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Originally Posted by STROKEXD
JE forged pistons. Still doing research to find a catalogued item that suits the planned 12:1 compression/Chev rod combination.
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You're in custom piston territory. No sense in trying to make an off-the-shelf piston work with what you're trying to accomplish. Considering the lift of your cam, you'll want to be very certain to specify fly-cuts for valve clearancing. Most stocking pistons don't have enough exhaust valve clearance. Don't waste your money buying and off the shelf piston only to have to spend more money on it (than custom would cost from the outset) to make it work.
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Originally Posted by STROKEXD
Scrap the 2V heads and fit CHI 218 heads with all the good gear because of cam choice ie stud girdle, Crane RR's
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I'd recommend going straight over to the AFD 4V heads. The money is the same, so why spend this level to only do it again when you want more in another 6 months? Also, when you blow up your factory block and decide to buy an SVO block, the 4V heads will support a big inch engine with a big bore. That's what I'd try to talk you into if you wanted to listen to it. Sell your current set up. You don't have enough value in the factory block and your 378 rotating assembly to justify keeping it together and using only the crank and block in a new engine. If you're going to buying pistons, buy an SVO block and run the bore out to 4.125 or larger, run a new forged 4340 3.850" crank and end up with a 411 CID engine with big 4V heads that will easily make 600 HP and 550 TQ on 11:1 then run your compression out to 12:1 if it makes you happy.
You're attacking this "problem" with some notable "conservatism" yet your apparent desire is to get a lot more power. Everyone is on a budget, so sell your current combination as it is and add your new dollars and you've got a real engine that you can clearly say that it isn't a big compromise. By the time you hard block the 2-bolt block, you're back to reboring it and re-align honing it anyway. What cost does that add? Why even touch it?
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Originally Posted by STROKEXD
Crane R252 solid roller: 252/262 @ 50", .727/.727 lift
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I'd go back to the idea of a custom SR camshaft. You can probably get away with a lot less overlap between the intake and exhaust valves with the CHI or AFD heads as they are not as disparate as the factory iron heads. It sounds to me like it is definitely time for you to quit thinking "off-the-shelf." Obviously, if some DD2K time suggests that it isn't "enough better" with a custom cam to warrant the extra $50 USD cost, then go ahead, use the shelf cam.
As soon as you say 12:1 compression, you're really entering into a whole new world of "off-the-shelf doesn't fit with something else somewhere else in the combination."
Let me put it in other terms. My silly 393 combination was obviously destined for a very light car (compared to any street car). The chrome moly dragster isn't very heavy until you add me! My parameters for it were much different too. The car would only be strip driven (duh). It didn't need to be an "ฯber" anything, it is a "play car." With that in mind, and taking into consideration that I was more interested in driving it than dicking around with it every couple of minutes, I definitely opted for 'lower' compression than is typical of all-out race vehicles. 11.28:1 isn't billy bad-ass. One point to note is that the higher the compression ratio, the more important absolutely "fine tuned" the engine needs to be for performance and longevity.
12:1 isn't the end of the world or even that finicky, but it does depend on the fuel used. You can get away with loosing a bit of static compression for building a bit more dynamic compression, especially with the alloy heads. Unless you're planning on shifting at 8000, you may want to reconsider the entire combination from a perspective of how you're actually intending to use it. It sounds like you're putting it into the same chassis, using the same transmission and same converter and same gear set and same tires. If this is the case, then work backwards and let your "unchanged" elements dictate where the camshaft, compression, flow, carburetor and other factors be determined.
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Originally Posted by STROKEXD
Replace Weiand inlet with Parker Funnelweb
Replace 750DP with BG Mighty Demon 825
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You're changing a lot of variables at once. You must really like tinkering with your combination. Considering the price of the parts you're considering, why not take a look at a 4500-series HP Holley? You'll have a lot more carb for not much more/about the same or even less money.
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Originally Posted by STROKEXD
As my plan is to send the work out, can anybody from WA recommend someone in the trade who's work is impeccable? XD408 who did your engine assembly?
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If you find that someone, then you should also be able to take that person's advice on what to build and what you'll get when you're done. I'd ring up or email Ken Lowe and ask him who he trusts for killer Cleveland engines. I would also open my mind to outside of WA, if that's what it takes to get it right.
