Recommendations on intake manifold for A3 heads and shop that can bung it for EFI

Thats no heap its a proper Classic car, my lad has bought a Mercury station wagon showing 20K miles, engines buggered but another piece of history.

When there gone there gone, good luck with your repairs bets Pete

I've had four of those intakes. The last one sold about a year ago for $850.

A 2v intake port goes the wrong way. It would never fit.

I don't know what the Cook ports look like. I don't know anyone who has one to look at.

At one point I took a regular Torker and epoxyed up the ports. There was a slight mismatch on the top of the A3 port since it was raised almost 1/4" from the stock 4v location.

There is a 5/8" difference in port floor heights.

If you're going to weld the FI bungs on, you could have the ports welded up also instead of epoxy.

You can reduce that by about 1/8" on by porting the top of the Torker port.

Used Torkers are pretty easy to find.

Here's the A331 manifold compared to a 2V intake gasket. Notice how the manifold's runners "peek" above the top of the 2V gasket.

Here's the A331 manifold compared to a 4V intake gasket. The manifold's runners are just "a bit" higher than the top of the gasket.

Here's the A331 manifold compared to a C302 gasket (Fel Pro 1265). Manifolds designed for the B351 and C302 heads can be easily opened up to mate with A3 heads.

The Scott Cook dual plane manifold will mate with an A3 head.

However, if it were me, I'd choose the CNC Trick Flow heads and their long runner fuel injection intake. The Trick Flow heads have a better combustion chamber than the SVO heads, and great low lift flow due to that combustion chamber. The CNC ported versions flow well up to 0.600" lift. Since FI is your goal, the Trick Flow long runner FI intake is far better at doing that job than a single plane carburetor manifold (longer, equal length runners).

There will also be off-the-shelf headers available for the Trick Flow heads in your Cougar's engine compartment. No such thing for the A3 style exhaust ports.

quote:

Originally posted by Looftie:
I am in the process of buying a virgin set of A3 heads for a mild turbo/EFI 351C that I am building for my 1973 Mercury Cougar convertible.

How much boost? Intercooled? What static CR are you targeting? Automatic (what stall) or stick? What rear end gear?

Best,
Kelly

Thank for the info, Doug. That's an excellent suggestion regarding using a standard 4V Torker and welding up the port floors since I'm going to have to have it modified for port fuel injection anyway.

Now that I think about it, if I went that route, I could just look at other intakes as well. For a 4v head application that probably wont be pushed past 6500RPM, is a Torker still the way to go or is there something better suited to street/occasional drag strip use?

quote:

Originally posted by PanteraDoug:
I've had four of those intakes. The last one sold about a year ago for $850.

A 2v intake port goes the wrong way. It would never fit.

I don't know what the Cook ports look like. I don't know anyone who has one to look at.

At one point I took a regular Torker and epoxyed up the ports. There was a slight mismatch on the top of the A3 port since it was raised almost 1/4" from the stock 4v location.

There is a 5/8" difference in port floor heights.

If you're going to weld the FI bungs on, you could have the ports welded up also instead of epoxy.

You can reduce that by about 1/8" on by porting the top of the Torker port.

Used Torkers are pretty easy to find.

George,
Thank you for sharing all of those pictures. That really drives the point home. It's been a long while since I had a close look at a 4v head and intake (I used to have an M-code '71 Cougar convert). I forgot that the top of the 4v ports is also quite a bit higher as well as lower than the 2v port. That 2v gasket is a huge mismatch on the A3 intake.

Is it typical that the A3 intakes have such narrow ports or is yours possibly the Roush A331 casting?

I saw a picture recently of an Edelbrock casting of the A331 (unported) and it looked like the port size and shape almost perfectly matched the A3 head.

quote:

Originally posted by George P:
Here's the A331 manifold compared to a 4V intake gasket. The manifold's runners are just "a bit" higher than the top of the gasket.

The A3 head intake port is really the same width as the 4v port but the roof is raised about 1/4" and the floor is raised about 5/8".

It resembles a BB Chevy rectangular port head.

The 2v port goes the wrong way. It really is lowered in relation to a 4v and forget about it with an A3.

The casting of the bottom of the A3 head is different then the 4v is. You need to fill in the bottom of the intake port just so it will seal against the A3.

All things considered, George's suggestion of using a different head all together is a very good suggestion.

I don't know what you are getting those heads for but you are going to find that they are VERY easy to sell and in fact might even have people coming to the door and refusing to leave until they cut a deal for them.

