cam profile

[seaweed]

Hi! I need some advise regarding what cam to chose for my -72 440.

It got

heddman hedders

Eddie performance RPM intake

Eddie 800 AVS carb

MSD ready to run distributor

346 heads (that I'm about to port using MP templates and thinking of milling them of 0.020)

TRW 2355 pistons.

Stock converter and 3.23 rear end.

Now i want to buy a Lunati 60303 cam but before i do i would like some opinion from you all,
do i need more compression?
It wont work with 3.23?
Or is there a better cam for my built?

My goal here is a daily summer driver that Cruise nice and overtake BMW on country roads, and a floppy idle

[68CoronetRT]

I have a similar build to yours and I was given a 60304 cam. I did look into the 60303 and they are a little smoother at idle. After a bunch of research(60303vs60304) I'm very happy with the 60304 in my car(Nice lope at idle). I too only use it for the street. I'm sure others will chime in for more technical data, but this is just my .02.

[BSB67]

I think the 303 cam is good, well matched with your converter and gear.  It will come down to personal preference as you could use the 304 too but will have more chop at idle.

Measure the distance the piston is in the hole at TDC
Measure the combustion chambers if you can ( or we can estimate)
and we can figure you're compression ratio and recommend what to do.

Not sure what your overall plan is for the heads.  The porting template does not get you much, but I still recommend for you to go for it.  What really needs to be done with that is a really really good competition valve grind.  That will be worth every bit, if not more than the template bowl work.

[seaweed]

the 304 cam is from 2200 rpm, how would my car behave with that?
the pistons are 0.020 down the hole and I'm not sure how to measure cc out of the combustionchamber, i have heard that they are betwen 88cc -92cc.
I will also use a 0.020 steel shim gasket. I will also do a 30 degree back cut on the valves.

[500Jon]

Just love that GREEN Seaweed!

Its all about VACUUM, how much do you need???
Are you running a Booster?
If so, you will want a good load of it at idle.
Lunatti have solved this problem with the dual pattern cams.
Don't go bigger than .500 lift in my experience.(for lots of reasons)
5J

[seaweed]

Thanks!

I have had about 18 hg of vacuum, don't know how much is needed to supply powerbrakes and distributor and headlight doors?
I think that i will be landing around 9.4:1 in compression. How will that affect my cam choice?

[BSB67]

At 90 cc you are at 9.5:1 static CR.  What is your elevation?

I think you will be on the edge of detonation with the 303 cam and that CR at lower elevations.  Personally, I hate to give up CR and if you don't mind the work, I would go for it.  And the reason is that you will be able to make some changes to probably get you there.

So if you put it together and it rattles, you can: 1) retard the cam, 2) put the larger cam, possibly retard it, 3) put on a thicker head gasket.  One or some combination of these will make it livable.

If you want to do the work only once and take no risk on detonation, us the thicker gasket.

FWIW, a 30° backcut on the valve is not the definition of a really good competition valve job.  Just sayin.

[seaweed]

BSB67 thanks for your reply maybe you could help me with the math?

Since i don't know the cc's of the head Ive just round it of to 90cc
and i know that pistons are 0.020 down (flattop with valverelives -7cc)
First i was thinking to put a 0.040 composite gasket in and therefore mill the head 0.020, but if i go with steel shim 0.020 instead then maybe i don't need to mill?
Milling head and grinding back of valves is something that i can do myself ( i have the machine and the knowledge )
but the competion valve job that your talked about, can you explain that a little?
I'm on a budget so i want to do everything myself (its good for the experience also)

Oh and i always drive on 98 octane.

[BSB67]

For some reason I don't think that your 98 octane = our 98 (R+M/2) octane.  You probably need to do a little research there to make sure that we are truly talking apples to apples.

I'm not a valve grinder so it would be best that a professional answer your question.  I will say this, every angle matters, and seat and face widths and location matters.  The guys that are really good at it won't tell you what they are.  And you cannot get there without straight and tight stems and guides.

Sounds like you just want to clean up your existing heads, bowl work and back cut and then back to the races?  Correct?  If you are just wanting to try something different for fun, on a tight budget, and not expecting the world, go for it. 

When you are guessing at head volume, it is hard to turn head milling or gasket thickness into a science.  For talking purposes,  milling .020" from the head will have the same net change on CR as using a head gasket that is 0.020" thinner.   Milling 0.020" and using a 0.40" gasket (verses a 0.020" gasket) will result in nearly the same CR.  If you know the head volume and have a target CR you are shooting for, then you can get into the weeds on gaskets and head milling.

To help target the CR, can you tell us what you know works.  Have you run this motor with the 2355s before?  What cam?

[69wannabe]

I like the comp cam grind's myself and I had a XE274 cam in my last 440 build and it ran great and sounded great too and it was just under a 500 lift. I think that the 303 lunati is a close to the same spec's as the 274 but I would be concerned about the 513 lift on the exhaust. If you plan on this cam you may want to get the valve guides machined down to keep the retainers from bottoming out onto the top of the guides. I have been told that 509 lift is as high as you can go on a cast iron head without having the guides machined down. Maybe Ron will chime in since i'm sure he will know for sure. I ran the 274 with power brakes and they worked fine!! I plan on building another 440 pretty much like what you have and it will have the XE 274 since it ran so good in the one I had before!!

