383 Stealthram

CWash2

Member
My 383 motor for my 88 trans am is Scat Stroker with AFR 195 Eliminator 72 cc heads, flat pistons. The càm is Comp Cams Nitrous cam 227/236, .502/.520 lift, 113 lsa. I have Stealthram and TRI-y jet hot coated headers. I will get a Crane Gm small cap distributor and Crane Gold Race narrow body 1.6:1? roller rockers. This is not an everyday driver of course but it will at least go on the Dyno . I have 31 pound flow tested injectors. Also I am just now getting around to having a baseline chip burned and I do have my own chip burner and software. I plan to buy a reman performance 700r4 with 6 pinion close ratio planetary and 2400 rpm stall torque converter. I have 3.23:1 rear and I am wondering if anyone can estimate horsepower, torque, and mileage or give any suggestions for improvement or comments about parts I should keep or get rid of. This has been a ten year project but now I am about to finish it.
 

B&R Racing

solid fixture here in the forum
My 383 motor for my 88 trans am is Scat Stroker with AFR 195 Eliminator 72 cc heads, flat pistons. The càm is Comp Cams Nitrous cam 227/236, .502/.520 lift, 113 lsa. I have Stealthram and TRI-y jet hot coated headers. I will get a Crane Gm small cap distributor and Crane Gold Race narrow body 1.6:1? roller rockers. This is not an everyday driver of course but it will at least go on the Dyno . I have 31 pound flow tested injectors. Also I am just now getting around to having a baseline chip burned and I do have my own chip burner and software. I plan to buy a reman performance 700r4 with 6 pinion close ratio planetary and 2400 rpm stall torque converter. I have 3.23:1 rear and I am wondering if anyone can estimate horsepower, torque, and mileage or give any suggestions for improvement or comments about parts I should keep or get rid of. This has been a ten year project but now I am about to finish it.
The Tri Y Headers give ground clearance and often more low end and midrange torque. Along with a unique exhaust note non Drag car some want.
Without using an engine simulation looking at 450-520- 530 Hp likely.
More power with Cylinder head Porting and paying attention to details in the Valvejob done, more than lapping in by hand.

I would recommend a modern stand alone Aftermarket EFI computer if you can wing it buy it.
Options out there some affordable others not for most.
Electromotive EFI System I recommend and is actually affordable True Pro IMCA Road Racer Worthy and Top Sportsman drag racing worth quality reliable 100%.
Made in the USA 100% Electromotive EFI.
All.others I can think of import China made.

No Chassia Dyno EFI Tuner today can work with OBD1 .
They are lost.
 

B&R Racing

solid fixture here in the forum
How you setup your Car gearing is personal choice on the street.
Too much with a low of gear will break non Pro Quality Differential drag racing parts while Street racing if you dabble into
 
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B&R Racing

solid fixture here in the forum
On the Chassis Dyno at the rear wheels expect 125-150 Hp less than calculated at 4th the Flywheel power.

700R4 & 4L60E are known to eat tons of Hp and torque up power passing through so dont be surprised if numbers measured are lower than your expected.
Some report it eats up 150 Hp !
But on the street 1st gear low is nice.
1-2 takes forever after shift for engine to recover it seems but you have the 6-pinion front planet gearset upgrade takes some of the Shift Recovery time out.
4th gear overdrive is nice.

Turbo 400, Turbo 350, Powerglide 2-speed use least amount of Hp passing through why used exclusively Drag Racing now plus proven reliable 100%.
 

CWash2

Member
I have a question. If a 383 is a 350 bored .030 over with 3.75 inch rods and a stroker crank, then what displacement is a 350 with the same 3.75 inch rods in a 350 block that is only bored .020 over? My machinist insisted that with a smaller bore there were some advantages. Well can anybody at least tell me the advantages over a .030 overbore? I am using the 72 cc AFR 195 Eliminators as well. If I increase to 1.6:1 ratio roller rockers my lift would move from .502/.520 to .532/.550? The 195s flow great there. Also I have TRI-y headers. With the stall and torque curve of the Stealthram and the rest of my setup, listed above, I hope to have less of a shock to my suspension and to minimize excess spinning if I need to do a rapid stab to the has pedal. But what about the .020 overbore?
 

B&R Racing

solid fixture here in the forum
I would want the larger .030" overbore so there is less intake and exhaust valve shrouding at max valve lifts intended.
. 020" allows slight thicker cylinder walls in a OEM Block.
Allows another Rebuild bore over down the road.
Most oils are so good its possible to get 400,000 miles use before a rebuild is needed with proper maintenance and not Racing hard.
Hard use Racing streets 10,000 miles life longevity is excellent.
 

B&R Racing

solid fixture here in the forum
What is it about the 700r4 that causes it to "eat" horsepower?
The Reverse Clutch pack and mass of the drum 2-4 and band.
They have to be setup with tight clearances so they hold up don't fail like stock all they did eventually.
Adds Friction to turn.
They make Turbulator steels for 700R4 4L60E Reverse clutch steels.
Have oval punched out Lightning holes
Fell out of favor back in 2006.
Still can buy them have to special order direct from Alto or Transtar.

Also Turbulator steels made for a Turbo 400. I have never used any in my own Automatic rebiilds.
Asked one Pro trans builder about Turbulator steels, he mumbled Junk waste of money.
So I never pursued that idea.
 

B&R Racing

solid fixture here in the forum
I think 700R4 and 4L60E is efficient in Overdrive.
My 87 Corvette gets 28 mpg at 70 mph cruising worst days.
Good weather see 32 mpg.

