oregonmon

Looking for a new motor for my rotrex'd VVT swapped 90. I was on the hunt for a bp4w as they are around here in Florida and a lot of the guys recommend them. Searching the threads, it's recommend for the slightly lower compression for rotrex boost.

There's also a couple VVTs, including an imported low miles JDM motor. Days of searching I'm getting conflicting info that the JDM BPZE/BP6D is 10.5:1 and the USDM is 10 1. Can anyone confirm or deny?

If I'm strictly 93 pump gas, is 10:1 compression fine for 230ish whp for track, autox, street car? If the JDM is 10.5:1, is that safe or getting out of hand?

Thanks.

Monk

iTrader: (3)

I have a set of JDM VVT pistons.
Can confirm they are 10.5.

concealer404

iTrader: (3)

The 10.5 motor won't be any weaker. Just may require a different tune. It can safely do 230whp just as well as the 10:1 motor can.

I wouldn't pay extra for one. I wouldn't pay less for one, either.

oregonmon

Thanks, did you order them or found used?

oregonmon

It's already a pretty good deal AND comes with a square top and warranty for $999.

18psi

iTrader: (76)

rotrex doesn't make torque. you're totally fine with the higher compression

concealer404

iTrader: (3)

Sounds like a no-brainer.

oregonmon

Thanks for the input guys.

MX5RACER

Can you please post pictures of the pistons? I purchased a JDM motor a while back and I would like know if this motor has the same pistons as yours.

konmo

iTrader: (2)

This is what my broken 10.5:1 JDM pistons looked like.

MX5RACER

That looks a lot like a standard VVT piston.

Savington

iTrader: (31)

Stock USDM 01-05 pistons do not have that third step-up in the center.

MX5RACER

Brought the pictures up on an actual computer with a real screen not an iPhone and I see the difference now. Thanks.

konmo

iTrader: (2)

Just leaving these here for who ever is interested.

18psi

iTrader: (76)

/\ very helpful, thanks

oregonmon

Yes, very helpful!

Placed the order for the JDM VVT with square top motor yesterday, hopefully it's not ****.

Savington

iTrader: (31)

Interesting that they dropped the dome away from the spark plug in the center of the 10.5:1 slug.

nitrodann

Those are great photographs, thankyou.