DD Dyno seems to overestimate from what I hear but its in a Corvette so thats good for another 30 hp right?

 

I will venture a guess,,,

350 RWHp @ 6200rpm.

 

Sounds about right to me.

 

how about a guess on my setup?
4bolt main .030 over 383
-5cc srp flat tops
forged eagle crank 3.75 stroke,5.7 h beam rods
afr 195's 74cc w/spring upgrade
cc306 (same cam)or a recomendation.
crane gold 1.6
HSR.58 mm tb
hooker 2055's
singlecat cat. cat back flowmaster 3"in3" out dual.
75-100 shot to be added later

 

i think i'm gonna be mad if you make more power than me with the same heads and less cam lol

i say about 345rwhp/335rwtrq...

mine made 355/340 with a much bigger cam... cc xr288, but stock bottom end zz3

 

What was the compression ratio and intake? How did the xr288 idle, and did it run in closed loop?

-- Joe

 

lol carbed - a 110lsa cam would make any efi setup irritated - plus it was a TBI car so it was easy to just use the current fuel system with a regualtor..

as far as the compression ratio, obviously, since i took a zz3 bottom end and tossed 64cc heads on it, i'm not exactly sure. the best # i have come up with is 9.2:1 - mostly because of the eyebrow relief style pistons... the eye brow is on both sides which further takes away compression. I know it would be a LOT happier with 10:1 - but i can run 87 octane in it if i have to and not pull any timing lol

The intake is a victor jr, carb is a holley 4150, with a proform main body on it... approx 800cfm. also of some importance, i am running long tube headers...

Idle with the carb is lopey - i run a vacum pump for the brakes, although i may have been able ot get away with a canister... i was more comfortable with the pump.

your cam should be much better on the vacum side of things since it has less overlap.

btw, i need to get back to the dyno.. i swapped on 1.6 rockers and got the distributor fixed (had a mystery timign drop of 6* between 3800 and 5800 making the trq number off a little) The car feels like an animal now compared to last year, so i'm wondering if i'm not making much more peak and just feeling the under curve power i was missing before or what... i should be back at the dyno this week...

 

I'm sorry but I just don't understand the obsession with the 306 cam.

Maybe my understanding of split duration is totally whacked. A cam with 14 degrees more exhaust duration is making up for a really weak exhaust port. I thought the Trick Flow heads had a decnt intake/exhaust ratio. Maybe a split duration of 6 degrees.

It sounds to me like Comp designed the 306 for LT1 motors on spray. Not a naturally aspirated motor with decent heads.

Don't take this personal. I'm just curious as to why you chose that cam?

index

 

not sure if your talking to me or not, but my cam is only 8* split... i think he'll be fine, the split diration like that actually helps th ebottom end out alot from what i understand...

 

Id guess 380ish HP around 6500 360is Trq around the same rpm

down low in the 3-5k range Id guess 350ish HP and 320ish trq

BTW, your IAC is in the mail.

 

I'm thinking about the 306 just by what I have read here and elsewhere. Alot of people seem to be running this cam in stroker motors. But if anyone has any ideas I am definately all ears!

 

306 cam is about the closest you can get to max power without it not being computer friendly. I ran the next size down cam for years and was happy, but the motor hit a brick wall at 6000 with the singleplane. The 306 gives a little more usable powerband, and helps with the lame exhaust ports on the trickflows.

Trickflows are good bang for the buck, but every mag that flows them shows the flow #'s to be a lot lower than trickflow posted. Still, they are 500hp capable heads.

-- Joe

 

def - with the 1.6 rockers on now, i'd bet that the motor is pushing close to 480... untouched heads! made 455 with the 1.5's...

 

What are you using for springs?

We tested the #2 spring kit .. 130lbs installed, and 360lbs at .540 lift. had like almost .100" clearance before bind.

-- Joe

 

the springs that came with it - here;s a copy of the specs from their site...

1.460" o.d. double with damper
125 lbs. @ 1.780" installed height
376 lbs. @ 1.180" open
420 lbs. per inch rate
.600" maximum valve lift

Sounds like the same springs?

figuer i am around .555i/.576e

The springs will be getting replaced this summer at some point as preventative maintenance as i have been running these for about 2 years ruffly (not that much run time, but still, i've noticed with the extra lift it now starts with valve float around 6500, where as before it was fine right to 7200. i pulled a rev kit spring and they are still the same rate (within 10lbs) as they were before. I havent pulled a valve spring... too much work on the motor to deal with lol...

