I am about to carry out one of my bucket list items, which is to rebuild an engine myself. The engine in question is the original 440 engine out of my 69 Chrysler 300. I think I would probably be very happy with the performance if I just rebuild it to stock specs, but I want to make sure I give it the right amount of thought before I dive in.

I will not be taking this car to the track or anything, just tooling around, to work, to the grocery store, maybe take some trips. I will be running dual exhaust, most likely through the factory non-HP exhaust manifolds. I have a 3.23:1 open rear, and unless one falls into my lap I don't plan on replacing it with a sure grip. I am not planning on doing anything fancy with the heads, just reconditioning the factory 906s, maybe getting hardened valve seats put in, and installing springs to match whatever cam I decide to put in. Given all these factors, I don't see a need to go all out on horsepower and spend $10,000 on a rebuild, but I could easily be talked into whatever upgrades are necessary to raise the horsepower from the factory 350 to 400 or so.

The real questions for me are what pistons and camshaft I decide to use. I feel like I could pick a camshaft and end up with something that will make me happy, but the more I look into pistons, the more confused I get. Some of my questions are:

1. Cast, forged, or hypereutectic?

2. Flattop, dish, dome, or stepped with a quench pad (like the Keith Black KB184)? I guess these need to be selected with some thought as to which is the best match for the combustion chamber shape of the 906 heads.

3. Should I be looking at one of those engine rebuild kits that contain pistons, bearings, gaskets, etc., everything for a short block rebuild (except the camshaft)?

4. What compression ratio should I be shooting for? According to the literature, my 69 440 had 10.1:1 compression. It will ping if I use regular or midgrade fuel - it needs premium, which is okay with me, I just don't want to have to use octane booster. I've read up a little on quench, and it looks like you can have higher compression ratios and still be able to run on pump gas if you have tight quench, but this may not be possible to achieve if I use open chamber 906 heads. But maybe I don't care about quench. When I got the car it had over 100,000 miles on it, it was definitely a tired engine, and it still felt plenty strong to me, so maybe I should be looking for factory replacement type pistons, which I think were flattops.

4. Maybe I should be shooting for a specific horsepower, maybe that's the right way to go about picking parts. Does anybody know of any software that you can use that's like a "virtual dyno" where you can play around with the specs and see your horsepower and torque curves?

I would appreciate any advice from anyone with relevant experience on this.

Thanks!

I'm a quench fanatic & that'll take some $$ (if you keep the 906's) to machine the chamber recesses level/equal and then the dome (KB hypers) & mocking up/measuring several times to get .035"-.040" on each piston top & w 035 you want your measuring dead on (piston rock) but it will give you an EFFICIENT long block w nothing left on the table and give you the most power/mileage out of a given octane. After you end up going w a specific cam then build a specific static CR that will let you run on pump gas w a fast dist curve w your cam selection.

I agree with Robert, quench is virtually a must have for a street build, more useable power on pump gas with less chance of detonation.. Why guys build street engines without it makes no sense to me.... It would be a much easier job if you grab a set of 915 heads & they seem to be popping up pretty regularly for allot cheaper than they were five years ago...

Do a quench build. I would suggest picking up a used edelbrock ch4b intake. It's a decent upgrade over stock yet still looks like a stock intake and does well for performance and fuel mileage/driveability.

Really for you, I think the 'big' summit cam would do well. My brother has one in his 440(runs smooth but it's enough cam that you can hear it when it's idling) and it's a decent cam for the price that I think it would be right at home in your stock headed 440 if you put in the recommended set of valve springs. You can reuse your rockers/pushrods/etc. I would really suggest doing a set of cheapie headers or HP manifolds because in a combo like this, exhaust is the place where you will find the best gains for your buck. If you build this with 9:1 compression with quench I think it would give you a nice boost over stock.

When it comes to powering heavy full size cars, I'm a firm believer in building 'torque' motors.
Creating power with picking hot cams is not the way to go in a big car imo, especially not in a convertible cruiser.

