440 Cylinder Heads and Piston Compression Height Decisions

[bronco9588]

Hey Guys,

I just took apart a 440 and sent it to the shop. It will be bored over 30 and other than that I have some decisions to make in regards to piston compression height, deck height, and cylinder heads.

Anyways, I am looking a speed pro pistons with two options:

1) I could go with a 2.061 piston with a couple valve reliefs and a edelbrock performer rpm heads. The 88cc would have around a 9.37:1 compression ratio and the 84cc would have a 9.62:1 compression.

2) Or I could go with the pre-emission control 440 compression height of 1.99 (after '72 the CH went down to 1.91), stock '72 346 heads (that should be 81.95cc), and mill 20 or 30 off the deck estimating about 9.5:1 to 9.6:1 compression.

The option 1 costs the bore, pistons, and heads (1400 new), and probably some new valve train components such as push rods and rockers that are compatible with the tappets and heads. Option 2 costs bore, milling the deck (100) , pistons, head work ($500 estimate from the mechanic).

So in short I am trying to justify the use of one head over the other. The Edelbrock RPM heads are going to run me about $800 or more over the stock 346 heads. It would be nice to compare the lift flow numbers of both heads as well as how the differences of material effect detonation. I'm shooting for a zippy street car.

Thanks in advance

[valiant64]

Depends largely on your desired hp level. A well ported set of stock heads can make alot of power, be more durable & cost less than the aftermaket heads. Have you checked out the Keith Black hypereutectic pistons? Stronger & lighter than regular cast pistons & arent much more expensive. Need more details on your build

[cudabob496]

Always go with the most power you can make. If you don't, chances are you will regret it later, when you get wupped by a Camaro. Its very common to build an engine, then two or three years later think, "Gee, I wished I had done that!" If possible, go with a stroker crank.
Check out 440source.com

[crisser]

Go with option 1 and a modern cam.

[bronco9588]

the pistons I'm looking at are forged and are cheap... with wrist pins they about 360 plus shipping. looking at a comp cams's 21-222-4 grind number CRB XE262h-10.

[crisser]

Originally Posted by bronco9588

the pistons I'm looking at are forged and are cheap... with wrist pins they about 360 plus shipping. looking at a comp cams's 21-222-4 grind number CRB XE262h-10.

If you`re looking for a smooth idle, then that cam will do fine. But, i`d kick it up a notch or two to take advantage of the Eddy heads. Maybe the XE268 or the 274?

[bronco9588]

I'm that kinda guy who wants the get up and go power, but i cant sacrifice reliability and fuel efficiency of a daily driver (or weekend driver with rising gas prices). The 268 or 274 won't be too crazy at idle? Moreover, would 9.37 or the 9.62 aluminum head with headers operate on 87 octane?

[crisser]

Depends on what "crazy" is. The 274 will have a mild rough idle and the 268 a slight roughness. So, it gets back to what you want.

[bronco9588]

any reason beside money why stock heads would be the way to go?

[crisser]

Originally Posted by bronco9588

any reason beside money why stock heads would be the way to go?

No. And the eheads will take some weight off the front making it a better driver anyway.

[Paul Precht]

I have CC'd and milled countless 346 heads. Uncut they will have about 88 CC's
The KB 237 is an excellent piston, just remember the top end gap needs to be near .040" Don't deck the block, Paul.

[cudabob496]

If you want zippy, forget about gas mileage. Get a little honda commuter, and save the big block for weekend cruising.

Annapolis? I'm USNA 75. How's the town?

[bronco9588]

I like the speed pro L2355F 30's that are forged aluminum. Secondly, that 88cc figure makes sense, but a mopar chat archive explains that the heads are "blueprinted at 81.95 but act like 90". Can you make sense of that for me?

[bronco9588]

hey CudaBob,

It appears we have something in common. Class of '11. Plebe year is hard to view the town, but I bet the leadership has made papers your way.

[Paul Precht]

The 81.95 bluprint spec is for NHRA Stock and Super Stock racing. Racers running these heads can mill them to that minimum, 88 is about average for an uncut head, It they had a valve job or two 90 would be about right, Paul.

[cudabob496]

Originally Posted by bronco9588

hey CudaBob,

It appears we have something in common. Class of '11. Plebe year is hard to view the town, but I bet the leadership has made papers your way.

You're a plebe. Poor guy. I remember my first plebe winter when we lost to army. Not fun. You guys get the internet? That's great. We didn't get radios till Easter! Hang in there, man. Three years after I left, they let the gals in. No more throwing a guy tied up naked out into the parking lot.

[DartGT66]

The advertised chamber sizes of the factiry heads are blueprint numbers. Because of the factory tolerances and practice the reality in unmodified factory BB open chamber heads is around 90cc. You must measure to know.

If you go through all the trouble of rebuilding an engine, use good quality parts and machine work. The old TRW pistons are reliable, but they weigh a lot. I would take a look at the wiseco pistons, and also take a look at 440 sources offerings. With lighter pistons you'll stress the rest of teh parts considerably less, and also gain some power. If you still decide to go with TRW pistons (they work too and are less expensive), it's hard to beat Summits "engine rebuild kits" including 2355 pistons, like FEM-CSMHP815-311 with the under and oversizes you need. I would still opt for new 4340 steel rods, it takes more money to rebuild an old set than buy new once from for example 440 source. http://www.440source.com

As far as the heads go, Edelbrocks work well. I would take the smaller closed chamber heads with flat top pistons, and if at all possible machine the block to achieve zero deck. 440 source are about to bring their aluminum heads to market in hte future too, they are made in China and cost less than the Edelbrocks and should have about the same performance properties except that they are with straight plug heads and hterefore fit with a wider variety of headers.

The cam choice depends of your car and teh drivetrain, converter gear, weight etc., must know them first.

[bronco9588]

anybody know how the 440source heads compare to the edelbrock rpm heads in respect to breathing rates?

[Steve DeTar]

84cc Eddy head. the 2.061 piston and the .557 mech cam with 1.6 rockers with a 3,000 stall and some 3:91'S OR 4:10's with a 28inch tall tire.

[rampage_82]

Well here's a reason to go with the stock heads. There is no use spending big bucks on the Eddy's if you aren't going to put in a cam big enough to use em. The TRW / SpeedPro pistons are reliable, but as stated before are wicked heavy, which in turn strains the rest of the components. With the type of cam you're talkin about earlier there is no reason a stock set wouldn't be just as good as the Eddy's. In fact you need about .550 lift before you can start taking advantage of the aftermarket heads. I just saw the heads the 440 source guys have, however I know nothing about them...

However that's just my .02. I'm sure someone will disagree.

[valiant64]

Right on Rampage. If the cam isnt big enough to work the better flowing head, I think I'd spend the $1,400.00 on a good trans/converter or gears & suspension. Your money, your choice. Forget about fuel mileage with this build Its gonna guzzle gas, but big blocks always do. Have fun!