I also run the hydrarev kit... the motor is full roller...

 

Thats the #3 spring package. I ran that for about 2 hours but it exceeded the lifters ability to pump up. After speaking with comp and trickflow, they both agreed the springs are too heavy for hydraulic roller application, and that either the #2 spring option, or comp 987's are the best bet.

The springs i'm using are about 130lbs seat, and 360 open at .540 lift.

-- Joe

 

What no power adder? hehe

Joe, you need to come check out my vette when you get a chance.

 

I've been wondering where you dissapeared to. Hows the project coming?

I couldn't find a singleplane that would fit under the stock hood, so I sold the holley setup and got a miniram. I shoulda bought a vette way back like you suggested, everything is just so much better. Any pix of your car?

Power adder will be NOS. The vortech or ati setups for a c4 is just crazy money. My s-trim for the firebird was like $1200, I can't touch a c4 setup for under 5k.
My motor should handle a 200+ shot i'd think.

-- Joe

 

I havent finished my vette yet , been working on a customers car, and I have three more cars to convert to megasquirt lined up.
Here is david givens car that is just about finished.

https://www.thirdgen.org/forums/dfi-...dfi-455-a.html

The vette needs a set of brake lines, sway bars installed, and a couple other things to be driveable. It runs perfect. Also the whole interior/roll cage needs to go in. I am also thinking about going the nitrous route, i have a whole NOS/jacobs progressive controller setup which would work great with megasquirt controlling it. I also have a big T-6 turbo but that is way in the future.

How long until the car is done? I'm glad to hear you like the switch to vettes.

 

The switch to vettes has been a good choice. I lost my shirt on the firebird, but whatever. I just finished the transgo shift kit last night. I'm gonna clean up the torque arm (has grime on it from a past leaking tranny) and try to get the motor and tranny in tonight, then spend the weekend getting everything bolted back up. I'm waiting for my TPIS fuel fittings to show up, and I foolishly sold my '730 ecm + memcal, so I need to grab another one. But should be a week or so until its driveable.

Oh and I need some mufflers.

Have you done carpet in one of these cars? I bought a new carpet set, some new interior bezels, and some iggae seat covers.

car, parts, engine, etc I'm into the vette about $13,000 and about 100 hours... I lost about 4k on the firebird, not to mention a few hundred hours of labor. Oh well.

-- Joe

 

Really? I haven't had any problems at all... what were you running for preload? i run almost none - about an 1/8th of a turn thats it...just enough to keep me from being able to turn the pushrods with my fingers... Combats valve float...

I do run 20w50 mobile 1... although the motor break in was on 10w30 dino oil...

 

Do you guys check your valve stem tips to see if the valves are rotating?
I never felt or heard my valves floating, but I have the chewed up springs shims to prove they were. And there was a nice star shaped pattern on my new valve stems. I ran out of port area before I floated them bad enough to feel it.

 

just put new rockers on - no sign of any wear at all... some of that wear can be a function of the pushrods not quite the right length...

 

If I was doing the buildup I would use the XFI230 cam and the cheapest Trickflow heads. Then swap out the springs in the Trickflows for the Comp Cams 918 beehive springs.

Next you need to find out what your dynamic compression ratio is. Sounds like you might be leaving power on the table with your compression. Also what is your quench distance? I would try to get it somewhere between .035" and .040".

 

I ripped out the entire interior in my car, and bought all new carpet. I put down frost king sound and heat insulation first, havent got the carpet in yet. I bought two recaro type seats, cheaper than new foam and covers. i added up all my reciepts and am into the car for 7-7.5K, I need new door panels tho.

Are you going to put in a roll bar? I have one, but it seems like ALOT of work to get it in.

 

I'm not gonna run a bar or cage. Not even sure how fast the car will go. I'm progressing though. What are you running for headers, hooker 2149? I put my right motor mount bolt in the wrong way so it hits the header, gotta flip it around and reinstall the header tomorrow.

I gotta do something about the rear end ratio too.. 2.59:1

Here is what the miniram looks like:

-- Joe

 

guys with hotcam LT4 converted LT1's are making 350ish whp. cc306 is alot bigger cam. your combo should be well into the high 300's whp. i'd say near 380whp

 

I'd say 375 rwhp, 360 rwtq