USDM H22 oil pump on JDM H22A

[Acclude1420]

Hey Guys,

I bought an OBD1 JDM H22 from HMO and during the timing belt tensioner conversion, broke a piece of the oil pump housing off. Unfortunately, I had to purchase a complete oil pump housing.

I'm running into a BIG problem during the pump install. As you can see in the picture, the rear balance shaft moulding in the housing is slightly thicker than the JDM housing. This is preventing me from getting the thrust washer and balance shaft gear back on. What's interesting is that the thrust washer is 1/8 of an inch thick, and the new USDM pump moulding is almost exactly 1/8 inches too thick; almost as if the new pump doesnt require the thrust washer at all. Also, in the pic you'll notice that the old housing has a balance shaft bearing when the new one does not. What really concerns me is that if I leave the washer off, will it cause any damage to my engine? My Helms manual shows the washer but doesn't mention a scenario of it not being necessary.

I'm in desperate need of some help!

[euraphex]

Try to take the screwdriver out the hole in the back or the screw.I don't know what you are using to keep it in place. The balance shaft should slide back and forth. See if that gives you clearence to put the washer in and the once you have a bolt in the gear try to put your stay tool back in the balance shaft. I ran into this samething. Invest in a paint marker and mark all your points so it is easier to be able to tell everyhtuing is lined up right.

[Acclude1420]

Try to take the screwdriver out the hole in the back or the screw.I don't know what you are using to keep it in place. The balance shaft should slide back and forth. See if that gives you clearence to put the washer in and the once you have a bolt in the gear try to put your stay tool back in the balance shaft. I ran into this samething. Invest in a paint marker and mark all your points so it is easier to be able to tell everyhtuing is lined up right.

What I ended up doing was taking the balance shaft out and sticking it in the hole of each pump housing. I found that the shaft sticks out 1/8 of an inch more in the old housing. That's about the same thickness as the washer. Do you think I can just discard the washer and be fine?

[euraphex]

What I ended up doing was taking the balance shaft out and sticking it in the hole of each pump housing. I found that the shaft sticks out 1/8 of an inch more in the old housing. That's about the same thickness as the washer. Do you think I can just discard the washer and be fine?

I wouldn't I would just pull the balance shaft out like I said and put the washer on there. Honda Engineers wanted it there so I put mine on

[Acclude1420]

I wouldn't I would just pull the balance shaft out like I said and put the washer on there. Honda Engineers wanted it there so I put mine on

I would but the problem with doing that is the balance shaft gear will not be fully seated on the end of the balance shaft because the shaft doesn't come through the pump housing far enough (even when it's off the engine). I spoke with Hondapartsnow.com and they are letting me return the new pump. The rep suggested that the JDM and USDM pumps are not interchangable, I think he might be right. At this point, I'm going to have to hunt down a JDM pump.

[cp[mike]]

I would but the problem with doing that is the balance shaft gear will not be fully seated on the end of the balance shaft because the shaft doesn't come through the pump housing far enough (even when it's off the engine). I spoke with Hondapartsnow.com and they are letting me return the new pump. The rep suggested that the JDM and USDM pumps are not interchangable, I think he might be right. At this point, I'm going to have to hunt down a JDM pump.

if you get stuck locating one, you might want to consider having it looked at by a machine shop. maybe they could trim down the housing enough to fit the washer, or they might have other suggestions.

[Acclude1420]

Does anyone know where I can get a JDM pump? I cannot find one for the life of me. I'm completely DEAD IN THE WATER until I get this figured out. Hondapartsnow.com sent me the correct part for a USDM motor, but it will not allow enough clearence for the rear balance shaft thrust washer to fit on and allow the balancer driven gear to be fully seated as well. Again, this is because the new housing is too thick where the rear balance shaft goes through.

Option#2

Should I just completely bag the manual tensioner conversion and put a new auto tensioner on instead? If I did this I wouldnt have search for a new JDM oil pump because the auto tensioner doesnt use the timing belt adjuster base bolt.

Suggestions? Anyone? Bueller?

[JustSomeGuy]

Balance shaft delete all together. Free up some horsepower and get around your issue.

[Acclude1420]

Balance shaft delete all together. Free up some horsepower and get around your issue.

The thought had occurred to me, but Honda has them there for a reason. I'm not building the motor or doing anythig crazy with it and I'd like to just keep it stock with a nice smooth idle.

[Acclude1420]

UPDATE:

I just spoke with a ridiculously cool guy at the Honda service center and he confirmed that the USDM oil pump is in no way shape or form, compatible with an OBD1 JDM H22A. I am going to just order a new auto tensioner and slap that thing on so I can get this project done. He also said that he has only seen the auto tensioners fail when the owner neglects to replace them during a timing belt installation. I will be reinstalling the original pump as soon as the seals arrive.

On a side note, anybody want to purchase a brand new manual tensioner conversion kit? I paid $95, I'd be willing to let it go for $50.

[Acclude1420]

Another update:

I found a guy on a prelude forum that is selling his JDM oil pump that came with his new engine. I spoke with him last night and am arranging the purchase. Now I can proceed with the tensioner conversion and get this sucker done!

[CyborgGT]

Because Search, shut up ...


Has anyone actually looked to see if that internal eccentric gear assembly is the same on every pump? Maybe we could avoid all this nonsense of the slight differences between the overall pump assembly designs, just get any old USDM pump, and swap out the internals.

I'd pop on down to the junkyard to get an American pump to compare myself, but H22s are always snatched up too quick for that.

[Jarrett]

Is the difference he was noting not just the absence of part number 28 in this fiche? It looks like the new pump is missing the locating dowel sleeve.

http://www.hondaautomotiveparts.com/...-+OIL+STRAINER

[CyborgGT]

There's that, and the thickness of the housing around the dowel.

I wish the model year of OP's "new" pump was given. I'm seeing conflicting info in my searching about whether 92-95 USDM pumps are interchangeable with the JDM pumps.

[illinois_erik]

i thought id throw this out there even though i eliminated balance shafts.
i still have the jdm h22a pump if anyone needs reference info
(1996 casting.closed deck,odb1)

anyway, i bought a new pump from ks tuned with the b/s plugs preinstalled, it went on no problem..i didnt even think to see if theyre were differences, the only difference i noticed was the bosses for the odb2 crank sensor were not tapped.