Woodruff Key: 1 , Evan: 0

[Evan]

As everyone who was at Shenandoah this past weekend knows, I wasnt racing. Why wasnt I racing? Well read on:

Im still a little bit confused as to exactly what happened to the engine. It was a chain reaction of events that Im not sure is even related.
It started out with me starting up the car to warm it up to check the timing. While it was running I moved the truck/trailer around, and did some other little stuff. Came back about 20 minutes later and checked the timing (which was perfect, ironically) I got in the car to shut it off and OH FUCK the temp gauge is pegged. Could have been pegged for 10 minutes for all I know. Shut it down, let it cool off.
Figure out that the fan motor had gone bad. So I pulled a fan motor from my street miata, replaced it, started up the car and I hear a "fwap fwap" coming from the top end. So I pull the valve cover and the brand new less than 1000 mile timing belt is ripped. No clue how overheating could have caused this, but hey, it happened so I gotta deal with it. A pain in the ass to replace on the friday before a race, but I have a spare so no big deal.

Pull everything apart and the woodruff key wont come out of the crank. Odd, since it should just slide in and out. Pull it, tap it and it still wont come out. I decide that Ill just use a spare key so it doesnt matter if I mangle this one and proceed to twist it, beat it, pry it, take a torch to it, etc and it just wont come out.
Eventually it breaks off in the crank, which at the time I thought was a good thing, then I could just drill it out. So after pulling the radiator (which I had just finished flushing and putting in $15 worth of additives.......) I get to drilling. I end up putting a hole all the way through the woodruff key and it didnt budge.
I surrendered.
The crank is pretty messed up, if not for the stuck key, but how badly I mangled the key slot while prying, bending, and drilling. It sucks because I liked that engine. At VIR I could keep up pretty good with the 1.6s
Since not only is the crank mangled, but the overheating could have caused other problems, I think it would be a good idea to go with a new engine for the car.
So right now Im shopping for engine #3. I was planning on just getting my old engine rebuilt. Then at least I know it will be good and make good power. If the rebuild is too expensive I may just do a new crate engine from mazda. Either way isnt cheap, but hey, thats racin!

[Andy]

Have you looked into a matched crank from Advance. They sell a reman'ed crank w/matched bearings for a hundred or so

[.RJ]

matched perfect and staggered special?

[Evan]

Have you looked into a matched crank from Advance. They sell a reman'ed crank w/matched bearings for a hundred or so

Thanks for the tip, Ill look into it. I figure since Ive got to pull the engine out anyway I might as well get some work done to it. I definately would feel better with a new crank in it, even if I do my old engine


edit: advance wants $220 + core for the kit

[Sijray21]

that sucks man

i hope you can get this thing up and running with a new engine soon, hopefully not missing too many points races.

[Kaan]

You need motor work... RJ needs it... lets get to it. i'm down if you ever need help... just call.

[Andy]

Have you looked into a matched crank from Advance. They sell a reman'ed crank w/matched bearings for a hundred or so

Thanks for the tip, Ill look into it. I figure since Ive got to pull the engine out anyway I might as well get some work done to it. I definately would feel better with a new crank in it, even if I do my old engine


edit: advance wants $220 + core for the kit

If it helps, I have a 20% discount at advance.

[Evan]

[Maengelito]

you couldnt slide the crank pulley off? it should slide right out to give you easier access to the key

[ViPER1313]

Doesn't look to bad to be - get that thing out of there :!:

[white_2kgt]

You said you overheated the engine prior to trying to remove the key, did you wait for it to cool down before trying to take out the key?

[Evan]

you couldnt slide the crank pulley off? it should slide right out to give you easier access to the key

would have been the smart thing to do, but at the time i didnt think of it and didnt realize it would slide right off. Frantically trying to make a race the next day is not the best state of mind for making good decisions
after prying it off this afternoon


it might be hard to tell from the pic, but the slot in the pulley actually closed down on the key. Maybe the overheating had something to do with it?




so the good news is this engine may be revivable, at least temporarily.
The #1 problem is the mangled keyway (its actually worse than the pics make it seem), which with some loctite specific for fixing keyways may make a temporary fix. Not something i will run long term, but for a few races should hold together. New pulley and key is obviously in order, both of which i have from my old motor
concern #2 of course is the damage overheating did itself. the car idled fine but its impossible to know without load on the engine.

[Evan]

You said you overheated the engine prior to trying to remove the key, did you wait for it to cool down before trying to take out the key?

yes, it was very cool. I overheated it on thurs, and did the timing belt on fri

[ViPER1313]

I thought the key had nothing to do with the socket / crank pulley other than alignment at assembly time - that the pressure from the crank bolt held the whole shbang together through static friction between the pieces. So as long as the sides of the keyway are still decent, what would be the problem with putting a new key in and torquing it down?

[.RJ]

I thought the key had nothing to do with the socket / crank pulley other than alignment at assembly time - that the pressure from the crank bolt held the whole shbang together through static friction between the pieces

Yes, the woodruff key provides alignment for the sprocket/crank but without it the sprocket would never stay in alignment with the crank, and if the keyway is loose the key will eventually wear the keyway even further causing obvious problems.

[JustinG]

JB WELD....

[Evan]

I thought the key had nothing to do with the socket / crank pulley other than alignment at assembly time - that the pressure from the crank bolt held the whole shbang together through static friction between the pieces

Yes, the woodruff key provides alignment for the sprocket/crank but without it the sprocket would never stay in alignment with the crank, and if the keyway is loose the key will eventually wear the keyway even further causing obvious problems.

What RJ said.
Ironically, worn keyways are a problem for 1990 and early 91 miatas due to a short nosed crank. So there is plenty of documentation on the problem of a worn keyway and workaround/fixes.

this is an example of what happens when a little play develops in the keyway, then the vibration of the pulley wears it away


of course mine is not that bad (yet?) but it could easily develop into that.
there is a loctite compound developed by loctite engineers specifically for this problem, its Loctite 660 compound. Ill be using that to fix this, or at least for a temporary band aid.
I wont be too happy if i put all this work in fixing the crank and the headgasket is shot / head warped from overheating....

[Jeff]

I think the JBweld joke might have some valid aspect. If you can keep the key from moving that is all you need to do. Get the gear on there and JB the assembly together (new key to crank and then a bit on the gear itself) it outta be fine. I mean this is a ghetto way to do it but if you are gonna have to tear a motor apart anyway I would build a spare and run this one ghetto as long as you can.

NOTE - the post above was made as I was writing this.

[Andy]

I have a big ass thing of unused Loctite 660. Yours for 10 bucks.

[Maengelito]

speaking of crank problems on miatas, check out a sorta common problem on a loose bearing in cyl #4 for the 1999 miatas.

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yeah, that amount of play isnt very good. imagine the amount of fun that crank is having at 7k rpms. so atleast thats not your problem evan.