BBC 396 from sick solid roller to hyd Roller EFI...
Thread Starter
Racer
Joined: Jul 2004
Posts: 254
Likes: 1
BBC 396 from sick solid roller to hyd Roller EFI...
Customer's customer had a mint Nova that was his baby but the complaints of fuel smell, bucking in high gear at low rpm, and hard starting had him hating the car. The engine was a BBC 396 + .040" with a set of '69 model factory closed chambers. The car had a custom solider roller .5XX/.6XX 243/251 .050" on a 112. The engine builder wanted to go hyd roller and did not care if we lost a little power going to a hyd roller as the customer wanted driveability.
So the engine builder dyno'd the engine as is. Made 510HP at 6000 rpm and 446#/ft at 5000 rpm. He left timing, carb, and everything as is and put in a Clay Smith 160-3101 with a set of the Morel Street lifters. Engine made 520.9HP at 6200 rpm and 476#/ft at 5000 rpm.
He then put on the atomic EFI system and began to tune. The end result was 550HP at 6500 rpm and 510#/ft at 5900.
It idles, it starts, it rpms, and the engine builder says it is a totally different car now. Not shabbby out of a 396!!!
So the engine builder dyno'd the engine as is. Made 510HP at 6000 rpm and 446#/ft at 5000 rpm. He left timing, carb, and everything as is and put in a Clay Smith 160-3101 with a set of the Morel Street lifters. Engine made 520.9HP at 6200 rpm and 476#/ft at 5000 rpm.
He then put on the atomic EFI system and began to tune. The end result was 550HP at 6500 rpm and 510#/ft at 5900.
It idles, it starts, it rpms, and the engine builder says it is a totally different car now. Not shabbby out of a 396!!!
Burning Brakes
Joined: Jun 2010
Posts: 1,165
Likes: 93
From: Bellmore NY
Things like this impress and amuse me at the same time. I dont think anyone thought for a second that the hyd roller would produce more power with all things being equal.
With that said, do you feel that these results are related to one cam profile being superior to the other, OR the profile of the cams with respect to the cubic inches.... ie, if this was a 454 would that solid roller now work to its potential and produce more power than the same hyd roller?
With that said, do you feel that these results are related to one cam profile being superior to the other, OR the profile of the cams with respect to the cubic inches.... ie, if this was a 454 would that solid roller now work to its potential and produce more power than the same hyd roller?
Thread Starter
Racer
Joined: Jul 2004
Posts: 254
Likes: 1
Dave,
Its all about building a combination based on what the customer wants to do. I have always said the right cam will make more power than the wrong cam no matter what it is.
Now the EFI making that kind of power. That surprized me but I am a carb guy.
Its all about building a combination based on what the customer wants to do. I have always said the right cam will make more power than the wrong cam no matter what it is.
Now the EFI making that kind of power. That surprized me but I am a carb guy.
Burning Brakes
Joined: Jun 2010
Posts: 1,165
Likes: 93
From: Bellmore NY
The EFI took me a little by surprise too, because the gains were huge!
I know you are kind of a magician with this sort of thing..I think you recently set up a team chevelle friend of mine from CT with a reground solid roller that started out as a ZZ502 grind. He and I talk about low compression 454 builds...curious about what you would slap into a stock LS4, 4 speed car
I know you are kind of a magician with this sort of thing..I think you recently set up a team chevelle friend of mine from CT with a reground solid roller that started out as a ZZ502 grind. He and I talk about low compression 454 builds...curious about what you would slap into a stock LS4, 4 speed car
Thread Starter
Racer
Joined: Jul 2004
Posts: 254
Likes: 1
I'll be shot for this but compression doesn't factor in to camshaft duration or lift. I can manipulate Events to help but simply put a compression 454 or a low compression 454 with all things equal will need the same amount of lift and duration to make power in the given rpm range.
Burning Brakes
Joined: Jun 2010
Posts: 1,165
Likes: 93
From: Bellmore NY
Thank you sir!
As of now the motor is bone stock [or at least I believe it to be], so it shooooould be a 8.25:1 454. I have an edelbrock performer that has had the runners hogged, an 800 spreadbore dp, and a set of 1 7/8" headers sitting around waiting to become part of the package.
Trans is an M21 built as an M20, and I have a 3.55 pumpkin ready to replace my 3.36 rear.
Id like the car to have good useable power from as close to idle as possible, to about 5k. Yes, I know this range is almost laughable, but its where I see myself with this car. Once upon a time I had a 454 that went to about 6400 with a comp 306s, 4k stall, and 4.10s...that was then and this is now
Thanks for any tidbits of advice or direction you could point me in!
As of now the motor is bone stock [or at least I believe it to be], so it shooooould be a 8.25:1 454. I have an edelbrock performer that has had the runners hogged, an 800 spreadbore dp, and a set of 1 7/8" headers sitting around waiting to become part of the package.
Trans is an M21 built as an M20, and I have a 3.55 pumpkin ready to replace my 3.36 rear.
Id like the car to have good useable power from as close to idle as possible, to about 5k. Yes, I know this range is almost laughable, but its where I see myself with this car. Once upon a time I had a 454 that went to about 6400 with a comp 306s, 4k stall, and 4.10s...that was then and this is now
Thanks for any tidbits of advice or direction you could point me in!
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Burning Brakes
Joined: Jun 2010
Posts: 1,165
Likes: 93
From: Bellmore NY
Im completely embarassed right now and feel like an amateur for saying this, but I havent pulled a valve cover in the 3 years of ownership, as I have tended to all sorts of other nonsense on this car in that time. I know I shouldnt assume that they are 781's, but thats what shouuuuld be there.
How about this...I have an ignition project coming up soon on this car [just threw my msd in the pass dash panel and putting in msd dist soon]...at that time I'll pull a cover and shoot you a PM?
How about this...I have an ignition project coming up soon on this car [just threw my msd in the pass dash panel and putting in msd dist soon]...at that time I'll pull a cover and shoot you a PM?
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
I'm curious about using less lift on the exhaust compared to the intake. In the old days the exhaust had more duration and lift, now they still have more duration, but less lift. How come?
Thread Starter
Racer
Joined: Jul 2004
Posts: 254
Likes: 1
Thread Starter
Racer
Joined: Jul 2004
Posts: 254
Likes: 1
Cam lobes are designed in families. If a family started at say 230@.050 it may go to 248@.050". The lifter velocity rate stayed the same, so naturally the larger lobes had more lift.
My "cam beginnings" started from John Reed. John started mixing families of his profiles in the 70's. Intake tract and exhaust tract do not operate in any capacity alike... depression.....high pressure. The lobes should not be the same. On exhaust as soon as you crack the valve the exhaust wants out. Time (duration) is what the exhuast port needs and based on how good the port flows, less time for a good port more time for a bad port, is what is important. Lift, hell it just is there.
