Exactly. If you run the numbers, to get 11:1 comp ratio, you would have to have both milled heads and a decked block. I don't see 11:1 happening with -15cc pistons.

 

His heads are stock LT4's they aren't ported. How much do you think he should be putting out?

 

Guessing at the cam spects you have 10.93 Static compression and 7.99 DCR.
The cam is small for a 385 and ya need more flow from the heads and intake( ya can get the stock castings to flow 280CFM pretty easy) and ya need to up the compression too.
Then the HP number's will start looking good.

 

Saying the numbers are extremely low is an exageration on my part, but I would think he should be able to get about 365-375rwhp out of that setup. With stock compression, heads, intake, cubes and that cam I would think he should put out atleast 340rwhp. I would think the additional mods should add more than 5hp.

 

The deck was zero'd out.

Here's the parts list:

Scat 4340 forged crank 3.75 - 385 stroker
Eagle 4340 forged H-beam 6.00 rods
Forged SRP Pistons -15 dished For a 11.1 Compression
4 bolt Billet Steel splayed main caps
Speed Pro Plasma moly rings
Clevite bearings
Comp Cam 224/236-535/544 114 LSA +4 Deg.
Crane springs 10308-1
Comp Cam Pro-Magnum 1.6 RR's, 7/16 studs
LT4 Heads – GM
GM guide plates
Thunder Racing hardened push rods 7.200
ARP bolts all around
MSD 6AL ignition w/ coil
Holley fuel pressure regulator
LT4 Intake –Stock
Lucas 42# injectors
48mm Stock throttle body
Walbro 255 LPH in tank fuel pump
MSD 8.5 Super Conductor wires

 

Rule of thumb is anything close to a 383 will always make 30 more hp, 50 more TQ at the wheels

Seriously they dont seem all that low. A blower/nitrous grind in a larger displacement motor with LT4 heads. I'd say its not that far off from respectible for that setup. I dont see a E-WP, underdrive pullies, or what headers, etc. 12 bolt soaking up some power. So I think its decent for what its got.

-Dustin-

 

unported heads is unported heads....numbers seem ok to me.

 

Well that seems to be the norm..... problem is that you have to make everything else work with the cubes to make the extra power you expect from them.

Bret

 

I suggest sending your heads to AI and calling Joe O to pick you out a cam. You will make pleasing power then. Possibly more than pleasing power...

 

So you guys think my numbers are good for what I have?

Another question that's on my mind is, do I really have 11:1 cr with this setup? Maybe that's the problem. I know before I bought the pistons, one of the sites had a calculator for configuring cr. That's how I came up with 11:1. Maybe my cr is lower than I think it is.

If my timing chain is stretched, how much would that effect the hp?

 

Read the above I posted earlier!!!!!
Your DCR should be between 8.5 or below 9.0 on pump gas.
I don't know your cam spects so it's a guess.

If the engine were right it should put 400 min to 450+ at the tire.

 

Sorry I missed that. To raise the cr without changing pistons, I would guess I could shave the heads down a little. Right? What cr should I shoot for?

 

Give me your cam spects. ADVERTISED duration. If ya don't want to post them PM me and I will figure it out and make ya a few sugestions on what might help.
Bret may have some ideas too.

 

Here's the complete list:

The deck was zero'd out.
Scat 4340 forged crank 3.75 - 385 stroker
Eagle 4340 forged H-beam 6.00 rods
Forged SRP Pistons -15 dished For a 11.1 Compression
4 bolt Billet Steel splayed main caps
Speed Pro Plasma moly rings
Comp Cam 224/236-535/544 lift is with 1.6rr 114 LSA +4 Deg.
Crane springs 10308-1
Comp Cam Pro-Magnum 1.6 RR's, 7/16 studs
LT4 Heads Stock– GM
GM guide plates
Thunder Racing hardened push rods 7.200
LT4 Intake –Stock
Lucas 42# injectors
48mm Stock throttle body
Walbro 255 LPH in tank fuel pump
Moser 12 Bolt 33 Spline w/4.10 Gears
TPIS 3.5" aluminum drive shaft
SLP coated Headers w/y-pipe - No Cats
Car weight with full tank without me in it - 3750 with me 3950

Thanks guys,
Scott

 

Scott,

You need to have you deck height (or how far the piston is in the hole) along with the head gasket specs to know the CR.... it could easily vary from 10.25-11:1 with that setup.

Bret