If the budget is there, I personally would consider a 4.15" stroker kit for your 440.
The added .40" distance in the crankshaft-journals will let the engine make torque much easier with stock valvetrain parts, then going the 'hot cam'-way.

I've put a 500" stroker in my '60 NewYorker and that car is way more fun to drive. It accelerates so easy now it makes you think the car weighs only 2000 lbs.

1. Cast, forged, or hypereutectic?
For you, whatever you can get the cheapest that nets you a decent 9.5:1 (or better)

2. Flattop, dish, dome, or stepped with a quench pad (like the Keith Black KB184)? I guess these need to be selected with some thought as to which is the best match for the combustion chamber shape of the 906 heads.
For your application quence is not that important.

3. Should I be looking at one of those engine rebuild kits that contain pistons, bearings, gaskets, etc., everything for a short block rebuild (except the camshaft)?
Yes Summit, Jegs and PAW have good kits that include cam shafts.

4. What compression ratio should I be shooting for? According to the literature, my 69 440 had 10.1:1 compression. It will ping if I use regular or midgrade fuel - it needs premium, which is okay with me, I just don't want to have to use octane booster. I've read up a little on quench, and it looks like you can have higher compression ratios and still be able to run on pump gas if you have tight quench, but this may not be possible to achieve if I use open chamber 906 heads. But maybe I don't care about quench. When I got the car it had over 100,000 miles on it, it was definitely a tired engine, and it still felt plenty strong to me, so maybe I should be looking for factory replacement type pistons, which I think were flattops.
I try and stay between 9:1 and 10:1

4. Maybe I should be shooting for a specific horsepower, maybe that's the right way to go about picking parts. Does anybody know of any software that you can use that's like a "virtual dyno" where you can play around with the specs and see your horsepower and torque curves?

Not really needed for your application. A stockish rebuild with a upgrade in camshaft, inatke and carb will get you were you want to be.

If it were me I'd have the block checked. If you need a bore get one then have it decked. I'd call one of those places above and order their rebuild kit. Add the upgraded camshaft Like the Summit 488, look online for a used dual plane intake, 750 holley (vacuum or mech), Electronic Ing (get the curve kit too), 2200 stall and you should be good to go.
No need to spend a ton of money.

Why not just rering it and use your pistons?unless it has alot of bore wear.New bearing as long as the crank is ok.As for a cam stick with one with low duration(260-270).The higher lift the better.Unless you plan on changing your converter to a high stall.As for those summit cams(488)without a converter it will be a dog out of the hole.something like this cam
http://www.summitracing.com/parts/CCA-CL21-222-4/

I found a company called Aerohead that sells reconditioned cast iron heads with new valves, springs, etc., 3 angle valve job, for about $600, and they apparently have 915 heads. If I did want to build it so I get the maximum benefits from the quench effect, if I went with 915s, is there a piston that I could use that would not require a lot of custom machine work to get good quench? If I stick with my 906s, is there a piston that would give me some of the benefits of quench without spending a lot of money?

Keep in mind that this build is for a C-body convertible that I will never take to the strip and will probably not ever even take the rpms above 4500, or whatever the valve body in the transmission lets it get up to if I floor it from a dead stop before it shifts. I will not replace the torque converter. I will probably continue to run the stock exhaust manifolds with duals, although I may put Hedman shorty headers on it at some point or HP exhaust manifolds if I can find a pair. I have a 3.23 open rear, no plans to go looking for a sure-grip, but if one fell into my lap I would install it. There is a chance I may even put the 2.90 chunk back in if I end up doing more highway driving, but that's a long shot. I have power brakes, power steering, and plans to get the A/C working some day (top down with the A/C blasting! That's America!).

Having said all that, I've been doing a lot of reading of other posts and checking stuff out on other web sites, and this is what I think: I think it is really sad to put any money into an engine rebuild, no matter what the engine will end up being used for, and not think about quench. There's nothing bad about quench, no tradeoffs that I can see, and there's no reason not to incorporate quench design considerations into any engine that is being rebuilt, unless you are a total "factory restoration" guy.

