Lorax

Your talking about the same dummies that created the 928!!

I don't always trust them
I think the way you are looking at street vs track is backwards in this case. I think the sleeves are going to see much less stress in a street car than a track car. especially dry ones.

Chris White

“Thermodynamics” ? as in the study of the conversion of heat energy into different forms of energy?
Not to be too much of a ***** but if you want to discuss technical issues at least start off in the right place - like metallurgy.
Yes, differential expansion rates are an important issue to understand – much like the fact that your block and head studs are made of dissimilar material with different expansion rates. The block and pistons also are made of different alloys with yet again different expansion rates. The stock engine is full of dissimilar materials. If you take the expansion rates into account it becomes a non issue.
As with many other things - if you don’t know what you are doing it becomes....a mess.
WWPD (What would Porsche Do)? As much as Alusil has some nice properties going for it abrasion resistance is not one of them. Almost all stock turbo blocks have evidence of scoring.
If done right a sleeved block will last as long or longer than a non sleeved block – and it will allow a much greater choice in pistons and rings and be far more tolerant of abuse. If not done right it will fail.

333pg333

Yes, remember that Porsche didn't design our blocks or cars for 500whp. Had they done that I'm betting there would have been plenty of significant changes, the block being one of them.
Maybe not so much now but back then anyway. Now, Porsche don't seem to care too much that they put out a great deal of cars (Boxters and 996s) that have significant engine design flaws and they are keeping the failure rate very quiet.

Dougs951

944J - For a 500 hp LS engine you could easily run a stock LS7 block(if you can get one). These engines routinely run 500Whp in the Z06 Corvettes with a few choice mods. Thats the setup I would go with, but again add to that a GREAT clutch and a new transmission, suspension and brakes to support the new engine.

What is you budget btw, that could help determine the way you go about power gains.

944J

from what i've read sleeved has proven to work, what' the issue again here? the sleeve rattle loose due to it heating and shrinking differently than the surrounding block? i supposed it would then be up to experience on how to do it so that it wont do that... how do you do a sleeved block right is the question?

question is the lsx with an iron block a good choice?

944J

im the kind of guy who would find used parts when possible and clean them up to make something average, this is just a fun project to learn (like all of them i suppose)

no im not interested in dumping huge amounts of money like you guys do

i'm the guy who's purchased a running 944 for $550 and a better condition 928 for less.

i think a lot of research goes a long way...

at the moment my take is that if you want 300-400whp go with a 944 turbo setup, if you want more then go with an ls1

i think the real trick is to see how people outside the porsche world do things like the japanese ive read about who have little 1.8L's and giving them massive HP and do some of that to the 944...

Dougs951

You wont need an iron LS block for this app the stock LS series blocks are aluminum. If you plan on making HUGE numbers (think 1000hp) then you would want to upgrade to an LSX bowtie block, those have been proven to 2500hp. But then again if you can make a 944 be able to use 1000hp you would be a god among men. (or turn it into a full out drag car...)

tone3721

Actually Chris, the correct term would be thermodynamics.

thermodynamics |ˌθərmōdīˈnamiks|
plural noun [treated as sing. ]
the branch of physical science that deals with the relations between heat and other forms of energy (such as mechanical, electrical, or chemical energy), and, by extension, of the relationships and interconvertibility of all forms of energy.
The first law of thermodynamics states the equivalence of heat and work and reaffirms the principle of conservation of energy. The second law states that heat does not of itself pass from a cooler to a hotter body. Another, equivalent, formulation of the second law is that the entropy of a closed system can only increase. The third law (also called Nernst's heat theorem) states that it is impossible to reduce the temperature of a system to absolute zero in a finite number of operations.

metallurgy |ˈmetlˌərjē|
noun
the branch of science and technology concerned with the properties of metals and their production and purification.

When I said a few people around here could build a sleeved motor properly, I mostly had you in mind. Ive sat through a few lectures on thermodynamics, but you would definitely be more familiar than I, with the properties of these particular alloys we are talking about. All due respect. All Im saying is their is some doubt there, my builder recommended against it, maybe they just didnt want to be responsible for that. My background is chemistry, and computer networking, not mechanical engineering. I believe you when you say you do it properly, and it becomes a non issue. I dont see how whether or not your on the track, makes a difference in the metals expanding, and contracting due to heating/cooling. Your engine running hot can happen on or off the track. Im sure the track theoretically would push the extremes more. For example tho, in phx during the summer, my engine runs pretty damn hot sometimes with the ac on, just as hot as it would during a day at the track.

Dougs951

Oh and never, ever add receipts...

tone3721

+1 Yeah bad idea.

tone3721

BTW Chris, do you know where I could find the percent composition of the alloy our blocks are made from? Obviously aluminum, and silicon, but theres got to be more than that. I havent found that info anywhere.

333pg333

With all due respect, good luck on your project.

tone3721

Yeah.....well that was an attempt to capitalize on the American muscle car scene, while giving a luxury GT. Kinda late tho. Not a thoroughbred racehorse.

Again, I dont see the difference as far as heat transfer goes. See my comment above.

95ONE

Aluminum bores absorb heat faster - transfer heat to coolant faster.

Being mostly from the Honda world. Sleeved motors have been done over and over again with great results. Just too many machinists out there that have tried it without knowing how. This is where all the failures come in.

tone3721

I think you may be right about the machinists. I think the transfer rates would vary greatly depending on the exact composition of the alloy, therefore varying from block to block. Or more simply, each block would expand/contract differently depending on the exact alloy, the block is made from. I wonder how similar the composition of the honda blocks are to ours.