The intake has always been the issue for them.


Here's a thought, you could go to a Weber intake. Hall Pantera already has those that will bolt right up to the heads with little or no port matching.

Then you could go to individual runner fuel injection. Those throttle bodies are already available off the shelf now.

If you still wanted to use the blower, then you would just have to plumb the blower to a common air cleaner or air chamber.


It sounds more involved but you could actually wind up being cheaper to go that route.

Modifying a used Torker would probably be the most economically solution over all though.


The A3 heads, although quite good for their time, and actually still quite good now, are more of a collectors item these days.

Most don't even know what we are talking about when they are mentioned now.

They are 1981-3 racing items and some here weren't even born yet then.


On that thought, I sold A3's to what he described himself as, "an engine builder". When he got them, he got on the phone and claimed that I misrepresented them.

These things were virgin, virtually out of the box. He told me they were "radically modified". Now this is a "Ford Engine Builder"?

Seems he didn't know what an A3 head was and thought that was some sort of a generic term for a C302B head.


That "small port" A331 intake manifold that George posted with the C302 gasket on it was probably mine and those are the size of the ports the "builder" expected?

Oye carumba...kids!


Oh, just in attempting fairness to all, some will say the C302B head flows much better after it is ported.

I'm not going to deny that BUT the sets that I have seen AFTER they have been "done" bear a very very similar appearance in port dimensions to the stock A3.

Now that's just my observation which obviously I could not have seen all but inside secretly I'm laughing.

Kelly,
I haven't really set a limit on boost yet. My long-term goal is 500whp (650ish at the crank) at ~6-65000rpm on an interia-style chassis dyno. The bottom end is currently a 20-30k mile stock rebuild so I'm going to crawl into boost, rev limit to around 5800rpm and settle on lower power until I can put a set of forged pistons with some nice, beefy ringlands inside and maybe a 393 or 408 storker crank to help the turbo spool.

Based on previous turbo projects, I used a recent machine shop check of my heads as an excuse to put down a set of Cometic MLS gaskets and ARP head studs. I doubt I will need them just yet but both parts will be reusable when I go through the short-block.

For my larger goal, the boost required to get there is going to depend on how well my heads, intake and cam are matched and how well my charge piping and exhaust piping are sized/plumbed (among other things like charge density). My plan was to use my stock 2v heads (new guides, seats, springs match to cam, stainless 1-piece valves, unported) as a baseline to see if I can hit my number on pump gas. If I can't, the injectors and fuel pump are sized for and compatible with E85. Switching to that will give me better detonation resistance and a massively improved latent heat of vaporization. Plus, it's cheap race gas in the midwest. I'm running a -10 supply and -8 return which should be overkill at my power goal, even when a conservative BSFC for a turbocharged E85 application is used.

After I find out what the 2v heads can do, it was my intention to switch to a better flowing aluminum head. My hope was that I would gain improved detonation resistance and hopefully hit the same power/torque numbers on lower boost. Area under the curve is another story. I've accepted the fact that after all the A3 effort, the 2v heads might still be a better fit for my mostly street car application.

I am actually working on the intercooler support brackets right now. Since a restraint I set was not cutting the car's chassis (no shock tower delete and Mustang II suspension swap), I decided to go the air-to-water route. I couldn't make the 2.75" OD tubes that I calculated necessary fit in front of the radiator without some convoluted piping arrangement that snakes under the radiator. Moreover, any air-to-air core that I managed to make fit would have to be undersized or very thick because there is not much room vertically or left to right.

The heat exchanger I chose is a crude looking, cheap aluminum core shaped like a shoe box. The brand (Frozen Boost, ChiCom stuff) has excellent reviews from folks on theturboforums, yellowbullet and others. It is alleged to have a ~0.2psig drop at its 600hp rating (I'm skeptical and plan to test with PTs and thermocouples).

Static CR is not precisely known. The engine was rebuilt when I was a snot-nosed teenager with more car ego than knowledge or experience. I found the original machine shop build slip but even they didn't know what the CR was. The pistons they chose were Sealed Power 30-over replacements for a stock H-code Cleveland. They are cast which makes them a time bomb. My assumption based on the minimal decking needed for the block and heads is that I am probably no higher than 8.5:1 based on my head castings and '73 h-code specs (8.0:1).

