Which heads are best

-
hemichuck said:
Yeah, Im aware that statement is somewhat of an oversimplification of what has to be done. I really just wanted to buy some heads and get a motor in this car so it wont be sitting out its 24th summer of cruising. I have a bone stock 340 bottom end and I think I will just freshen it up and stick some iron heads on it and a stock 340 cam and go cruising. Maybe some day I will use the 408 in a drag car but I doubt it. I have a Viper if I want to go fast so I really wasnt trying to build the Dart into a beast. Ive been doing this junk for 40 years and I'm really to the point where the older cars dont have as much appeal as they used to. I think I would rather just get a new ACR Viper or a Hellcat and sell all this old stuff and clear out my garage. Theres a lot to be said for turnkey rides that will easily go 150 mph with the air conditioner on.
Click to expand...
Getting the car going is a good goal. Sounds like you have a good alternative in the stock bottom end. With your situation, it sounds like turnkeying the head/cam/valvetrain would be a good way to go. Or sell the 408 bottom to someone who is going racing.....Yes, my '09 Challenger is nice to just turn the key and go... but I still like to put stuff together and make it work. When I can no longer pull myself under a car, it will be time for more ham radio!
 
hemichuck said:
So I am gathering from this whole conversation that I can just call Indy and order a pair of the $499 cast iron reworked heads with the 2.02 valves and they will be as good as anything. Then I just need to figure out what cam I need to use to make it all work.
Click to expand...


Like I said, guys get all bent up over BULLCRAP like DCR and running power brakes and a cam that idles too rough etc. Most of that is BULLCRAP as well. If you are running a carb and you can tune, what is considered a large cam will idle at 900 RPM. It's all in the tune. There are men who bum around on these forums, like thumper dart for example, who specialize in carb tuning and they are Chrysler guys. Deal with them.

As for power brakes, I won't ever have them on a muscle car. I learned that in 1981 on my 1972 Demon. Even with a stock cam it never stopped well. My dad was friends with a guy who owned a wrecking yard. He turned me on to the CORRECT sized manual master cylinder and the car stopped better than new. Just converted my 1973 Dart Sport to manual. Both had disc/drum.

You are running 408 cubic inches!!!!! Think about that! 20 years ago that was BIG displacement. What was a large cam in a 340 is a pea shooter in a 408.

The last thing I want to say is about compression. I love it. I do everything I can, to squeeze every single bit out I can for the application. BUT I will NOT compromise combustion chamber modifications at the expense of compression. I mean I will not keep .5-.75 more compression if it compromises air flow or chamber design. You can mentally beat yourself to death over picking the fly poop out of the pepper.
 
moper said:
The smaller cam will run the brakes, but won't work because of the pistons. The larger cam will work with the pistons, but won't run the power brakes.
I agree with Yellow about D. Hughes and his opinions.
None of this is hyperbole unless everything is hypothetical. We have real specs for the lower end and the OP's goals. Unfortunately those "givens" now dictate the top end to work within the provided parameters. You need to lower static, giving up any chance of quench in order to be able to run a cam small enough to run power brakes and run on available pump fuel. IMO - the "right way" would be replacing the pistons with dished, rebalancing, and running a modern, closed chamber, aluminum head. I steer clear of Magnum based stuff because the valve train costs are higher and the return on investment over an LA-based head marginal (by my opinion).
If you don't want to redo the lower end, either run a stock head (the chambers will be larger than 74cc as cast...) and a thicker gasket to end up around 9.8:1 static, or run the open chamber RPM which are no different than the closed chamber except for the .100" deep chamber milled out of them. There is no power difference you will notice between the two models of LA based RPM.
Click to expand...
I've seen more around 68cc from the stock untouched 360 heads I've cc'd. I wouldn't count on them being 74cc unless heavily worked.

yellow rose said:
Like I said, guys get all bent up over BULLCRAP like DCR and running power brakes and a cam that idles too rough etc. Most of that is BULLCRAP as well. If you are running a carb and you can tune, what is considered a large cam will idle at 900 RPM. It's all in the tune. There are men who bum around on these forums, like thumper dart for example, who specialize in carb tuning and they are Chrysler guys. Deal with them.

As for power brakes, I won't ever have them on a muscle car. I learned that in 1981 on my 1972 Demon. Even with a stock cam it never stopped well. My dad was friends with a guy who owned a wrecking yard. He turned me on to the CORRECT sized manual master cylinder and the car stopped better than new. Just converted my 1973 Dart Sport to manual. Both had disc/drum.

