Rare cylinder heads? Anyone?

[barnfind08]

Bought a set of flathead cylinder heads today from a older gentleman who had a lot of racing equipment. These are cast iron and center dump 24 stud and have the ford script with the part number 99A-S Never have seen any in all my scrounging. Information anyone? Thanks in advance.

[ford3]

99 a indicates a 1939 engine, the S?, i dont have a clue

[flatjack9]

For 3 3/16 bore engine (Mercury) and I believe they were a higher compression ratio.

[59ab]

"Denver" heads ????

[Lawson Cox]

Denver heads are aluminum aren't they?

[41ford1]

Sponsored Links (Register now to hide all advertisements)

99A-S are 7.1 CR heads. They are most likely one of 3 types of the infamous Denver heads. 99T are only 5.5s.

[Kube]

99as heads were made by Ford. They are as noted 7.1 : 1.
They are fairly rare.

[FL&WVMIKE]

barnfind08 ....................
I "Googled" your 99-AS heads and I found, where they had been discussed, before on FORDBARN. It seems that they are "Denver" heads and are very rare.
They are the 7.1-1 ratio and are called "cheater" heads, as they look to be stock.
MIKE

[Bruce Lancaster]

Denvers came in 81AS, 19AS, and 99AS...I have the CC spec around somewhere. The smallest chambered ones, the 81's, were 60CC.
They were listed for natural gas or high altitude use. I am pretty sure the S means something like special and is for a replacement part that was not used in actual production...
I think they were only briefly available and were discontinued before stock car racers discovered them, hence they were always rare and desirable. They weren't even cheaters, really...I think most of the stock car racer rules specified real Ford iron heads...voila!
By mid-1950's the allowable better head was the Canadian C7RA, aluminum and only slightly smaller capacity than regular 59, and these were soon joined by fake C7RA's made by Weiand with considerably smaller chambers. The Weiand ones were more or less standard equipment in the last days of flathead stock car racing.

[41ford1]

The Ford TSB for subject 6000 dated Feb., '42, has the table for the heads. It lists the head part numbers, associated CRs and chamber volumes. It shows 3 part numbers with the A-S suffix. All 3 have CRs greater than 7:1.

[Bruce Lancaster]

Like the heads, the specs are rare! In the Service bulletins, pages were to be replaced when a new sheet was sent out, and the S heads were dropped in later bulletins...so most sets of bulletins lack those specs.
I found an elderly Canadian bulletin listing out all the early V8 heads, USA and Canadian, with CC specs and computed CR's for use on both 221 and 239 engines regardless of original application.

[barnfind08]

W/V/FLA MIke thanks so much for the ride in your phaeton it was indeed an honor. Took a lot of pictures of the interior details and you have a great collection of some cool stuff.

[SUHRsc]

I found a pair of 81S-B heads at Hershey this year.... anyone have any specs on them?
I'd guess maybe the same as the 81AS?

thanks
Zach

[41ford1]

Those are listed as 7.5 : 1 and a chamber volume of 60 - 62 cc. These numbers are from AS6000 dated 2/6/42. Are they going in the 39 sedan delivery?

[SUHRsc]

Thank you!
I bought them just because they were there, actually. I have been looking for a few years now, through piles of rusty old heads trying to find some with an S on them. No real direct intention of them going on anything specific. But When I bought these this past week, I was thinking they would be great for my Sedan Delivery... So we'll see!

Zach

[41ford1]

I should have read you post after coffee. The numbers I gave are for 81AS heads. The 81S-B are not listed. The same 81AS nos show up in the Mercury section with a 8:1 CR. 221ci and 239ci is the difference.

[SUHRsc]

thats alright 41.... I just went to the garage and took a few photos..
A quick measurement for the depth of the combustion chamber... laying a ruler across the flat and measuring down. I got around .725 for a stock 59AB head that appears as though it may have been milled slightly??.. the 81S-B measured .500 depth, so that seems like quite a bit right there!

Here are the photos, you can see the spark plug is in a different spot slightly too

59AB - 81SB


81SB
59AB


All the rest are the 81SB heads

[Bruce Lancaster]

I haven't seen that #, but the "S" is very interesting. Go to the baby section of the drugstore, look it over for the various syringes and cups there with CC markings.
Set heads upside down and level, dump in 6o worth, and see where you are. Go on til its full and report!
This is a CRUDE CC'ng job done this way, but it WILL give you a decent approximation.
I think all the normal 81 types are way up in the 70's.

[SUHRsc]

I will try to do that at some point Bruce... I know the photos don't show it well but it appears like its pretty drasticly smaller volume area then the 59AB head

[Tim Ayers]

Perhaps the S-B stands for Super Bad as in Super Bad hopped up mill...

I think I read that is a Ford service bulletin somewhere.