Dynamic CR is another matter. I wasn't content with the Crower Baja Beast cam that was originally installed so I swapped it for an Ultra Beast (220/226 dur, 0.529"/0.540" lift) before I committed to turbocharging this engine. I think the overlap is too much for my static compression and might lead to reversion issues with my turbo. It was a boneheaded choice on my part but I still want to see how it does. A mild hydraulic roller will be in the final setup.


Right now the car has a stock FMX and set of 3.89s with a PowerTrax locker. The locker is awesome for laying even stripes but as a middle aged guy, I can no longer stand the clicking around corners. It's being replaced with a Traction Loc or aftermarket LSD.

I was going to go back to milder gears with a built 3-speed auto (probably not an FMX) but I am now leaning towards keeping them and swapping to a built 4R70W with a Baumann controller. Converter stall speed is still an unknown. Transmission tech isn't my strongest suit. I'd like it to be electronically locking if the two-piece input shaft will allow at my target power level.

Sorry for the novella. I love talking about this stuff and I know from years of lurking on this forum that you guys are a very knowledgeable set.

quote:

Originally posted by Panterror:

quote:

Originally posted by Looftie:
I am in the process of buying a virgin set of A3 heads for a mild turbo/EFI 351C that I am building for my 1973 Mercury Cougar convertible.

How much boost? Intercooled? What static CR are you targeting? Automatic (what stall) or stick? What rear end gear?

Best,
Kelly

I appreciate your input. You definitely raise good points. In your estimation, what would a set of virgin A3 heads typically go for (before shipping)?

I've seen two sets recently but the one on ebay a couple of weeks ago scared me away (guides were knocked out, one chamber was missing valve seats and had been peened around both seats).

I'm not 100% set on the A3s. Trickflow, CHI or AFD might end up being a bit cheaper to get up and running and probably have a better combustion chamber design. I don't normally flip Cleveland stuff but if there is value, maybe.

There is just something about the A3s being a Ford Motorsport part and having some of the '70s prostock "fixes" that appeals to me. It's probably not the most practical choice for me. In an alternate universe, had the Cleveland not been axed, I could see it eventually going to a production aluminum head with raised ports (maybe not as big as an A3 though).

quote:

Originally posted by PanteraDoug:
The A3 head intake port is really the same width as the 4v port but the roof is raised about 1/4" and the floor is raised about 5/8".

It resembles a BB Chevy rectangular port head.

The 2v port goes the wrong way. It really is lowered in relation to a 4v and forget about it with an A3.

The casting of the bottom of the A3 head is different then the 4v is. You need to fill in the bottom of the intake port just so it will seal against the A3.

All things considered, George's suggestion of using a different head all together is a very good suggestion.

I don't know what you are getting those heads for but you are going to find that they are VERY easy to sell and in fact might even have people coming to the door and refusing to leave until they cut a deal for them.

The intake has always been the issue for them.


Here's a thought, you could go to a Weber intake. Hall Pantera already has those that will bolt right up to the heads with little or no port matching.

Then you could go to individual runner fuel injection. Those throttle bodies are already available off the shelf now.

If you still wanted to use the blower, then you would just have to plumb the blower to a common air cleaner or air chamber.


It sounds more involved but you could actually wind up being cheaper to go that route.

Modifying a used Torker would probably be the most economically solution over all though.


The A3 heads, although quite good for their time, and actually still quite good now, are more of a collectors item these days.

Most don't even know what we are talking about when they are mentioned now.

They are 1981-3 racing items and some here weren't even born yet then.


On that thought, I sold A3's to what he described himself as, "an engine builder". When he got them, he got on the phone and claimed that I misrepresented them.

These things were virgin, virtually out of the box. He told me they were "radically modified". Now this is a "Ford Engine Builder"?

Seems he didn't know what an A3 head was and thought that was some sort of a generic term for a C302B head.


That "small port" A331 intake manifold that George posted with the C302 gasket on it was probably mine and those are the size of the ports the "builder" expected?

Oye carumba...kids!


Oh, just in attempting fairness to all, some will say the C302B head flows much better after it is ported.

I'm not going to deny that BUT the sets that I have seen AFTER they have been "done" bear a very very similar appearance in port dimensions to the stock A3.

Now that's just my observation which obviously I could not have seen all but inside secretly I'm laughing.

I was pretty excited when I saw that Trickflow finally came out with the EFI Cleveland intake based on the 5.0 long-runner design. I bought my current setup a few years before that but I briefly considered selling it in favor of the then-new TF setup.

