Head suggestions 516 or 452????

[TBass]

Alright guys, I am not much on lingering around on forums asking opinions, but I am kinda beside myself on this and need some CURRENT input. I have a 66 B body with the original 361. It runs like a dream because the guy I got it from did a farm boy overhaul on it. However, the dude let it freeze in the cold weather and cracked the block really bad. I've dealt with it for close to ten years now and I am about ready to start building it's replacement. First I will say that I decided on using a 400. I wanted to stay with a B block in this car because my intent is to keep it looking virtually stock. (I am also tossing around the 451 stroker option) Obviously my 361 has a good set of 516 heads. The 400 I bought came with a set of 452 heads. I have read endless forums and articles about the differences in all these heads. There are as many people fond of the 516s as there are of 452s. I am looking for a pump gas cruiser, but I want it to have the muscle car "thump" when I'm ready for it. This car is an A/C car with power steering and power breaks, so I am obviously not going for 12.5:1 compression with a .510" lift cam. I want my accessories to still function properly so I am going with a VooDoo cam with an operating range of 1800-6200. I have no issues getting the exhaust valves changed in the 516 heads if it is worth it. But is it worth it? Most information out there is from people who are all out racers and looking for flowing 300CFM or more. I am not about decking the block or shaving the head and jacking with all that geometry. I am going to run headers and a stock 4-V intake. Just trying to decide which heads to invest in on this.....I will most likely end up yanking the steel crank from my 361 and putting it in the 400 with Keith Black pistons that will raise that compression height. If the 516 heads truly bring up my compression, I will buy Mopar Performance porting templates and attack those heads and sell my 452s.

 

[Seax440Dodge]

IMO - I'd go w/ the 452's

they flow a lot better than the 516, and since you want to run pump gas, you wouldn't have to have the hardened valve seats installed like you would on the 516

 

[Meep-Meep]

The short answer is it won't make a bit of difference assuming your compression remains the same. And your intended build is right on target in my opinion - meaning keep the street driver in the street driver RPM range. I don't recall the specifics on the B engine regarding compression and the various combinations that you can do. Zero deck is a good start so you will just need to make actual measurements of the gasket volume and piston at TDC (to get the valve reliefs in the equation) and then the chamber.

9.5:1 for pump 91 and about 170 PSI should be pretty happy. Choose a cam with low overlap. Typically the 112 LSA cams are great street cams and you can use all your factory intakes and stuff without major power loss. My 4000 lb 440 Belvedere runs high 12's with a cam that most people wouldn't use as a hood prop and that's with a factory iron intake! I do, and recommend you run headers and a free flowing exhaust to get the most out of an aftermarket cam.

If you want to save a few bucks (and who doesn't?) and your 452's are in really nice shape, meaning the factory hardness hasn't been ground out of the exhaust seats, then use those. 516's will require hard seats and might as well update to the 1.74" valves while you are at it. An extra expense you may not need and for virtually no gain. Pocket port is good on either head.

There is the subject of quench that will play a roll in how the fuel is burned in the chamber, but don't sweat it too much. The fact is BOTH heads have quench. It's just the 516 closed chamber has a bit more. What's more important I think is having a clean unobstructed chamber, meaning flat top piston. It might also be true that too much quench will not let the flame in to completely burn the residual fuel mixture. So the answer is the proper amount of quench - whatever that is. The open chamber design head was originally put into production to solve a detonation issue, so maybe some truth to the preceding statement. It's also an emissions head and the wider quench distance will play a roll in reducing hydrocarbon emissions by more completely burning the fuel vapor in the chamber. To back that statement up, modern piston design has been focusing on raising the top ring to make that annular gap around the top of the piston smaller so less fuel vapor gets trapped there, thus leading to fewer HC emissions. By the way, the higher top ring prompted some piston design changes such as high silicon aluminum castings (hypereutectic) to make the piston stronger and resist ring land breakage.

A mild good running big block MoPar is not that hard or that expensive to build. Or let's say it shouldn't be.

