PRH
Well-Known Member
No doubt in my mind.
Take my old bracket combo and port the heads…….done.
I’m sure at that point, a swap to a port matched/plenum tweaked Victor and you’d get a bit more out of it.
Nicks Garage 383 build
- Thread starter RAMM
- Start date
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No doubt in my mind.
Take my old bracket combo and port the heads…….done.
I’m sure at that point, a swap to a port matched/plenum tweaked Victor and you’d get a bit more out of it.
PRH
Well-Known Member
I know I’m not saying anything here you’re not already thinking……..but, wow…….that thing was weak!!
Nick's 383 Dyno Test - Part 1
OK here are the Bullet Cam card specs from the first test:
Gross Valve Lift >
489/488
Duration >
268/281
Separation >
110
Duration @ .050 >
220/281
______________
Can now compare these specs to the Factory 1970 383 4 barrel specs.
OK here are the Bullet Cam card specs from the first test:
Gross Valve Lift >
489/488
Duration >
268/281
Separation >
110
Duration @ .050 >
220/281
______________
Can now compare these specs to the Factory 1970 383 4 barrel specs.
I was bored and wanted to see other 383 dyno numbers to see how they should be and ran into this video of his which was 400+ TQ.. but one thing that caught me is him saying that when you line bore the mains you bring the crank closer to the cam.... umm... bout 5 seconds in here..
junkyardhero
Well-Known Member
full agreement. i did a 383 for a guy about 15 years ago, nothing wild style just a good solid build. summit forged slugs and machine work for an honest 10:1, old school isky 509/292, the heads were 906's that were full boat done up by DLI along with a performer RPM and a holley 780 with headers.
he didn't want to run it on the dyno, but i drove and rode in the 65 belvedere it was installed in and it hauled the mail.
however, a few years later the "needs mas" bug bit and he wanted to mix it up so he had me put on a tunnel ram with pair of afbs. besides tuning the set up for decent street manners no other changes were made and he had me run it on the chassis dyno where it clicked off a respectable low 390's before the imposed 5500 redline (his arbitrary #). i was bummed it didn't hit the magic 400 (and i'm sure there was more in it with another 1K) but if you extrapolate the data, that would indicate it was making damn near 500 at the crank.
so absolutley capable, but like anything getting there is a matter of compression and heads which don't come cheap or easy.
Not when it's done correctly.
I know.. i was just shocked to see him say that's how line boring works..
I think Nick is sharp at what he DOES and I like him. He has a youtube channel and has basically a dyno TV show. Nobody knows it all, BUT it does seem like he would know some of this stuff that he's leaving out. Maybe he does and he just doesn't want to get in too deep on his show? I don't know, but I still like the guy.
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Newbomb Turk
Well-Known Member
I would suggest his biggest issue is he’s not an engine builder, or more specifically a machinist. He’s an assembler.
If you can’t walk up and use the machines to machine an engine you aren’t really an engine builder.
That changes how you look at everything.
Plus, like I said I don’t think he’s much of a tuner.
I’ve been lucky to have mentors my whole life that have helped me with that part of it.
I just came home from dynoing my stock stroke 400. The specs are 8.5:1 compression, pocket ported 346 heads, Weiand dual plane intake, Summit 6400 cam (214/224 duration and 444/466 lift). I was trying to concentrate on low end torque to move a 4200 pound 1966 Charger with 2.94 gears. With the 650 DP dyno carb it made 420 lb/ft of torque at 3900, with over 400 lb/ft from 3000 to 4300. Horsepower was only 340 and it peaked early at around 4800 rpm. The torque was about as expected, and the horsepower a little disappointing, but given my stated goal, it should do the job.
.
.
And you know, ALL it takes to run any automotive machine equipment is two things. Common sense and the ability to read a mic. If you possess those two abilities, you can figure out the equipment, even if it's state of the art...in fact, most of those machines are easy to operate.
Comments from the 383 Dyno Videos:
☆☆☆☆☆
OEM 383 camshaft grind numbers to achieve the desired goals of their Dyno tests.
1970 383 was already taking a compression reduction as per the new emissions restrictions, as a result output numbers will be down.
Interesting the 383 2 barrel and 383 4 barrel engines used the same camshafts.
☆☆☆☆☆
1970 383 was already taking a compression reduction as per the new emissions restrictions, as a result output numbers will be down.
Interesting the 383 2 barrel and 383 4 barrel engines used the same camshafts.
☆☆☆☆☆
The 383HP engines did not use the same camshaft. They used the "Road Runner Cam" that I and a few others have referenced multiple times.
Newbomb Turk
Well-Known Member
RAMM
Well-Known Member
Yep it mimicked a stock resto 383 I did about 20yrs ago, 325hp/380tq on a SF-901. Prior to that I worked at a shop that we did a 383 for a beautiful '67 Belvedere , we never dynod it but it was such a slug that we wound up trying a different cam with no noticeable change. Hence my disdain for a rebuilt "stock" 383, theyre so weak they arent even satisfying to cruise IME/IMO. J.Rob
PRH
Well-Known Member
Headers used on the dyno?
Any idea what size?
Let’s see a sheet.
I realize for your combo, the cam requirement is going to call for something pretty small.
But I feel cams like that generally don’t produce power curves that look impressive on a dyno sheet.
PRH
Well-Known Member
Over 20 years ago I tested a coupe of Chevies that were supposed to be “hot street” type builds.
Both were already installed and running in vehicles, where the owners weren’t satisfied with the “driving experience”.
One was a BB 396, and the parts combination was specified by a local 396 officinado.
It was supposed to be a 400hp combo.
It was pretty basic, but was lacking in two specific areas.
It had no headers, and it had a SP2P intake on it.
Seems like the story was something like the headers would only be worth 10hp, no why bother.
And the intake was just a favorite of the guru.
It had a Comp 280H cam and roller rockers and an Ede 750 carb(that really sucked).
It was in a 68 Camaro with I think 3.31 gears, and some mild converter.
I remember the first ride in got in it.
Found a nice straight stretch of road……we take off and I’m kinda keeping an eye on the tac, at 4500 it is absolutely done…….and in my mind I’m going “shift…….shift……..shift”.
6000 finally rolls around and he shifts(it was a pretty long wait from 4500 to 6000).
He had a store in town I stopped in fairly often, we’d talk about cars, and the discussion turned to how to get more out of the 396.
I tell him the right way to do it was put it on the dyno as is, and see where it’s at, then go from there.
The motor gets pulled, he brings it down, along with the manifolds and a couple of feet of the head pipes.
I guess 285 is kinda, sorta close to 400??
Tried the headers, and even with the horrendously bad intake they were still worth about 30hp.
I ended up installing a small solid cam and an RPM A/G, along with a 650DP Demon carb……..made 416hp with the headers on it.
Totally different feel in the car.
The tac needle would swing right up past 6k like nothing.
Both were already installed and running in vehicles, where the owners weren’t satisfied with the “driving experience”.
One was a BB 396, and the parts combination was specified by a local 396 officinado.
It was supposed to be a 400hp combo.
It was pretty basic, but was lacking in two specific areas.
It had no headers, and it had a SP2P intake on it.
Seems like the story was something like the headers would only be worth 10hp, no why bother.
And the intake was just a favorite of the guru.
It had a Comp 280H cam and roller rockers and an Ede 750 carb(that really sucked).
It was in a 68 Camaro with I think 3.31 gears, and some mild converter.
I remember the first ride in got in it.
Found a nice straight stretch of road……we take off and I’m kinda keeping an eye on the tac, at 4500 it is absolutely done…….and in my mind I’m going “shift…….shift……..shift”.
6000 finally rolls around and he shifts(it was a pretty long wait from 4500 to 6000).
He had a store in town I stopped in fairly often, we’d talk about cars, and the discussion turned to how to get more out of the 396.
I tell him the right way to do it was put it on the dyno as is, and see where it’s at, then go from there.
The motor gets pulled, he brings it down, along with the manifolds and a couple of feet of the head pipes.
I guess 285 is kinda, sorta close to 400??
Tried the headers, and even with the horrendously bad intake they were still worth about 30hp.
I ended up installing a small solid cam and an RPM A/G, along with a 650DP Demon carb……..made 416hp with the headers on it.
Totally different feel in the car.
The tac needle would swing right up past 6k like nothing.
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RAMM
Well-Known Member
I have a couple of very similar experiences with a 396 and a 402 (bigger 396). Both were mutts and I kind of lump them in with the BBM 383/400 category and I find you even have to build them with the same kind of "recipe" . Thats a great story Dwayne and yes a solid lifter cam is always a go to of mine if the customer isn't terrified of checking the lash once a year. J.Rob
PRH
Well-Known Member
Another one from a similar time period…….
SBC 400.
Was in some sort of off road/trail rig.
I don’t know much about it, other than he was friends with the dyno owner.
I kind of got the impression he was thinking he was going show off his engine building prowess with how awesome the power of the build was.
I don’t recall if it was tested with headers or not.
It had some sort of factory heads on it, but not the “good” ones, and he’d done some clean up on them.
As I’m thinking about it, I seem to recall talk of roller rockers and 1.6 ratio.
This was one of those situations where I could tell as soon as I had it running…..it was not going to make big power.
Like the 396, it was also in the 280’s, but that might have been with headers.
Made a few pulls, Played with the timing, swapped a carb, no real difference.
Took it back off.
SBC 400.
Was in some sort of off road/trail rig.
I don’t know much about it, other than he was friends with the dyno owner.
I kind of got the impression he was thinking he was going show off his engine building prowess with how awesome the power of the build was.
I don’t recall if it was tested with headers or not.
It had some sort of factory heads on it, but not the “good” ones, and he’d done some clean up on them.
As I’m thinking about it, I seem to recall talk of roller rockers and 1.6 ratio.
This was one of those situations where I could tell as soon as I had it running…..it was not going to make big power.
Like the 396, it was also in the 280’s, but that might have been with headers.
Made a few pulls, Played with the timing, swapped a carb, no real difference.
Took it back off.
RAMM
Well-Known Member
Holy Smokes Dwayne! This is some Twilight Zone stuff , had a similar experience. Shop I was at was commissioned to build a SBC 400 for a guy with a stepside pickup. He wanted it Chevy Blue as it was real close to the colour of the truck. Anyways we used some nice forged Speed-Pros, CS179 cam (it was the shop owners goto cam-lol) and some '642 castings enlarged with a big (lol) 1.94" valve I think. We didn't have a flowbench or a dyno so in it went and I got to test drive it. Now we had built some fairly impressive 383 strokers (DART/Sportsman heads) by this time so I figured that 4.155" bore and 406 cubes would be pretty strong. Boy was I wrong. It would barely turn the tires and it was all done around 4300rpm. I was embarassed for him and the shop owner as those two called all the shots. What a dog that thing was. J.Rob
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