I think that you're on the right track, but I also think that you're attacking the problem from your own (sorry, rather limited) set of skills/experience in high performance engine building. For a guy moving from bolt on roller rockers who was very recently still in hydraulic cam territory to moving up to 12:1 with a SR, alloy heads and more...(nothing wrong with all of it at all), you're probably better off developing your combination from a statement of purpose. What is it that you want to achieve? Don't be general. It doesn't help to say "more power." You need to decide what performance test will validate your accomplishments so that you can aim for that achievement and verify that you've made it with the money and time you spend to get there. You're not at the "bolt-ons" phase any more. It isn't as if a set of mail-order extractors and a chrome dress-up kit are going to accomplish your goals. Don't get me wrong, there are nothing wrong with even THOSE modest "performance" goals, rather, it isn't a part of the solution in your case. Neither is about 9 million other choices for parts. I believe that you really need to start thinking about producing a solution for your particular problem set. Identify the "problem" and work toward that goal. Take the advice of trusted professionals and forget about 99% of what you read on forums, as you're in a territory that is alien to at least 90% of others from what I read you're trying to accomplish "on the cheap."
Another word of advice, bite the bullet. If you're willing to compromise, ensure that you have some reasonable data to support your compromises so that you are more willing to accept moderate over absolute when the time comes. Otherwise, eat a piece of lead and buy the parts that it takes to accomplish your goals as set forth by your statement of the problem. I always want more power, too, but at the same time, I know that I'd rather just drive and not have to touch the tune-up, so I'm perfectly satisfied "giving away" a lot of power so that I won't have to fiddle with the combo. The more you know about your own preferences and what you're trying to accomplish, the more reasonable you're going to find the solution--in whatever form it takes. Speculating on parts choices does little to solve the "problem" when it hasn't been stated. Choosing a carb without understanding how the static versus dynamic compression value with your engine displacement in your transmission/differential/chassis combination will react to it is a waste of time and energy...and probably money if you buy the wrong carb for the combo.
I typically spend about 6 months choosing the combination for my car(s). You seem to change them every 6 months :) Not to worry, we're obviously different and have different needs/desires/interests.
Of course, I am also a hypocrite in at least the case of my latest engine, which is an engine without a chassis or "other combination parts" to round it out and therefore select important things like cam/carb/etc., but it is really a different animal from what it sounds like you're trying to accomplish. My iron headed 4V, flat top, solid flat "modest" cam, 4-bolt "Q-Code" engine (but with closed chambers) is a general performance part destined for a lightweight chassis, or otherwise a whole lot of converter and gear in a heavier car. I balanced it with a flexplate and a flywheel so that I'd have the option based on whatever chassis I eventually find for it. I can always gear/tire/converter/trans the chassis accordingly...or at least arrive at a suitable compromise considering that I'm not expecting it to be anything more than a "lively performance" piece. If it makes 430 HP/TQ on the dyno, I'll be satisfied with it...and most of it is from used/reconditioned factory parts and low cost parts, like a used Torker inlet and a used 800 CFM DP that I rebuilt to factory specs.
My performance goals for whatever chassis it finally finds a home in is currently nothing. I want only a "lively" ride that is also reasonably streetable for the occasional cruise or other function. I really should have put a SR camshaft into it, but couldn't justify the money for what I want out of the engine and without having an idea of transmission/gear/tire/weight, I'd be buying a "generic" SR camshaft when what I did do was buy a "general purpose" mechanical flat tappet camshaft. I already recognize that my power band is likely to be about 3800-7000 RPM in this engine.
What power band do you want? What is your intended usage? A big-inch engine with good RPM range will nearly always be more "fun" than a smaller, narrow-banded engine in every case but a true racecar. Your H-beam choice sounds like you're thinking of extending your RPM range and safety at RPM. Seriously, a set of I-beam 4340 rods will easily accomplish what it sounds like you're trying to achieve...for about half the cost and significantly less weight.
You're on the right track in terms of thinking alloy heads and solid roller cam, but I think that you need to fine tune what you want out of it before you spend money on parts. Since no one wants to read long posts, I shut the hell up now.
:davis:
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