Unfortunately, I don't think it will clear my hood. The 75/90mm R-series are 11.0" tall from block to top. The the Box-R-Series are 12.0". It's been a while since I checked but I seem to recall having around 9" from the block to the stamped steel reinforcement in my hood. If the entire middle section of my hood was at the same height as the ram-air cutout, I think the R-series option would work.

quote:

Originally posted by George P:
The Scott Cook dual plane manifold will mate with an A3 head.

However, if it were me, I'd choose the CNC Trick Flow heads and their long runner fuel injection intake. The Trick Flow heads have a better combustion chamber than the SVO heads, and great low lift flow due to that combustion chamber. The CNC ported versions flow well up to 0.600" lift. Since FI is your goal, the Trick Flow long runner FI intake is far better at doing that job than a single plane carburetor manifold (longer, equal length runners).

There will also be off-the-shelf headers available for the Trick Flow heads in your Cougar's engine compartment. No such thing for the A3 style exhaust ports.

[QUOTE]Originally posted by Looftie:
I appreciate your input. You definitely raise good points. In your estimation, what would a set of virgin A3 heads typically go for (before shipping)?

I've seen two sets recently but the one on ebay a couple of weeks ago scared me away (guides were knocked out, one chamber was missing valve seats and had been peened around both seats).

I'm not 100% set on the A3s. Trickflow, CHI or AFD might end up being a bit cheaper to get up and running and probably have a better combustion chamber design. I don't normally flip Cleveland stuff but if there is value, maybe.

There is just something about the A3s being a Ford Motorsport part and having some of the '70s prostock "fixes" that appeals to me. It's probably not the most practical choice for me. In an alternate universe, had the Cleveland not been axed, I could see it eventually going to a production aluminum head with raised ports (maybe not as big as an A3 though).

[QUOTE]

FYI, the b351 head is a smaller port version. It probably would be a better street head. It is more specifically tuned to the 351 then the A3 is. It was designed to use smaller valves though.

Some would say the C302 versions would be best for the street but if you look at the port size they are very close to the port dimensions of a 302W head. I think you need a flow bench, a GREAT grinder to get them to work?



I would think that your A3 heads would be in the value range of what a current good set of top aftermarket heads bring? MAYBE more because of the Ford oval thing? Unfortunately for buyers, talk on this forum about them has perked a lot of interest and probably spiked the value just a bit? I am guilty of that as well.

I can't answer other than that. If my set needed to be replaced, I'd be interested but having said that, mine came off of a circle track race car and had already been prepared for that.

For one thing they were shaved in order to get the chamber volumes down to 60. So I'd have some work to do on brand new box stock heads.

They DO need some relatively minor work done to them like shaving them in my opinion.



Maybe put them up for sale here for "best offer"?
See if that brings you an offer that you can work with to switch heads?

Incidentally, I agree with you on having the Ford oval on the part. To me it's a plus. Not everyone cares about that though? They are seemingly developing a reputation making them more desirable similar to the 427MR & HR heads?



OOOOH! One other thing, the headers for these heads in your chassis may in fact qualify as a "nightmare".

I had these in my 68 GT350 and the headers had to be hand made.

I CAN tell you that Jay Bittle, aka, JBA, DID in fact make a set for that application and that if you call them the part number is still good BUT don't count on them having any? Just another consideration.

Those exhaust ports on all of those heads, i.e., A3, B351, C302 are all raised A LOT from the original 4v iron heads, and the angle of the port is UP, not down.

That takes some finagling to get right. Mostly the chassis is going to make you turn the exits as straight down as you can. A 1.71 exhaust valve needs a 2" primary tube. A 1.60 like on a C302 head would use a 1.75" primary tube.

Exactly how you are going to get 2" primary tubes on THOSE headers to fit that chassis is going to be like being an alchemist?



The original flow numbers test on the exhausts used a 3" radius stub tube(as I remember). The ironic thing about that though is that they flowed better that way then with a straight out "gasser" type of exit.

The point is that the "high port" aluminum heads of that series (of which the A3 is one) will work much better in a car like a Pantera then a Mustang/Cougar simply because you can do more with the exhausts in the Pantera.

The Mustang/Cougar chassis is VERY LIMITING to the headers and will negate getting the maximum from the exhaust port improvements of the head.

Most of the improvement provided with that head is from the significantly better exhaust ports vs. the 4v iron heads.

