Winfield head question

adavis

adavis

Senior Member
I run a Winfield aluminum head on my model B engine and I'm wondering if anyone would happen to know what 03-113 stamped on the "pad" on the top of the head means? I've read that the compression ratio is sometimes stamped on the pad, so does 03-113 somehow translate to compression? Just wondering. Thanks.
 
Yours is a repro from Speciality Ford Parts in Rosemead, CA. It was made in 2003, #13 in that year. In original Winfield heads the first numbers on the pad indicated compression ratio. The Speciality heads were of good quality too.
 
Thanks for the info! Any chance they have records of compression ratios? I'm going to cc the head tonight. How does one calculate the compression ratio with that info?
 
adavis said:
Thanks for the info! Any chance they have records of compression ratios? I'm going to cc the head tonight. How does one calculate the compression ratio with that info?
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If you would take the time to call Specialty Ford Parts they could tell you the original compression ratio based on the numbers stamped in the head
 
The number that I'm finding on Google for Specialty Ford Products rings to a fax machine. Anyone have a good number for them?
 
adavis said:
I'm going to cc the head tonight. How does one calculate the compression ratio with that info?
Click to expand...


If you had left the head installed on the engine it would be more accurate and easier to calculate the compression ratio as it would take into account many things that you must now calculate if you want the correct compression ratio for your particular engine; such as the bore and stroke, the volume of an irregular shaped head gasket while under compression and the deck height or in other words the distance that the piston may or may not rise above the block gasket surface at Top Dead Center.

But, with head off you can get pretty close except you might have difficulty determining the volume of the head gasket since it is an irregular shape and even though an old gasket is flatter than a new one of like kind, it's not in its compressed state, exactly, once it's been removed.

First, determine the volume of your cylinder head's combustion chamber in cc's. Next determine the volume of your head gasket in cc's. Take these amounts in cc's and convert them to cubic inches by multiplying by .0610237. If you don't do this then you will have to convert the following calculated volume totals to cc's.

Next determine the volume of your cylinder by multiplying 1/2 of the bore diameter in inches times itself or in other words the radius squared. Take the answer and multiply it by 3.1415927 or in other words pi. Take the answer and multiply it by the stroke in inches.

Next, use the figure obtained above from multiplying 1/2 the bore diameter times itself times pi and multiply that number by the distance that your piston rises above the block surface at TDC. This will be the volume that is occupied by that part of the piston as it rises up in the combustion chamber.

It is possible that your piston may be flush or even with the top of the block but not likely unless the engine rebuilder who last rebuilt the engine made it that way. Moreover, it is also possible but highly unlikely that your piston comes out slightly below the block surface. In fact, there's almost a guarantee that your piston rises above the block surface because when the engine was brand new, using original length pistons, they rose above the block .031". In addition, if still using original length pistons, there's a good chance that your piston will be higher than .031" since most blocks have been resurfaced a time or two or three or .....? The volume of the area occupied by the piston above the deck is shown in the calculation below at a height of .045".

Also, if you really want to fine tune it then determine the volume of the area occupied by the valves as they sit above (or maybe below) the deck when they are closed. This amount generally would not be much on most Model A's, maybe a cc or two, but it would still add a tiny bit to the accuracy.

Now lets show an example of a slightly hopped up Model A engine with a standard bore and stroke of 3 7/8 x 4.25 and a guess at the gasket volume while under compression using the following figures:

Combustion chamber volume = 130cc = 7.93 cubic inches
Gasket volume = 18 cc = 1.10 cubic inches
Volume of the cylinder w/standard bore/standard stroke = 50.12 cubic inches
Volume of the area occupied by the piston above the deck @ .045" = .531 cubic inches

7.93 + 1.10 + 50.12 - .531 = 58.619 cubic inches

7.93 + 1.10 - .531 = 8.499 cubic inches

58.619/8.499 = 6.9 to 1 compression ratio
 
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Here is a site to calculate the compression ratio. http://www.csgnetwork.com/compcalc.html
Put a zero in the gasket thickness box, and add 16 cc to the combustion chamber volume to account for the gasket thickness. That is pretty close. Also, the stock pistons had .031 pop up. That has probably changed over the years if the block has been milled.
 
Thanks for the help everyone. I called Specialty this morning and he thinks its a 6.5:1.

edmondclinton.....when I use your calculation I come up with 7.5:1. I'm guessing it is because I'm not getting correct numbers on the cc amount. I took a flat piece of glass and drilled a small hole in the middle. Then I put a THIN layer of lubriplate all around the #1 cylinder pocket on the head and layed the glass down on it. I took a syringe filled with alcohol that I dyed red with food coloring and filled it up, but I keep getting an air pocket. I'm guessing I'm doing something wrong??? The cc amount I come up with is 118 but I'm guessing that air pocket is accounting for a lot of cc's.

