Sherman Aluminum Head ?

Ken(Ark)

Well-known Member
I see on the other board there is Sherman aluminum head for sale . The ad states the compression is too high for low grade pump gas and it pings unless the timing is retarded too much .
I thought the 9n head was 6:1 and the 8n was 6.5:1 modeled after the Sherman .
I don't see even 8:1 being an octane problem ?
 
A CR of 8:1 could very well cause spark knock on a regular fuel flat head industrial engine intended to pull hard at relatively low RPM.

Dean
 
(quoted from post at 14:58:37 02/19/15) I see on the other board there is Sherman aluminum head for sale . The ad states the compression is too high for low grade pump gas and it pings unless the timing is retarded too much .
I thought the 9n head was 6:1 and the 8n was 6.5:1 modeled after the Sherman .
I don't see even 8:1 being an octane problem ?
herman ad literature of the time period shows 7.5:1
http://www.oldfordtractors.com/acc/headlit.jpg
 
(quoted from post at 15:40:45 02/19/15)
(quoted from post at 14:58:37 02/19/15) I see on the other board there is Sherman aluminum head for sale . The ad states the compression is too high for low grade pump gas and it pings unless the timing is retarded too much .
I thought the 9n head was 6:1 and the 8n was 6.5:1 modeled after the Sherman .
I don't see even 8:1 being an octane problem ?
herman ad literature of the time period shows 7.5:1

I don't know since I have not worked on this application but I would be looking at quelch , a hot spot , or fuel ratio . Compression is your friend , I wouldn't think an aluminum 7.5 would be a problem you couldn't solve ? I don't have a dog in this fight but curious .
 
(quoted from post at 16:59:24 02/19/15)
(quoted from post at 15:40:45 02/19/15)
(quoted from post at 14:58:37 02/19/15) I see on the other board there is Sherman aluminum head for sale . The ad states the compression is too high for low grade pump gas and it pings unless the timing is retarded too much .
I thought the 9n head was 6:1 and the 8n was 6.5:1 modeled after the Sherman .
I don't see even 8:1 being an octane problem ?
herman ad literature of the time period shows 7.5:1

I don't know since I have not worked on this application but I would be looking at quelch , a hot spot , or fuel ratio . Compression is your friend , I wouldn't think an aluminum 7.5 would be a problem you couldn't solve ? I don't have a dog in this fight but curious .
arkley & Farmerdan (ntc) have them running.
 
(quoted from post at 16:02:09 02/19/15)
(quoted from post at 16:59:24 02/19/15)
(quoted from post at 15:40:45 02/19/15)
(quoted from post at 14:58:37 02/19/15) I see on the other board there is Sherman aluminum head for sale . The ad states the compression is too high for low grade pump gas and it pings unless the timing is retarded too much .
I thought the 9n head was 6:1 and the 8n was 6.5:1 modeled after the Sherman .
I don't see even 8:1 being an octane problem ?
herman ad literature of the time period shows 7.5:1

I don't know since I have not worked on this application but I would be looking at quelch , a hot spot , or fuel ratio . Compression is your friend , I wouldn't think an aluminum 7.5 would be a problem you couldn't solve ? I don't have a dog in this fight but curious .
arkley & Farmerdan (ntc) have them running.

I knew Dan has been pulling for awhile . Always glad to see his pic's . Are the Barkley's using theirs for manual labor ?

Since Dan is probably limited by pulling rules he probably has no option to make big changes in his carburetor , etc . Just wondering what options would / would not work for a working tractor . A few HP would be nice but not at the expense of premium gas .
 
(quoted from post at 17:02:09 02/19/15)
(quoted from post at 16:59:24 02/19/15)
(quoted from post at 15:40:45 02/19/15)
(quoted from post at 14:58:37 02/19/15) I see on the other board there is Sherman aluminum head for sale . The ad states the compression is too high for low grade pump gas and it pings unless the timing is retarded too much .
I thought the 9n head was 6:1 and the 8n was 6.5:1 modeled after the Sherman .
I don't see even 8:1 being an octane problem ?
herman ad literature of the time period shows 7.5:1

I don't know since I have not worked on this application but I would be looking at quelch , a hot spot , or fuel ratio . Compression is your friend , I wouldn't think an aluminum 7.5 would be a problem you couldn't solve ? I don't have a dog in this fight but curious .
arkley & Farmerdan (ntc) have them running.

Is there a modern production engine on the road today that has a compression ratio less than 8:1????

