I am in the process of getting ready to do an engine rebuild for my FD. I have already selected a mechanic but I have yet formulated the receipe for the rebuild.

I cannot decide whether or not I should use used or new parts in this rebuild.

The main parts in question are:

Rotors
Rotor Housings
Side Housings
Eccentric Shaft
Oil Pump and Chain
Stationary Gears
<if i am missing something, please insert here>

After talking to several mechanics, I have come to the conclusion that many are just salespeople. If I tell them I'm limited for funds, they say you don't need new parts, if I say I have the funds, they seem to always be able to give me a reason why I should use new instead of used.

Would a nice soul out there please educate me and explain whether or not I would need new parts and if the difference warrants the price?

My goal is to get the 0-60 on my FD to around 4.5 (when driven by a professional driver, since I understand skill is a definate factor).

Thank you.

 

Wish I new those answers also. All I can contribute from my research is that Mazda min' specs are not good enough and top builders go by their own specs. I will enlarge the water & oil passages when I do mine so I will replace whatever parts I am told need to for that.

I can share some secret sauce: All internals can be heat coated. I can't say if every part is worth it since it may burnish/ware of from friction. I've only found one builder that has heat coated the side housings and that is RR&R. Pinnaple will cryo treat. I'm not sure what kind of heat coating that is. All the heat shields can be coated. Turbo intake pipes. Turbo, exhaust, upper & lower maifolds can be coated. If you prefer you can use a chrome looking coating for the manifolds. This is import to protect the wiring harnes. Why that has been overlooked, I don't know.

 

Bump

 

You only need new rotors if yours are dented or scraped up. They clean up nice. Side housings can be re-sufaced. Rotor housings can be re-used if they aren't damaged badly. Essentric shaft can be re-used if it hasn't been burned up (lots of blue areas). Stationary gears can be re-used if there isn't any noticable damage. Oil pump and chain can be re-used. Check the chain though. If it's too sloppy you will need a new one (NO biggie).

 

That's good to know. There is someone on the forum that had a race ported engine done and they reused dented rotors. I don't want to mention the shop or person or the price.

Eccentric shaft could be reused it it was heat coated in the first place. Glad to see bi-state coats their rebuilt twins.

 

Parts use depends on the shape of the old parts. If they spec out they can be reused without a problem.

1) Rotors can be used if they are not damaged. The apex seal/corner seal, side seal etc need to be mic'd to see if they are ok to reuse. High milage rotors may look ok but can be out of spec.

2) Rotor housing can be reused if they are in good shape and have NOT be overheated.

3) the rest of the stuff is usually ok unless the engine failed beacuse of oil pump failure etc. inspect all the parts to see if they meet Mazda spec.

BUT buy all new seals, springs and gaskets, do not skimp.

 

0-60 has nothing to do with rebuilding your engine

it should not be your main focus

20k -60k should be your focus

that is, how soon do you want to repeat this process

 

I don't think anyone has ever translated this to Pisston english. You expect a timing belt to go at about 80k mi but it can break at 60k or even last 100k. The best solution is to change it before it breaks leaving you to replace internal engine parts.

So if we look at the apex seals as wearable like the timing belt, then we should be "expecting" a rebuild every 80k mi. But if we do it "before" the Apex seals puke out the turbos then parts can be reused and cost kept to a minimum.

Yes we can get screwed with o-ring failure which is more common on our cars but doesn't mean you can't thrash a pisston block just the same.

The main difference here is the price. If you look at it like an exotic sports car like a Porsche or Ferrari then the price is expected for the luxary of owning one.

 

Hmm, perhaps the minimal number of responses in this thread was due to the preception to the lack of common sense on my part to acheive a lower 0-60. I need an engine rebuild because the o-rings on my car have failed. I refered to the 0-60 to give an idea to any helpful people that could provide advice on how strong of an engine rebuild I would need. I understand that there are a number of factors involved in determining ones 0-60. Suspension, tires, skill, and etc all play a big factor. I am just preparing the engine to reach such a feat as easily as possible. Hope that clears things up.

 

From my experience, which although not extensive, is very recent, I have found this. Usually, the cheapest way to go about a rebuild is to get a remanufactured motor from Mazda (cheapest place to get it is through Ray Crowe at Malloy Mazda 1-888-533-3400, it's $2240 with gaskets and shipping) and have the shop of your choice rip it apart and inspect everything. The reason for this is that the quality of Mazda's rebuilds has been sketchy, and it's the best way to ensure you're not putting a time bomb in your car. And if you have the shop crack open your motor, and things are out of spec and need to be replaced, which KDR told me they often are, it usually ends up being cheaper to start with a fresh motor.

While checking the mechanic should be able to modify the engine. I'm having mine street ported, which is basically englarging the intake and exhaust ports to yield higher top end power, some say as much as 20%. The shop is also enlarging the coolant passages to keep it cooler. Advantages of street port: more power, but not too much less low end power or loss in driveability as other ports. Disadvantages: some loss in low end torque. This alone should be a big helper in you achieving performance goals.

You could do it with a non-ported motor, and it has been done may times by members of the forum, but it just gives you that extra push. I figured if I have to buy a new engine, might as well go all out and get the engine I want. Without the port you would just need more mods or more extensive tuning to get to the goal. Your choice. Good luck.

 

The above makes sense if your engine blew it's apex seals but does not seem to be a good solution for o-ring failure. With the $2.4k you can buy new rotors and housings, so unless the side housings need to be replaced as well it comes out to the same initial cost.

For those of you that have had both types of failures, which is more costly? ...or does more internal engine damage?