PC/SR.....when I plug the same numbers in to the website you linked I get almost 10:1, which really freaks me out! I must be entering something in wrong.

If anyone wants to see what they come up with, my engine is bored .100 and I get somewhere north of 118cc. I layed a straight edge across the piston top at TDC and it and I could fit a .020 feeler gauge under each side of the straight edge on #1....only a .018 on #2. I have read several places that stock pistons are supposed to be .031 above the deck so I'm not sure what's going on there. I'm using a BEST head gasket.

Thanks again everyone.
 
Here are a couple pictures of the head I'm working with. The shiny spots in the pockets are where I used a flap disc to clean up some of the rough casting.....

As you can see, the relief cut for the piston is still very much there so I'm ASSUMING not much if any has been taken off the stock head. The person I got the head from said it was completely stock.....
 

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adavis said:
Thanks for the help everyone. I called Specialty this morning and he thinks its a 6.5:1.

edmondclinton.....when I use your calculation I come up with 7.5:1. I'm guessing it is because I'm not getting correct numbers on the cc amount. I took a flat piece of glass and drilled a small hole in the middle. Then I put a THIN layer of lubriplate all around the #1 cylinder pocket on the head and layed the glass down on it. I took a syringe filled with alcohol that I dyed red with food coloring and filled it up, but I keep getting an air pocket. I'm guessing I'm doing something wrong??? The cc amount I come up with is 118 but I'm guessing that air pocket is accounting for a lot of cc's.

PC/SR.....when I plug the same numbers in to the website you linked I get almost 10:1, which really freaks me out! I must be entering something in wrong.

If anyone wants to see what they come up with, my engine is bored .100 and I get somewhere north of 118cc. I layed a straight edge across the piston top at TDC and it and I could fit a .020 feeler gauge under each side of the straight edge on #1....only a .018 on #2. I have read several places that stock pistons are supposed to be .031 above the deck so I'm not sure what's going on there. I'm using a BEST head gasket.

Thanks again everyone.
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Using your figures I got 7.55 to 1.

Your compression ratio will only be 6.5 to 1 if your bore and stroke are standard and the deck height is exactly stock and all are as they were when new from Ford. Plus, the same gasket the Winfield manufacturer used or whoever did the measuring. Your engine has been bored out and your deck height is less than .031” assuming you rotated the engine to TDC correctly. You also need a depth mic to measure from the top of the piston to the block. Or a bar device with a dial indicator made for this purpose. It all depends on how accurate you want to be.


The calculation on my post was just to show how to do it. The cc number was not a number for any particular head.


Try your measurement routine over again and use a solution like naptha, for example. Also, make sure the head is level in all directions. Lubriplate is a little thin but may be ok as long as the solution doesn’t seep. I use wheel bearing grease smeared thinly under my glass with great results.


Also, it’s kind of hard to be accurate with a little syringe but if that’s all you have then so be it. You really need a measurement device known as a burette.

If you want the most accurate method then put the head and gasket on the engine, torque it down and use a light oil to measure the combustion chamber volume and the cylinder volume by pouring the oil through the spark plug hole. If you want to do this then ask and I will explain it. It's really quite simple and it also takes into account the shape of the head gasket, being irregular, and its volume under compression, the piston above the deck and maybe a cc or two reduction or addition occupied by the valves.
 
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When you figured the head CC's did you also figure the gasket thickness into the volumn? You need to add the gasket thickness and subtract any piston displacement above deck height. Also add or subtract for the valves being above or below deck height.
 
Tom Wesenberg said:
When you figured the head CC's did you also figure the gasket thickness into the volumn? You need to add the gasket thickness and subtract any piston displacement above deck height. Also add or subtract for the valves being above or below deck height.
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Also, with the piston at TDC, the volume between the piston and the cyl wall from the top of the block to the top of the top ring.
 
If Specialty said 6.5 to 1 I would go with that. They have no idea if the head has been milled or heavily surfaced. There is a dimension given some where's for the thickness of a stock head. I measure a known stock head and use that in approximating how much the suspect head might have been milled. In my experience some of the heads didn't quite measure exactly what was advertised. One thing about the heads is that they are a good performing head producing good power. We won the SP1 class at the Murrieta 2014 hillclimb with one on our engine.

