Well my new garage is finally done and winter is just around the corner so I’m getting the itch to start working on my car again. Just for a refresher I have a 1989 Mustang that I pulled the 302 out and dropped in a 351W that is reasonably built (runs high 11 sec ¼ mile)

So my current plain is to go forced induction and I’m leaning towards doing a DIY twin turbo set up. I shouldn’t have too much problem fabricating what ever I need, I’m a pretty decent welder, although I have never welded aluminum but my mig welder supposedly can be set up to weld aluminum by switching the wire and going 100% argon gas. But I could just make everything out of steel tubing if I have a hard time with welding aluminum (it probably won’t make that much of a weight difference anyway).

So here is my dilemma. Currently my motor is running ~11:1 compression so I will defiantly need to drop that down to go with the turbos. So new forged pistons are a must. But my dilemma is that with turbos I could easily see over 700HP with out a problem. I’m currently running the stock cast crank and rods so running that much HP would definitely be pushing the stock rotating assembly. So running forged crank and rods would have no problem handling the power. So if I’m going to spend the $$ on all forged parts I might as well get some more cubic inches out of it (there is no replacement for displacement). I could pick up an all forged stroker kit for around ~$1500.00, I was thinking on running the 383 stroker if I decide to go that route.

Now the problem is that if I do decide to go with a whole new rotating assembly the time before the car is back on the road will be much longer (due to a limited budget) So my options are as follows…

1) just do the turbos now and worry about going all forged if and when I throw a rod etc..
2) Jut go with the stroker kit for now get it back on the road and worry about the turbos later
3) Do both and if it takes longer to get back on the road, so be it.

So what would you guys do if you are in my position?

4.) Get the turbos, get the stroker kit, get the forged internals, get turbo cams with valve springs and retainers. If its fuel injection, get bigger injectors, a higher volume fuel pump, and a computer to tune it.

Yes sorry I didn’t mention earlier but I’m definitely getting new injectors, new cam, new fuel pump regardless if I decide to stroke it to a 383 or not.

Don't forget to cryo all those important internals, it'll make them so much stronger (can't recall the name of the company I read about in San Diego that does it, I'll have to check back on the Supra engine build up I found it in). But I'd recommend building it all up first and then doing the turbo, just for safety's sake.

I looked up that cryogenics treatment you were talking about and by my understanding of what they do, is basically take your parts and slowly freeze them to –300 deg F. Now let me say that I’m not a metallurgist but from my understanding of heat treatment what they are doing won’t do anything.

Now basically to turn iron into steel you add carbon the more carbon the harder the steel becomes. Now the heat treatment process is to heat the steel to critical temperature (~1800 deg F) and at this temperature the carbon is free flowing, then quench it in, water, saline solution or oil and that will freeze the crystalline grain structure of the carbon. It is the grain structure of the carbon that determines the strength of the steel.

So here is the problem that I have with them freezing it. The carbon is already in a frozen state just at room temperature so making it colder won’t change the grain structure so it won’t affect the strength. Now if they were saying that they reheated the steel and then flash froze it to try to keep a tighter grain structure at least that would be logical (but it would probably shatter the steel in the process).

Now most steels aren’t just simple carbon steels these days there is typically other alloys tike chromium, manganese, nickel, etc.. so it is possible that the deep freezing will affect one of the other alloys that have nothing to do with the carbon structure.

Now here is something else that would make me a little hesitant to do this. The more carbon in the steel the harder it becomes, but it also makes it more brittle. So the crank that I chose was made of 4340 steel, which is actually a mild carbon steel, would heat treat to a med hardness but would have a lot of shock resistance and flexibility before it would crack. So if they needed a harder crank why not just make it out of a better alloy like 4350 of 5160 with the higher carbon content of either of those metals it would be a much stronger steel, but would be a little bit more brittle. Which is probably why they went with the 4340, more forgiveness. So if in fact this deep freezing does work I would be worried that it would move the hardness and brittleness of the steel out of range for what it was designed for. Maybe this process would work for a stock crank that is even a milder steel (if it actually works) that way you are not pushing the brittleness too far considering it isn’t that brittle to begin with.