Chassis Dyno tests seldom done in Overdrive gear top speeds.
They can jump off the Chassis dyno break the straps and chains keep going.
Highest wheel speeds I seen on Mustang AWD Chassis Dyno was 180 mph the Superchaged C6 Corvette almost came off jumped 2 feet over at 180 mph the Race shop I worked at in Chicago.
Owner there a Street Racer wanted it tested to 200mph top end.
Stupidity on a Chassis dyno.
Usually only only 3rd hit direct high before Ovedrive . Wheel speeds 120-130 at max engine rpm like 7000, test cut off for safety reasons.
So get some arguable biased results.
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
loads and wheel speeds on dyno don't take into account factors like the drag and air resistance on the roads at speed




 
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B&R Racing

solid fixture here in the forum
20 years from now it will still function Electromotive EFI.

It's like BLP BoLaws Of The EFI world buying the Very Best made
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
I have a question. If a 383 is a 350 bored .030 over with 3.75 inch rods and a stroker crank, then what displacement is a 350 with the same 3.75 inch rods in a 350 block that is only bored .020 over? My machinist insisted that with a smaller bore there were some advantages. Well can anybody at least tell me the advantages over a .030 overbore? I am using the 72 cc AFR 195 Eliminators as well. If I increase to 1.6:1 ratio roller rockers my lift would move from .502/.520 to .532/.550? The 195s flow great there. Also I have TRI-y headers. With the stall and torque curve of the Stealthram and the rest of my setup, listed above, I hope to have less of a shock to my suspension and to minimize excess spinning if I need to do a rapid stab to the has pedal. But what about the .020 overbore?

ok lets straiten a few thing out most small block 350 or 383 engines use a 5.7" or a 6" connecting rod,
the difference in displacement is mostly the result of the longer stroke on the crank in the 383 configuration
you calculate displacement ,
by multiplying the bore diam,
x bore diam.
times stroke length,

times the number of cylinders
time .7854=displacement in cubic inches

heres a link that may help
https://spicerparts.com/calculators/engine-displacement-calculator


http://garage.grumpysperformance.com/index.php?threads/bits-of-383-info.38/

http://garage.grumpysperformance.co...-length-too-stroke-info.510/page-3#post-75144

http://garage.grumpysperformance.com/index.php?threads/building-a-s̶t̶r̶o̶n̶g̶-̶3̶5̶0̶-383-for-frank-the-tank….11173/

http://garage.grumpysperformance.com/index.php?threads/another-383-build.12786/






deckh.jpg
skirtclearance.jpg
 
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CWash2

Member
I would want the larger .030" overbore so there is less intake and exhaust valve shrouding at max valve lifts intended.
. 020" allows slight thicker cylinder walls in a OEM Block.
Allows another Rebuild bore over down the road.
Most oils are so good its possible to get 400,000 miles use before a rebuild is needed with proper maintenance and not Racing hard.
Hard use Racing streets 10,000 miles life longevity is excellent.

Well I was told leaving more metal in the block would also help wick heat away from the pistons (I used coated pistons) and would make for an overall stronger block. I was also trying to help control heat by fighting piston rocking (supposedly?) and since I have the 72 cc chamber AFR 195s, the lower compression with size of cam should allow me to easily run premium pump gas and more timing without detonation problems. I wonder if the 227/236 will help with detonation AND sound good with the TRI-y headers and probably a magnaflow or dynaflow stainless muffler. Which one was it that Mr. David Vizard designed? With the jet hot inside and outside coated tri-y headers can anyone tell me if they think I should go for 1.6 rockers for better scavenging, both intake and exhaust, just intake or exhaust, or better to stick with the 1.5 rollers. My cam is the CC roller I described above.
 

CWash2

Member
ok lets straiten a few thing out most small block 350 or 383 engines use a 5.7" or a 6" connecting rod,
the difference in displacement is mostly the result of the longer stroke on the crank in the 383 configuration
you calculate displacement ,
by multiplying the bore diam,
x bore diam.
times stroke length,
times the number of cylinders
time .7854=displacement in cubic inches


heres a link that may help
https://spicerparts.com/calculators/engine-displacement-calculator

http://garage.grumpysperformance.com/index.php?threads/bits-of-383-info.38/

http://garage.grumpysperformance.co...-length-too-stroke-info.510/page-3#post-75144

http://garage.grumpysperformance.com/index.php?threads/building-a-s̶t̶r̶o̶n̶g̶-̶3̶5̶0̶-383-for-frank-the-tank….11173/

http://garage.grumpysperformance.com/index.php?threads/another-383-build.12786/




deckh.jpg
skirtclearance.jpg

Using one of the displacement calculators. a .030 bore and a 3.75 rod would be 382.67 cu. in. Rounding up makes 383. But .020 bore and a 3.75 stroke makes 380.77 cu. inches which rounded up comes to 381 which just does not sound like a hot rod number. So it's less than 3 away from 383. What sounds better 380, 381, 383, OR my favorite 350?:rolleyes:
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
in the real world theres very little difference, .030 was used as its about the least over bore that cleans up an average worn engine for a rebuild,\
realistically you can expect about 1 hp and 1.3 ft lbs of torque for each cubic inch of displacement added to a sbc engine if everything, well matched and done close to correctly,
that of course assumes that you sellect the correct cam timing and match the compression and air flow requirements reasonable close to the intended application and rpm band
 
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