To achieve quench, it seems like there are two ways to go: flattop pistons with closed-chambered heads, or quench dome pistons with open-chambered heads.

If money is not an issue, then it seems like a no-brainer to go with aftermarket aluminum closed-chambered heads and flattop pistons . You pick the right pistons with the right height, such as a KB237, you make sure your block is square and has the right deck height, you pick the right head gasket, and you're there. You can take the compression ratio up to about 10:1 and if you have the right camshaft with the appropriate duration you will probably be able to run on premium pump gas. Let's call this "Option One."

If money is an issue (which it is), and you don't already own a good set of 915 closed-chambered heads, then you buy a set of quench dome pistons, such as a KB184, and you use your stock 906, 346, or 452 open-chambered heads with a basic valve job. Let's call this "Option Two."

The problem with Option Two is what I've read in this post and others about the machine work that you may have to do to the open area of the combustion chambers in the heads, or to the quench dome of the piston, or both, so that you have the right gap between the quench dome of the piston and the open area of the combustion chamber to achieve quench. If a lot of machine work has to be done to the heads and/or the quench dome of the piston, then Option Two can get expensive. The cost difference between a basic valve job on a stock steel open-chambered head to the cost of brand new 440 Source aluminum heads is anywhere between $600 and $800, depending on whether you get hardened valve seats installed, which would probably only be an issue if you have 906 heads (which I have). That's with reusing the original valves. So I could see Option Two becoming almost as expensive as Option One if you are doing a lot of machine work to tailor the pistons to the heads to get good quench. And you don't get the new, bigger valves and better flow that comes out of the box with the aftermarket aluminum heads.

The only way that Option Two makes sense is if you can just slap in the KB184 pistons, throw on the heads, and even with the variability in quench area that you might end up with, it's good enough and better than stock.

I've seen other posts where people have described mixing and matching the pistons in the cylinders and finding the best quench for their particular combination of pistons, rods, block, and heads, without doing any machining to the pistons and/or heads. You may or may not get lucky doing this, depending on how the factory built the parts that you are using.

So I guess my point is, if you just get basic machine work done to the block and heads to clean them up and throw in a set of KB184s (Option Two), how well can you expect that to work out?

Have you been over to Hensley Racing in Knoxville, and talked to Ken? A lot of people about their prices, but they do excellent work. I've never been less than very satisfied with every dealing I've had with them.

As mentioned, you may be able to just freshen up the stock short block, but I am guessing the heads will need alot of work, usually the valve guides will be pretty worn, and the exhaust seats sunk from running unleaded fuel?

Quench engines are really good to prevent detonation, and they are really easy to build if you are using a closed chamber head and flat top pistons. Using an open chamber head, and quench dome pistons like the KB pistons can be a pain to setup. I built a 360 with the KB quench pistons, and found the cylinder head deck to flat part of the chamber was too deep and also different depths on each head, so I had one head milled 0.040" and the other 0.050", along with milling the intake manifold side of the heads. Then I had to cc and equalize each chamber. Then the block was not exactly square, so the block needed to be milled so all the pistons sat right at 0.002 below deck (not including the 0.050" tall quench dish.) In mocking all this up, the ridge in the cylinder chamber that goes partway around the intake valve was too close to the quench pad, so the quench pad had to be slightly clearanced to work with the stock heads. This was alot of trouble and extra machining just to get a small amount of quench (the quench pad is fairly small in area compared to using a closed chamber head and flat top piston.)
Between the cost of rebuilding the stock heads, and the extra machine work to get quench out of them, your really better off to just get new aluminum heads unless you have the use the original heads for some other reason.
Some pros of using new heads:
Closed chamber design / easy to build quench
Cooler chambers less prone to detonation
No exhaust crossover, cooler intake, less chance of boiling the fuel in the carb.
Better flowing, possable 50+ HP gain just by changing from stock heads.
Stainless valves and hardened seats for performance and durability / compatability with unleaded fuels.
Head come with new performance valve springs / retainers / locks / seals.
Aluminum heads are easier to repair if damaged by engine failure.
Quench engine can be built with flat top pistons, there is a larger selection of off the shelf flat top pistons which should equate to lower cost for the pistons.