You are running 408 cubic inches!!!!! Think about that! 20 years ago that was BIG displacement. What was a large cam in a 340 is a pea shooter in a 408.

The last thing I want to say is about compression. I love it. I do everything I can, to squeeze every single bit out I can for the application. BUT I will NOT compromise combustion chamber modifications at the expense of compression. I mean I will not keep .5-.75 more compression if it compromises air flow or chamber design. You can mentally beat yourself to death over picking the fly poop out of the pepper.
Click to expand...
I can take or leave power brakes easily. I don't think they're necessary on a 4000lb truck, much less a car that weighs several hundred less and that's one I can't see why it'd be a necessity. You should have brakes that don't suck- the late model discs with 10" rear drums is a decent enough combo.

You forgot "low-end torque" like a 2900lb car is going to see a huge benefit from making over 300 ft/lbs at a 500RPM idle most couldn't tune out of it rather than making more at higher RPMs. Doesn't even make sense for a medium duty truck that'll haul all day long...
 
That is a small cam for the intended high compression ratio. Bottom line.
IF you already have the short block built with a high ratio slug, then order up thicker gaskets to run a lower ratio. Drop the ratio down to 9.0-1 with that cam and you'll be good to go.
 
I used to like building cars but it seems like in the last couple of years Im kinda burning out. You didnt used to have to make these decisions. In the good ol days(LOL) you just stuck on some X or J heads and zero decked it and stuck a 509 hydraulic in it and went driving. You didnt have to worry about which head because there wasnt any alternatives and you didnt have to worry about detonation because the gas didnt suck. I remember running the old 13.5 to one TRW's on the street with pump gas. I guess im just getting older, bad knees, hard to climb around under cars now. I just got done putting a clutch in my Viper and it took me several days, used to do that crap in a night. Thanks for all the opinions guys. I dug out the 340 and I guess I'm going stock.
 
Ok, one more question, I was looking at a chart on cylinder head volume in mopars and it said the 345 casting heads had a 74cc combustion chamber. When I plug that into the comp ratio calculator with a .052 gasket on my combo it comes up to 10.37 comp. ratio. Anybody familiR with these?
 
Pretty much every Mopar head, big or small block I've ever checked was larger than the advertised specs said. I'm sure others have had different results as was already posted. That's because even chamber to chamber you can get some wild fluctuations... That's just factory casting QC, old valve jobs, etc. If you stay open chamber, they will be fairly big. Have them CC'd, and made to be what you need them to be. I think anything over 10:1 static will want a cam around 230° @ .050 at minimum to keep out of detonation with some available pump swill, even with careful tuning. Not because the combo suck - because the fuels can be that bad. Personally I don't consider a 900-1000rpm idle as liveable in a cruiser but maybe you're good with it.
Really - lose the requirement for power brakes and you'd be miles ahead of where you are now.
 
moper said:
Pretty much every Mopar head, big or small block I've ever checked was larger than the advertised specs said. I'm sure others have had different results as was already posted. That's because even chamber to chamber you can get some wild fluctuations... That's just factory casting QC, old valve jobs, etc. If you stay open chamber, they will be fairly big. Have them CC'd, and made to be what you need them to be. I think anything over 10:1 static will want a cam around 230° @ .050 at minimum to keep out of detonation with some available pump swill, even with careful tuning. Not because the combo suck - because the fuels can be that bad. Personally I don't consider a 900-1000rpm idle as liveable in a cruiser but maybe you're good with it.
Really - lose the requirement for power brakes and you'd be miles ahead of where you are now.
Click to expand...


I was with you until the idle part. Back when these cars were NEW, the idle speed was 750-800 RPM. Then, you add ANY cam and it went up from there. A 1200 RPM idle is nothing, unless you are concerned with CAFE standards, because that is why idle speeds have dropped. In fact, it can be argued (and I have to do it often) that lower idle speeds will do more to damage a SFT or HFT cam than almost anything else.

My new cam will idle no lower than 1200 RPM because I run enough spring pressure that I want the lifters sliding over the lobe with a purpose and have enough oil coming off the rods to keep the cam lubed.
 
Ok, lets say I plan on using this short block in a hot street or street and strip car. What heads and cam would make a lot of power. I have a 4 speed and a 4.88 gear and a Holley strip dominator I could use on it.I have some 1 7/8 Headman hustlers for an A body too. I would just have to buy a car to stick it in.
 
