Ha! Very funny. :laugh: "Two barrel Gary" is interested in seeing what is able to be done with whatever works, nevermind if it's iron, aluminum, or how many holes are in the intake. Making people think is the name of the game. Who knows who will be inspired, and hey if I can give a laugh or two at my own expense, so be it. Keeps things interesting or at least entertaining. :grin:
Well a big 2 barrel does in fact do very well with stock heads and below 5,000 RPM. Just think of it as half a dominator. Cut the fuel/air requirement in half and work with that. Its centralized placement on the intake helps too. Makes people think anyway (or think I'm crazy, but I'm cool with that too). Maybe some of those old 2 barrel intakes will see some action. lol The low peak lift flow on the iron heads, the high swirl design and tall narrow runners make for a perfect environment for a huge set of centralized throttle blades. You should see the power curves when used with the Crower level 3 cam! Almost like primitive fuel injection. TBI systems would work similarly, and those are good for low-mid range combinations. Everything has its place! Having said that, I'm looking forward to these heads... Gary
I know that I have been quietly watching this thread, wondering if these aluminum heads would be good for my target build of low/midrange power for driving a heavy Jeep Wagoneer with maybe a trailer behind it. Sure, the reduced weight of aluminum heads and TA dual plane manifold is never a bad thing. But I'm excited to see how these heads flow and how much they would improve overall performance. And while my focus is on midrange power, there's nothing wrong with seeing the torque curve stay up well into higher RPMs. I may not use it all the time but I wouldn't be disappointed.
You won't be able to determine too much without knowing the MinCSA and some velocity #'s...or at least some dyno data with enough info to apply to your own project.. Even then, a higher peak torque as a result of a CSA increase has little to do with being able to predict low speed performance, or part throttle performance. Going out on a limb here, I'm going to suggest that it should increase low speed response. CFM gains from mindful design or porting are mostly from velocity increases as result of evening out the dead areas and "fixing" the problem spots that cause trouble closer to the valve seat. It wakes them right up. The impressiveness of an LS engine has more to do with the much better starting point of the heads, along with good combustion chambers and long runners helping tune the low speed operation more so than computer controls. I would highly doubt the port dimensions would start out too huge to consider for mild build. It would be difficult to mess these up.
Folks, I have read about these test on and off for some time in regards to this TA 350 manifold vs stock test. This intake was tested to death when we first released it. When it was in design I went as far as have flow boxes made from the cores before the hard tooling was made. This was to compare results to which ever stock intake we had at the time. They were made out of plaster, still have them. Ed Mosler designed the intake in 1982-83, still have all the pencil drawings which are pretty cool. Jim Bell was on board to help with testing. On the wagon it was worth 3 tenths. Car went from 12.60's to 12.30's. From what I know today some of this could be from my driving habits back then. But I do not remember any results of no improvement like I've seen here in the past years. The 350 intake is sold to all level of builds and the feed back we receive has been positive. Every test, every engine will provide some different information. I do agree that if a intake can provide enough air to satisfy the engine a aftermarket intake may show no improvement. The other thing I remember is when Ed Mosler did his flow testing of the intake he said it picked up the air flow of the head. Which he indicated then that it was because of a problem with the head. At the time he also indicated that would be a plus, but not making it right. I cannot tell you which head it was tested on, what the valve job looked like and so on. Jim Bell also had positive results when tested on Forrest Thornburg's 350 Skyhawk. The intake was tested by GSCA members back then as well. I do not want to get into a debate over this, just wanted to share some history. If we didn't see positive results, and those of you who know me, you know I would have gone back and fixed it. On another note, I once talked with Jim Poston way back when about the S-Divider intake, about its lack of performance, which he acknowledged. In the end Jim said to me, "Why should I spend the money to fix it, when I will sell 100 intakes a year either way". Well, that's not me folks, I would have fixed it. One more thing. The 350 heads have been designed around 1.940" & 1.550" valves. If I remember correctly a 2.050" intake can be installed. We never tested with that size intake valve. We also increased the the spring installed height by using longer valves. The stock 350 is 5.0" long I believe. Were going to use 5.15" which is the length of the 455. So the 2.0" performance intake valves we stock can be used. The exhaust can go to 1.600" but at this time we feel it will not be necessary. I have a bunch of 1.625" 455 exhaust that I may have machined into 1.550" or 1.600". I'm excited to see what everyone will do with these heads over time.
If they space the valves out a bit more so we can run the standard 2.02", and 1.60" valves with 11/32" stems, I think it would help a bit to increase the overall flow on both intake and exhaust on higher horsepower applications. I'm totally stoked to get these and run the higher ratio roller rockers on our engine build.
