Aluminum blocks

[wsuwrhr]

--i could of saved 3k bucks :frown:
Don't think like that.
Money well spent.
Brian

[NUTHIN]

Don't think like that.
Money well spent.
Brian
looks kool too!! but still..

[steelcomp]

Steelcomp,
I remember when the rocket block came out, that thing is a beast. Almost as heavy as my 440 RB Y Blocks.
I am of the school that you are 100% correct, for all those reasons.
If nothing else, holding a bore as round as it can be is where the most power will be made.
I don't know why Cyclone seems to be agitated, but like I said, when I bought my block 50 HP less wasn't even on my list.
My motor will never be used for competive racing where the last 10% of power is important.
Thanks for your insight.
BrianI'm not arguing the benefits of aluminum blocks...if there weren't any, no one would race them. LIke you said, if you're not trying to extract every last bit of power from your deal, then you aren't going to see the difference (or arent concerned about it) but the point remains that, as a flat statement of fact, an aluminum block will not make the same hp as an equivalent cast iron block. You're right about bores not staying round, and that's a big factor, but the heat expansion of aluminum in general...the deck height change, the sleeves moving in the bores, the seal between the heads and block, the movement in the cam bores, lifter alignment, crank alignment...all these things when allowed to move, even a little, will effect hp. Small engines like motorcycle engines can be so over-engineered that they can eliminate a lot of this. F1 engines are stressed members of the car's actual construction and are over-engineered as well, yet even there, the idea of cast iron blocks has been talked about because of it's power potential. Unfortunately, the CG rules won't allow it. IN their case, they'd gladly have the extra weight where it would significantly lower the CG. They'd lose it in other places, and the car would take another huge step in handling and cornering, and in accelration. Computations have been made in Pro Stock to compare the acceleration between the light weight, but less power of the alum. block vs. the heavier, but more powerful iron. The iron won. (There are enough of both types of motors out there to make legitimate comparisons on power without having to build back-to back purpose-specific engines)

[396_WAYS_TO_SPIT]

Dayum its getting warm in here Good info fellas

[LakesOnly]

What's 50 hp compared to 200lbs ? I'll take the less weight over 50 more ponies... :crossx: :crossx:Generally speaking, in Pro Stock less than a 20HP difference will be a 100% worthless engine.
But I digress...Weiman, your original question in this thread was what the advantages were in a JET BOAT. I'm curious: what specifically are you building that is cause for you to consider an aluminum block and pose this question? Please be more specific in this regard and then maybe your inquiry will have a more focused light shed upon it, in the form of Jet Boat related replies.
LO

[LakesOnly]

You look at the comparison between the beefiest aftermarket block, and compare it to a Pro Stock block and you'll see what I'm talking about. They want unlimited rigidity...the kind that calls for 9 cam bearings, just as an example. (latest DRCE block)...Comp (and BRIAN),
I was speaking with 058 just last night and he was telling me about the new Pro Stock Dodge blocks he happened across at a machine shop here in NorCal that were delivered pretty much just for Rockwell testing. Nine 62mm cam journals completely enclosed from the crank; the crankcase itself designed so as to "wall off" each crank throw from the adjacent ones and keep them all in separate crankcases, in effect, and then use a 5-stage accordingly; tiny main journals; 1" lifter bores; and a block so shiney that the amount of nickel and tin or whatever it was made of that...well, the Rockwell testing across the block was deemed the most consistent material they had never tested. He felt the design of these blocks completely dated the DRCE engine. Sorry, no pics...wish I saw it myself....
LO

[cyclone]

Steelcomp,
I remember when the rocket block came out, that thing is a beast. Almost as heavy as my 440 RB Y Blocks.
I am of the school that you are 100% correct, for all those reasons.
If nothing else, holding a bore as round as it can be is where the most power will be made.
I don't know why Cyclone seems to be agitated, but like I said, when I bought my block 50 HP less wasn't even on my list.
My motor will never be used for competive racing where the last 10% of power is important.
Thanks for your insight.
Brian
Actually brian i'm not agitated. i just don't take everything i read or hear as fact. does most of what's been said here sound like good common sense? sure. does that make it fact? nope.
questions lead to answers and progress...all i asked for was a little proof,to what was being touted as facts, not comparisons between pro stock engines and jet boat engines or what dart did with an iron block back in the day.
ah its a dead horse so...

[SmokinLowriderSS]

Comp (and BRIAN),
I was speaking with 058 just last night and he was telling me about the new Pro Stock Dodge blocks he happened across at a machine shop here in NorCal that were delivered pretty much just for Rockwell testing. Nine 62mm cam journals completely enclosed from the crank; the crankcase itself designed so as to "wall off" each crank throw from the adjacent ones and keep them all in separate crankcases, in effect, and then use a 5-stage accordingly; tiny main journals; 1" lifter bores; and a block so shiney that the amount of nickel and tin or whatever it was made of that...well, the Rockwell testing across the block was deemed the most consistent material they had never tested. He felt the design of these blocks completely dated the DRCE engine. Sorry, no pics...wish I saw it myself....
LO
Wow LO, that is one serious casting there. Should be just about as stiff as it is possible to get in Al. That sure would have been cool to get to eyeball in person. :boxed:

[67weimann]

But I digress...Weiman, your original question in this thread was what the advantages were in a JET BOAT. I'm curious: what specifically are you building that is cause for you to consider an aluminum block and pose this question? Please be more specific in this regard and then maybe your inquiry will have a more focused light shed upon it, in the form of Jet Boat related replies.
LO
Oh nothing special, just tossing around the idea of building an aluminum block for weight savings and COOL factor. I'm only looking to build around 500 HP. 75 MPH is my ultimate goal. I've been thinking about an all aluminum 406 SBC...

[wsuwrhr]

For 500HP you could build a practically stock big block nowadays.
5 large for a block, 500HP, why would you even consider aluminum?

In a fiberglass hull, I don't think 75MPH would be feasable with a smallblock, just not enough torque.
Brian
Oh nothing special, just tossing around the idea of building an aluminum block for weight savings and COOL factor. I'm only looking to build around 500 HP. 75 MPH is my ultimate goal. I've been thinking about an all aluminum 406 SBC...