1966 383 516 heads what pistons?

There is no way to justify dumping that much money in a set of #516 castings. I'm sorry but those heads are not worth putting a thousand dollars into.
Going to a open chamber head is a bad idea also. As mentioned before just freshen them up and put them back on. Worst that will happen is the valves will sink .050 and rpms will be limited because of excessive preload on lifter. Even if the 1.74 valve sinks .050 it will still outflow the 1.60 that is sitting proud with a fresh valve job.
Machine shop guys will get all huffy puffy about cutting corners, but their crap doesn't last any longer than a quickie valve job, it just cost way more money.
At that point you would be better off buying a set of 440source stealth heads and bolting them on.
Good money after bad heads is foolish IMO.
 
I noticed that some of the comments are recommending roller rockers to reduce side loading on the valve stem. Although this is true there are other factors to consider before going ahead with this. First is the cost of the rockers themselves. Second is that in order for the roller tip to do it's job it must not wipe across the valve tip but must remain perfectly in the center of the valve tip from fully closed to fully open. Third is the fact that aftermarket rockers do not always use the same fulcrum point as the factory rockers and is different from manufacturer to manufacturer. Fourth, in order to get the roller tip centered properly requires a set of custom made push rods that have to be determined using adjustable length push rods and light weight checking valve springs. In a low rpm stock engine that will see limited miles a year I can't see the cost being justified. Afterall the stock rockers, valves and guides worked just fine for over a 100,000 miles and many decades of cars.

Why needlessly complicate things? My motto is keep it simple and reliable and enjoy the ride.
 
CBODY67 said:
If you have the piston part numbers, you should also have access to the specs for the pistons in question. Look for "Compression Height" in the specs, this relates to the "installed deck height" of the piston below the block's deck surface. You want minimum deck height to maintain close to the factory compression ratio with the smaller chamber heads.

ALSO, look at the engines and related factory carburetor usage, too. IF the piston will work for a 383 2bbl and also a 383 4bbl, the 4bbl being a 10.0CR motor, you can bet the ending compression ratio will not be 10.0CR, but closer to the 9.0CR range of 2bbl motors (9.2CR for 1967 and prior).

In order to get away from the "consumer" pistons (and their lower compression distance spec) and in to the "high performance" realm to find pistons which more closely match the factory pistons as to "Compression Height" in a forged piston rather than the normal cast pistons.

Piston pins should all be the same. I don't have that spec, but it should be in the Chrysler factory service manual, "Engine Section" for 383s.

Also consider that you will need about a .030" over-size in order to get to "new metal" in the cyl walls, in a rebuild situation. Provided the block has not been bored previously.

What is the desired outcome from the piston research?

Enjoy!
CBODY67
Click to expand...
how bad is the block worn? dose it need to be bored 0.030 over? has a shop checked it ? is it out of round? or has a bad tpper ? lots of things that need to be done before u bore it? just saying
 
Being around my late machine shop operative for many years, the general rule was that any non- rebuilt block would need a +.030 overbore as a normal situation. If the customer could not afford all of that, then he might put rings on the old pistons, plus new crank bearings and such, and call it a day. He grew up when that was what usually constituted "an overhaul" in the 1940s and later.

It took .030 to get to fresh metal for the new cylinder wall. Just a normal situation. There's a reason that smaller oversize pistons are not usually stocked anywhere. Same cost to bore and hone the block, so no money saved with the smaller oversizes. Go to the common size and be done with it. It usually took that .030" oversize to get the bore cleaned up.

IF Mahle makes a piston package (piston and "MM" rings) for a 383, that would be the way to go. Thinner "MM" rings mean less friction between the rings and the cyl wall for more power at the flywheel. Less bore wear, too. Especially when paired with "plateau honing" techniques. I also suspecgt the Mahles would produce higher compression than other brands of pistons might.

Enjoy!
CBODY67
 
well I will get some more pictures and tear the block down the rest of the way and get it cleaned to to a shop to be looked over.
I was told $450 a head to go 1.74 and hardened seats. The aluminum heads look nice but thats at least double.
I'll see I guess
 
Stealth heads are $1400 for the pair and would make a huge difference in performance.
Even if you 'only' had to spend the $900 to get your 516's serviceable imo you should find the other $500 in your project budget. No single other expense would bring as much benefit.
 
furious70 said:
Stealth heads are $1400 for the pair and would make a huge difference in performance.
Even if you 'only' had to spend the $900 to get your 516's serviceable imo you should find the other $500 in your project budget. No single other expense would bring as much benefit.
Click to expand...

