I am building a Small Block Chevrolet and would like to know it's HorsePower and Torque potential. The shortblock is a .030 over 350 madeup of a 4 Bolt Block (010), Forged Steel GM Crankshaft, Forged Steel GM Connecting Rods, and TRW Flat Top Forged Steel Pistons. The Pistons are advertised to produce a 9.72 Compression Ratio with 64 cc Combustion Chamber Cylinder Heads. I am using a set of the GM Performance Parts Fast Burn Cylinder Heads that have 62 cc Combustion Chambers which should result in a slight increase of Compression Ratio. I am using a Comp Cams 270HR Hydraulic Roller Camshaft (218/224 Duration and .495"/.502" Valve Lift @ 110 Degree Lobe Seperation) with Hydraulic Roller Lifters. The other key parts of the Valve Train is a Pete Jackson (Noisy Gear Drive), Crane 1.5 Ratio Rocker Arms, and a Crane "Quick Lock" Stud Girdle. The Gear Drive has been set up straight up. The Fuel Induction System includes an Edelbrock Mechanical Fuel Pump, Edelbrock Dual Plane RPM Air-Gap Intake Manifold, and at this time an undecided Carbuertor. I am currently leaning toward a 750 CFM Model with Vacuum Secondaries. Any suggestions on Brand? Holley or Edelbrock!!!!!!!!! I have two Ignition Systems to choose from the first being a complete Chevrolet Ignition System containing Distributor, Coil, Rev Limiter, and Ignition Box or a Mallory Unilite Distributor with a Mallory Promaster Coil. For an Exhaust System I plan on using a set of Thorley Headers. So if someone has the time would they please Desk Top Dyno this combination for me. If any additional infromation is necessary just let me know. Thanks in advance for your help. `

without running it on DD, I'd say your at roughly 380 hp.

Without knowing the cam specs,, piston part number I come up with 379 hp x 361 tq at 5500. My program is an early version.

I could not get cly volume to where you stated as 62cc but was able to select 10.5 compression

Here you go. Note I ran the cam 4 degrees retarded as theat helps both HP and torque with this cam. The roller version of this cam actually hurts performance somewhat over an equivalent solid cam with the same specs to the tune of about 5HP and about the same ft-lbs of torque below the peak. Check the specs on the table to see if I screwed anything up. The image is a little fuzzy becasue I cut the resolution down to minimize loading time on the dialups.





http://home.townisp.com/~markcanning/camaro/61105dd200.jpg

These are the flow numbers I have for the fast burn heads. I had the valve sizes wrong (they should be 2.00/1.55) in DD 2000 but they don't figure into the analysis.
GMFastBurnPerf

Intake
lift flow in cfm

0.05 24.780001
0.1 54.520000
0.1 93.480003
0.2 129.350006
0.3 165.759995
0.4 195.360001
0.5 219.039993
0.55 227.619995
0.6 233.839996

Exhaust
lift flow in cfm
0.05 13.930000
0.1 30.250000
0.15 58.900002
0.2 82.949997
0.3 116.760002
0.4 143.100006
0.5 150.000000
0.55 163.770004
0.6 171.720001

Mark,, its off the subject , but how did you show your engine and overshadow the air cleaner to see thru?

As for the Dyno test,,, Tq really takes a dive early.

I'm guessing that the estimates given so far are a bit low. Your engine is VERY similar to the GM Crate ZZ430. Same CID, heads, intake and CR. Even the cam is quite similar. The ZZ430 use a HR with 218/228 @ .050 and.525/.525 on a 112, using 1.6 rockers. GMPP conservatively rates this motor at 430HP at around 5,800 and 425TQ somewhere around 4,500. GMJim, who post on this board, had his ZZ430 dynoed at I believe 448 HP with minor head work.

http://www.camaros.net/forums/showthread.php?t=17478&highlight=zz430+dyno

PS I'd use a Holley, just cuz I like 'em.

X ray camera. ;)


No, really all you need is a digital camera on a tripod, take one picture with air cleaner, and one without the air cleaner without moving the camera. then you have to have some kind of photo editing software that can use layers ( I use paint shop pro 8) and you lay one image over the other as a new layer, in this case the one with the air cleaner over the one without then you adjust the transparency of the top layer till you get the look you want. Works with anything, take a picture of a convertible with the top up and top down and have a transparent top, picture of a car with wheels and without, transparent wheels, etc.

Back on subject the ZZ430 uses a hot LT4 cam (at least the specs given for it are from that cam) which is what I have in my car which is similar to this one as well. My Compression is higher at about 10.7 but I'm running thru stock (I used HPcast iron manifolds in DD2000) and 186 stock Z28 heads. Mine comes up on DD2000 as 369HP at 5000 RPM, and 446 ft-lbs of torque at 3000 rpm. HP is above 350 from 4700 to about 5800 RPM, torque is above 400 ft lbs from 2000 to 4750 RPM. If I used the same large tube headers on mine as I did in this simulation with no other changes my HP jumps to 410 at 5000, and torque would peak at 471 at 3500 rpm.

The heads (or at least the flow numbers I have) are whats killing this combination. Someone should check my flow numbers against a known value as I just downloaded them a couple of years ago and have no clue if they are right.

