Mattdes26

iTrader: (1)

I am new to the rotary engines by about a week and I will be starting to strip the car down this fall to build up the engine. The car has 74,500 km on it. Should i do a refresh? also who in Canada does this and what needs to be done and how much?

thanks in advance for your help,

Matt

Mahjik

iTrader: (1)

A compression test will tell the health of the engine:

http://www.rotaryresurrection.com/3r...ion_check.html

Mahjik

iTrader: (1)

Also from the FAQ: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/faq-3rd-gen-other-useful-links-68640/

24) When does an engine need to be rebuilt? I heard FD engines only last 60k, is this true?

It needs rebuilt when the internal seals or components are damaged.
FD engines usually fail at one of these seals:
Apex seal - hard, spring loaded seal that separates the chambers of a rotor from each other. Often damaged by detonation, which is usually triggered by running lean under boost.
Corner seal - hard seal that fits at the ends of the each apex seal, helps separate the chambers of a rotor from each other.
Oil seal - Rubber O-ring that separates the chamber from oil flowing around the center of the rotor.
Coolant Seal - Rubber O-ring that separates the chamber from coolant flowing in passages in the rotor housing. Also called a water jacket.

Low compression indicates chamber-chamber leakage, either from overall wear or broken apex or corner seals. Broken apex seals cause the engine to suddenly run very rough and shaky with poor idle and little power. The car should be driven in this ‘limp mode’ as little as possible to avoid further damage to the engine internals and turbos. The most common cause of apex seal failure is detonation (from running too lean during boost), where the shock wave shatters the apex seals. This is sometimes referred to as 'grenading', 'blowing', or 'popping' your engine due to the sudden nature of this problem.

Symptoms of burnt coolant or oil in the exhaust, or combustion gases in the coolant can indicate damaged engine o-rings. A coolant pressure test is one test to detect this kind of failure. Overheating is the primary cause of o-ring failure, either by one overheat episode, or repeatedly driving the car too hard before it’s fully warmed up. Overheating can warp the housings, which exposes the coolant o-rings directly to combustion that breaks them down prematurely. Stock engines have had a history of coolant seal failure between 50-75k, probably because average owners were not careful enough with their treatment of the car, and because the stock temperature gauge does not provide a clear warning of overheating. Generally, the cooler the engine is run the longer it will last, and so most of the 'Reliability Mods' address cooling. Refer here for more info on the stock cooling system: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/big-fat-fd3s-cooling-thread-571088/

In good hands, stock FD engines without modifications have lasted over 100k. However, FD motors will never last as long as older NA motors because turbochargers add heat to the engine. Boost and higher horsepower always reduce the life of the engine.


25) What does a rebuild cost?

The cost of a rebuild varies. Exchanging your engine core for a Mazda remanufactured unit will cost around $3000 plus labor. Rebuilding an engine with no warped or damaged hard parts may cost less than $1500, plus labor. It is possible for an experienced DIYer with proper tools, clean workspace, and patience. Having a rebuilder do the rebuild provides options for additional performance, ranging from $2k for a stock engine to $5k+ for a performance ported engine. Many owners recommend keeping a few thousand in the bank in case (or when) it happens.

Mattdes26

iTrader: (1)

Mahjik,

thanks for the quick reply and ample info.

this site is great and has been more than helpful.

Does anyone know a good shop that works on these motors in the Ottawa/Hull area in Canada?

thanks,

Matt

RE-Amemiya

I'd search first, then ask in the regional section;

https://www.rx7club.com/canadian-forum-42/

Mahjik

iTrader: (1)

You'll have better luck checking the Regional section for Canada:

https://www.rx7club.com/forumdisplay.php?f=42

I'm sure there is info in that section for shops which work on rotaries. Good luck!

Mattdes26

iTrader: (1)

i guess my next question would be..

I have a good knowledge with standard big block engines and Motocross engines aswell. I race motocross and have torn down both 2 stroke and 4 stroke engines numerous times and my brother in law has a 427 pick-up truck and a 454 Chevelle that we rebuilt ground up.

Would I be able to do this work myself?

Mahjik

iTrader: (1)

Sure, if you have: time, patience and the proper tools. There is a lot information here and other places for working on the car, but like most other things in life you only learn by doing. For instance, I just did an engine rebuild but it failed after running for about 30 miles. Now I have to pay for parts to do it all over again and it's not exactly cheap. However, I'll never learn if I don't do it.

So you need to think about what's more important to you and then decide what fits. For some people, they have more money than time. Others, they have more time than money.

fd0

iTrader: (8)

Definitely true about you not learning without doing it.

When I first got my FD, I never pulled an engine and rebuilt one. I did all of that with only having oil and tire changing knowledge.

Now that I did it, I can say that I have no worries taking an engine apart.

Now for rebuilding one...still scared BUT at least I know all of the engine internals and how it should go...I'm sure I'm missing some sound engine building knowledge which I don't have from not enough experience.

BTW, mine lasted 1,000 miles...

2wheelsmoker

You guys are much braver than I am. I've had bad experiences in the past so 3 things I don't dare work on anymore are engines, carburetors (not with our cars), and body work/paint.

I leave those things to others who can give me peace of mind.