Suggestions For 355 Build

Carp1329

Member
I have a rebuilt vortec short block with flat top pistons with valve reliefs. It is supposed to be a 330 hp engine with vortec heads. All I have right now is the short block and of course want more than 330 hp. It is going into a third gen camaro with a th 400 , 3000 stall and ford nine inch with 3.50 gears and a Eaton tru trac. I am looking for a street / strip combo with 400+ at the crank. I am thinking about a camshaft with around 230 duration at .050 and low .500 lift. I am leaning towards some. brodix ik 180 with 64 cc heads. Let me know if I am heading in the right direction with my build. If you guys have some suggestions let me hear it. Thanks
 
the ik 180 cc heads are decent but there are better heads available,
your most likely close in selecting a cam with close to 230 duration in this application.
64cc combustion chambers might put you a bit too high in compression to get by on crappy gas octane
do you intend to go with a carb or efi induction?

Id be rather tempted to go with a crane 119661 hyd roller in that combo
like I run in my corvette (be aware the roller block generally uses a cam retainer ring vs the older cam button, so you will need a cam designed to match the block)
stepnoser1.jpg

http://www.wallaceracing.com/dynamic-cr.php

https://www.searchencrypt.com/search?eq=esg0HaDc6PqxTnncbweVnB+5Clhl7HamssWUfmoQ3acHm5VIZ+kxtH4WL9CdW5Ex+WZCem4uJoVJnYw5VADJQw==&ett=1

https://uempistons.com/p-28-effective-compression-ratio-calculator.html

http://www.diamondracing.net/tools/

350comps.png

he following are different static compression ratios (SCR) with a 3.48" stroke and different camshaft intake closing points @ 0.050" tappet lift on Keith Black's dynamic compression ratio calculator. The calculator, starting at 8.25:1 SCR. The dynamic compression ratio (DCR) has been kept at just over 8.0:1, a figure that is acceptable for use with today's pump gas with a little cushion:

  • Static CR....Intake closing point @ 0.050"....Dynamic CR.
  • 8.25........10* ABDC......8.010........................................................................................................
  • 8.50........20............8.012........................................................................................................
  • 8.75........27............8.022........................................................................................................
  • 9.00........33............8.018........................................................................................................
  • 9.25........37............8.061........................................................................................................
  • 9.50........42............8.029........................................................................................................
  • 9.75........46............8.016........................................................................................................
  • 10.00.......49............8.038........................................................................................................
  • 10.25.......52............8.043........................................................................................................
  • 10.50.......55............8.029........................................................................................................
  • 10.75.......57............8.069........................................................................................................
  • 11.00.......60............8.022........................................................................................................
  • 11.25.......62............8.038........................................................................................................
  • 11.50.......64............8.042........................................................................................................
  • 11.75.......66............8.035........................................................................................................
  • 12.00.......68............8.017........................................................................................................

crane119661.png


http://garage.grumpysperformance.com/index.php?threads/sellecting-cylinder-heads.796/

here Id select
195cc port 70cc combustion chamber heads ,
select a head gasket that gives about a .042 quench

https://www.profilerperformance.com/176-sbc-23-degree-heads.html
second option
https://www.jegs.com/i/Dart/301/127...riteo&utm_medium=cpc&utm_campaign=retargeting

a dual plane intake
https://www.summitracing.com/parts/edl-7501
 
Last edited:
I will be using a carburetor. 670 street avenger vacuum secondaries .Thank you for the information.
 
Last edited:
please keep us informed of your choices and progress.
Id also suggest you find and install a compatible 7 quart baffled oil pan
 
Last edited:
What do you guys think about comp cams XR276HR. I am definitely leaning towards the profiler heads. The short block I have is a rebuilt one from atk . I am not sure on how rpms it will spin and stay together.
 
Last edited:
why would you select that cam?
now Id be first to point out it will work ok,
but youll be favoring lower rpm torque and restricting upper mid and upper rpm power
and limiting lift to just over .500 is not taking full advantage of your engines true potential
 

RICKS most likely correct here.
its mandatory you do the required math carefully,
and verify your doing it correctly,
before handing out the cash for parts

if thats the result of the math on the CompCams XR276HR.
the comp cams Xr282hr will produce even lower dynamic compression
do your math for both compression ratios carefully and get the static compression high enough to get the dynamic at very close to 8:1
 
looks like you need that smaller 64cc combustion chamber,
to boost static compression,up to the required static compression needed,
with that cam selected
 
8C2A4DA3-813E-44E4-967F-5BCD669E044E.jpeg Another idea i was thinking of is. With the int/exh flow % of those cylinder heads
.200 81%
.300 72%
.400 73%
.500 78%
Avg% 76%.
I have heard heads like this and AFR head may do better with a single pattern cam. Plus more lift with these cams A065DF76-0114-4143-A706-4699FB40FCD5.jpeg367ED50B-1207-46C8-96A1-8B1395DC318B.jpeg

Do you have any headers yet or any picked out? Should be a nice engine.
 
single pattern cams only provide marginal benefits in most cases if your running low restriction too flow, open headers,
the longer exhaust duration, on the exhaust lobe, timing,
aids and helps the exhaust, extending the time available, for exhaust gases, to exit the heads,
and scavenge the cylinders,
as it tends to aid power if your running a marginally restrictive exhaust system,
behind the headers ,exhaust collectors, as it provides a bit more time for the mass of exhaust gas to bleed down.
running an X-pipe also helps, mods that work well on a dyno or circle track car ,
with open headers don,t always provide similar benefits if your running a full length exhaust,
on the street with mufflers, third gen firebirds & camaros are known for having restrictive exhaust systems.
longer cam duration is beneficial at higher rpm power bands,to produce better power,
but higher rpms also result in less available time between individual exhaust pulses to exit the exhaust system.
(thus extended exhaust duration may help)
one of many of the reasons I selected this , crane cam below,
for my vettes 383, and of course I intended to use a wet nitrous TPI plate
with the modified stealth ram/tpi efi
crane119661.png


nos-05153.jpg

http://www.jegs.com/i/NOS/741/05151/10002/-1
be damn sure you get a WET nitrous system, and retard the ignition advance curve,
the OEM TPI computer processor speed is way too slow,
and sensors won,t keep up and you,ll burn valves or pistons,
with a dry nitrous system on a TPI engine


exhaustpressure.jpg

EXFLOWZ4.jpg


http://garage.grumpysperformance.com/index.php?threads/is-backpressure-hurting-your-combo.495/

http://garage.grumpysperformance.com/index.php?threads/x-or-h-pipe.1503/

http://garage.grumpysperformance.co...-between-shorty-and-full-length-headers.1303/

http://garage.grumpysperformance.com/index.php?threads/exhaust-thinking-of-your-options.13115/

http://garage.grumpysperformance.com/index.php?threads/calculating-required-exhaust-pipe-size.11552/

http://garage.grumpysperformance.com/index.php?threads/my-current-corvettes-383-combo.430/
 
Last edited:
We sure are doing a lot of guessing guys! We really need some hard facts from Carp1329 such as .....

Bore?
Stroke?
Deck Height?
Piston PN or does it have 2 or 4 valve reliefs assuming it's a flat top?
Rod Length?
Quench Distance?
What octane gasoline will you be using?
Induction System?
Headers Used?
Camshaft? (Did you buy the CompCams Xr282hr?)
Heads? (Did you buy the Profiler 195, 70cc?)
 
yes dealing in facts, doing the required math, is the only logical way you can proceed
 
Back
Top