2jz oppos, need your advice!

Hey guys,

I know quite a few of you guys run 2jz’s so I figured I would ask.

I recently acquired a 2jz-ge from an SC300 to put into my datsun 240z.

My plan with most engines is to buy a seal kit and replace them as I go.

With my engine torn down pretty far I figured I would tackle the front main seal and the rear main seal. I come to the ever so widely discussed topic of the front main seal.


My engine does show some oil residue up front along with a dirty oil pan which makes me think that replacing the front main seal along with the cam seals would be a good idea.

What I am running into is everyone saying to go genuine toyota seals or not to even bother doing it. Is it really the case? Should I just toss my seals in my generic kit and order new ones from toyota? For paper or stamped gaskets I’m pretty comfortable using what is at hand, but the main seals I would rather not have to revisit.

Also finding that some people say if the seal is leaking it would be worth it to get a new oil pump. Additionally people have said to modify the oil pump for better flow by porting and drilling out some holes.

What are your thoughts?

Edit: For anyone who finds this topic just thought I would share my results.

I went to the machine shop with my generic seal kit for valve stems, the brand of most of the seals were evergreen and the machine shop recognized them and was happy to use them on the head. So not as bad as I thought.


The seal I had was a Lok 46631. The height of the seal (depth that it goes into the oil pump) was 6.2mm

Turns out my motor had the updated seal in NOK BH4513E. This one has extended “teeth” on the bottom, some people said it was to increase grip on the walls, but they are located inboard, so my theory is that they are there to help space the seal away from the oil drain hole. 6.6mm height and 7mm at the teeth


The factory toyota oil seal NOK BH4513F is 6.4mm

The oil drain hole starts at 5.2mm and goes all the way down to 10.2mm. So it will be partially covered regardless of the oil seal. The question is if it is better to block more of it to have more surface area in contact with the oil pump or if it is better to keep the oil drain hole clear and free.


One thing I did was I used the toyota FIPG on the outside of the seal making sure none got on the bottom or behind the seal. Then I coated the inside of the seal with generic high temperature grease.

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