Hi,
I\'ve read lots of posts about people blowing engines and I was wondering if anyone has ever blown an engine in a completly stock and well maintained car. No engine changes, aero changes which restrict airflow into the engine etc.
I don\'t believe the FD is such a fragile car. I can easily believe that modifying it makes it that way.
Also is a rebuild necessary after 60-80k. Its my understanding that low compression doesnt mean the engine is going to let go. It gives poor starting and less power but doesnt mean the engine is going to fail.
I think the Rx is getting a bad rep here. I know a friend of mine in the US had a T2 which had over 120k on it no rebuild and it ran perfectly, T2 probably puts less stress on the engine though.
Paul
I would tend to agree with you. I don\'t have an FD but My 1st Gen had done over 140k miles before it went kaputt.
Bearing in mind that in the months before it died I had distributor/ignition and fuel flow problems which probably didn\'t help things too much. :(
It would be interesting to hear from anyone with a high mileage well maintained FD.
The naturally aspirated wankels (12a, 13B etc) can go on practically forever (My last Egi did 155k b4 the rebuild), but as wankel engines are essentially a low compression engine anyway, forced induction does kill them off fairly quickly in terms of mileage. (I\'ve seen a few FC3S with c100k and as a general rule they will start from cold but wont easily start from hot).
As a general rule low compression is the first sign that your engine is about to let go. What happens usually (From my experiences) is some or all of the following:-
1) Housing wear -> Chrome is eventually stripped off and a channel gets dug in the housing by the triangular section of the apex seal.
2) Plate wear -> Side and corner seals start to wear channels into the end/center plates.
If the engine fails on the above, its usually got high mileage, what can happen is preignition of the next lobe due to gases escaping through the worn areas, eventually the rotor loses compression and little or no ignition takes place.
3) Apex seal failure -> When high engine speeds and temperatures are reached the tip can distort, this increases wear, in some cases it actually starts to disintergrate. (See the thread on FD engine rebuild for a look at what that does to a housing!)
4) Worst case scenario (IMO) is tip seal wedging, I\'ve never seen it but from the sounds of it you can kiss most of the internals good bye if it happens. Basically, the apex seals are mounted on two springs to keep them pushed out and maintain the seal to the housing. When wear becomes excessive the amount of gap between the seal and housing is increased beyond the seals total depth and seal is sucked out of its slot in the rotor tip and becomes wedged between the rotor and the housing....
(Pro\'s please feel free to correct if I\'ve got that wrong)
On a N/A unit this sort of wear based failure occurs c125-150k miles.
On a forced induction unit this sort of wear based failure can occur as early as 35k but I\'ve seen some go as far 80k.
So, basically if you run the engine until it stops working then your rebuild is going to cost you anything upto £5000 (Loads more new parts, less parts can be reconditioned), wheras if you can get the rebuild done as soon as compression becomes an issue then it will most likely set you back around £3000. (Unless you do it yourself, in which case I normally budget around £1300)
I dont think the rex\'s rep is taking a knock here, people are speaking as they find. I totally agree that a standard car, well maintained and not thrashed should fall into the higher bracket of milage. (So around 140-150 n/a, 65-80 F/i) :)
I\'ve blown standard engines on Series 1, 2 and I\'m working on the 3 now....... :rollin :rollin :rollin
Of all of the rotary engines that Mazda have ever made the FD engine is the one most prone to not lasting very long.
I have done rebuilds on them in completely standard form from anywhere between 30,000 and 80,000 miles.
I strongly beleive that this is down to two things,
1.Driver style.
2.Maintenance and type of use.
To address point 1,
What I mean is if you are one of those people who has to drive the car like a nutter all of the time then it will not last no matter how many oil changes or how much maintenance you do.This is putting the engine under maximum stress all of the time.Driving hard from cold will do the same.
To address point 2,
If the car is properly maintained by regular oil and plug changes and is also not thrashed everywhere,or driven hard from cold,doing alot of Motorway mileage then the engine will obviously last longer in terms of mileage.
In the States that is why they often do higher mileages than here.
Cruising at a steady speed means that you are not running much boost and the stress on the engine is lower.
Short in town hops also increase wear dramatically.
The older engines including the turbo 2 were not anywhere near as stressed as an FD engine.They are bound to be able to put in higher mileages.
This is an honest opinion of how these engines really are.
Kind regards
Carl
From what I\'ve seen over the past 2-3 years theres a lot of luck involved. They can go on for a long time, they can call it a day very early in life however :(
The 13B I had in my FD for about 15 months was a lucky one. It took heaps of abuse including a 1 mile each way trip to work with no warm up/down. Consistent boost of 1-1.05bar on the stock fuel system. Regular (i.e. every time I hoffed it - which was all the time) boost spikes to any thing from 1.2 to 1.5bar. In that period it did about 12000 miles, 10000 on a set of plugs (10 and 11s). It flooded twice when it got cold, largely down to the ecu (chipped RE-A) I imagine. Last time I heard the guy who bought the engine had stuck another 10K on it I think, its now been sold so no ideas who\'s got it or if its poo\'d itself yet. I had it with 35K, sold it with 47K so it must\'ve been about 60K by the time the guy sold the car on...
I\'ve busted motors in all except two cars I\'ve owned. Those 2 cars being my red FD and my silver FD :)
As Carl says, I dont think these motors have huge longevity to be honest. You have to balance the cost of an FD (not a lot) against its performance (exceptional) against its fragility (not inconsiderable) and the cost of engines \'now and then\'. If you want reliable then a Porsche is x times the cost of an FD and maintenance costs probably a lot higher. For me the FD is still a VERY cheap performance car all in, you get a lot of FD rebuilds for the cost of a skyline rebuild :D