422 engine

[Bob999]

JJ;
So far the only difference I can see in the owners manual and parts manuals for the 18hp, 20hp, and 22hp engines is the carburetor and governor settings.

Has anyone checked to see what differences there are in the PT pumps and motors between the 18, 22, and 25? Those differences might be as important, if not more important, than the difference in HP of the engine.

 

[Beechwood]

Has anyone checked to see what differences there are in the PT pumps and motors between the 18, 22, and 25? Those differences might be as important, if not more important, than the difference in HP of the engine.

Thats a good point. Before I get too involved with this project I'll have to look into that. Thanks- I really didn't give that much thought.

 

[J_J]

Thats a good point. Before I get too involved with this project I'll have to look into that. Thanks- I really didn't give that much thought.

According to the specs, the 18,22, put out 8 gpm at 2000 psi, and 25 puts out 8 gpm's at 2500 psi for the PTO.

 

[BobRip]

The parts that I listed are all different at least between two of the three engines.

 

[Beechwood]

The parts that I listed are all different at least between two of the three engines.

Unless I'm missing something this is the parts list I have;

PISTON std size not oversize --EH63-64-65 #263-23411-A3 (same)
CONNECTING ROD --EH63-64-65 #263-22501-00 (same)
CRANKCASE--EH63-64-65 #263-10101-01 (same)
CRANKSHAFT-- (depends on PTO shaft size needed for 180, 422, 425)
CAMSHAFT-- EH63-64-65 #263-31701-03 (same)
INTAKE MANIFOLD-- EH63-64-65 #263-33001-03 (same)
GOVERNOR SPRING-- EH63-64 #263-42503-A3
EH65-72 #263-42501-03
BAFFLE#1--EH63-64-65 #263-52601-01 (same)
BAFFLE#2--EH63-64-65 #263-52704-A1 (same)
CABURETORS-- EH63 #263-62503-00
EH64 #263-62403-00
EH65 #263-62303-00
THROTTLE SHAFT-- EH63 #263-62532-08
EH64 #263-62531008
EH65 #263-62530-08

According to the parts manual all other components not listed here are the same for all 3 engines not including the EH72-25HP engine

 

[Beechwood]

As far as I can tell- The only different parts are;

GOVERNOR SPRING
CARBURETOR
THROTTLE SHAFT

So if someone wanted to derate their 422 W 22HP robin engine to a 18HP just install the parts above for the EH63 18HP Robin ,or vice-versa to up grade from a EH63 18HP to a EH65 22HP Robin install the parts above for the EH65, then adjust carb settings, governor settings and throttle shaft settings to the 22HP specs. I don't know about anyone else, but this all makes sense to me.

 

[Bob999]

According to the specs, the 18,22, put out 8 gpm at 2000 psi, and 25 puts out 8 gpm's at 2500 psi for the PTO.

If I understand correctly the specs JJ lists are for the PTO pump. That still leaves the pump for the aux circuit and the variable displacement pump that powers the wheel motors. And of course there are the wheel motors that are probably different.

 

[Beechwood]

If I understand correctly the specs JJ lists are for the PTO pump. That still leaves the pump for the aux circuit and the variable displacement pump that powers the wheel motors. And of course there are the wheel motors that are probably different.

I don't know yet what effect a 22HP engine would have on the 180 pumps and wheel motors. I don't think 3-4 more HP will make that bigger difference, but I will be contacting White MFG tech. dept. to find out what the max recomended HP is for those rolla-stator wheel motors etc. If the 18HP is maxiing out the 180 wheel motors, pumps, etc. now --that will put an end to my quest to add a few more horsepower- I'll have to be content with keeping everything as-is.

 

[KMA]

I believe what Bob999 was getting at (please correct me if I'm mistaken) is that the wheel motors/pumps used on the 180 may have a more impact on "power" than the engine output. In other words, additional HP is likely not the only thing that makes the 422 and the 425 more "powerful".

 

[BobRip]

I believe what Bob999 was getting at (please correct me if I'm mistaken) is that the wheel motors/pumps used on the 180 may have a more impact on "power" than the engine output. In other words, additional HP is likely not the only thing that makes the 422 and the 425 more "powerful".

The wheel motors do have impact and so does the engine, but try this test. When you climb a steep hill does the engine bog down or do the wheels just stop turning. If the engine bogs down, then a more powerful motor will help. If the wheels just stop turning with the motor at full speed then the limitation is the wheel motors. This is just my opinion, and I am not an expert.
On the 422 I think a bigger engine would help. However the 425 has a bigger engine, bigger hydraulic motor that drives the wheels, and more powerful wheel motors so PT felt all three were needed. If my engine died I would definately put in a bigger engine.