Wow...quite a mouthful of comments/questions, etc to answer, but I'll try!
Those heads plural, meaning any of them. X,J,O, or Us.
OK, assuming by this you don't prefer ANY open chamber heads. I'm sure you can build more HP and torque with closed chamber heads, or aftermarket heads like the Edelbrock, etc.
Which seems rather silly to me as I have two performance head options available that a perfectly capable of putting me in my target range of 275-325 HP...which was entirely adequate for a street machine in 1970 and would be today. Head options that are bought and paid for. Yes, budget is a consideration, but it seems silly to fork out a couple grand to buy something I already have two sets of. Am I missing something?
-FYI. The ethanol fuels are NOT crap, well mostly not anyway. They are actually more resistant to detonation. And once you get the tune into them they do very well for our streetrods.They just dont keep their volatility long in open storage, such as your carbed fuel system.
OK, maybe "crap" wasn't the best word to use. Let's change it to 'inadequate'. Ethanol blended fuels are not as energy-efficient as those without ethanol, and were designed for today's engines using computer-controlled ignition, multiport fuel injection and a host of other technological advances. An original musclecar motor does not appreciate these fuels any more than, say, a Rolls-Royce Merlin in a WWII era P51 would. At best you are getting 93 octane where your average premium when these engines were designed was 97 octane with enough tetraethyl lead added to supress detonation up to 12.5:1 CR's. So, the premium fuels today would be 'inadequate' for CR's above maybe 10:1 in engines
of those designs. Not saying for a minute today's engines can't deliver superior performance off fuels like that, but we are referring to engines designed during the Viet Nam war.
Its hard to get a sense of your mood, personality or ego from just the few posts you have made.And the following is not meant to be in any way hurtful.
Perhaps I've only made a few posts on this particular subject, but there is a 250 page thread attached to my signature on this forum, that coincidentally has been published in book form, that pretty much gives my whole life story if you wanted to know about my mood, ego, or personality...and I say that with a chuckle. No offense taken or intended. I do appreciate your comments. This is how progress occurs...question & answer.
-Getting back to the heads and the now stated "streetrod" usage. I cant think of a tactful way to say this, but I will try;It seems to me that your budget is quite small, or you are stuck in the "oldschool" way of building.
My budget IS small...I don't believe in spending money that doesn't need to be spent of gizmos and gadgets. The high performance engines of the 70's are hat these cars came with and I don't see the need to re-invent the wheel. It worked then; I just need to make it work now on what I have to work with (read; "fuel") to extract the same amount of performance out of a smallie that I did back when the engines were new. If that labels me as "stuck in the oldschool way", then color me guilty. Let's just say I was fine with the performance I had 30 years ago, all I'd like to do is duplicate that as close as I can. No offense intended to you guys who are making huge strides in HP, torque, ET's and super high HP smallblocks; my hat's off to you for your advances. It's just something I don't feel I need to do any more. Not my cup of tea.
-If your budget is quite small then you may have to make do with what you have.
I would like to keep it reasonable as I have an entire car to restore....
-If, on the other hand, you are building oldschool ways, then there will be no changing your mind, and you will reject any, and perhaps all, advices offered.Every single person who responded to your post, has given good advice. But you came back with hell this and crap that. But to your credit, you asked which heads and why.
??? I think I may have called the ethanol fuels "crap" but I've addressed that. And I used the word "hell" as a matter-of-fact expression, not an expression of anger or derision. Wasn't meaning to offend anyone with the verbage....Also, I think both terms were used in the original post, so I was not "coming back" to anyone with the particular terms. But yes, I did ask what heads, and why...not "which heads are the best on a smallie" or "which heads make the most horsepower", but rather
"I have two sets of heads currently available, which would you choose?" How that turned into something else is a little confusing at this point? Plus, every person that responded gave a slightly different answer...yourself included...which leaves me to pick which answer I like best. Nobody is "wrong", just differing opinions!
-So, if you truly want to use one of those iron open chambered heads, in a streetrod,and even though I doubt it makes a whole lot of difference which ones you use, I would answer; the Js, and the why is because you already have them, and they sound fresh.
I have BOTH sets...J's and X's. I have two complete 340 motors.
-On the off chance that Im wrong, and that you might be open to change,you could ask/say something like; Hey guys, Id like to build a fun 340 for my A-body streetrod.I will be using a 4 speed and either 3.55s or 3.91s.It will be used mostly on the street with little/no highway cruising and only occasional trips to the track, just to see what she will do.These are the parts I already have: -( then list what you got). What changes might you suggest and how do you suggest I assemble it to run and survive on todays oxygenated fuel.Then tell us what fuel you would like to run or be willing to run, and a budget to fit it all into.And the final qualifier would be something like;I would like it to pull like a freight-train, in 2nd gear from 35MPH.
If you do this, you will get some of the most knowledgeable fellows in all of Mopardom to help you reach your goal(s).
-Hope this helps
Hmmm...a tall order there. I've already mentioned the cam and pistons and heads available to me, plus the rear end gears available and type of tranny. Nothing else is set in concrete yet and won't be until I get past the piston/CR/heads stage, because one thing affects another and those things need to be decided first. I certainly appreciate all the time and input you've given, and even though I'm an old school guy, I'm always willing to listen to ideas and comments as long as it doesn't add up to thousands...remember; I have an entire car to restore.
rayer:
