Identifying big block Kohler block styles

[Kelly 1,029]

I can not count how many times I've been asked about will this engine fit, or will this oil pan fit?? most times the first question I ask is what style block do you have ?? large or small base ?? BUT there is one exception to that rule I will cover that later.

 

   I'm writing this post to help clear up that question, first this only applies to 10, 12, 14 and 16 HP Kohlers, they used two style blocks commonly referred to as large or small base blocks.

 

  We will start with the large base or eared block used on most WH tractors from 1967 to the last Magnum about 1987, these blocks use the bigger oil pan, and the pan bolts on from the top side through ears on the block, this style oil pan is the one that bolts directly to the frame, the two bolts on the right side that hold it to the frame go from under the frame into blind bolt holes in the bottom of the pan, the pan will hang over the frame some on that side, with the mounting ears on the pan NOT being used.

 

This is a large base block and pan, note how long the pan is and where it bolts to the block

 

Here you can see where the pan hangs over the frame, at this point under the frame is where the bolts go from the bottom in to the blind holes in the pan.

 

The holes outlined in red are the blind holes used to bolt the pan to the frame from the bottom, the holes in green are the ones that hang over the frame.

 

Here you can see the bolts that hold the pan on, going through the ears in the block.

 

That pretty much covers the large base blocks.

 

 

Next is the small base block used on the shaker plate engines, and some of the mid 60's 10hp engines in WH tractors,  this style block is also common in Cub tractors, and others but we are talking WH here.

 

  The small base block the oil pan bolts on from the bottom of the engine, it does not have ears on the block, the pan is closer to a square in shape than the large base block, here is a pic of a small base block and oil pan.

 

There are many many styles of oil pans to fit the small base block, other brands of tractors use pans in all shapes, and depths so when swapping this style pan you have to watch how long the oil dipper is on the bottom of the connecting rod, it can be cut to fit a shallower pan, WH used two basic pans on this engine a very shallow pan on the early 10 hp and a mid depth on the shaker plate engines.

 

This pan is a shaker style pan used in the late 70's early 80's on the shaker engines

 

This pan is the flat bottom style used on the 1045, 1055, 1075 and 1046 also used on many Cub engines and other brands, the dipper on the connecting rod is very short on the engines that use this pan.

 

This is a deep pan on a Cub engine, I do beleive it uses the same dipper as the large base blocks with the big oil pan.

 

  Here is a shot of both styles together, to give you a idea of how the blocks look side by side, note on the large base block the cut outs at each end, I will be talking about them and the 4 holes you see where a small base oil pan could fit with a few mods. 

 

Here are the pan gaskets side by side and over top of each other.

 

Ok now we will talk about how a small base oil pan can be used on a large base block, note the red circles they point out the cut outs in the block where the small oil pan will not seal, this area can be filled up with JB weld or other compound that will stick to metal and take the heat, then note the green circles they show the holes that will need to be tapped to bolt the pan to, so far all blocks I have seen have the holes but are not tapped, with these mods a small pan can be used on this block, also if needed you could cut most of the ears off the block.

 

Now some blocks (very few) are set up from the factory to except both style oil pans, most common found on JD tractors as they use a shaker mount set up that uses the ears on the block to mount it but still uses a small oil pan, here is a duel pan style block note is does not have the cut outs in the block like a normal large base block does.

 

 

Just remember to check the dipper on the rod, to long and it will hit the pan, to short and it may not splash lube properly.

 

  I hope this helps clear up a few questions about block styles and how they differ 

 

 

 

 

 

 

 

 

 

 

 

[TT-(Moderator) 1,145]

Thank you Kelly!

Where's the pic of your bloody finger?   

[Kelly 1,029]

These are all new pics from today, no blood today, please correct me if I missed or messed anything up, I tried to double check this before posting it.  

[varosd 1,185]

perhaps this excellent thread can be pinned in the Instructional tab for future questions/info.

[TT-(Moderator) 1,145]

I think it's excellent!   

I assume you're working on the next installment ~ dipstick and PTO mounting face variations.

[varosd 1,185]

So how many times are you asked if such and such will fit....?????

[Kelly 1,029]

Dip sticks are a whole new game, there are about a dozen different set ups, as for the PTO side of the block I only know of 2 styles one machined at the outer edge like a Case to aline the pump housing and the nonmachined one. 

[Kelly 1,029]

as for how many times asked ?? no idea, but I get the do you have a Kohler to fit my tractor ?? no more info given, or the it don't matter they will all fit, or I have no idea what style block I have ?? the list goes on........................