Cons:
Cost (actually very affordable in comparsion as noted above.)
Do not look 100% stock
Angled plugs of edelbrocks don't clear some headers/manifilds
Not as thermally efficent as iron heads (iron heads contain more heat, but are also more prone to detonation.)
Most aluminum head require purchase of reduced wrench size head bolt package adding to cost ($80 for ARP kit, $45 for 440 source kit.)

That's kind of where I'm at, that if you care about quench, and you don't have a set of 915 heads to start with, you might as well buy the 440 Source aluminum heads and go with flat top pistons. It might cost a little bit more, but not a whole lot, considering the significant amount of machine work that will be required to obtain quench with stock open-chambered cast iron heads, and for that little bit more, you gain better performance. It also makes the rebuild a lot simpler, which suits me.

As far as the comment about contacting Hensley Racing, which happens to be about a 20 minute drive from my house, all I can say is . . . duh! I never even thought about it. I should do that. Not to talk myself out of it ahead of time, but I kind of picture them as a place to go when you want to drop $10K on an engine rebuild, whereas I want to drop as close to $0K as possible. (Although that's kind of out of the question now that I've kind of decided to buy aluminum heads). I checked their web site and they don't list hours of operation, so I guess I will just try to give them a call when I have a chance.

The 40 year old 440 in my convertible runs OK, but I know the heads are shot. I bought a set of stealth heads to just drop on so the engine would not smoke so bad on startup. A car club member did this to his car and it worked out well, he even went with cheap CAT 1.7:1 rocker arms to get more out of the stock cam.
I have not installed the stealth heads on my 440 yet because I decided to make it a 505" stroker (source 4.25" 7.1" rods, 10:1 dished pistons.)

When I rebuilt the 906 heads on my 383 engine I had over $700 into rebuilding the heads to near stock condition, so to me the aftermarket heads have been a good / affordable improvement.

I finally got around to calling Hensley Racing and talking to Ken Hensley. We had an interesting discussion for about a half hour. I have to say I was a little intimidated talking to a guy who has been building mopar engines since I was a little kid.

When we talked about quench, his perspective was that quench was just a different way to achieve a desired compression ratio. The way he described it, if you wanted to get really high compression, you could, for example, use a stepped piston, like a Keith Black KB184, which leaves plenty of room on the low side of the piston for the valves, or use a flattop piston with valve reliefs. If you used stepped pistons, you could use closed chamber heads, or go to the trouble of machining the high sides of the pistons and/or the heads to get quench if you went with open chamber heads. He said that he thought you might actually lose power with closed chamber heads and a quench design because of valve shrouding, and the better flow of an open chamber head would result in greater power. He was perfectly open to doing it either way, he was just pointing out what he had learned from experience (of which he has plenty and I have none).

He invited me to come in and see his shop, and I will definitely do that soon (I was going to do it today but didn't have time). He seemed a little embarrassed when I told him how lucky I am to have a world class mopar engine guy almost literally in my back yard, which I think speaks well of him.

I'll keep you posted on my visit when it happens.

"If you used stepped pistons, you could use closed chamber heads, or go to the trouble of machining the high sides of the pistons and/or the heads to get quench if you went with open chamber heads."

Hummm...this sounds backwards to me. I'd use stepped pistons with open chambers and flat tops with closed chambers....right?

blah blah blah...quench quench quench... Just put it together and roll. Dude it's a MILD street motor. Quench is not that important. For what he's using it for he could get a Summit rebuils kit..forged or not, slap a Summit cam in it a roll. If he can get away with it re-use the stock pistons and home hone the block, re-ring/bearing it and go.