steves86ta

iTrader: (5)

Hey there,

Figured i would make a post for people looking around

Im finishing up my 5.3 rebuild, and have a dyno appointment next Monday. This 5.3 is in a jet boat, and ran well in stock short block form (with this cam/heads)

Specs are
Standard bore iron 5.3 block
Speed Pro H855cp pistons (Flat top) Fly cut .090" Intake .060" Exhaust
Stock rods with ARP 2000 rod bolts
Block was decked to bring pistons to an even .010" out of the hole
BTR Stage IV NA LS1/LS2 Cam (235/242 .621/.595 111ls1)
Stock 243 heads milled .030" with BTR springs/Trunion kit
Edelbrock Victor Jr intake manifold
Worked Holley 750 (flows 775)
NOS Cheater system (150 shot)
Static Compression should be about 10.5:1
Dynamic should be about 8.58:1

Im curious to hear what your guesses are. This will be an engine dyno, so fwhp. My goals are int he 450 range NA then whatever the 150 shot takes me to.

Ill post back the results when i hear

Doug G

523 NA ....630 on the juice.

Wild fingers crossed guess.

baronsmith98

iTrader: (2)

I'll say 475 on motor and 600 on the hose

steves86ta

iTrader: (5)

The dyno didnt go as planned, but finally got it on the dyno again this last monday

It made 450hp @ 6500rpm and 633 @6000 rpm on the bottle.

I am damn happy for a 325ci engine. (please ignore the ugly headers they need to be coated)







And it even lit the candles :-)

baronsmith98

iTrader: (2)

Badass with the candles lit! That bitch loves the bottle good job!

steves86ta

iTrader: (5)

Thank you!

Serioussn95

iTrader: (1)

Nice work man. strong numbers from the 5.3. hard to believe that with the decking and the 243s your compression is still only 10:1!

steves86ta

iTrader: (5)

thanks bud

Heres a screenshot of the calculator i used

I cc'd the heads right around 61cc though im not a professional machinist. I could have read my reading wrong. But it repeated. Though my dynamic calculation is dead on with my cranking compression..

They say its .005" for every 1 cc. I believe the 243's are 65cc stock, so that would come out to right at 60cc.

Unless im mistaken?

Heres summits calculator with both 61 and 60 and i even threw in a 59cc for good measure. It looks like im somewhere between 10.54-10.82:1. But im trusting my CC measurement.

Either way doesnt matter to me. I ran it on 91/100 on the dyno and no signs of detonation. And ran it on pure 110 ont he bottle.

59cc


60cc


61cc


And my dynamic compression. Which when on the dyno we did a compression test. And it came out to right at 175 on all 8 holes. I think its close enough



am i crazy?

Serioussn95

iTrader: (1)

No everything looks spot on! Sounds great