Hello all,

I am about to buy a motor and trans online, hopefully today. $7500 gets me motor/trans including shipping to my door. I can’t find any local and I’m ready to move forward. Anyone have someone they use or trust that’s similar priced?

Im immediately going to tear it down and have the short block rebuilt. I could use all the extra parts and then I’ll sell won’t I don’t need to recoop some of the cost.

but as you know - no warranty. The guy said he would do a FaceTime compression test. What could go wrong??

 

Seems a bit pricey. For a little more you can have a brand new reman, no?

 

Yeah I considered this, it's about $8500 for a short block new. But I kind of need all the extra parts to piece my situation back together and possible the trans. I could send the trans out to be rebuilt while running my current one. Then I could sell off what I don't use to recoup.

 

Beware trying to just swap in a used JDM motor. I would budget a rebuild kit so you can pull it apart and inspect at minimum. I've seen lots of imported kegs opened and have the coolant passages completely plugged with rust because of lack of maintenance or sitting for a long time. This in turn leads to possibly needing to replace irons and so on.

 

Can you check the seller's history. Lots of scammers out there.

 

my intention is to immediately have it rebuilt and do a haltech. I wasn’t going try to just throw it in. But good advice on the coolant passages. I guess how do you know? Just rolling the dice I guess…

 

Exactly that yes. A dice roll. Even if the irons and housings are in perfect condition, a corroded water seal groove turns it into scrap. Sometimes you get lucky and sometimes you don't. Same with the rotors if any kind of moisture was allowed to build up. What once was a good motor is now doo doo because the rotor turned to a boat anchor and took everything it touched with it.

 

the current one I have with a coolant leak. Hence why I’m replacing. Just started tearing it down last night




Still has water in it…

 

Don't let your children see this.

 

ha ha

 

So I’m looking to buy from a company in CA called LA JDM. Has anyone used them before?

 

Count on the housings being trashed, the plates needing to be lapped, and the rotors a toss up... Over the years it seems very few people get lucky with a good imported engines around here.

There are a few venders selling new mazda kegs for ~9k. Expensive but no headache.

 

Around 2009 or 2010 I bought an engine longblock (including manifolds, turbo, throttle, electrical harness) from someone here on rx7club named Japan2LA but I don't think he's active anymore. It made good compression and the internals were in good shape, and I think I've put about 10000-15000 miles on it since then without problems. But lots of the accessories like the pulleys and brackets were rusted as though it had been sitting near the ocean. Also I imagine prices have gone up and supply quality has gone down since then, the donor cars are likely in worse shape than they were 15 years ago.

 

You're literally 5 million times better off getting a brand new mazda crate motor, then source all the peripherals and the trans etc as needed.

I'd stay far away from these 'jdm junk' importers, esp at that price.

 

It is costing me about C$8000 to have a near new motor put together based on NIB parts I have bought on here and on Yahoo Japan., plus e-shaft and stationary gears, i acquired, used locally.

I am having a second motor put together from used parts I randomly acquired and it is costing me about the same, due to machining and the fact I had to scrap a number of the used parts I bought.

The third motor is being put together from two motors, one with with a blown front rotor and one with a blown rear rotor. Again the cost will be about C$8000.

The cost of labor and seal kits (etc.) being a fixed cost component on each.

 

Here is compression test from seller:

https://www.dropbox.com/scl/fi/4r9z4...9zuvwineu&dl=0

Seller has good reviews, been in business for 10 years. Plugs look good. He has assured me the motor was running 6 months ago. In all honestly, does this make you feel any better?

 

You have to be a bit of a rotary witch doctor to derive a conclusion from a compression test with a standard compression tester.

Standard compression tester has a valve that "stores" the first pulse. Therefore the next two pulses are masked.

You see the needle makes several beats, which could represent the pulses from the other two faces, but you can't really know the strength.

it is too bad he did not do the test with a proper rotary compression tester (cost about $300 on ebay).

 

I know a rotary compression tester is ideal. But you can see it is creating compression and he is purging the line. Even give or take a 10psi tolerance with the wrong tester you can see that it is creating a good compression at 95-105.

again I’m immediately rebuilding this motor. I’m not throwing it in as is.

To me the only concern at this point is if this thing has been sitting long and coolant/water has decayed passage retaining walls.

 

I agree that test video would have been better if they held the pressure release valve the entire time so you can see the individual pulses, but it sounds and looks decent to me. I'm not a rebuild expert but I think bad coolant seals would mean you replace the front and center and rear irons, so you could price that out and see if it's worth rolling the dice. If you're planning to rebuild and you need a transmission it might be worth it. I would also check with tomsn16 who sells lots of used FD parts on this site, he might have transmission or used engines or engine parts for sale. You can usually find his for sale threads on the first page or two of the marketplace/classified section of rx7club.

 

Releasing the pressure just releases the accumulated pressure and so is not of help. Likely impossible to release the pressure after each pulse.

When he is cranking you can hear the pulses in the other chamber as it seems he leaves the plug out.

And it seems you can hear pulse from each face, but again you do not know the strength.

If he has been in the rotary business for ten years, why has he not got a proper rotary tester?

And he should know that a standard compression tester is missleading.

Your value-at-risk you have here is the difference in value between having a running motor or have a collection of parts, some of which you can fix, or sell, to recover your value. So, a rough guess, you might lose $3000.

In other words, you might have to spend an additional $3000 to replace any unusable parts you find when you take the motor apart.

 

Here is a fellow who has been selling a disassembled motor for some time with no takers.

I understand that he has saran wrap on the faces, so you might want to ask to see pics with the saran wrap removed.

@Blk 93

https://www.rx7club.com/market/1166985

 

I appreciate the help and advice guys, I do. And he’s not a rotary engine importer for 10
years, he’s just a JDM importer who has probably sold some rotary engines in that time. I don’t know his business and if it is worth him investing in a rotary tester. If it was me I would certainly invest in one. Hell I’d pay more for him to do a video of him hooking it up and run the engines but again I don’t know his business.

it’s a dice roll! As you mentioned I guess worst case I’d be looking at new irons. Call it $2500. Im
hoping that’s not the case. It’s such a conundrum.

option 1: buy a brand spanking new short block for $8500, have it rebuilt with better seals and ported for 3-4k. then start looking for any pieces I am missing and possibly a transmission.

option 2: buy a JDM import for $7500 with everything. have it rebuilt with better seals and ported for 3-4k, (add $2500 for irons if needed). Then sell off what I don’t use to recoup.

decisions decisions….

 

By irons, we might assume you mean the iron plates. But the critical parts would be more likely the rotor housings and the rotors.

Have someone take a look at the pics of Blk 93's disassembled motor. or at least have a conversation with him.

Those parts could be a good basis, and, if you have to find a few replacements for any of them, you may be ahead of the game cost wise.

 

This car has an all original excellent compression DROP-IN-ENGINE.
Car is still drivable and runs like a bandit.

 

link
https://www.rx7club.com/market/1169414