What kind of power expectations?

[3rdGen383]

Well im pretty much in the home stretch, pulled the rods that were hitting the cam, in cylinders 1,3,5, and 6 . Got late today, grinding them down tomorrow. Also got a new timign chain and gears, went with an extreme duty "truck" chain and gears, fits better and scrubs the block much less, now I only got a littl ebit of grinding. Now that im in the home stretch, anybody have any kind of engine expectations for this motor? Ill list a lot of it here, maybee you guys can help. I based it off a 355 build that made like 467ft/lbs and 445hp or something, but I went with a 383 and a few different parts.

9.8 Comp.
383
5.7 rods, 3.75 stroke
kb hypeuratic pistons
scoggin dickey modified vortec heads, (perf. valve springs, retainers, studs, ect.)
XE274 cam
GM 1.6 Aluminum Roller rockers
Performer RPM intake manifold
Performer 800cfm carb


Any other info u might need, just ask. Im just looking for a ballpark estimate of peak power, average power, and where that power is in the band. Thanks guys.

[mod67]

heads... It all comes down to the heads. What you got?

[BigTruckDriver]

Carb seems big.Did you only grind down the rods that were hitting?IMO after grinding those down ,all of the rods (all 8) should of been lightened to match your lightest one.

[3rdGen383]

Yea i went ahead and ground down every single one, figured it would make sense. They are vortec castings, with lt1 beehive style valvesprings, lt4 retainers, and upgraded valves I believe. Scoggin dickey sells them, ill try to find the link and post it. I was told they are one of the best, cost effective heads on the market. BTW I went for the slightly larger carb, 700 was recommended, because I will most likely be using a 100/125 wet shot. I intend to run an electric pump through a seperate fuel line to use with the spray, so i did some research, and 800 seems to be the mainstream as far as that size motor with round about power levels have, and a small shot of spray. I took the basis from here, http://www.carcraft.com/techarticles/81998/ , except I went with quite a few better parts, mainly in the shorblock area, and upped it with a stroker crank, to make a little more torque and drop it down in the powerband. As I said, it is my father doing the main fo the work, teaching me as we go along, but I was set to do as much research as possible, and put together a combo that works. I added arp main studs, hypeuratic pistons over the cast, a cast steel crank, forged rods, perfect circle moly rings, clevite 77 p series bearings, and a slew of some other slightly different parts from that build. Hope ti all works out, the long block was just buttoned up today, intake and carb is this weekend, just have to order ignition adn exhuast. Most likely going with a DUI distributor, seems liek teh best bet, but pretty expensive. Other choice would be an msd hei, I already have the wires, so after that its exhaust and Im done for now

[1JohnnyO]

Sounds like a pretty nice combo. Im a big block guy, but I'll add my .02 cents for what it's worth. Is this primarily a street car? I would have a slight concern about grinding on those rods, and then not having the rotating assy. rebalanced. I doubt it will be an issue, but it makes me think. Also, I agree with BigTruckDriver, the carb is big for the engine. But then again, it's a vacuum secondary, so it's more forgiving in that aspect. If you dont jet up to much on the primarys, you'll be OK. I actually ran an Eddy 800 on my 454 for about a week, and honestly it ran like crap! I hope you dont have that problem! Anyhow, a good HEI will be fine, dont spend a ton on a fancy HEI. Even a stock will likely support anything you're planning for this engine. You can always re-curve the advance if you want for about $12.00. And be careful with the spray, and those hyper pistons. If you were going to use nitrous, you really should have gone with forged, only would have been a tad more. Just my opinion. But have fun, sounds great. John

[southerner]

With that set up I will say around about 450 HP and should have good midrange power.

[rhamm1320]

Looks really good. The peak HP and TQ are higher, but the best part is your average TQ goes above 450 and stays for a long time. As would be expected, the peak TQ and HP are lower in the rpm range with your longer stroke.

I also reposted their original dyno graph so you can compare.

http://www.virtualengine2000.com





original 355 dyno:

[3rdGen383]

That is some awesome info there, seems like an amazing program, i downloaded the free one, butits nothing liek that lol. Thanks for that, as far as the rod grinding goes, 4 were hittign the cam, so we took exactly the same amount of eachone, and accurately by with 1/4 - 1/2 gram. It was only the tiny corner on the rod, not much, so technically if u do a tad of each corner, i figure ill get some piece of mind that none will hit, and that it will be in a much closer balance than taking off just 4 rods. BTW, Im nervous about spray, but I wanan put myself a little higher, figuring 100-125 wet wound be perfect. The compression ring gap is set at 25 thousanths now, an well experienced machinest said to do that becuase the number one reason for failure of hyperuatics is that the piston expands more than forged or cast, and a lot of people are getting cracked pistons especially with spray. At least that is the drift i got from it, he recomded 24-26, so 25 was the median and the winner. This is a common driver, more than a wekend warrior, so i wanna be safe, but if done right, retarted timing, not running lean, and with a wot switch I think I will be ok, at least I hope son, any other opinions on the spray, im pretty happy with the natural power will be. BTW i didnt get forged because I got an awesome deal on the whole rotating assembly because it was discontinued with the hypeuratics, so summit dropped it down to like 750 with a steel crank, forged rods, and the silvolites. Its been a bumpy build but I hope it all works well. Also, If I do use a plate style nitrous system, the 3/4" or 1" thick plate will serve as a carb spacer all the time correct? The base build I mirrored used a 1 inch open spacer, so who knows. Thanks guys.