TOH
 
(quoted from post at 17:35:57 02/19/15)
(quoted from post at 17:02:09 02/19/15)
(quoted from post at 16:59:24 02/19/15)
(quoted from post at 15:40:45 02/19/15)
(quoted from post at 14:58:37 02/19/15) I see on the other board there is Sherman aluminum head for sale . The ad states the compression is too high for low grade pump gas and it pings unless the timing is retarded too much .
I thought the 9n head was 6:1 and the 8n was 6.5:1 modeled after the Sherman .
I don't see even 8:1 being an octane problem ?
herman ad literature of the time period shows 7.5:1

I don't know since I have not worked on this application but I would be looking at quelch , a hot spot , or fuel ratio . Compression is your friend , I wouldn't think an aluminum 7.5 would be a problem you couldn't solve ? I don't have a dog in this fight but curious .
arkley & Farmerdan (ntc) have them running.

Is there a modern production engine on the road today that has a compression ratio less than 8:1????

TOH
ot likely. New engines with over 10:1 run fine on 87, BUT they have knock sensors adjusting timing dynamically!
 
(quoted from post at 16:35:57 02/19/15)
(quoted from post at 17:02:09 02/19/15)
(quoted from post at 16:59:24 02/19/15)
(quoted from post at 15:40:45 02/19/15)
(quoted from post at 14:58:37 02/19/15) I see on the other board there is Sherman aluminum head for sale . The ad states the compression is too high for low grade pump gas and it pings unless the timing is retarded too much .
I thought the 9n head was 6:1 and the 8n was 6.5:1 modeled after the Sherman .
I don't see even 8:1 being an octane problem ?
herman ad literature of the time period shows 7.5:1

I don't know since I have not worked on this application but I would be looking at quelch , a hot spot , or fuel ratio . Compression is your friend , I wouldn't think an aluminum 7.5 would be a problem you couldn't solve ? I don't have a dog in this fight but curious .
arkley & Farmerdan (ntc) have them running.

Is there a modern production engine on the road today that has a compression ratio less than 8:1????

TOH

To muddy up the ditry water some more , we have very little info on the dynamic ratio . I have seen almost no flathead cam specs to do basic calculations .

Most application work OK on pump gas between 7.5 to 8.5 dynamic compression . With these small cams the dynamic and static ratio is a lot closer than modern ohv engines

Mainly was wondering why anyone would want to run a user unfriendly head if that is the case ?
 
Ken, I seriously doubt that there is a problem here. We have no input from an actual user saying that there is, just hear say. Next, 87 gas today is far better than 1939 gas.
Just a "talk" thread without any current user hard facts.
 
(quoted from post at 17:36:14 02/19/15) Ken, I seriously doubt that there is a problem here. We have no input from an actual user saying that there is, just hear say. Next, 87 gas today is far better than 1939 gas.
Just a "talk" thread without any current user hard facts.

I was working off of Dan's post . Maybe I read too much into it ?


In order to avoid spark knock you have to run 93 octane gas and retard the timing 4 degrees. I'm trying to get back to running the same cheap gas I use in the lawn mowers. And I've got two new cast iron heads that don't care what kind of gas I use so I might as well let this go to someone that wants it. I have noticed more power at low rpm.
 
(quoted from post at 18:58:01 02/19/15)
(quoted from post at 17:51:41 02/19/15) Dan's post?

It is on the ad section on the other site , half way down , Sherman head for sale
K, I'll call that first hand. Also agree that the flathead combustion chamber is a dog compared to modern open chamber designs.
 
(quoted from post at 17:55:38 02/19/15)
(quoted from post at 17:35:57 02/19/15)
(quoted from post at 17:02:09 02/19/15)
(quoted from post at 16:59:24 02/19/15)
(quoted from post at 15:40:45 02/19/15)
(quoted from post at 14:58:37 02/19/15) I see on the other board there is Sherman aluminum head for sale . The ad states the compression is too high for low grade pump gas and it pings unless the timing is retarded too much .
I thought the 9n head was 6:1 and the 8n was 6.5:1 modeled after the Sherman .
I don't see even 8:1 being an octane problem ?
herman ad literature of the time period shows 7.5:1

I don't know since I have not worked on this application but I would be looking at quelch , a hot spot , or fuel ratio . Compression is your friend , I wouldn't think an aluminum 7.5 would be a problem you couldn't solve ? I don't have a dog in this fight but curious .
arkley & Farmerdan (ntc) have them running.

Is there a modern production engine on the road today that has a compression ratio less than 8:1????

