rebuilding my 440 906 heads?

[ralley440]

All right here it is I'm rebuilding my 440 it is a 1974 motor out of a motor home standard bore with flat top pistons going to be using mopar purple shaft cam 292 duration with 509 lift and edelbrock torquer II intake. my question is i want to use the 906 heads but someone was telling me that these heads are good for short distance driving and occasional race, they said the valve seats will beat out of them on long trips for instance from florida to texas and back. Has anyone heard of this before, would i be better off using a set of heads off of a 71-73 440. any help would be appreciated. thanks guys

[aifilaw]

If memory serves me correctly, the only pre-1973 heads out there that have hardened valve seats is the 346's. get something later like the 452's from late 70's
So, while the engine is apart, you could take it to a machine shop and have them install new exhaust seats on the 906's you have now. If you don't, then yes, you are going to have a problem.

[firefighter3931]

The 906's will need hardened exhaust seats sould you decide to rebuild them. The 452's have induction hardened seats and are the best option....those are 76-78 castings. The 346 (71-74) & 902 (75) castings have flame hardened seats and will work with unleaded fuel as well. If i had my choice it would be the 452 head.....hands down.

The 509 is a big cam with lots of duration better suited to racing.....not exactly a hwy cruiser type profile. To make it work right you need lots of stall and gear. 

I would re-think the cam choice given your intended application. 



Ron



Ps. welcome to the site 

[ralley440]

Thanks guys lot of help, may go to the 452s  have to check price on having the seats replaced on the 906s first. as far has my cam I want something with a good lope to it I built a 383 a couple of years ago using the 282 duration with the 484 lift but it didn't seem have much lope run like bat out of hell though. not going to be driving long distances with my charger mainly local 30 miles or so with the occasional drag strip visit. is there a cam alittle smaller than the 509 that will give me a good lope. thanks

[is_it_EVER_done?]

not going to be driving long distances with my charger mainly local 30 miles or so with the occasional drag strip visit.

I agree that the 452 heads should be your first choice, not just because they already have hard seats, but they just work better than 906's in my experience. Plus they usually only run about $50.00 bucks or so per set used.

However, if you have a set of 906's that only need a valve job (a 3 angle is a big help in flow by the way), you can run them for 10's of thousands of miles with no problems with stock valve seats, but you can also run them indefinitely if you add a bit of leaded race gas (about a half gallon) every couple thousand of miles.

The lead eliminates the valve seat wear, and it doesn't take much, nor does it have to be introduced continuously. Just a bit every couple thousand miles.

One of my 69 cars has over 300K miles on it and has never had the heads off (440 with 906's). It still has decent compression and runs perfectly. I just add some leaded fuel periodically. Eventually I will restore the car, but as long as it keeps working so well, I'll just keep driving it 

452's (or Eddies) is the best solution, but I just pass this info along as a workable fix for those that want/need to use stock heads. Plus I have had replacement valve seats fall out on an engine I overheated, so I'm not a fan of replacement seats.

[aifilaw]

I'm surprised the seats fell out on you, I would take up arms against the machine shop that did that work because it generally doesn't happen if they are installed correctly.
There are far superior camshafts than the MP grinds regardless of what you are trying to do. I don't pay attention to the off-the-shelf grinds as I mainly custom design one, and then for costs savings compare what I've come up with, with the off-the shelf grinds, if it comes close I get the shelf one, if not I have it custom ground, usually ends up $50 more for a custom job, and sometimes the same, sometimes less.

[is_it_EVER_done?]

I'm surprised the seats fell out on you, I would take up arms against the machine shop that did that work because it generally doesn't happen if they are installed correctly.
There are far superior camshafts than the MP grinds regardless of what you are trying to do. I don't pay attention to the off-the-shelf grinds as I mainly custom design one, and then for costs savings compare what I've come up with, with the off-the shelf grinds, if it comes close I get the shelf one, if not I have it custom ground, usually ends up $50 more for a custom job, and sometimes the same, sometimes less.

I agree, but my point was intended to show that installing them properly is not a "given". It takes knowledge and experience, neither of which can be "assumed". particularly as more and more time goes by, and machinists have less and less experience with seat replacement.

