4V closed chambered heads on

Help Support 7173Mustangs.com:

armorclass

Member
Joined
May 7, 2014
Messages
7
Reaction score
0
Location
Denver, Co
My Car
1972 Mustang Mach1 351c
Will my 2v headers bolt up to 4v heads?
The heads will not bolt up the intake will not either. Further, I had to use some hammer based modification to my hooker headers to get them to fit when I switched to the 4v heads.

I wish I would have just spent the money on Aluminum 3v heads.

 

1973grandeklar

Well-known member
Joined
Mar 28, 2014
Messages
386
Reaction score
38
Location
North Carolina
My Car
1973 Mustang Grande 351C 2V
1972 Mustang 'Q' code Mach 1
$1400 bucks sounds like an awsome deal! Well done!
Agree, especially since they're date correct for my engine.

Before rebuild

After rebuild
Those look awesome! Do you have the rebuilt heads in the house on the coffee table for that picture? Looks like your couch in the background?

 
Joined
Jan 13, 2012
Messages
1,989
Reaction score
7
Location
Washington
My Car
1971 Mach1, 351 Cleveland, Ram Air (not factory), C6 Automatic, AM/8 Track, Bright Red.
$1400 bucks sounds like an awsome deal! Well done!
Agree, especially since they're date correct for my engine.

Before rebuild

After rebuild
Those look awesome! Do you have the rebuilt heads in the house on the coffee table for that picture? Looks like your couch in the background?
Yeah, the wife was in D.C. for a week on business, I took advantage of it to get some work done in the warmth, rather than the cold garage! Of course it was all back in the garage by the time she got back.

Jim

7.jpg

 

JimNiki

Schmuck
Joined
Jul 14, 2010
Messages
1,248
Reaction score
10
Location
Queensland, OZ
My Car
71 Mach 1
Nice job but I reckon the sun glare from the dash will drive you nuts ...ask me how I know!

 
Joined
Jan 13, 2012
Messages
1,989
Reaction score
7
Location
Washington
My Car
1971 Mach1, 351 Cleveland, Ram Air (not factory), C6 Automatic, AM/8 Track, Bright Red.
Nice job but I reckon the sun glare from the dash will drive you nuts ...ask me how I know!
LOL, yep took it off after the first sunny day, sprayed it with satin black and then scuffed it with a scuff pad after it had dried, lesson learned.

 

Manu Mach1

VIP Members
Joined
Nov 3, 2012
Messages
1,032
Reaction score
43
Location
France
My Car
73 Ford Mustang Mach 1 351 CJ all matching numbers, under restoration.
73 Ford Mustang Sprint from Mexico.
Well done Jim, nice job.

So now you can use unlead gas with no problem for you exaust valves and seats. Before that you added some additive in your gas?

Manu

$1400 bucks sounds like an awsome deal! Well done!
Agree, especially since they're date correct for my engine.

Before rebuild

After rebuild
 

1973grandeklar

Well-known member
Joined
Mar 28, 2014
Messages
386
Reaction score
38
Location
North Carolina
My Car
1973 Mustang Grande 351C 2V
1972 Mustang 'Q' code Mach 1
Yeah, the wife was in D.C. for a week on business, I took advantage of it to get some work done in the warmth, rather than the cold garage! Of course it was all back in the garage by the time she got back.

Jim
Ah, the old wife is away idea. Have to admit that I have drug in some car parts into the house when she has been gone, to work more comfortably. She would come home and ask, "Does it smell like gasoline in here?" Sorry dear, I cannot smell anything:D

Those interior parts look good! Did they make your car seem faster as well? At least looking good going faster!

 
Joined
Jan 13, 2012
Messages
1,989
Reaction score
7
Location
Washington
My Car
1971 Mach1, 351 Cleveland, Ram Air (not factory), C6 Automatic, AM/8 Track, Bright Red.
Well done Jim, nice job.

So now you can use unlead gas with no problem for you exaust valves and seats. Before that you added some additive in your gas?

Manu

[

Manu, lots of controversial discussions on whether our 71-73 heads need hardened valve seats or lead additive when running on unleaded. My take away from it all is, the earlier the heads and the more the car is driven, the more reason to be concerned.

