The short story is I detonated my JDM swapped vert, broke the tip off apex seal, spun it around, crushed it and apparently spit out the pulverized pieces. So far as I can tell there is not damage to the turbo and I thought I had escaped damaging the rotor. BUT I cleaned the carbon off today and found this













And then also the apex seal groove took a hit where the seal broke













Useable?

 

Oh yeah...the culprit

 

i would replace the rotor. and definatly not use the mazda 3 piece seals lol. i have heard of a few guys in a pinch file down the areas that are dimpled with a sharpening stone and file the apex groove aswell but on a boosted motor i wouldnt unless you have no other choice. i actually have a matching set of fd rotors i can sell if you need a set of rotors.



randy

 

I'm taking the rotor to a machine shop to have them measure the suspect groove. My first choice won't be to use the rotor. If that spot allows the seal to wiggle too much I don't want to get into milling for 3mm seals. From what I've read they don't seal well and they are more prone to breaking...especially in turbo applications. On top of that there are no reputable rotary shops near me so if I did have the rotors milled I would send them off to be done. By the time I paid shipping and labor I could buy a rotor.



I'm interested in your rotors. My understanding is that FD rotors and FC turbo rotors are the same? Would you sell me one of yours if it balances with my good FC C weight rotor? I'm also going to need a front housing if you have one of those.

 

typical damage from preignition....



that groove looks like it might be savable, i would check all the other groove clearances first, and then see if you still wanna save it.



i had a rotor the other week that had similar damage to the apex groove, but it had a couple side seal grooves that were out of spec also, so its a paper weight.

 

I'll check side seal grooves over the weekend. Over all though everything other than the pics of the scar and the apex seal groove everything has been in spec. I put old corner seals and apex seals in and tested clearance between apex seal and groove. I did it with no springs and the seals only cleaned with a little acetone. I pushed the apex seal as far against the groove as they would go and tried sliding feeler gauges in. I have .003 difference between the suspect area and the same groove side on the opposite end of the rotor. I could slide a .003 feeler with difficulty across the hole seal. It was easier to slide on the suspect area. I could barely get a .006 into the suspect area but there was barely enough feeler to get pinched between seal and the groove. .007 wouldn't fit. I tested on another groove as a reference and had the same .003 that could barely slide, .007 wouldn't fit and .006 I had to work at.



Forgot to add this. I took the rotor to a machine shop and had him measure the groove. At it's widest where the damage is it measured 2.03mm

 

i'd have to look to see what spec is, but .003 is kinda big.



also the groove needs to be similar along the whole length, the ends like to spread apart.



again the other week, i had a rotor that was .0025 in the middle, but more like .003 near the corner seal. they gave me a pile of rotors, i picked the best 2...

 

[quote name='j9fd3s' date='09 July 2010 - 01:46 PM' timestamp='1278701202' post='934300']

i'd have to look to see what spec is, but .003 is kinda big.



also the groove needs to be similar along the whole length, the ends like to spread apart.



again the other week, i had a rotor that was .0025 in the middle, but more like .003 near the corner seal. they gave me a pile of rotors, i picked the best 2.



Haynes has standard clearance as:.0024-.004

and Limit: .006



I don't really understand Limit but I couldn't slide a .004 feeler and couldn't even fit the feeler down very far between the groove and seal

 

yeah its a little funny the way they list it. if you buy a new rotor and seal, it'll be right at the lower limit. .0025"



i guess its technically good until its .006, but i've never seen one that big, and usually they aren't straight. used rotors are usually bigger at the ends of the groove, so it'll be like .0027 in the middle and .003" at the ends. if it was .003 all the way across, that would be ok.





BTW the factory shop manual is at foxed.ca

 

I've got the FSM saved on my computer, but so far it's been easier to carry the Haynes around rather than find and print the FSM pages. Do you know any resources for the Mazdaspeed specs? Someone suggested I use those specs if I want a really reliable build. I was on Mazdaspeed Motorsports Development but I can't find or access any build specs.