Never rains but it pours!!

[Prof]

Fated not to drive my car much this year
 
I got to work this morning and noticed a smell of burning oil/rubber - so popped the bonnet and there was oil around the filter - thought it might have just been a lose filter or failed O ring seal, as the engine was running fine.
 
Looked under the car to see a lot of oil dripping out underneath - not good.
 
Shut the engine off, checked oil level - just below low level on the dipstick - yikes - I only filled/checked this on Sunday at Japshow.
 
So filled it and started the engine again - oil pressure good, temps normal, engine running ok - drove carefully to Rotechniks and it\'s still ****ing oil out.  Seems it has a hairline crack on the rear iron casting just along the ridge between the rear rotor and the oil filter tower - bugger !!
 
It\'s an engine out and rebuild - which is a ****er because the engine is running fantastic now - means I\'ve got another run in period to go through !
 
Hopefully get the car back before JAE - but I won\'t be able to smarten up the crappy paintwork or get any further with the upgrades - is this car ever destined to look the business and go like the clappers ?
 
one very ****ed off and dissapointed prof...
 
(by the way - I don\'t hold Rotechniks to blame for this - the engine was running sweet from day 1 of the post rebuild run in, and this crack has become apparent only today - guess it must have been a casting weekness that\'s just taken time to come to light)

[pete sparrow]

Unlucky sir:( Hope all goes well with the re-build etc.What upgrades are you planning?

[sadgoth]

that is ****! Sorry to hear about that mate

Hope you get it sorted soon.

[Brett]

Man that really, really sucks
When is the lump coming out?

 You might as well just give all the goodies to me until the engine is sorted :Giggle

[grinder]

bloody hell dave - i bet your not impressed at all

[kev-yorks]

Dave reuse all the seals etc just change the rear iron and you will just need a few miles to resettle it all down.
Kevin

[Carl]

This should be fairly easy and cheap to fix,Rotechnics ,as Kev said,only need to change the back plate,the engine should not need totally dismantling either.
Usually a crack in that part of the back plate has been caused by some serious detonation.
Regards
Carl

[mpk490p]

Bad luck Dave sorry to hear about this, like you say just as things were running sweet, at least you wernt doing 90 on the motorway only to see your oil behind you!

Mark

[colin5524]

unlucky, but at least it will be  one less thing to go wrong next time, chin up!;)

[Prof]

Been doing some research on this - seems Mazda started strengthening the rear iron in the area of the oil filter pedestal from late 89 onwards.  So s5 irons should be stronger, but possibly I got an early one - who knows?
 
There is an article on this over on rx7club :  http://www.rx7club.com/printthread.php?t=576705
 
makes some interesting reading.
 
Again echo\'s what Carl said re detontation, and I did lose an engine a while back due to overboosting - so possible the iron was weakened then - and finally failed now ?
 
I don\'t know if Rotechniks reuse old irons - but I know I got new rotors and housings this time around.

[g.miller]

Sorry to hear about your car Dave.
After all the work and thought you have put in you deserve the thing to work.
good luck with it, and lets hope Ro T. keep the price down.
Grant

[Prof]

Well it should be back in my hands next week - so in time for JAE and a good excuse to put mileage on it.
 
It\'s getting a beefy back casting - the one with the angled section between dowell landing point and the oil filter pedestal.  The dowell landing area is also twice the thickness.  The iron that was on the back was the earliest incarnation - no strengthening and smaller dowell landing.
 
Still trying to understand why it failed, but one theory is that it may have cracked due to torque twisting - harder engine mounts and soft gearbox mounts leading to a twisting motion.  On 2nd gens the engine mounts are on the centre iron, so any twisting force is transmitted through the dowells to the rear casting and then through the bell housing and gearbox.
 
Possibly a casting weekness ?  The engine has not been run hard or tuned up to any great power levels - the boost controller is still running very low settings and of the 2500 miles on this engine, 1000 of those were run in miles.  It\'s not been driven that hard since the accident, as I wanted to be sure there were no suprises waiting around the corner for me.  The bent offside hub was the last gotcha - everything else including tracking is all sorted now.  Just some bodywork and painting to do.
 
The thread over on the rx7club is also not conclusive as to why this happens, except to reveal I had the weaker casting on the engine.  You have to ask why Mazda would strengthen the casting twice in that area - must be some problems they noticed with cars coming back for service.
 
Interesting...

[noyzboy]

Dave,

Looking forward to seeing you sitting in Rexxy with a big grin on your face at JAE.
I\'ll be late. Have to send family to Cyprus AM Sunday.

Martin H