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New Guy 383

2K views 15 replies 9 participants last post by  speedydeedy 
#1 ·
I'm just trying to organize my parts for a SBC 383 build and I thought I could use some input. It's going into a 1927 Model T sedan and I'm building my own frame. So far this is what I'm thinking:

Eagle Street/Strip Kit, SB Chevy 350/383, 3.750" Eagle Crank, 5.7" Eagle Rods, 9.8:1 SRP Pistons
Bore size: .030
Kit Upgrades: External Balanced Assembly (Inludes New Harmonic Balancer and Flexplate)
Comp cams XE268H
Dart Chevy Iron Eagle 180cc - 2.02/1.60, 1.550D Spring, Straight Plug, 64cc, Assembled
Comp Cams Magnum Roller Tipped Rockers - SB Chevy V8 265-400 - 3/8" Studs 1.52" Ratio *Self Aligning*
Victor Reinz SB Chevy 350 Performance Gasket Set 1967-1985
SB Chevy .250" Double Roller Timing Chain W/ 3 Keyway & Press Fit Thrust Bearing

It's a '75 350 that's gonna go to the machinest and I was thinking of an Edelbrock Performer Intake and 750 carb. Any comments or changes you guys think I shoul make before I order???? I want it streetable, no racing, I have a T400 tranny as well, thinking maybe a 700R4.

Thanks,
Sean.
 
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#2 ·
SInce you said street only, no racing...ditch the 750 carb and go with something smaller like a 600. You will get better throttle response with the smaller carb and only lose a couple ponys in the top end which you wont even notice since its going to be street only. Will probably help with mileage too.

Mike
 
#4 ·
Agree with the carb sizing, 600 or 650 cfm would be better for driveability & mileage. For your street-only useage and self-imposed 5000 rpm redline, the springs on those Dart heads are way too big... the high pressure will rapidly chew up the lifters/ cam lobes on that Comp XE268, end even moreso because of the removal zinc ZDDP additives from oil recently. Those double springs will probably get you to 7500 rpm (on a solid lifter cam), but are way overkill for what you're doing. The valves and intake ports are ever so slightly too big also, you might want to think about heads with 1.94 x 1.50 valves and maybe 170 cc intake ports.

Also, lots of people here with not so good opinions of the Eagle connecting rods - big ends seem to deform too much when they're torqued down.
 
#5 ·
Following up on Tea Two, while the budget range Eagle stuff is frowned upon (it seems) the budget stuff from SCAT seems to be pretty well respected, for what it is. Personally, my 383 uses a SCAT Internal balance crank with Lunati Street Race rods which are very light and supposedly good to 450 HP at 7000RPM.

Pat
 
#6 ·
I would use a 270H instead of the ex268H. Those xtreme series are more prone to go flat. Sure the xe's make a little more power but at the expensive of durability. Besides, you don't need a cam with more exhaust duration on dart heads. Those head flow well on the exhaust port. The 270H has 224/224 degrees at 0.050 and xe268H has 224/230.

9.8:1 cr is pretty high for a small cam. Should be OK with the 270H but you are pushing it and you will need to run high octane fuel and maybe retard timing a little. Make sure the 9.8:1 cr rating on the kit is for 64cc heads. Darts also come in 72cc if you want to lower cr a little bit. FYI, 9.8:1 with 64cc will drop to 9.25:1 with 72cc heads.

I would use a Performer RPM intake. Not the air gap, just the regular RPM with an exhaust crossover port. The Performer will have a hard time in the upper rpms especially with a 383.

I would also recommend cast or hyper pistons pistons. Forged pistons don't work well in a mild street engine. Not sure what your kit comes with

If you don't want to rev over 5000 rpms then you are using too big of a cam and using too much compression for iron heads. 9.0 to 9.25:1 cr with a compcam 252H or 260H and a performer intake would be a good match for a stock converter and 3.08 gear. Both the xe268H and 270H make max power at 6000 rpm and will need a 2000-2400 stall with a 3.55 gear.

Consider using a Q-jet built by "Cliff" for best mpg and good power, look him up on the web and he will build you a custom carb. Other wise, a 3310 Holley 750 cfm with vacuum secondarys will work well.
 
#7 ·
#8 ·
Okay, maybe I should start again. I think maybe I should just ask for a good set up for my engine. I want torque obviously but it doesn't have to be 500ft/lbs. I've been given all types of components but I don't have the background to match parts. I kinda want the 383 to start and work from there.

Thanks for the help,
Sean
 
#10 ·
Ok, let's start from the beginning.

what gear do you want to run?
Do you want to use a stock torque converter?
do you what to run low octane fuel?
Is mpg important?
Is long engine life important?

That gm 383HT is a very nice street engine in a car with a tall highway gear, stock converter, and 3 speed trans. The price is also very good. if you add up what you will spend on building your 383, the price will be close. Plus you get a warranty with the gm engine. I was really dumb and spent 4000.00 on a 396 BBC over a few months without realizing it. Those little parts really add up.
 
#11 ·
Well I guess reliabilityis important as well I want to run on reg pump gas if I can. I have a t400 tran. I wanted to try and rebuild but I found a fresh rebuilt 700R. The rear end isn't done yet either, I will build that to suit the engine. I'll take a look at those scat cranks, I've actually heard good things about them as well. I've heard the Sportsman or Vortec heads are good for the price, I thought if I spend $1000 on Dart I might as well go AFR. I've looked through Ryan's Dyno page but I think I'm overwhelmed by it. There's sooooo many choices with these engines!!!

Thanks for the input, I'll be waiting for that perfect combination!!! :D (maybe stock??)

Sean
 
#15 ·
#15 is a pretty radical engine. It would require a 2500-3000 stall converter. Plus I would not totally trust those HP/TQ numbers since the testing was done by AFR.

I'm thinking you need a engine like 94 or 95 or something in between.

The beauty about those builds is they use a mild, and not to aggressive flat hyd cam. Rollers are nice but they cost about 4 times more.

Combo 94 uses a 252H compcam (206/206) and is a good for a 2.73 to 3.08 gear with stock stall.
Combo 95 uses a 268H compcam (218/218) and is good for a 3.20 to 3.55 gear with a 2000 rpm stall.
You could use a compcam 260H (212/212) with a 3.08 gear and stock converter.

These combos are using a 355 cid. Just add around 5% to get 383 estimated power. And a compcam 260H power will fall in between the 252H and 268H numbers.

So. I'm guessing 382Hp @5200 and 420ftlbs @3900 with a compcam 260H and a 9.5:1 383 with 190 or 195 afr heads. And will work well with a stock converter and highway gears and low octane fuel. Or 365hp and 400ftlb if you just build a 355. Is a 383 worth it? Maybe not.

Also check out Edelbrock performer heads, the edelbrock RPM's are not good for a street engine due to lack of an exhaust cross over. They are the same head, just the rpm doesn't have the cross over.
 
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