Thinking about building a 383 stroker
Im sure it will help to know but I’m working with the stock th-400 auto trans and stock rear end im not sure of the gearing in the rear
Im sure it will help to know but I’m working with the stock th-400 auto trans and stock rear end im not sure of the gearing in the rear
Last edited by Little Mouse; Jan 10, 2019 at 06:30 PM.
Last edited by Little Mouse; Jan 10, 2019 at 06:32 PM.
The Best of Corvette for Corvette Enthusiasts
You can build a SBC 355 with a roller cam easy today to 425 gross HP. A 383 can fairly easily get to 475 Gross HP built solidly. If you feel 500+ Gross HP is the goal it can be done with a 383 but more easily with more cubes, 396/406 and more dollars? The sweet spot today for the most economical 450 Gross HP is a 383...............
Im sure it will help to know but I’m working with the stock th-400 auto trans and stock rear end im not sure of the gearing in the rear
Please state your budget for engine build.
Please find out what your rear gear ratio is and state it.
do you have a carb? have an intake? have brackets? have exhaust manifolds/headers? etc etc?
A 355 like mine easily got to 425 Gross HP. There are guys on the forum with 450-475 Gross HP 355's as well. You would never know my 355 is any different than the OEM l-82 just idling and cruising.
A 383 can easily get to 440-450 Gross HP as well. The most economical way and reliable path to to sub <500 Gross HP is a 383 built correctly with decent 10+ compression, roller cam and top flowing heads like AFR's. With the advent of great cylinder heads and especially roller cams, the old formula's for cubes to get Gross HP numbers have changed......quite a bit in the last 10 years.
Last edited by jb78L-82; Jan 11, 2019 at 07:56 AM.
Try ohio crank...talk to your machinist first he can buy it cheaper than you possibly save you too. They have their preference and will probably not stand behind anything you bring them some will refuse the job.
You can do a cast crank 383 pretty reasonable. Spend on heads
A 383 can easily get to 440-450 Gross HP as well. The most economical way and reliable path to to sub <500 Gross HP is a 383 built correctly with decent 10+ compression, roller cam and top flowing heads like AFR's. With the advent of great cylinder heads and especially roller cams, the old formula's for cubes to get Gross HP numbers have changed......quite a bit in the last 10 years.
A 383 can easily crest 600 just have to live with it. Joe Sherman was running 9s with a 350 with old crappy parts in the 70s.
Spot-on machine work is where to spend the money, don't cut corners - have it square decked and torque plate honed. Less oil burning and less into the combustion chamber.
You'll have an inexpensive engine that will be a blast on the street.
"The key here was to match the capability of the cylinder head with a camshaft that could extract as much power as possible without sacrificing torque down low. Besides the excellent low-lift intake flow, the big thing that really demands to be noticed is the excellent exhaust-to-intake flow relationship. The AFR 180 head has an outstanding exhaust port, which can over-scavenge the cylinder and hurt power if used with a dual-pattern camshaft. Dual-pattern cams use a longer-duration exhaust lobe that is not necessary with these heads.
When it came time to choose the cam, Comp Cams suggested going with one of the time-honored single-pattern cams from the Magnum series but in a hydraulic-roller configuration. We ended up with the 280HR10 Magnum roller, which generates 0.525-inch lift (see the "Cam Specs" sidebar) and fits perfectly with the AFR 180 head's flow curve. Ed Taylor used a two-piece front timing-chain cover from Comp to make this swap a little easier and performed the cam change on the dyno in a couple of hours. This was originally a hydraulic-roller cam engine, so we didn't have to worry about setting the camshaft endplay since the factory limiter plate does that job for us. We also reused the original roller tappets as well as the pushrods and the 1.5:1 roller rockers.
A serious break-in period isn't required on the rollers, so after a 10-minute warmup we were ready again to rock and roll. Despite the additional 16 degrees of duration (at 0.050-inch tappet lift), Daffy was in command of the torque curve over the smaller cam by 3,000 rpm, and as the engine speed continued to climb, so did the power. Longer-duration cams always drive the peak horsepower point up higher in the rpm curve, but the conservative timing figures generated only a 5,800-rpm peak horsepower point. Despite the low peak rpm, Daffy still managed an honest 425 hp while torque was broad and very flat with a peak of 440 lb-ft at 4,600 rpm. This sounds like the torque peak was a little higher than you would expect, but the engine was also making 429 lb-ft at 3,800 and never made less than 382 lb-ft even at 2,600 rpm."
Lets think about this 355 for a second! 15 years ago this 355 engine made 425 gross Hp with less compression than my engine and with the first generation AFR 180 heads! This 355 15 years ago, again, made 382 TQ at 2,500-2600 RPM with no fancy parts..NONE
AND desktop dyno estimates 440 Gross HP for my engine
AND other 355's with updated AFR heads slightly more compression than my 10.2:1 with .560 roller cams dynoed 475-480 Gross HP
AND the builder who did my bottom end who has built 100's of Gen 1 SBC V8 with his in house mustang dyno estimates if I wanted to go dyno the car, 425-450 Gross HP. He knows the numbers generated with the parts combination. Does that answer your question or doubts?
The numbers are not rocket science by any means....heads, compression, roller cam and you can hit the number within +/-10 gross HP......The days of not knowing what a particular engine will produce with certain parts is long gone..............I am really perplexed by the persistent question that making 425-450 Gross HP is dubious when there lots of articles on 355 builds with moderate parts, real life examples of those with 355's making more than 450 Gross HP, and expert opinions on this subject...it is not very hard to achieve with a 355...period!
A 383 can make the numbers more easily but the 28 additional cubes of the 383 are not going to make miraculous bigger numbers than a well built 355...sorry! To really make bigger numbers than a well built 355 you need to go MUCH bigger stroked SBC's.
Last edited by jb78L-82; May 9, 2019 at 08:06 PM.




















