4.8L crank in LS2
Yeah but he is at least willing to try the small stroke so my hat off to him. This tread caught my eye as I was looking at the other thread of the Edelbrock heads. As for the real part he isn't going to race in a weight to cubic inch class or claim he is building an all out N/A motor either. As the original guy stated if you don't like it go somewhere else. There are plenty of 402 threads to go see. But you must be interested or you wouldn't keep coming back.
Stop and think about it. A new ZO6 made 505hp at 427 ci. A new ZR1 made 635 hp at 370ci (Alot less stroke and a hair of bore) with a blower. I wonder why GM didn't make the ZR1 a 427 with a blower and just detune it to make 635. Oh yeah by the way I consider both of those real motors cause the mass produce them so people can use the technology from the 2.8 hp/ci motors.
FormerVendor
Joined: Nov 2001
Posts: 3,065
Likes: 6
From: Houston, Tx.
We have done 5 of these engines for two shops and they didn't really do anything. They are strong though!
If you keep the same compression they have more belt tension due to the karge blower and smaller engine with higher boost and make slightly less power and detonate more and can't run as much timing due to higher and hotter boost level.
If you lower the compression so the boost level and compression is right then the engine loses off boost efficiency and mileage off boost big time and is smaller so the worst of all worlds really.
The advantage is much stronger piston but the stock stroke already allows gorilla strong pistons.
Witha turbo maybe there would be a little better trade off.........but I don't know really and the factories never seem to pursue this route either.
If you keep the same compression they have more belt tension due to the karge blower and smaller engine with higher boost and make slightly less power and detonate more and can't run as much timing due to higher and hotter boost level.
If you lower the compression so the boost level and compression is right then the engine loses off boost efficiency and mileage off boost big time and is smaller so the worst of all worlds really.
The advantage is much stronger piston but the stock stroke already allows gorilla strong pistons.
Witha turbo maybe there would be a little better trade off.........but I don't know really and the factories never seem to pursue this route either.
FormerVendor
Joined: Nov 2001
Posts: 3,065
Likes: 6
From: Houston, Tx.
To make it more simple if I had a "2300" model blower and it made 10 psi boost at some overdrive on a 400 inch engine and the blower took 30 hp to operate that level and rpm.
...Then I destroke the same engine by half to a 200 inch model but the same "2300" blower now makes 20 psi boost (also higher IATs) since the same blower is blowing into half the inches at the same rpm.
Now the blower has say 60 hp load making twice the pressure as before at the same rpm or maybe more but certainly not less so this same engine already has to be down by at least 30hp or whatever the new higher belt load is.
Also there is no way now that this smaller engine can run double the boost at the same compression ratio so it must be reduced to satisfy the same octane requirements of the fuel being run as the lower boost larger engine with less belt load and cooler IATs.
This means that the new smaller engine will have less than half the tq off boost as the larger one and less total hp as well on boost. Lower compression off boost will also hurt fuel mileage as well as this engine being a gutless pig off boost.
Of course as soon at you get on it with a positive displacement engine it will still have good power but the blower and belt will still wear out sooner at the higher boost level etc.
Just like in racing bigger blower engines make more power and I expect Chevy may have something larger waiting in the wings later.
...Then I destroke the same engine by half to a 200 inch model but the same "2300" blower now makes 20 psi boost (also higher IATs) since the same blower is blowing into half the inches at the same rpm.
Now the blower has say 60 hp load making twice the pressure as before at the same rpm or maybe more but certainly not less so this same engine already has to be down by at least 30hp or whatever the new higher belt load is.
Also there is no way now that this smaller engine can run double the boost at the same compression ratio so it must be reduced to satisfy the same octane requirements of the fuel being run as the lower boost larger engine with less belt load and cooler IATs.
This means that the new smaller engine will have less than half the tq off boost as the larger one and less total hp as well on boost. Lower compression off boost will also hurt fuel mileage as well as this engine being a gutless pig off boost.