 

[Cornpatch MO]

PersonLLY, i USED 516 HEADS ON MY 1978 LOW COMPRESSION 440. I didn't want to take the crank or pistons out and increase the C.R. Had the 516 heads O/H with larger exhaust valves and exhaust valve hardened seats. With a set of steel shim head gaskets, the math turns out to near 9.5:1 compression. If you are going to change pistons, I would use the 452 heads with a composit head gasket. Do the math to figger what pistons you would need.........................MO

 

[bm02tj]

I used the 516 heads and opened them up and used the 400 valves back when you could still get leaded gas
the car has been parked for 17 years so will have hard seat installed when I freshen up the motor before I start it

 

[Garys1969RR]

I use the closed chamber 915 head. That has the same closed combustion chamber as your 516s do. But the 915 has better port layout. I like the closed chamber type, as it promotes plenty of turbulence when used with a tight quench distance. This is what Meep Meep uses with 915 heads to get his 4000 pound Belvedere into the 12s. And of course we both use the larger 2.14/1.81 valves with pocket porting to improve flow. The early Mopars (including the max wedge) were built with tight quench. And they ran really good! Must be a good reason the Chrysler engineers designed them this way. It really works! Shoot for .035" to .040" quench distance, C/R of around 10 to 1, and that thing will scream! I'm at .037" in my 451, 69 RR. And it runs mid 12s at 5600 feet. And also get your heads to flow well with larger valves and pocket porting. A lot of the new heads from Edelbrock are a closed chamber design.

 

[tallhair]

Hey TBass i think you'll be ok either way but the 452's may be the cheaper route, but like meep said once you do the valve job the hardness will be gone. Whatever you do keep posting and reading and before you do any of that head over the the Welcome Wagon forum and tell us a little about yourself and show some pics of what you've got.

PS i spent 8 years at Sheppard AFB and went schoole at Ft Sill and logged a lot of time around Lawton myself

 

[62 Dart Convertible]

Hi Mate

I won't weigh in on the head debate, but just have a tip on the cam you plan to use. I just built a 413 with the Voodoo 10230703, so keep in mind you should run the recommended valve springs, which are doubles, so your heads will need extra machining (and $$) in the spring lands and guides to accomodate those and the smaller stem seals.

BTW, my engine is otherwise stock (stock converter too) and it runs great. Sounds beefy and breathes well, yet idle is still acceptable.

Please exclude video quality, and my post cam run-in excuberance, but you get the idea -
http://www.youtube.com/watch?v=tRvM52TWvuE

 

[Meep-Meep]

Hey 62 Dart, that sounds nice and crisp. Look at those squeaky clean AFB's on there! Mmmmmm, nice.

 

[TBass]

A friend of mine dumped a purple shaft MP cam for this same VooDoo. It seems to be a pretty good stick. I've always had great luck with Lunati cams. I actually won this one from Lunati and they let me choose the grind I wanted, so I chose this one. I don't think I will be disappointed. I also haven't completely talked myself out of the 451 or 470 stroker kit. I've been on the Muscle Motors site quite a bit since I got the "go ahead" on this build. Just trying to decide which way to roll with these heads. They seriously seem like splitting hairs. I have been into the quench debate of Ford 351C heads a lot and in that world the technology had leaned in favor of the non-quench heads because you had more piston options. These 400s don't have a lot of piston options without going with a stroker. However, JE apparently has or had a piston that made up the difference for the .120" that the piston left on the table at TDC. But if I am going to pay $1000 for a set of slugs, I may as well pair it up with another $1000 and buy a full rotating assembly with all new parts that I can slap into my block that cost $300-$400 to have prepped. Once that is all done, all I have to do is determine what heads.....PLUS, I just discovered Aeroheads. I can buy a set to bolt on with my appropriate springs and -angle valve job for about $600. That seems too good to be true. I must research them a little deeper. Headers are not a question. I already have a good exhaust system, just gotta adapt it to my Hedmans. This car is stock, and when I say stock, I mean "1966 technology" stock, so I get to do it right. I've anticipated this build for several years, so now that it's time to pull the trigger on it, I needed some opinions and will likely need more before it's all over with.

 

[TBass]

Sooooo......Today I find myself trying to make more decisions with this. I just stumbled into a potential deal on a '68 383 2-V motor out of a Charger. The guy has already switched it to a 4-V but it is a running engine. He yanked it to put in a 440. This engine may be more suited for my needs than a monster 400 stroker, plus, more budget friendly. Of course I will do basic things such as install a windage tray, valve guide seals, rear main if necessary, and probably a new oil pump. I will also likely put my VooDoo cam in this motor with appropriate valve springs. What I am curios about is compression. I have not built a 383 yet, but I had a short block several years ago out of a '67 wagon. It had pistons with a slight dish in them. The 2-V obviously had 9.2:1 compression and the 4-V had 10.0:1. Were those pistons the difference or was it in the head gasket as I have read? I have never seen factory built engines with anything other than the stamped steel shim plates. So I find that unlikely. Maybe some you guys that have played with numerous 383s can answer this for me? I am not planning on digging too deep into this engine to change pistons for .8:1 more compression. Just wondering if anyone has this info readily available?