The machine shop that redid my heads advised me if they were his, he would install hardened valve seats since my heads were made in 1970, he advised depending on where the heads were made and the year, they may not need hardened valve seats or lead additive on the 71-73's.

Since my 71 is just a weekend cruiser and not a daily driver I probably could have driven it for a long time on unleaded without the hardened seats before there was any wear but since the shop had them tore down I had them put in, I did it for peace of mind more than anything.

I'm sure others can add their experiences concerning using a lead additive or need for hardened valve seats on the various years.

Jim
 

1973grandeklar

Well-known member
Joined
Mar 28, 2014
Messages
386
Reaction score
38
Location
North Carolina
My Car
1973 Mustang Grande 351C 2V
1972 Mustang 'Q' code Mach 1
I once asked an old engine builder about the hardened seat inserts back in 1987 for my 1070 GTO Judge. He told me that I should not worry about it unless I plan on racing it. I have since ran many 1960's Pontiacs, Oldsmobiles, Fords, and even a 1955 Desoto with never touching the valve seats. In fact, I put over 50k driving the 55 Desoto as a daily driver for three years. When I sold it to my father in-law, he tore down the motor for a refresh and found that the valve seats looked like new and left them alone as well.

The only time I actually had a valve seat issue was a 1984 V-6 oldsmobile (actually it is the Buick V-6). I had to have the seats regound due to burning from overheating by the previous owner.

I realize these examples are ancedotal at best, but I have never had a reason (or good explanation) why I should put hardened seats in. But if peace of mind is for you, glad it worked out.

 
Joined
Jan 13, 2012
Messages
1,989
Reaction score
7
Location
Washington
My Car
1971 Mach1, 351 Cleveland, Ram Air (not factory), C6 Automatic, AM/8 Track, Bright Red.
OK I've got a few hundred miles on the 4V closed chambered heads, runs much better (after it's warmed up) but I've had to kick up the idle to keep it running while it's cold and I have to wait until it's warmed up before driving it or it'll stall. Once it's warmed up it runs like a bat out of hell, idles and even starts faster than with the 2V heads, but it's much more cold natured now, even in warm weather. The choke is functioning just fine and no adjustments were made with timing or anything, same carb I just added a 4V intake, 4V exhaust manifolds and the 4V heads...any reason 4V heads would make it more cold natured? Any suggestions?

Jim

 
Last edited by a moderator:

goodnigh

VIP Members
Staff member
Moderator
Joined
Apr 19, 2011
Messages
4,303
Reaction score
64
Location
San Jose, CA
My Car
1971 M-code Grande
My quench acted the same way in cold weather although it rarely goes below freezing.

I put the original air cleaner back on so I could get warm air through the snorkel.

Much better than the chrome dome I was using before. My understanding is the quench

head remains too cold for the flame wave propagation to burn completely. So you lose

power until the cylinder and pistons warm up.

mike

 

c9zx

VIP Members
Joined
Sep 30, 2010
Messages
5,429
Reaction score
336
Location
Mustang, OK.
My Car
1972 Mach 1 Q code
2007 GT
1969 Cougar Eliminator B302
CSX 7000 Shelby Cobra FIA
2020 Edge ST
2002 F250 V10
This is only my take on the issue. The intake runner volume of the 4v is much larger than the 2V. The cranking speed of the starter is the same. Therefore the pressure differential across the carb and the velocity of the fuel and air mixture is lower than the 2V. Because of this, cylinder filling is less and the mixture is lean and tending to have poor anatomization. Recalibration of the carb may help somewhat but, the fundamental physics are what they are. It is a small inconvenience for the gain in power the 4V head provides. Chuck

 

hyena429

VIP Members
Joined
Apr 16, 2011
Messages
3,502
Reaction score
10
Location
wa
My Car
1973 mach 1
OK I've got a few hundred miles on the 4V closed chambered heads, runs much better (after it's warmed up) but I've had to kick up the idle to keep it running while it's cold and I have to wait until it's warmed up before driving it or it'll stall. Once it's warmed up it runs like a bat out of hell, idles and even starts faster than with the 2V heads, but it's much more cold natured now, even in warm weather. The choke is functioning just fine and no adjustments were made with timing or anything, same carb I just added a 4V intake, 4V exhaust manifolds and the 4V heads...any reason 4V heads would make it more cold natured? Any suggestions?

