Suggestions for a 383 build
Thread Starter
Instructor
Joined: Mar 2007
Posts: 169
Likes: 0
From: Tullahoma Tennessee
Suggestions for a 383 build
Alright here's my current setup...
Stock L48 bottom end, performer RPM air-gap intake,
Holley 4160 (750 cfm Vacuum Secondaries), 1 inch carb spacer
(four hole style), mallory HEI distributor, accel plug wires, 14 inch
drop base air cleaner, stock exhaust manifolds, everything from the trans. back is stock.
And my new setup...
Same top end as above plus- AFR 195 eliminator heads,
Comp Cams XR 676 HR, Dynomax Blackjack 1 5/8" full length
headers, Eagle 383 rotating assembly kit (dished pistons, cast crank),
1.6 rockers, 700r4 tranny rebuilt to handle the torque, and a 3.73 gear
in the back.
My desktop dyno says this should make 478 ft/lbs @4000 and
450 hp @5500, now I realize these programs tend to overestimate
actual power but I'd be happy with 400 ft/lbs and 350 hp at the rear
wheels anyway. Will this setup deliver? Anything I should change to
unleash more horses? My whole goal is to have a low end torque
machine that's happy on pump gas and gets tolerable mileage. As always any input is appreciated.
Stock L48 bottom end, performer RPM air-gap intake,
Holley 4160 (750 cfm Vacuum Secondaries), 1 inch carb spacer
(four hole style), mallory HEI distributor, accel plug wires, 14 inch
drop base air cleaner, stock exhaust manifolds, everything from the trans. back is stock.
And my new setup...
Same top end as above plus- AFR 195 eliminator heads,
Comp Cams XR 676 HR, Dynomax Blackjack 1 5/8" full length
headers, Eagle 383 rotating assembly kit (dished pistons, cast crank),
1.6 rockers, 700r4 tranny rebuilt to handle the torque, and a 3.73 gear
in the back.
My desktop dyno says this should make 478 ft/lbs @4000 and
450 hp @5500, now I realize these programs tend to overestimate
actual power but I'd be happy with 400 ft/lbs and 350 hp at the rear
wheels anyway. Will this setup deliver? Anything I should change to
unleash more horses? My whole goal is to have a low end torque
machine that's happy on pump gas and gets tolerable mileage. As always any input is appreciated.
Burning Brakes
Joined: Aug 2006
Posts: 1,155
Likes: 0
From: San Diego California
That sounds like a good build and a fun drive. I'll bet you're close to your goal. What's the size of the dish on those pistons... and your estimate of the CR? Not sure the carb spacer does much good if your looking primarily for torque. Are you also running a true dual 2 1/2' exhaust?
Burning Brakes
Joined: Dec 2003
Posts: 1,004
Likes: 7
From: Adelaide South Australia
The rear wheel figures you are expecting, in my opinion, are optimistic.
I had a dynosim model on my 383 setup indicate 460hp and 490lb-ft of torque. I achieved 311 rwhp and 365 lb-ft rear wheel torque..... and that was with a manual gearbox. Your auto trans will chew up more horses.
Maybe we have different methods of power calculation in the southern hemisphere.... but 350 rwhp sounds optimistic to me for your setup.
But I'm only too happy for you if I am proved wrong.
By the way..... A genuine 300 horses at the rear wheels will be more than enough to put a smile on anyone's dial....
I had a dynosim model on my 383 setup indicate 460hp and 490lb-ft of torque. I achieved 311 rwhp and 365 lb-ft rear wheel torque..... and that was with a manual gearbox. Your auto trans will chew up more horses.
Maybe we have different methods of power calculation in the southern hemisphere.... but 350 rwhp sounds optimistic to me for your setup.
But I'm only too happy for you if I am proved wrong.
By the way..... A genuine 300 horses at the rear wheels will be more than enough to put a smile on anyone's dial....
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
You didn't say anything about a torque converter. The difference in low end performance between a stock converter and one around 2,800 rpm stall is amazing. It won't help your gas mileage though.
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
I think you should have went with the flat top pistons instead of the cup piston,would have run alot better.10 to 1 compression would not have been too much compression,it probably would have been a little lower then that.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
You can lok at my setup in my signature. This is definitly not your daily driver type motor. It did make 409 at the rear wheels though. 
I figure it to be just shy of 500 HP at the crank. My calculations are also about 10.8 to 1 compression.
I figure it to be just shy of 500 HP at the crank. My calculations are also about 10.8 to 1 compression.
Thread Starter
Instructor
Joined: Mar 2007
Posts: 169
Likes: 0
From: Tullahoma Tennessee
Looking for about 9.5 to 1 compression, and honestly I hadn't decided on a stall converter yet, I'll wanna be able to break the tires loose at a light every now and then. Also, my decision to go with dished pistons was based on a suggestion I got from a forum member who said I was best to go with small chamber heads and dished pistons to maximize effeciency. The pistons will be 18cc dish with 64cc heads. Hope that answered all the questions.
P.S. BKbroiler, I'd also like to know what kind of numbers you're running to get the front end up like that.
P.S. BKbroiler, I'd also like to know what kind of numbers you're running to get the front end up like that.
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Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
Looking for about 9.5 to 1 compression, and honestly I hadn't decided on a stall converter yet, I'll wanna be able to break the tires loose at a light every now and then. Also, my decision to go with dished pistons was based on a suggestion I got from a forum member who said I was best to go with small chamber heads and dished pistons to maximize effeciency. The pistons will be 18cc dish with 64cc heads. Hope that answered all the questions.
P.S. BKbroiler, I'd also like to know what kind of numbers you're running to get the front end up like that.
P.S. BKbroiler, I'd also like to know what kind of numbers you're running to get the front end up like that.
9.50 cr is good
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
The tires aren't off the ground but the front suspension does extend to its full travel. You and Rab16 asked about HP and TQ. I don't know the numbers but you can check my sig for the details. The car is full weight and runs 104/105 in the quarter. One key to that chassis reaction is bottom end power and gearing etc. The 3,000 stall speed converter, 3.73 gear and TH350 combine for good off the line performance, usuallly - this is on street tires and sometimes they spin badly and really slow it down.