Thanks for tips on the XRay issue.
As for the 186 heads killing performance ,, I think you are correct as thats what I ran before going to the AFR 195's ... I found some flow data on the 186 at .400" lift and looked for a head that did better. I found the AFR's and went with this... I can tell differance at hi rpm.
Airflow data pulled on test @ 28" water were: 182 cfm intake and 125

The AFR 195 was measured at 240 intake / 178 cfm... This data as pulled from an independant testing other than AFR... Its reasonable and in the right directions... If you ready test, you have to compare at same lift with any head in the same catagory and thats the way I read it ..

Not my combo, original appearences does have its own limitations, but i was talking about the Fastburn Heads in the DD2000 setup above. The 186 heads flow better than the fastburn heads according to the files for DD2000 that I have.

Thanks for the Efforts and Comments from everyone. But now I guess my question is what can be done to improve on this engines performance? The ShortBlock including the Camshaft and Timing Gear is assembled. In response to zdld17's comment the CamShaft is a Comp Cams Hydraulic Roller (Part # 270HR) with the following specs:

Camshaft Specification Table
Part Number 08-422-8
Engine -9999 Chevrolet
305ci-350ci
8cyl.
Grind Number CS XR270HR-10
Description

--------------------------------------------------------------------------------

Intake Exhaust
Valve Adjustment 0 0
Gross Valve Lift 0.495 0.502
Duration At 0.006 Tappet Lift 270 276

--------------------------------------------------------------------------------

Valve Timing At 0.006
Open Close
Intake 29 61
Exhaust 72 24

--------------------------------------------------------------------------------

These Specs Are For The Cam Installed At 106 Intake CL
Intake Exhaust
Duration At 0.05 218 224
Lobe Lift 0.33 0.335
Lobe Separation 110

--------------------------------------------------------------------------------

Recommended Valve Springs 986-16

The Pistons are Forged Steel TRW 4.030" Bore (Part #: TRW-L2256F30). The advertised Compression Ratio is 9.72 with a 64.0 cc Chamber. The Dome is listed as -6.1cc, Flat Top Design with 4 Reliefs.

I would like to especially Thank Mark C for his running of the DeskTop Dyno Analysis that I had originally requested. Mark you are correct the Valve Size is actually 2.00/1.55 as you noted. Not that it would matter the Camshaft you have in the Specs says Crane where it is a Comp Cams Brand.

Now for my updated question. What can be done to increase the Performance of this engine? I was under the impression (probably incorrectly) that the Fast-Burn Cylinder Heads were as advertised by GM as having "The Highest Performance Potential of any 23 Degree Small Block Head developed by GM". However, I also have a set of Cast Iron High Performance (Large Valve) Cylinder Heads Casting Number 3991492 that was introduced in 1970. The FastBurns have a Intake Runner Volumne of 210 cc versus the 157 cc Intake Runner Volumne of the Cast Iron High Performance Cylinder Heads. The Combustion Chamber Volumne of the FastBurn Cylinder Heads of the is 62 cc versus the 64 cc Combustion Chamber Volumne of the Cast Iron Performance Cylinder Heads. This I was under the impression would result in a slighly higher Compression Ratio if the FastBurn Cylinder Heads were utilized. So I am confused by Mark C's comment that these Cylinder Heads are what's killing this combination. Mark please don't take my comment wrong as I am probably overlooking something as I am pretty inexperienced at Engine Design. I don't have them handy right now but somewhere on this site at one time I did see the Flow Numbers for several versions of Small Block Chevrolet Cylinder Heads. If someone remembers the appropriate thread that this information was listed under please let us know so Mark C (if you would please) check his numbers. Thanks Again Mark for your help. In regards to CamShaft Selection I also have a couple of other CamShafts available if they would be more appropriate. The first is one that came in the ShortBlock when I purchased it. It is a ComCams 292H Hydraulic Flat Tappet (Part Number CCA-12-213-3) with the following specifications: Duration 244/244 Degrees, Lift 0.501"/0.501", and a Lobe Seperation of 110 Degrees. The second is a CompCams Nosatlgia 30-30+ Solid Flat Tappet Camshaft (Part Number 12-673-4) that I had purchased to install in my 1969 302 CI Small Block. This Camshaft has the following Specifications: Duration 247/254 Degrees, Lift 0.504"/0.498" and a Lobe Seperation of 112 Degrees. So guys help me out. Which Cylinder Heads and Camshaft would you recommend? What other changes should I consider? What difference would be realized if I changed the Rocker Arms from 1.5 to 1.6 Ratio as utilized by the ZZ4 Crate Engines? Does anyone have any input on Camshaft Installation? I did not originally Degree the Camshaft when I installed it but after reading this months Chevy Rumble Magazine I am considering on backing up and adjusting the Camshaft Position. Mark C had retarded the Camshaft Position 4 Degrees when he ran the DeskTop Dyno Analysis. The engine is going to go in my "RedNeck Truck" which is a 1984 4X4 with 38" Tires and 6" lift Kit so I want to keep the RPM down and make as much Torque and Horsepower at as low a RPM as possible. If I understand what I have read retarding the Camshaft Position raises the RPM Operating Range. So Guys Fire Away!!!!!!!!!!!!!! Give me your opinions on what I should do and what results I can expect. Thanks Again Everyone for your Input and Ideas.