You just can't take an existing set of headers for a 351-4v in that car, and change the flanges and expect them to bolt up. For one thing you won't find pre-made 2" primaries. 1-3/4", yes.



Lastly, the A3's show that they work better with more cubes like a 383, etc, then a 357. Frankly for me though, you won't hear any complaints here.

What ALL the NUMBERS showed was that the B351 head was noticibly better. For me, they noticibly sucked. The A3 was better. Not just a little. Quite a bit but then again I liked the Torker with a 750 DP Holley BUT the Torker LOVES a 12.0:1 engine. I can't do that any more.

Keep in mind though that all of this information just proves to many others that I am loosely hinged in reality which really is good for me. They are all afraid to talk to me and leave me the F... alone. That definitely CAN have benefits. So just take this all with a grain of salt.

Just food for thought?

quote:

Originally posted by Looftie:

... Is it typical that the A3 intakes have such narrow ports or is yours possibly the Roush A331 casting ...

The manifold in the pictures is a standard off-the-shelf example of the Edelbrock Torker version of the A331 manifold, its not a narrow port anything, its not the manifold I acquired from Doug.

quote:

Originally posted by George P:

quote:

Originally posted by Looftie:

... Is it typical that the A3 intakes have such narrow ports or is yours possibly the Roush A331 casting ...

The manifold in the pictures is a standard off-the-shelf example of the Edelbrock Torker version of the A331 manifold, its not a narrow port anything, its not the manifold I acquired from Doug.

Everything I previously typed somehow got deleted.

Here's a picture of the A3 intake next to the A3 heads that the guy in Texas had for sale on ebay last week. It makes me wonder if there were two version of the Edelbrock A331 casting in addition to the Roush A331 casting. These ports look quite a bit different than yours. They look more like this one:
http://351cleveland.wikifoundry.com/page/M9424-A331

I obviously have a lot to learn about these old school speed parts. Until a month ago, I didn't even know these aluminum heads existed. I still want to learn more about the B3s, which seem to be even less common. C3s aren't an option for me because they lose the Cleveland valve cant and require an expensive shaft mount rocker setup. I don't plan to ever pull the revs to justify such an expenditure.

Very cool stuff. I'm glad I joined this forum.

Justin

those pictures were from an old post of mine dated 2008. I was "sure" I hadn't acquired Doug's manifold yet ... but after seeing the picture you just posted, I thought to myself "yeah that's what the A331 looks like". So I double checked that old post and now I have to apologize, those pictures are indeed pictures of the small runner version of the A331 manifold, the one I acquired from Doug.

I'm getting old and forgetful. My concept of time is very bad.

It can happen to anyone George. Sometimes this stuff is confusing if the part isn't right there in front of you.

It does answer the question though, that it appears there are at least two versions of the manifold.

The only thing I would tell everyone is that particular small port is the only one I've ever seen.



Didn't Kelly Coefield in a previous post, say that in addition to the A331-A3 intake, he had one that fit the as cast B302 heads (like George's small port) plus one that fit the B351 heads but wasn't sure if that one (for the B351 heads) if that was just a small port opened up to match the B351's? Kelly?

Should we just call those A331-A3, A331-B351, A331-C302?



As I remember, that small port was about 6 or 7 pounds heavier as well because the runners were closed down so much?

As I said previously, the problem with the A3's is finding one of those manifolds to use.

A STOCK Torker closed down to match the head ports, is a very good alternative for them now.

You can use the tall spider manifold but it is not likely to fit under the hood.

I don't think either one of those "Torker" manifolds was listed in the Motorsport catalog back then either.



The ORIGINAL C302 heads used the standard Boss 302 7/16 rocker arms and studs, not the shaft mounted rockers.

Here's a complete set up for sale somewhere in the past,

http://forums.corral.net/forum...svo-a351-intake.html

They show studs, not shafts.

I think these are getting confused with the Yates heads? Those use the shafts instead of studs.

IF you were interested in this set of heads, you want to see what the intake ports look like.
Why the seller didn't post pictures of those, I don't know.

Things like this/that tend to show the misunderstanding of even what the owners of the parts know about the parts. I'm afraid that the Chevy people have seriously infiltrated our ranks for the purpose of just creating confusion amongst the most vulnerable of the Ford newbies?

Here's a picture of the Yates C3 head. It IS NOT the same head.
It is made for NASCAR and to optimize those engines for NASCAR rules restrictions.