Obviously, the W2 would be the BEST choice. The second choice is a used set of eddys. The third choice is any cast iron passenger car head that has the open chamber. I don't get all excited over the lest 3 digits of th casting number BECAUSE THEY ARE ALL THE SAME. Funny thing is, the heads I call tear drop non smog and tear drop smog heads start out with the biggest port volume. Those would be the heads that the exhaust pad extends down (non smog) and if it has the hole it is the smog head. You plug the smog hole and go. In fact, my engine has on head that is an early head and the other is a tear drop smog head. I put a small hole in one head and th only other head I had was a smog head, so I used it. Both heads flow within .5% of each other. Looking at it, you can't tell, and neither can th rest of the engine.

Any passenger car based head requires a good port job. The W2 will go with a good valve job and smoke all other comers.
 
hemichuck said:
Ok, lets say I plan on using this short block in a hot street or street and strip car. What heads and cam would make a lot of power. I have a 4 speed and a 4.88 gear and a Holley strip dominator I could use on it.I have some 1 7/8 Headman hustlers for an A body too. I would just have to buy a car to stick it in.
Click to expand...
Stick that in your car now!
LMAO!
260* @.050 or better with as much lift as you can squeeze in with at least very well ported Edelbrock heads if not W2 heads. I'd suggest W5 heads are a gamble on there abilty to be very well ported. They could be picked up inexpensively. The draw back to the W series heads is expensive valve train.
The draw back to the Edelbrocks would be a lower ceiling of performance. But they would still be very respectable and not far behind the W heads.
Now that I think about it, MoPars .590 cam would do it well. I'd go with 1.6 rockers myself.
 
yellow rose said:
I was with you until the idle part. Back when these cars were NEW, the idle speed was 750-800 RPM. Then, you add ANY cam and it went up from there. A 1200 RPM idle is nothing, unless you are concerned with CAFE standards, because that is why idle speeds have dropped. In fact, it can be argued (and I have to do it often) that lower idle speeds will do more to damage a SFT or HFT cam than almost anything else.

My new cam will idle no lower than 1200 RPM because I run enough spring pressure that I want the lifters sliding over the lobe with a purpose and have enough oil coming off the rods to keep the cam lubed.
Click to expand...

That's funny you mention CAFE. You sure you're referencing it right though? Many moons ago when they were required I used to raise idle speed on some carbureted engines to pass the state emissions. That was in the 80s. It had nothing to do with fuel economy standards, because those standards really were not important until after these cars were made.
I'd call the cam choice and resulting idle a personal choice on your part I disagree with. Not like it's a big deal- different strokes, you know?
To me, raising the idle is a lousy way to compensate for poor tuning or incorrect parts choices. I'd no sooner put mechanical injection or use gas ported pistons on a street car. Idles past 800 are not for me when it's got to idle in traffic or crawl through a mall parking lot and it sure pisses off any local cops where I live.
 
W2's are not all that expensive new are they? I see the rockers and everything at swap meets all the time. Price is not all that big a deal, at this point in life I can afford about anything I want. I just dont need another car sitting around that I will get little time to drive. Ive had this 70 340 Swinger since the early 90's and I have a 71 Charger SE thats a U code 440 HiPo car. The Dart was a factory air, PS,Power disc brakes, rear defroster, Am/Fm thumb wheel radio 340 Auto with a 3.23 Posi. I changed it to big bolt pattern and put a QA1 crossmember and upper/lower control arms and adjustable struts on it. I also put the Borgenson steering box on it. I really just want a cruiser I can get in and tool around town or go on a road trip in. The Charger is all redone and has the original 440 HiPo with auto, air , tilt, cruise, am/fm, rear def., power windows etc. Its pretty much all stock except the color. On top of all that we have 2 vipers, 2 diesel trucks, 2 Dakotas and a Grand Caravan not to mention a Sprinter and a 1966 Belvedere !! four door. Im running out of places to keep the stuff.
 
moper said:
That's funny you mention CAFE. You sure you're referencing it right though? Many moons ago when they were required I used to raise idle speed on some carbureted engines to pass the state emissions. That was in the 80s. It had nothing to do with fuel economy standards, because those standards really were not important until after these cars were made.
I'd call the cam choice and resulting idle a personal choice on your part I disagree with. Not like it's a big deal- different strokes, you know?
To me, raising the idle is a lousy way to compensate for poor tuning or incorrect parts choices. I'd no sooner put mechanical injection or use gas ported pistons on a street car. Idles past 800 are not for me when it's got to idle in traffic or crawl through a mall parking lot and it sure pisses off any local cops where I live.
Click to expand...