IMO this is being reengineered to death here.
 
just plain bill said:
If Specialty said 6.5 to 1 I would go with that. They have no idea if the head has been milled or heavily surfaced. There is a dimension given some where's for the thickness of a stock head. I measure a known stock head and use that in approximating how much the suspect head might have been milled. In my experience some of the heads didn't quite measure exactly what was advertised. One thing about the heads is that they are a good performing head producing good power. We won the SP1 class at the Murrieta 2014 hillclimb with one on our engine.

IMO this is being reengineered to death here.
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If they told you that it was 6.5 to 1 and in reality the ratio was closer to 7.5 to 1, wouldn't you want to know that?
 
edmondclinton said:
That's going a little overboard don't you think?
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IMO, that is the point of his post, i.e.-overboard already :) ! I guess it depends on how technical a guy you are,eh !

Yeah, I'd like to know what comp ratio I'm buying when purchasing a head !
Read the previous post referenced by Juggler, particularly #9 where Jim B states that he measured/ccd a supposedly 8:1 alum Winfield repop and found it to be 10:1 comp ratio :eek: !

Post #10 is where I was at Specialty Ford within that week, and spoke with owner (Jim) while looking over the Winfield alum heads that he had on stock. I asked Jim about the comp ration of the few heads (on the shelf) that we were discussing. He stated simply that...'don't know what comp ratio those are' ! I said, well how is a guy to know what repop alum head to ask for by looking...he just shrugged :rolleyes: ! And, so do you care about what comp ration head that your paying for...your call. Heck yeah, in my case. That's why I'm buying from Tod when his IRON Winfield heads are ready. I have every confidence that if I order an 8:1 cr from Tod, that that's what I'll get...and with extra support ribs and THICKERER deck :)!

BTW...NO comp ratio is stamped on the alum repop Winfields. Sooo , like Jim B says....cc those heads to be sure.
 
hardtimes said:
IMO, that is the point of his post, i.e.-overboard already :) ! I guess it depends on how technical a guy you are,eh !

Yeah, I'd like to know what comp ratio I'm buying when purchasing a head !
Read the previous post referenced by Juggler, particularly #9 where Jim B states that he measured/ccd a supposedly 8:1 alum Winfield repop and found it to be 10:1 comp ratio :eek: !

Post #10 is where I was at Specialty Ford within that week, and spoke with owner (Jim) while looking over the Winfield alum heads that he had on stock. I asked Jim about the comp ration of the few heads (on the shelf) that we were discussing. He stated simply that...'don't know what comp ratio those are' ! I said, well how is a guy to know what repop alum head to ask for by looking...he just shrugged :rolleyes: ! And, so do you care about what comp ration head that your paying for...your call. Heck yeah, in my case. That's why I'm buying from Tod when his IRON Winfield heads are ready. I have every confidence that if I order an 8:1 cr from Tod, that that's what I'll get...and with extra support ribs and THICKERER deck :)!

BTW...NO comp ratio is stamped on the alum repop Winfields. Sooo , like Jim B says....cc those heads to be sure.
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Technical to some but not so much to others. The volume occupied between the top ring and the top of the block and the cylinder wall would be insignificant for the purpose of figuring compression ratio and would change once the engine was at full operating temperature.

I might be interested in buying one of Tod's heads too but not because he makes a few posts on a message board. I would not buy any part made for a Model A engine that deals with the performance until they were tested and proved on the road even if the part is a copy of other's work. I spent many years in foundry practice and I know about the difficulty in producing water-jacketed castings or any casting that has a lot of intersections of thick and thin and/or hollow cavities.
 
Well, I have no reason to question the experience and knowledge that you say that you've gained. Sounds like any such knowledge would be beneficial to you , as a consumer. And, also beneficial to Fordbarn members generally.
No one will try to sell you or anyone else here, heads or other equipment. Sure Tod has made posts here...at other members behest and request. He has openly shared his knowledge/skills , which are abundant ! We are , indeed, fortunate to have him as a member...period. However, Model A / B engine owners here/otherwise have been using Tod made heads and other equipment (unknowingly) for years and are very happy to do so ! Re-read some of his 'few' past posts and you will see what I'm talking about.
Tods' services/skills at making blocks, heads and manifolds for racers and for us antique guys is well known before he ventured here as a member.

I do not doubt, for a moment, what you say about it not being easy to do such work...successfully. I think that even you might be surprised at the list/number of people/companies that seek out Tod for his expertise and success at what he does.
Otherwise , we all might be doing IT, if it was easy. We here have only had one other guy to make IRON heads for our A/B engines. He was a one man company and was , IMO, hounded/driven away from continuing to make heads for us. I think that Tod can and will make us heads and blocks that we will be willing to pay good money for! Let's all try to support him and his efforts :).
 
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