^^ Oops, tiny bore engine, remember? You would have to massively relocate the valves and tilt the axes for that to reach it's true potential. The valve itself isn't the final restriction. It's the port's architecture and bent path on it's way to the valve, and what obstructions lie in wait after the valve. A 1.940 valve covering a 90% throat area below the valve seat with an 80% efficiency (141 cfm/in(2) or so used as the 100%...) has potential to 286 cfm. That's enough for over 600 hp. The larger valve helps power by allowing more 'curtain area' at low to mid lifts, meaning there's a larger area opening at any given point (until the valve is open far enough to exceed the curtain area). This contributes to a greater cylinder fill, much the same as a roller cam's faster profile, by increasing the port's average capacity plotted over the entire lift curve.
You reminded me. We changed the valve angle to 13' and moved the valves to the center line of the bore to allow the use of larger valves. We also re positioned them side to side to get them to fit the best.
Thanks for the update Mike. My last post was supposed to be before yours....ou: I can't wait to get these installed with a roller cam, rockers, etc.
Okay we can re work the valve reliefs as needed based on the changes, I am guessing that the Ta roller rockers won't fit due to the changes or will they? And provision for SBC rockers?
Not knowing all the details yet of these aluminum heads, I too will go out on a limb and say that 'mid range' use with these heads will be quite doable. Depending on what the numbers end up being (and where), one could employ other tricks to make great power between 2500-5500 RPM. Much can be done with a roller cam to put the powerband where you want it, along with proper intake CFM (less dependent on 'oversized' carbs--but also able to accommodate larger CFMs at lower RPMs--fuel injection, anyone?) and exhaust velocity suitable for the powerband your application needs. While the torque peak may be higher, it will also be wider, giving great torque and a usable powerband throughout the entire intended operating range. Much of this will be dependent on the combination of parts and how well you make them work together, along with the tuning required to bring it all together. While these heads will surely be adequate for higher RPMs and big power (which is the main intent), intake and exhaust tricks along with valve timing events will play a huge role in where the power ends up. With the heads no longer being the limiting factor, will give more versatility with engine builds using other key components. They will move more air even at lower-mid RPMs especially when roller cams are employed. With low-mid scavenging tricks (small tube primaries--and 'small' may need to be redefined when compared to the old iron heads), wider roller lobe profiles making better use of air momentum, increased dynamic stroke and displacement with earlier closing events (all the aforementioned improving/maintaining good intake velocity), should see substantial torque improvements in these RPM ranges. "Game changer" indeed, Buick 350's using these heads (for mid range intent) will need to be built a bit differently than traditional 350's using the old iron heads, which is actually a good thing when the goal is to maximize power output. Even if you had to make the cam the limiting factor instead of building it around the heads being such, as long as there is good (better than iron heads) CFM numbers at lower lifts, would make these heads superior to iron heads even with the use of much milder cams... I might even be so bold as to say that using the TA dual plane intake and a large 2 barrel adapter with a low-lift roller cam to maintain good velocity within the lower section of the valve curtain, along with small primary tube headers, would make some seriously good grunt when comparing a similarly equipped Buick 350 with the old iron 2 barrel intake and iron heads. Nuts you say? Perhaps. It certainly wouldn't be the most powerful combination you could put together using these heads, but that's not the point. The point is would it be better than the iron counterparts? I think yes. Yeah I know. "Two barrel Gary" at it again. Well that may be, but it just goes to show what the wide range of applications these heads could be used for. At least I didn't suggest the Federal Mogul cam... :shock: If nothing else, I'm good for a few laughs. :grin: Gary
Gary Don't forget to add the fact that the new heads are closed chamber. The combination of quench and aluminum allows for a higher DCR. We are always running up against the Buick 350 DCR restriction when looking to build low end power with an early closing intake valve. This will help in that regard. Considering the Buick 350 has a small bore, add good quench with an aluminum head, DCRs at 8:1 or more should be doable. I'm really glad to see you adding roller cams back into your repertoire. Paul
I'm really tempted to be a guinea pig in my rebuild and try out these heads. I'd love to explore the potential of these heads and see what I can get out of the engine. I'm looking at throttle body fuel injection. Dealing with a carburetor over the passes can be a challenge. I have the Holley Avenger TBI on the AMC 401 in my truck though I don't have a lot of miles on it to be able to really know how great it is. On the other hand, I do know of a carburetor that does really well with elevation. The AMC V8's in the Jeeps came with a carburetor in the 80's that had an altitude compensation circuit that works really well. i.e. I know people who went from the low lands in Texas all the way over Engineer Pass in Colorado (over 13,000 feet) and never once had to adjust the carburetor. It's a 500 CFM 2bbl that's set up for an AMC 360 V8 (close enough to a Buick 350 that only minor tweaking would be needed). There's only one problem. It's a Motorcraft. Would the Buick gods strike me dead if I tried to bolt a Ferd carburetor to a Buick 350? It uses the standard Holley/Rochester 2bbl mounting pattern so it should be a drop-on fit with a cheap adapter. And it's stupid simple to work on. Besides, it would let me keep the Jeep "electronics free"...