In respect to CAFE, if your idle speed is 850 RPM you burn more fuel than if your idle is 500 RPM. It's really that simple. Thats what idle speed is about. Corporate Average Fuel Economy has absolutely killed common sense in automotive engineering.

As for MFI and gas ports on the street...MFI is doable, but you have to have a custom barrel valve and tuning is opposite of a carb. EFI has made MFI a non option. Gas porting (both vertical and lateral) are done all the time on the street. I remember when 1/16 rings were too thin to use in daily drivers. Now, all modern engines are about half of that.

Maybe you should unplug your tach lol.
 
hemichuck said:
W2's are not all that expensive new are they? I see the rockers and everything at swap meets all the time. Price is not all that big a deal, at this point in life I can afford about anything I want. I just dont need another car sitting around that I will get little time to drive. Ive had this 70 340 Swinger since the early 90's and I have a 71 Charger SE thats a U code 440 HiPo car. The Dart was a factory air, PS,Power disc brakes, rear defroster, Am/Fm thumb wheel radio 340 Auto with a 3.23 Posi. I changed it to big bolt pattern and put a QA1 crossmember and upper/lower control arms and adjustable struts on it. I also put the Borgenson steering box on it. I really just want a cruiser I can get in and tool around town or go on a road trip in. The Charger is all redone and has the original 440 HiPo with auto, air , tilt, cruise, am/fm, rear def., power windows etc. Its pretty much all stock except the color. On top of all that we have 2 vipers, 2 diesel trucks, 2 Dakotas and a Grand Caravan not to mention a Sprinter and a 1966 Belvedere !! four door. Im running out of places to keep the stuff.
Click to expand...

W2's are only expensive because any real performance heads won't use a factory rocker. Not even GM crap. Before I started building engines I walked in on a Chevy guy trying to adapt W2 heads to a SBC. He said there ain't a SBC head that was even close to a W2 head. Obviously, this was about 1981 or 1982. But the fact is, any conventional 23* Chevy head will get killed by a W2.

I say go for it.

BTW, I'm not even considering a set of quality ported W2's. Back in 2000 I made 565 HP on a 408 with ported eddys on a cam that made max power at 5200!!! It would have easily went over 600 if I could have gotten the fat, lazy, stupid, forum surfing customer to turn the engine 6500, which would have been easy with his parts. Add another 70-75 with W2's and add another 60 or so for well prepped, ported W2's. I have no idea why a 500 HP 408 is considered bad *** 16 years later.

EDIT: I hated that customer with a passion. If I ran into him today, I would throat punch him until his nose bled, for all the screwings that joker did to good people. They dyno was a 3rd party dyno for the haters.
 
I found a stroker kit for my 340 block last night, all forged internally balanced with dish pistons, supposed to be 9.5 comp with 65cc heads. Could that be used in my car to build what I am wanting. something not too wild but a torque monster below 5500 rpm?
 
hemichuck said:
I found a stroker kit for my 340 block last night, all forged internally balanced with dish pistons, supposed to be 9.5 comp with 65cc heads. Could that be used in my car to build what I am wanting. something not too wild but a torque monster below 5500 rpm?
Click to expand...

Sounds like it should work.

EDIT: if that compression ratio is calculated with a zero deck and you use open chamber heads, it will likely be a pinger. I would rather see 10.5:1 and get the piston .040-.050 OUT OF THE HOLE like Chrysler designed it to be run.
 
I need to build the 340 block anyway so this might be a good option. I can buy whatever heads I need for it. I also found econo W2 heads for $350 each(bare)
 
hemichuck said:
I need to build the 340 block anyway so this might be a good option. I can buy whatever heads I need for it. I also found econo W2 heads for $350 each(bare)
Click to expand...

You can either machine the stands down and use blocks, or you can use them as the econo versions they are. You still need offset intake rockers. Also, I don't remember the installed height for the econo' so but it is shorter than if you use blocks. If you go with the econo heads, make sure you check out b3racingengines.com and read up on geometry. You can use his shims to correct it.
 
They had the race heads for $400 each. Im going to get out my old DC bible and my Mopar Performance manual and read up on them.
 
hemichuck said:
They had the race heads for $400 each. Im going to get out my old DC bible and my Mopar Performance manual and read up on them.
Click to expand...

That's a good start, but the newer manual has info on the larger heads for 48* stuff and the closed chamber heads.

I hope you do this. Love to see the end results.
 
You must log in or register to reply here.
-

Back
Top