[seaweed]

The 2355 are brand new std size that i came over cheap by a guy who ordered wrong size. I believe that my engine never had been opened up before, so everything from heads down are stock.
I'm not trying to build a racer but now when i change the pistons I'd tough that it would be a good idea to freshen up the heads and change to a bigger cam.
what cam would you have bought?

I never race but i want a 440 worthy my car

[seaweed]

69wannabe that cam looks good.
What's your motor specs?

[BSB67]

The 2355 are brand new std size that i came over cheap by a guy who ordered wrong size. I believe that my engine never had been opened up before, so everything from heads down are stock.
I'm not trying to build a racer but now when i change the pistons I'd tough that it would be a good idea to freshen up the heads and change to a bigger cam.
what cam would you have bought?

I never race but i want a 440 worthy my car

So, it would probably be good to understand your plan, as where you are silent on some details, we are left to fill in the blanks.

Generally speaking, when you go to freshen up a 40 year old motor, usually you need to bore, hone, new oversized pistons, rebuilt rods and possibly crank work, to name some of the minimum requirements.  Same with heads, new valves, guides, and a professional rework.  My guess is the guy you bought the pistons from found this out after he bought the standard size pistons.

So it is not clear to me if you already know this, or not.  It is the difference between "doing it right" or "not doing it right".  I am probably one of the few people that are actually okay with not doing stuff right if you understand and accept the possible consequences.

There are some things that you need to consider when putting a new std piston in a 40 year old block.  The bore will be out of round, will have taper, and will have an uneven ridge around the top.  The out of round and the taper you can live with IMO, understanding that you are giving up cylinder sealing.  A good ridged Sunnen hone can help that a bit but you will end up with greater piston clearance.  If you don't mind piston slap, you can go up to 0.007" piston to bore clearance.  Your not going to do that by hand.  However, I think the ridge is a problem.  I'm pretty sure the ring set will be higher in the bore and interfere with the ridge. Ridge reamers generally ruin the block, and even if not, the transition can still be a problem.  You probably need to think through that real well IMO.

[69wannabe]

I agree with BSB67 on boring the block. I am not a machinist but I can usually take a look at the cylinders and almost know if it needs bored but I always take it to my machine shop and let them measure the bore and if it needs bored he bores it. The engine I had in my charger was a 30 over block, stock steel crank, stock rods with ARP bolts and TRW 2355 pistons. Had a melling high pressure oil pump with a hemi oil pan. Cam was the XE274 comp and had 346 casting heads with 214 intake and 181 exhaust valves with some mild porting and a eddy RPM intake. Had a 750 holley DP carb and was running the MP ignition set up with heddman 1 3/4 tube headers. I still have the rotating assembly from this engine that I plan to build up another engine just like this as an extra. I never had it on a dyno but this engine was pushing around 425 to 450 horses just guessing. It really ran great and was very dependable.

[seaweed]

Yes i know that it should be bored, Its just that i bought the pistons so cheap that i taught it would be wort to do just the swap.
But listening to your replies made me realise that maybe it would be stupid to try and "cut corner".
I have googled for a motor-shop with good reputation and have found a few, its around 400$ just for the bore. a new set of pistons is 380 + shipping and import charges 145$, And on top of that i a new cam 430$ (complete kit) + shipping and taxes 160$ = 1515$ 
I had plan on buying a new set of wheels but that can wait until next year instead.

[69wannabe]

It's very wise to build yourself a good solid bottom end and that way later in life you may want to go for a set of nice eddy RPM heads to get more performance out of the 440!! I am running a 493 ci now with the same 346 heads and it runs out great but it would benefit the engine if it had a nice set of eddy RPM heads on it. With the stock stroked 440 the heads worked great but I can tell that the cast iron heads are limited and with the bigger cubic inches it would really do better with a set of the RPM's on it.  10 years ago when I was at the strip almost every time it was open with a group effort 68 barracuda we were running I would have already opted for the RPM heads but now I just cruise around and rarely turn the engine very hard so as long as it's running good with the 346's I will just leave them on there and keep cruising. I had these heads built back in 07 and I wound up with around $650 in them so I don't think I did too bad on the head build. If you go ahead and decide to complete job on the 440 with boring and new pistons and you decide to unload them standard size 2355's I may be interested. I got a 78 block that is an RV engine that only had around 40,000 miles on it and by looking at the bores I could go back standard with it. Good luck on the build and keep us posted!!! 

[firefighter3931]

With the stock tq converter and 3.23 gears my choice would be the 303 cam. 

I would opt for the .040 composite head gasket as well 



Ron

[500Jon]

Hi Seaweed,

Its a no-no putting taller or high-comp pistons in an old bore.
But that's not the end of the road for you.
If its a budget build then anything goes!
The other major consideration is piston weight.
If the replacements are more than 20 grams heavier than the originals then you have a problem.
You will have an 'out of balance' set-up, not unlike a road wheel and tire imbalance!
The opposite problem occurs with KB/Icon Hypers, they are much lighter than stock.
70/71 Sixpack engines had the biggest issues with internal crank balancing.
Have you got a steel or cast crankshaft?
Cast cranks tend to have 'EXTERNAL BALANCING' added to the damper and torque converter.

There's a lot to learn with V8 engine building, get the basics wrong and it will bite you back!
Also note that stock heads will only run a .500 lift cam with modifications too.

Be careful not to make fundamental mistakes in over-building a good stock engine!!!
Nuff said by 5J.