[AMC RULES 37,134]

Very informative Kelly...           

and    for sharing the knowledge with us. 

[Kelly 1,029]

I may work on a few other things like this in the near future, like maybe the dip stick challenge  

[chazm 413]

EXCELLENT POST    Thanks for clearing things up for ALL of us 

[Wheel-N-It 2,969]

Most Excellant post Kelly. Thank you. I learned something tonight

[bewford 21]

Thank you Sir

[TravelinJavelin 620]

Wow thanks for the education on this I didn't realize there are such variations just on the oil pans of these engines

[Joefrommi65 18]

Very nice info !!!! Thanks for taking the time to explain!!

[darg 7]

Question, I have a 12 hp mag. engine. deep pan. The manual call for two qts of oil, you know the dip stick sot of lays down when fully inserted in the tube. The oil on the dip stick only shows oil up to the add mark. Is this correct. I do not want to over fill. One time I filled up to the full mark, and I noticed some foam on my did stick, I know when over filled the crank oil thrower will cause foam to form.

[RickJ 2]

Kelly -

 

Thanks so much!  I couldn't have asked for a more thorough review of Kohler oil pans!  This will take a while for me to digest; I think I will go back to the seller and take several photos of the engine and compare it to the photos you included in your reply.  Stand by for a few more questions from the Kohler dummy!

 

Rick

[alswagg 128]

Ok I have to ask.   Where does the 18 and 20 twin kohlers like what is used in the D series rate in this big block small block discussion?    Also, I have always said in truck and boat applications at least.  We refere our small block machines as "girls" as in a "she sure is a beauty ". In big block applications we refer them as "boys". As in "He sure is a brute".  

[redone 45]

Hi Kelly

   Thanks for this education on kohler blocks. Now I know what I have to replace. I have a blowen 16 hp kohler off of a 160 Hydro. cam gear went through the side of block. now I have to take another look for large or small block.

on the other hand, i will need to replace this block, and rebuild new. any ideas of were i can find a good block to be rebuilt. or find one already built.....

thank you for sharing.

Bill

Iowa

[Phatboy 565]

Thanks kelly,, i always wondered why my block overhang on the frame  and had no bolts in those holes lol,, that was very informitive thank you..

[Detector 72]

After reading this I'm a bit curious if my engine is original seeing the large oil pans were phased out in 1987, I have a 90 312-H, it has a Kohler M12S with the large oil pan that hangs off the frame, it also has the oil safety switch. 

[valleyboy 1]

c120 engine swap .I bought a rebuilt kohler 14 hp and intended to install it on my c120 which had a 12 hp from factory. after reviewing your info I discovered as you noted the 12 hp is a big block. The 14 hp engine is a small block and it looks like the large oil pan from the 12 hp  wont work on the small block 14 hp. I don't have the 12 removed from the tractor yet but if the large bloc pan won't work on the small block pan I won't be able to use the small block engine. Thanks for your info.  I should have checked this out before I bought the 14 hp.   If so I will sell the 14 hp. Hoped it would work out to get tractor back in service for cutting grass. Thanks again. Bob

[valleyboy 1]

On ‎7‎/‎6‎/‎2017 at 2:53 PM, valleyboy said:

c120 engine swap .I bought a rebuilt kohler 14 hp and intended to install it on my c120 which had a 12 hp from factory. after reviewing your info I discovered as you noted the 12 hp is a big block. The 14 hp engine is a small block and it looks like the large oil pan from the 12 hp  wont work on the small block 14 hp. I don't have the 12 removed from the tractor yet but if the large bloc pan won't work on the small block pan I won't be able to use the small block engine. Thanks for your info.  I should have checked this out before I bought the 14 hp.   If so I will sell the 14 hp. Hoped it would work out to get tractor back in service for cutting grass. Thanks again. Bob

adapting a big block oil pan to small block engine. wondering if a adapter plate could be made to accomplish this ? the thickness of the adapter plate would have to be milled off of the oil pan height to maintain the original engine height. and be bolted up to the small block engine with counter sunk holes and provide the missing lugs with holes for attachment to the big block pan.???

[JPWH 6,063]

If you have the flat bottom oil pan it should not be a hard swap. I just went through this with a deep sump oil pan on my custom build. I chose  to keep the deep sump and modify the frame. I did  not have the hood clearance for the flat oil pan because of the narrow modified hood. Check out Raider 12 modifications last page.

[CX519 11]

Awesome Job. Way to educate.