I have never had a problem with 452's or Eddies, and I would only use them rather than take the chance that whoever does the seat installation knows what they are doing.

I don't know if your cam reference was directed at me, but I couldn't agree more about using a custom grind! I used to post a "dissenting" opinion whenever the same shelf cam is suggested over and over again no matter what the build specs were, but I gave up on suggesting a custom some time ago as it's a waste of time and effort to argue! I must also disagree that the MP cams are deficient by design. Yes, fast ramps and rollers can be quicker/better, but for stock heads and cam longevity (without going to a custom grind), the MP's still work great, and are amazingly cheap.

[aifilaw]

I don't know if your cam reference was directed at me, but I couldn't agree more about using a custom grind! I used to post a "dissenting" opinion whenever the same shelf cam is suggested over and over again no matter what the build specs were, but I gave up on suggesting a custom some time ago as it's a waste of time and effort to argue! I must also disagree that the MP cams are deficient by design. Yes, fast ramps and rollers can be quicker/better, but for stock heads and cam longevity (without going to a custom grind), the MP's still work great, and are amazingly cheap.

Actually it was intended for the original poster...
I realize the MP cams are cheap, but honestly there are far superior grinds out there for absolutely every combination, and I'd rather spend the extra $50 or so on a different shelf cam, or even $100 on a custom grind and get the 1-200 hp more under the curve than save the $50... but that's just me and my perfectionist in power nature

[Musicman]

I realize the MP cams are cheap, but honestly there are far superior grinds out there for absolutely every combination, and I'd rather spend the extra $50 or so on a different shelf cam, or even $100 on a custom grind and get the 1-200 hp more under the curve than save the $50.

[ralley440]

well you guys preety much got me convinced to just get a set of 452s. as fars as custom grind cams who does that. I've always used edelbroke or MP, who would be a good contact to talk with about having a custom cam made. and what recommendation on duration and lift would give me the good lope sound but allow for reasonable street use

[firefighter3931]

and what recommendation on duration and lift would give me the good lope sound but allow for reasonable street use

Cam selection is the most important piece of the puzzle.....improper cam selection will make the car no fun to drive and frustrate you with tuning problems and poor performance. 

We need some specs to determine a good cam profile to work with your combo ;

Headers/exhaust ?
compression ratio ?
stall speed ?
rear end gearing/tire diameter ?
Carburator ?
Power brakes ?



Ron

[aifilaw]

since your doing a rebuild and looking at the big picture it might be important to know why we ask a few of those questions...

compression ratio is important as it will determine for lack of a few other terms whether you can run pump gas or not, and what type of pump gas (87, or 93 octane). If you already have a static CR in mind and its too big for one of those, a cam with a bleeding off valve timing will reduce your dynamic CR enough to run a less expensive fuel with no significant loss in power.
rear gear/tire OD are based on the whole, how will you use your vehicle.. same with stall speed if its an auto.
power brakes is the important one... running a big lopey cam (too big for your engine) is suicide with power brakes, which is why there are a lot of manufacturer's out there supplying things like a vacuum canister, or even a vacuum booster module to make that all-important vacuum to run your accessories. It's also the reason a lot of people switch to manual brakes as opposed to power brakes.

Also added to the list are things like, how much % wise will it be spent at the racetrack, what type of racetrack, daily driver or weekend warrior, just aroudn town, or occasional long-trips?

[ralley440]

Ok compression looking around 9:1 auto trans 727 already built with shift kit stock conveter, carb is holley 750 with vaccum seconderies, 323 sure grip rear end with 295/50 R15's , as far as track occasional drag strip maybe once or twice every 6 months. power brakes main use is around town 30 miles or less, long trips will be trailered

[firefighter3931]

Ok compression looking around 9:1 auto trans 727 already built with shift kit stock conveter, carb is holley 750 with vaccum seconderies, 323 sure grip rear end with 295/50 R15's , as far as track occasional drag strip maybe once or twice every 6 months. power brakes main use is around town 30 miles or less, long trips will be trailered

Well based on that build ; the infamous 509 would be a horrible match. 

Here's a member that has a very similar build :

http://www.dodgecharger.com/forum/index.php/topic,27276.0.html

http://www.dodgecharger.com/forum/index.php/topic,28392.msg310179.html#msg310179



Ron