Jesus Martinez

My motor has compression loss, I am still debating whether to go with a Mazdatrix mazda reman or having a shop in Texas rebuild a motor for me using Rotory Aviation master kit. So while in the process of having my engine removed, I will be buying the Remedy waterpump and thermostat, oil cooler mod, and the fan cooling mod. Along with new OEM hoses.

I am unsure if to go with a Koyo V core radiator since I can get it for $300, sometimes a little less, or to go with a Ron Davis dual core, or RX8performance dual core radiator.

Aside from all that, is there anything else you guys recommend I change out to increase reliability from a new engine?

On that note, if you guys wanna comment on what radiator to use, that would be great also. Either the Koyo Rad, or the dual core? And if I should go with Mazdatrix reman, or OJimports from Texas rebuild.

My goals for this car is to mainly do canyon runs, and track days, so it needs to run cool cause Southern California can get very hot in the summer. Also, at some point after the warranty is up, I would wanna add Nitrous to it.

gwilliams6

Seems like you have a good handle on items to help keep that reman happy.

With the motor out check the cat and the clutch. It would save you a ton of labor later (dropping the tranny) if you replace the clutch now if it is showing wear. Also good time to change the accessory belts if you haven't done so before.

Of course ,depending on their mileage, it would be a good time to change out coils, plugs, and wires, unless you have BHR coils.

BTW how many miles on that engine with low compression?

Some other club members would have better knowledge if a reman from Mazdatrix or OJImports would be best. I know some folks in the Dallas area also use Rotary Performance and some swear by engines from Pineapple Racing and Pettit Racing.

ZiG

Not like you can't do it easily enough later, but motor mounts. Especially if your passenger side mount is original/an older revision.

I also did my trans input shaft seal while it was easy to get to.

NotAPreppie

I had my engine rebuilt by OJ Imports in February. I'm still waiting on my compression tester to verify the compression but it's definitely stronger and the intermittent hot start/hot idle issues are gone.

Omar is easy to work with and his prices are very good. My only complaint was the freight company did a poor job on the return trip. The pallet was broken and most of the paperwork was missing. It was delivered to my friend who was helping me with the R/R and he didn't reject the delivery like he should have. We lucked out in that the engine still works.

Jesus Martinez

Forgot to mention, I replaced the clutch and the flywheel to a lightweight one, no joke, 50 miles before my motor went. So I should be covered on that. And while troubleshooting the engine, before the engine compression, I replaced the coils, spark plugs, and cables. But yes thank you for that recommendation.

The original engine has 86000 miles :/

Okay, just out of curiosity, are suggesting changing them, to help improve "performance" or since they'll be easily accessible? I could change them to performance ones. Any suggestions on which brand?

His prices, and reviews on another thread on this site, lead me to him. So it seems the shipping company is what I should be worried about. Interesting. I'll be sure to let my friend know, since he is the one who owns a shop and will be doing the R/R.

If you can, would you get back to us on compression results when you get them? I won't be doing any work till the car till at least July when I have enough for everything all at once.

ZiG

I'm suggesting changing them because they will be easy to get at and if they're not already worn, they will be very soon if you're tracking the car. I'm using race roots mounts and am happy with them.

Jesus Martinez

Awesome. I will look into it.

Btw, any one have any experience with these?

RX8Performance AST by RX8Performance.com | RX8Performance.com

RX-8 AST Closed Cooling System Upgrade

Would this be good to purchase to replace the coolant tank in the 8??

gwilliams6

No personal experience with these. But they both make good sense for our RX8s, and I have used Pettit Racing for work on my past RX7s and they make great stuff. If I would switch to this I would probably go for the best Pettit Racing option here as you would still have a visible tank to check. Just my opinion.

BTW, I replaced my OEM bottle w/sensor last year, after the sensor died, a common issue.

Jesus Martinez

I think imma go with rx8performance cause it has the cooling fan mod sensor built in. I wrote to them, and rhey said to make it like the pettit racing one, i just have to add a seperate plastic bottle. Eh, go figure.

Btw, to anyone reading. I bought the koyorad for the S1, but i read the Koyorad for s2 is a lot better. Did i mess up and get the wrong one? Even though my car is a s1, should i try and go througj the hassle and try and return it?

ZiG

My only comment is t that it seems weird to measure temperature from the reservoir since that coolant isn't actively flowing through the engine. Preflight personally I wouldn't be comfortable taking a reliable reading (for a gauge or to control a fan) from anywhere other than the correct spot, which is the base of hot side discharge to the rad. Incidentally, this is where the OEM sensor is located on the rx8 and every other car that I'm aware of since about the late 80s (for a time, GM used a port on one cylinder head for temp measurement before they realized even that wasn't the brightest idea, and now they just use that spot for the dummy gauge since it doesn't really matter).

xKp5609x

Did you ever get that compression test? Just curious hope shes running well!

Jesus Martinez

I bought a rebuilt motor off a local. He said that he did the compression on my old motor and the numbers were 30-30-0