Of course as soon at you get on it with a positive displacement engine it will still have good power but the blower and belt will still wear out sooner at the higher boost level etc.
Just like in racing bigger blower engines make more power and I expect Chevy may have something larger waiting in the wings later.
To make it more simple if I had a "2300" model blower and it made 10 psi boost at some overdrive on a 400 inch engine and the blower took 30 hp to operate that level and rpm.
...Then I destroke the same engine by half to a 200 inch model but the same "2300" blower now makes 20 psi boost (also higher IATs) since the same blower is blowing into half the inches at the same rpm.
Now the blower has say 60 hp load making twice the pressure as before at the same rpm or maybe more but certainly not less so this same engine already has to be down by at least 30hp or whatever the new higher belt load is.
Also there is no way now that this smaller engine can run double the boost at the same compression ratio so it must be reduced to satisfy the same octane requirements of the fuel being run as the lower boost larger engine with less belt load and cooler IATs.
This means that the new smaller engine will have less than half the tq off boost as the larger one and less total hp as well on boost. Lower compression off boost will also hurt fuel mileage as well as this engine being a gutless pig off boost.
Of course as soon at you get on it with a positive displacement engine it will still have good power but the blower and belt will still wear out sooner at the higher boost level etc.
Just like in racing bigger blower engines make more power and I expect Chevy may have something larger waiting in the wings later.
...Then I destroke the same engine by half to a 200 inch model but the same "2300" blower now makes 20 psi boost (also higher IATs) since the same blower is blowing into half the inches at the same rpm.
Now the blower has say 60 hp load making twice the pressure as before at the same rpm or maybe more but certainly not less so this same engine already has to be down by at least 30hp or whatever the new higher belt load is.
Also there is no way now that this smaller engine can run double the boost at the same compression ratio so it must be reduced to satisfy the same octane requirements of the fuel being run as the lower boost larger engine with less belt load and cooler IATs.
This means that the new smaller engine will have less than half the tq off boost as the larger one and less total hp as well on boost. Lower compression off boost will also hurt fuel mileage as well as this engine being a gutless pig off boost.
Of course as soon at you get on it with a positive displacement engine it will still have good power but the blower and belt will still wear out sooner at the higher boost level etc.
Just like in racing bigger blower engines make more power and I expect Chevy may have something larger waiting in the wings later.
What I have is a given level of boost air that an MP122 will pump for this build. I can't afford a TVS...that's out unless I strike oil, but I want a Maggie on top. The mp122 on my truck makes 7.5psi with a 2.8" pulley on a 6.0L (about 500 rwhp). You can't go much smaller than a 2.8" on a front drive (hence, that's about all there is boost wise).
I'm thinking I can get an MP122 at a very reasonable price for this build. I haven't found it yet, but they're out there. An MP122 on top of an engine of about 330 cid would be capable of slightly more boost than what I see now on my truck. On the 330, if I add a set of ported 243's or stock LS3's, I feel I can get similar power out of similar boost. That's the basis for what I'm trying to accomplish. Even if boost goes up slightly, up to 10psi is doable with a stock drive.
I think the engine size will match up fine with the mp122 and it's capacity. Trying to find out if this engine size and setup is doable.
FormerVendor
Joined: Nov 2001
Posts: 3,065
Likes: 6
From: Houston, Tx.
You can do it like I said we have done several but I used aftermarket rods and stock compression height pistons to keep it all cheap but still use better than stock rods. I think we used 6.250 long SBC H-Beams and then barely trimmed the small ends so they were essentially a zero offset type rod and then we could use any stock compression height pistons.
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The only part of this that confuses me is why you're wanting to run a maggie on a short stroke motor? You would be much better off with a turbo IMO as the maggie will fall on it's face before this thing even gets in it's power band. I do think this motor (4" bore 3.2" stroke) will be a screamer but it's going to take some R&D to get right. I bet you go through 3 cams before you find the right combination of valve events and you're going to need the right intake.