Jim
Same with my open 4v heads Jim...She was always a cold blooded one...I could not even put my car into gear till the temp hit past 150-160ish.."no matter the temp outside" Or it would fall on its face and die.lol..After that she run like a champ, was always like that the 20 plus years of driving her. Nature of the 4v head..She needs to warm up ;)

 
Joined
Jan 13, 2012
Messages
1,989
Reaction score
7
Location
Washington
My Car
1971 Mach1, 351 Cleveland, Ram Air (not factory), C6 Automatic, AM/8 Track, Bright Red.
My quench acted the same way in cold weather although it rarely goes below freezing.

I put the original air cleaner back on so I could get warm air through the snorkel.

Much better than the chrome dome I was using before. My understanding is the quench

head remains too cold for the flame wave propagation to burn completely. So you lose

power until the cylinder and pistons warm up.

mike
Reading the responses it sounds as if it's the norm for 4V quench heads to be more cold natured than 2V heads, guess I'll just have to accept it and let her warm up before dropping it in gear.

Thanks guys, makes me feel better knowing that.

Jim



OK I've got a few hundred miles on the 4V closed chambered heads, runs much better (after it's warmed up) but I've had to kick up the idle to keep it running while it's cold and I have to wait until it's warmed up before driving it or it'll stall. Once it's warmed up it runs like a bat out of hell, idles and even starts faster than with the 2V heads, but it's much more cold natured now, even in warm weather. The choke is functioning just fine and no adjustments were made with timing or anything, same carb I just added a 4V intake, 4V exhaust manifolds and the 4V heads...any reason 4V heads would make it more cold natured? Any suggestions?

Jim
Same with my open 4v heads Jim...She was always a cold blooded one...I could not even put my car into gear till the temp hit past 150-160ish.."no matter the temp outside" Or it would fall on its face and die.lol..After that she run like a champ, was always like that the 20 plus years of driving her. Nature of the 4v head..She needs to warm up ;)
Yep if I drop her in gear before she's warmed up, it just falls flat on it's face, I'll just have to adjust to it.



This is only my take on the issue. The intake runner volume of the 4v is much larger than the 2V. The cranking speed of the starter is the same. Therefore the pressure differential across the carb and the velocity of the fuel and air mixture is lower than the 2V. Because of this, cylinder filling is less and the mixture is lean and tending to have poor anatomization. Recalibration of the carb may help somewhat but, the fundamental physics are what they are. It is a small inconvenience for the gain in power the 4V head provides. Chuck
I agree, the power gain is worth the inconvenience, yesterday I took it out on the open back roads and the added power in the higher RPM's is very noticeable, it wants to be set lose.

 
Last edited by a moderator:

Ron Tanzi

Well-known member
Joined
Jun 10, 2014
Messages
322
Reaction score
58
Location
United States
My Car
1972 Ford Mustang Mach 1 bright red, standard black interior,pb,ps
gauge package.rim blow steering wheel,15" magnum 500s,351 C 2bbl running a 4bbl Holley 600,MSD 6a with stock distributor and Pertronix,Comp cam mild grind, The Engine(rebuilt by me in 2002 for the second time the first rebuild I did was stock in 1995) made 305hp and 358 lb ft on the dyno. 9" 2.75 rear end,Global west sub frame connectors,620 front coils.Rear defroster. My parents bought my car brand new the year before I was born. I cherish it like my child.
OK I've got a few hundred miles on the 4V closed chambered heads, runs much better (after it's warmed up) but I've had to kick up the idle to keep it running while it's cold and I have to wait until it's warmed up before driving it or it'll stall. Once it's warmed up it runs like a bat out of hell, idles and even starts faster than with the 2V heads, but it's much more cold natured now, even in warm weather. The choke is functioning just fine and no adjustments were made with timing or anything, same carb I just added a 4V intake, 4V exhaust manifolds and the 4V heads...any reason 4V heads would make it more cold natured? Any suggestions?