Maybe so. . . But he still needs to have his machinist go through those Stealth heads before he installs them; that is an additional cost to consider.
 
Ripinator said:
Maybe so. . . But he still needs to have his machinist go through those Stealth heads before he installs them; that is an additional cost to consider.
Click to expand...
Well from my experience. No matter what heads you take to a machinist they are going to say they need work. I say this because I would not tell you they are okay, because then I'm responsible for the valve job. I understand that a crap valve job can wear out quickly.

So IMO a fair valve job and not pushing the lifts and duration to the limits the stealth heads can just be bolted on. Worst case is it starts sucking a bunch of oil and maybe a couple cylinders that have 20# less compression. Then over the winter you pull the heads and have them done. Trying to forever a set #516 castings is bad money IMO. I have a set on my Challenger to get some sorth of compression on a 400. I bought said castings at a swap meet for $20 for the pair of bare castings. I put valves in them 2.08/1.74 seat was cut already. Wiggled said valves in guides, deemed good enough, lapped them in by hand. I have 5000+ miles on those and it uses no oil and runs fair, but that's my cam choice fault.
 
In prior times, I considered it needless to take apart new cyl heads to be sure of them, after all, they have passed the seller's QC controls? After seeing some YouTube videos of new heads being pulled apart for inspection, I NOW understand why the inspection is needed. All to just ensure that one gets what one paid for, basically. If they are good, put them back together and make things happen. To me, this is an "insurance" situation, just as replacing an OEM 50 yr old nylon-
encased cam sprocket is insurance against future failures of such.

CBODY67
 
Ripinator said:
Maybe so. . . But he still needs to have his machinist go through those Stealth heads before he installs them; that is an additional cost to consider.
Click to expand...
And there's no way those 516's are only needing to be cut for the 1.74's.
I own a set of stealths and I chose to have Dwayne correct the vj and port them a little, but those weren't mandatory steps.
 
furious70 said:
And there's no way those 516's are only needing to be cut for the 1.74's.
I own a set of stealths and I chose to have Dwayne correct the vj and port them a little, but those weren't mandatory steps.
Click to expand...
like they probably need guides?
I'm just testing the ice right now. and reporting back.

also CAD dollars are not as equal to USD. $200USD is $260CAD $60 pissin in the wind

Heres a 350 I built in 1993? 94? for my 78 pontiac Parisienne 2dr
I used to run bias ply and had kelly supercharger in the back and save O matic pizza cutters up front. true duals with blue bottles on backwards. that car sounded wicked
We pulled my motor and I hunted down parts for about a month, got it balanced and everything. You could just walk into the engine shop and say, I want a 69 4 bolt main 350 +30 and a few days later I could pick it up and then he's have the pistins upside down in a box all lined up ready to go after the rings.
Me and my buddy Casey (I was taking the picture) put the engine together in the hay barn in one day, I dont know how I had all the parts but we pulled it off and I drove the Parisienne back from Cultus lake to town and it ran great. My first and only time rebuilding a engine till now.

Things are drastically different since then.

iyRMFTI.jpeg
 
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Cartel said:
the thing is if the shop buys it I pay double. I might as well tow the car away for scrap because I cant afford to rebuild a simple engine. nobody stocks anything in Canada and if they do, its 3 times what rock auto or somewheres half decent in the states would charge. Pistons Are about $800CAD. I'm also looking for a fresh engine someone turns out they werent gonna use but even that seems impossible lately
Click to expand...
Sounds like you're on a budget, and it's real easy to cost-justify every next step on the stairway until you find yourself in the attic and out of money.

Anybody up your way have a mid-70s Newport that can donate a 400? An engine you can hear run and do an oil pressure check on?
Regasketing and putting a timing chain in would be a good idea, and a good used engine could buy you some years.


You'd need an aftermarket balanced flexplate to mate the 400 to the neutral-balance '66 torque converter, though.
You can't use the 400's converter as the spline count doesn't match a '66-older trans.
 
Cartel said:
the thing is if the shop buys it I pay double. I might as well tow the car away for scrap because I cant afford to rebuild a simple engine. nobody stocks anything in Canada and if they do, its 3 times what rock auto or somewheres half decent in the states would charge. Pistons Are about $800CAD. I'm also looking for a fresh engine someone turns out they werent gonna use but even that seems impossible lately
Click to expand...

It's too bad you're on the other side of the world from me. I have a complete 383 on an engine stand that ran really well before I pulled it from my 66 300 to replace it with a correct 440. Other than a carburetor, it's totally complete.
 
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