JD Flat heads

[alvan]

Looking to buy a head for my John Deere A. Been looking at Ex stream tractor parts at their head and at Murphy. Does anyone have any info on ether and if one better than the other. Thanks

 

[Kwkta]

Murphys

 

[Bill Marcusky]

Murphy's for sure

 

[buickanddeere]

Extreme is good but the delivery time table is "flexible". Murphy equipment is also high quality and they keep dead lines better.

 

[gtx1967jewison]

In my opinion the Murphy Heads have severely oversized ports to the point they don't even work right on a really big-blocked & stroked engine. I would never use one. I like the extreme head much better. I feel the same about the Murphy manifolds & yes I've watched several in action. No velocity, low vacuum signal to the carb.

 

[southpull]

I agree with what gtx said. For power, I think that Extreme's head is the way to go.

 

[gtx1967jewison]

I have purchased several items from both & both places have
exceptional quality & knowledge. Both great guys. Murphy's
WAS faster in my case, extreme depends on how labor
intensive your request is & has been steadily improving. Their
being swamped with work could mean something. Neither
place is cheap but the parts have all been worth it.

 

[forty40]

(quoted from post at 16:49:00 11/04/14) Looking to buy a head for my John Deere A. Been looking at Ex stream tractor parts at their head and at Murphy. Does anyone have any info on ether and if one better than the other. Thanks

Regarding the selection of a flat cylinder head to gain compression, my recommendation would be to discuss with either manufacturer, let them know the complete plan for the engine. What's interesting for these old tractor aftermarket two cylinder heads, there has actually been quite a bit of flow bench testing and cam design work to match the head/intake/rocker ratio/cam. Another key for allowing any engine to operate efficiently in the most used part of the RPM range is take the time and accurately degree in the cam. I know its a pain in the "A" for a JD, but I believe it is a necessary pain. I'm just finishing up my first all-out JD A puller and it was surprising how far off the cam timing was when first installed using the original crank and cam gear timing marks. The cam initially checked a full 13 deg off from where I wanted #1 intake centerline, so in this case the fix was easy. If you have been shopping for heads, you can tell which one I ended up with.

 

[Josh Blackburn]

Just had a engine go together with Murphy head at 644 cubes. 44 a smoked the clutch in 4th gear at 6500 with 18.4s. I have ray's head on my a. Makes great power But Murphy's port design is better. They both make power.

 

[buickanddeere]

I wonder if there is a way to build a wedge head with a quench similar to the later 20 & 30 series two cylinders?
Combustion chamber turbulence and the quench would allow higher compression pressure on the same octane.

 

[gtx1967jewison]

How many cubes is yours josh?

 

[rllk]

forty40 give me a call @717 548 2083 about jd heads

 

[buickanddeere]

(quoted from post at 00:52:39 11/05/14) In my opinion the Murphy Heads have severely oversized ports to the point they don't even work right on a really big-blocked & stroked engine. I would never use one. I like the extreme head much better. I feel the same about the Murphy manifolds & yes I've watched several in action. No velocity, low vacuum signal to the carb.

Makes a person wonder about what pulling classes that port fuel injection could be legal in.
This would keep the ports dry, no over rich bog on throttle up and the fuel atomized.

 

[moretoys28]

What about a heisler head? What is the opinion of one of these?

 

[BushogPapa]

The GOOD news is that Ray is much better now..

That Pancreatic business was mighty bad..

Glad he has that behind him..

Ron.

 

[Chris5]

I just got my head in from Extreme that I bought this summer. Waited so long I lost interest in the project and sold it. If your interested inbox me, Still in the crate.