Either way if I do go with the 383 the 4340 crank is rated at over 1000hp so extra treatment wouldn’t be necessary.

Haven't done a whole lot of research on it, but what I remember reading was that the parts they had cryoed (again, it was for a supra build up, and the article was in Turbo and High Technology rather than one of the girls-in-bikinis car magazines) became much harder, to the point that a couple of the parts that they hadn't ground to fit properly gave them a lot of trouble. But if your crank is already rated to 1000 hp then I guess you've got no worries about it anyway. Was just trying to help out some.

Well I appreciate the suggestion. I would also like to find out some more on the process and get some hard facts to what it does and how it does it. I’m just a little skeptical that it is just a scam and waste of money. But as I’ve said I’m no metallurgist so it’s possible that it does something that is well beyond my limited understanding of heat treatment. I will have to ask my father in law (he is a partner/engineer at a local heat treatment company) if he has ever heard of this process and if and how it works.

Cool, I'd like to hear some more expert opinion (since it is well known that magazines of all types will hype a product in an article just because they get paid). My only "knowledge" about metal at low temperatures led me to believe that once you get to about 60 below then it becomes extremely brittle, but then I've been on airplanes flying at altitudes where that was the air temperature and nothing bad happened. Who knows.

A while back someguy that does that in my state here was on the news, its supposed to harden any metal you freeze, and keeps razor blades 3 x sharper longer. Also when done to an engine its supposed ot increase your gas mileage greatly, though not sure how it does that but still if prices were good it would be good to look into.

See, it's comments like that gas mileage one that hurt believeability on things like this. The razor blade part makes sense, since harder metal will lose its edge more slowly, but the gas mileage sounds like a scam. As far as cryo strengthening the metal...this is just a bit of mental supposing...I would imagine that it has to do with the increasing organization of molecules as temperature is decreased. For those still wondering what I mean, as temperatures decrease to the point of freezing (the point at which a liquid becomes a solid) the molecules fall into rigid structures (this is what causes water to expand when it freezes, the structures are made up of molecules spread farther apart than they are when it is liquid). So, even though metal is already in solid form at room temperature (and quite a ways above it) it is possible that the lowering of the temperature could cause the molecules to settle into slightly different structures which may actually be more stable when returned to room temperature. I don't know if this is the case, but it seems the most likely IF cryo does actually work.

Well I did talk to my father in law and like I said he is an engineer at a local heat treat company (he actually designs the furnaces and quench tanks). Anyway he told me that they actually do it. He then went on to say that they had 2 plants that did it, but they shut down operations a while back in one of the plants and are getting ready to shut down the other one at the other plant. So he basically said that if it works as good as is claimed then they wouldn’t be shutting down that part of the business. But he said he doesn’t know that much about the process and will try to find out exactly how it works.

But he did go and speculate on what could be possible. He seems to remember hearing people say that the results would vary and be inconsistent. So he thinks that it might just be a type of stress release like tempering. So he was thinking that if you have a piece that has a bad temper. Tempering is when you reheat the metal to a few hundred deg after the hardening process, This process will actually take a little of the hardness away but will remove any stress points caused by the hardening process. So he was speculating that if you have a piece that had a bad temper then the cryo will actually help a lot but it won’t do anything to a piece that has been tempered correctly.

But again he was just thinking out loud so take that with a grain of salt. But again they are in the process of shutting down this type of operation so that must mean something.

Could just mean that it wasn't profitable for them, or not enough in demand. But I am looking forward to hearing what he finds out either way. This thread is a good example of what can happen when people don't get all hot-headed and start slinging insults. And let's get more of this science based stuff on here, education is good for you, right everyone?

yeah, if u like these kind of threads, u better stay away from the import/ beast thread for right now. lol

That was what I was hinting at. But, hey this shit happens every so often (been in a couple myself) and you just have to wait for it to die down, then people stay civil for a couple of weeks before the insults fly again. It's the price we pay for being involved in a testosterone fueled field.