A head question

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Odmark

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Hello! I have gotten the oppurtunity to buy a set of fully rebuilt 4V wedge heads for about 160 dollars.

P

The only thing is, the heads are milled down 2mm. So the combustion chambers are 56cc.

How will this work on my street motor with flat top pistons? 

Really appreciate quick answers.  :)

 
Last edited by a moderator:
Hello! I have gotten the oppurtunity to buy a set of fully rebuilt 4V wedge heads for about 160 dollars.

P

The only thing is, the heads are milled down 2mm. So the combustion chambers are 56cc.

How will this work on my street motor with flat top pistons? 

Really apapreciate quick answers.  :)
Click to expand...
Compression will be too high for pump gas with flat top pistons. you would need to go with a deep dished piston to get compression to a reasonable level.  I used a set of Aussie Ford 351C 2v closed chamber 58cc heads with a set of DSS Racing 4653X-4030 GSX -18cc Dish 4.030" Forged Pistons. with good results.

 
How are they milled ? both side ?

They same guy also sells open chamber 4v heads, could be something to mill down to 67-68 cc

Regards Rob

 
Rackern: As i expected, that was my concern.

Luke: Yes we have 98 octane, and E85.

Robsweden: Oh youve seen the ad as well :D i havent talked to the guy yet so i dont know, but i think ill pass anyway. I dont have any interest in the open chamber heads though. I rather mill my 2V heads in that case :)

 
Thats Cool, Il milled my 2v heads and they are enough for me in a street car :D

 
Correct me if I'm wrong, but would milling as much as 2mm off the face of the heads completely misalign the intake ports to the intake manifold? That's an .080" drop. Isn't the port matching based on a .040" gasket? If I'm right, then the intake would need to be re-matched, more work than necessary for a street car. I can see radical work for a race engine, but then that's a whole different ball game.

I don't think I would go more than clean up cut on the heads as then you have to consider push rod length changes as well. As for Aussie heads, would these have been cast with smaller chambers rather than milling, therefore they are the same thickness as 4V heads? Yes, no, maybe?

As for gas octane in Europe, and again I could be wrong, but from what I remember, European octane calculations are not the same as in the US and Canada. I know the UK's "regular" gas is 91 octane. So 98 might not be any different to 93 or 94 available here. I wish we DID have high octane fuel here, but that is not what the EPA want so we're s.o.l.

 
Correct me if I'm wrong, but would milling as much as 2mm off the face of the heads completely misalign the intake ports to the intake manifold? That's an .080" drop. Isn't the port matching based on a .040" gasket? If I'm right, then the intake would need to be re-matched, more work than necessary for a street car. I can see radical work for a race engine, but then that's a whole different ball game.

I don't think I would go more than clean up cut on the heads as then you have to consider push rod length changes as well. As for Aussie heads, would these have been cast with smaller chambers rather than milling, therefore they are the same thickness as 4V heads? Yes, no, maybe?

As for gas octane in Europe, and again I could be wrong, but from what I remember, European octane calculations are not the same as in the US and Canada. I know the UK's "regular" gas is 91 octane. So 98 might not be any different to 93 or 94 available here. I wish we DID have high octane fuel here, but that is not what the EPA want so we're s.o.l.
Click to expand...
Yes. The Aussie heads were essentially the same as the poorly designed 2v open chamber heads, but instead had 58cc closed chambers thus eliminating the deficiencies found with he open chamber heads. The ports were essentially identical to the open chamber 2v, so they bolt nicely up to the standard 2v intake and exhaust.

A side note Ford Racing made a 351C 2v 62cc closed chamber head back in the 80s, but it very hard to find them today. Part Number: M-6049-C351, essentially a BOSS 302 head for a 2v Cleveland with a chamber size of 62cc

 
Correct me if I'm wrong, but would milling as much as 2mm off the face of the heads completely misalign the intake ports to the intake manifold? That's an .080" drop. Isn't the port matching based on a .040" gasket? If I'm right, then the intake would need to be re-matched, more work than necessary for a street car. I can see radical work for a race engine, but then that's a whole different ball game.

I don't think I would go more than clean up cut on the heads as then you have to consider push rod length changes as well. As for Aussie heads, would these have been cast with smaller chambers rather than milling, therefore they are the same thickness as 4V heads? Yes, no, maybe?

As for gas octane in Europe, and again I could be wrong, but from what I remember, European octane calculations are not the same as in the US and Canada. I know the UK's "regular" gas is 91 octane. So 98 might not be any different to 93 or 94 available here. I wish we DID have high octane fuel here, but that is not what the EPA want so we're s.o.l.
Click to expand...
Yes. The Aussie heads were essentially the same as the poorly designed 2v open chamber heads, but instead had 58cc closed chambers thus eliminating the deficiencies found with he open chamber heads. The ports were essentially identical to the open chamber 2v, so they bolt nicely up to the standard 2v intake and exhaust.

A side note Ford Racing made a 351C 2v 62cc closed chamber head back in the 80s, but it very hard to find them today. Part Number: M-6049-C351, essentially a BOSS 302 head for a 2v Cleveland with a chamber size of 62cc
Click to expand...
 Aussie heads, yes of course, a different chamber casting, but otherwise the same head as the 2V, not 4V as I wrote.

 
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Here is some information I found online regarding the Motorsports 2v heads. The catalog pics are from the Ford Motorsports catalog in 1986. Kind of cool. My guess on this based on the information here as well as some other sources is that these were essentially the same casting as the Aussie 302 2V closed chamber heads but with some slight modification to the combustion chamber around the valve area to open them up to the 62 cc.





 
Here is some information I found online regarding the Motorsports 2v heads. The catalog pics are from the Ford Motorsports catalog in 1986. Kind of cool. My guess on this based on the information here as well as some other sources is that these were essentially the same casting as the Aussie 302 2V closed chamber heads but with some slight modification to the combustion chamber around the valve area to open them up to the 62 cc.

https://ibb.co/dc738v[/URL]
Click to expand...
 


 Interesting read there Jason. Wouldn't mind a pair of them on my engine, but with a 4 V intake

 
That is basically what I am in the process of doing. Got a set of bare 2v aussie heads and had a local guy here work the heads for me. Slightly larger valves and some work on the chamber to open them up a touch, especially around the larger intake valve. Mine ended up being 60cc when finished. I am pairing them with a high lift roller cam, and a 4 bbl intake.

 
My local speed shop told me I can use a thick head gasket to knock down the compression. I built a set of Aussie heads kind of mindlessly, and they are 58cc. I can't run them as is and planned on running a thick gasket and a nasty cam. Overlap will also knock down the dynamic compression. Cometic makes up to .120 gasket I believe, which sounds ridiculous but apparently work. The downside is you lose the quench effect with the thick head gasket.

 
Last edited by a moderator:
You will get away with 11:1 comp on 98 with an iron head. More with e85. My guess is with a zero deck height and a standard gasket it would be close to 12:1. Cheap but I would probably pass. 

Also nothing wrong with open chamber V4s they will make 500+ in the right combo.

Good luck

 

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