TOH
ot likely. New engines with over 10:1 run fine on 87, BUT they have knock sensors adjusting timing dynamically!

Modern Briggs lawnmower engine is 8.5:1 and no fancy engine management ;-) Let's just say I remain skeptical - especially of the 93 octane requirement. This article doesn''t say what "lower octane" is but it certainly isn't 93. Here is some food for thought from some folks that have a LOT of experience in this very matter::

[b:adc8ba2157][u:adc8ba2157]The Truth About Ford Flathead Engines- Destroying Flathead Myths[/u:adc8ba2157][/b:adc8ba2157]

[i:adc8ba2157][b:adc8ba2157]Simulated and actual test results indicate that the optimum compression ratio for peak horsepower for a normally aspirated street Flathead is about 8:1 to 9:1. Going with the low side of this range has the advantage of requiring lower octane fuel with minimal loss of low-end torque and mileage. Years of street driving experience validate these results. These results were also validated in a second similar study that included the buildup of an actual engine, documented in the July 2004 issue of STREET RODDER in the article "Out with the Bad Air, In with the Good."[/b:adc8ba2157][/i:adc8ba2157]

TOH

PS> At 7:1 the Sherman is well below the "low end" of their range and off their dyno chart which didn't even start until 7.3:1....
 

"Let's just say I remain skeptical - especially of the 93 octane requirement."

I have to agree. The N engine with 7.5 compression will be just fine with 87 octane and normal timing. It would definitely not need 93 octane.
 
.....Simulated and actual test results indicate that the optimum compression ratio for peak horsepower for a normally aspirated street Flathead is about 8:1 to 9:1. ...........

If all valves opened and closed at TDC these dynamic compression numbers would mean more , they are just feel good numbers .
A cam swap can change the static compression a point or two depending on when the valves actually start sealing the pressure .
I would have to say that flathead street cams are grouped closer together than those available for modern V8's

Interesting subject though .
 
I'd guess the aluminum Sherman head has been
resurfaced(likely multiple times) over the years and has
eventually gotten to the point of excess compression for 87
octane fuel.
 
Bingo, Ken.

Tractor engines are torque engines designed to operate at relatively low RPM. No doubt there is little valve overlap.

The dynamic CR will be relatively high vis-a-vis the typical flathead hot rod engine (or even stock flathead automotive engine).

Such engines are more prone to spark knock.

It would certainly not surprise me to find spark knock issues working an N engine hard if the static CR is 7.5:1 or so.

Dean
 
Dan is a good friend of mine and is only trying to recoup his investment. I don't think it was ever milled down. I think the Barkley head is in their showroom restored early 9N so doesn't get out for any exercise. Don had a NOS Sherman head so it was a virgin when he installed it. Someone could call and talk to them to confirm and see what they run. Spark knock will occur pulling or not so Derek or Don can answer that 93 octane question.

[i:654c4848f0][b:654c4848f0]<font size="4">Tim Daley(MI)</font>[/b:654c4848f0][/i:654c4848f0]<table width="100" border="1" cellpadding="0" cellspacing="0" bordercolor="#000000"><tr><td height="25" colspan="2" bgcolor="#CC0000">
<font color="#FFFFFF" size="3">*9N653I* & *8NI55I3*</font>​
</td></tr><tr><td>
TPD9N100.jpg
</td><td>
TPD8N100.jpg
</td></tr></table>
 
(quoted from post at 14:59:51 02/20/15)
(quoted from post at 10:48:34 02/20/15)
(quoted from post at 13:33:23 02/20/15)
(quoted from post at 13:01:45 02/20/15) $700.00 My wife would kill me.


he told me 750 obo.

no way I would pay anywhere near that

You are right, $750.00 obo... I was to lazy to put the "5" in there

That is probably the high end but still market value . I saw a finned aluminum Ford Flathead six head go for $1750 and aluminum 2 X 1V intakes sell $500 - $750 . I guess as long as people will pay $20K for a bottle of wine .....
 

True, it is what ever the market will stand. When we were restoring a 1969 Dodge Super Bee SIX PACK car I spent 2600.00 for an air cleaner. But that was a 60K car restored. I can not justify investing 10k in a tractor worth 4k when it is restored.
 
"87 gas today is far better than 1939 gas."
Any Facts to that statement?
In the late 60s when riding my little mini bike people would tell me
to run premium would burn a hole in the piston. Now days people
tell me due to the low quality of todays fuel they run premium in
everything, even there push mowers.
 

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