Jim
Is the heat crossover in the intake open? My Cleveland (H code with 4bbl) would not run well at all cold without that passage open to gets some heat under the carb. I run the stock air cleaner with intake heat. I used the Fel pro intake gasket set (no heat crossover provision) and carefully cut to match the gasket to the passages in the heads. I have used this set up for 18 years and have not had a problem with oil burning on the bottom of the intake.

It gets chilly in New England so you really notice the cold performance issue. Ron

 

Totalled

VIP Members
Joined
Sep 5, 2011
Messages
1,864
Reaction score
4
Location
Olympia,Wa
My Car
73 Q code Mach 1
I always had to fire mine, and then run it at about 2,000 rpm for a minuet or so. Otherwise it would load up and stall.

 
Joined
Jan 13, 2012
Messages
1,989
Reaction score
7
Location
Washington
My Car
1971 Mach1, 351 Cleveland, Ram Air (not factory), C6 Automatic, AM/8 Track, Bright Red.
OK I've got a few hundred miles on the 4V closed chambered heads, runs much better (after it's warmed up) but I've had to kick up the idle to keep it running while it's cold and I have to wait until it's warmed up before driving it or it'll stall. Once it's warmed up it runs like a bat out of hell, idles and even starts faster than with the 2V heads, but it's much more cold natured now, even in warm weather. The choke is functioning just fine and no adjustments were made with timing or anything, same carb I just added a 4V intake, 4V exhaust manifolds and the 4V heads...any reason 4V heads would make it more cold natured? Any suggestions?

Jim
Is the heat crossover in the intake open? My Cleveland (H code with 4bbl) would not run well at all cold without that passage open to gets some heat under the carb. I run the stock air cleaner with intake heat. I used the Fel pro intake gasket set (no heat crossover provision) and carefully cut to match the gasket to the passages in the heads. I have used this set up for 18 years and have not had a problem with oil burning on the bottom of the intake.

It gets chilly in New England so you really notice the cold performance issue. Ron
Good info Ron, probably something I should have considered but the intake gaskets weren't cut to match the heat crossover passage. It really doesn't get that cold here so I didn't think it would be an issue especially since the there wasn't an issue with the 2V heads.

Jim



I always had to fire mine, and then run it at about 2,000 rpm for a minuet or so. Otherwise it would load up and stall.
I'm doing the same routine now with no issues. It was the adjustment of just starting it and dropping in gear after a few seconds and going with the 2V set up that had me thinking there was something wrong.

Jim

 
Last edited by a moderator:

hyena429

VIP Members
Joined
Apr 16, 2011
Messages
3,502
Reaction score
10
Location
wa
My Car
1973 mach 1
Jim...I ran original stock set up with crossover and original valley splash pan, original carb for 10 years and stock air breather with heat exchange,,..and she was always cold blooded for me on my 4v with open chambers...I switched to edelbrock top end and matching carb with no more vally pan and no cross over...she acted just the same...Like totalled said..i would have to hold her about 2000 rpm till she warmed up a little or she would load up..I ran stock original top and..and aftermarket..10 years with both diff set ups....I could not tell any diffrence between them on start up...She would allways start right up..Just load up fast if she was cold.

 

ygolohcysp

Member
Joined
Feb 3, 2013
Messages
21
Reaction score
0
Location
Allentown, PA
My Car
73 Mach 1 Q-code
Minimal progress on restoration
I have a little bit of experience here. A lot, actually, but it's all obscured from years of not doing anything with my old Mustang. I rebuilt a 351 Cleveland, and at the time swapped from 2V heads to 4V Closed Chambered heads. I used a manual choke, but didn't really have any issues with it running cold. But, I had done some other changes as well. I also did a larger cam with a longer duration, and roller rocker arms before the 1.73 ratio was available, so I used 1.7. I also did an Edelbrock aluminum intake, and full length headers. I also did a 4 core radiator, oil cooler, open element air filter. I can't remember everything I changed. It ended up taking a much different timing than the stock 4 degrees BTDC. I did the whole thing of getting the engine warm, running the idle up to around 3500 to get the full timing advance, adjusting the timing till it ran best, then backing it off just slightly, and using that as a good starting point.

To be fair, there was a lot more changed than just the heads, intake, and exhaust.

 
Top