FD 20B street/autocross build
09-02-13, 10:14 PM
#26
These 2 housings are the worst thing I found, but I'm not sure if they're ok. Any thoughts?
This one has a groove that is close to the outer edge, inline with the edge of the apex seal. It's not real deep but seems to be marginal at best to me... It appears the apex seal was stuck, maybe got carbon behind it.
It appears that it got hot enough to discolor the chrome too.
This one looks really good except some chrome flaking, that from what I read is well within spec.
This one has a groove that is close to the outer edge, inline with the edge of the apex seal. It's not real deep but seems to be marginal at best to me... It appears the apex seal was stuck, maybe got carbon behind it.
It appears that it got hot enough to discolor the chrome too.
This one looks really good except some chrome flaking, that from what I read is well within spec.
10-01-13, 10:43 PM
#30
Thank you, I know everything is pretty dirty and cut and dry for now, promise to clean stuff up and take more fun pictures soon
Ok, thanks. I can't decide if I should send them to goopy to have them refinished or just run them. The 20b seal kit is so expensive I really want to do this right the first time...
10-02-13, 04:05 PM
#33
I'm liking the reviews on goopy, and really like the idea of his oversize ones and getting the clearance right at .0015. A bit of extra work but probably makes a nice tight high compression engine.
10-02-13, 04:20 PM
#34
Original Gangster/Rotary!
iTrader: (213)
What is the step wear on the irons? Looks like you measured for it.
Based on the pics I'm not sure I'd send those housings out to be resurfaced..... if there isn't grooving or irregularities it won't make a big difference IMO. Now the chrome flaking I don't like the looks of. Ideally you'd use rotor housings with zero flaking, but that gets expensive in a hurry with a three rotor.
Re: apex seals, for an N/A engine it's a bit silly to use any 'unbreakable' seals IMO. I've owned two shops over the last decade and have built quite a few engines. You have to ask yourself, what are your goals and application for both the engine and the car? For a non turbo rotary, you absolutely cannot go wrong with the Mazda OEM 2 piece 2mm apex seals. Any of the unbreakable seals are meant to save engine components under detonation from, you guessed it, a turbo application. They also will not be as kind to rotor housings as stock apex seals, I have yet to see this disproved.
Your rotor apex grooves should not be loose enough that oversized seals will help you..... I'd bet that if you clearance the setup with new OEM seals you'll have a nice two thousandths, which is perfect. If you're concerned with compression and a nice tight motor turn your attention to the side seal to corner seal clearance.
My two cents, best of luck with the build
Based on the pics I'm not sure I'd send those housings out to be resurfaced..... if there isn't grooving or irregularities it won't make a big difference IMO. Now the chrome flaking I don't like the looks of. Ideally you'd use rotor housings with zero flaking, but that gets expensive in a hurry with a three rotor.
Re: apex seals, for an N/A engine it's a bit silly to use any 'unbreakable' seals IMO. I've owned two shops over the last decade and have built quite a few engines. You have to ask yourself, what are your goals and application for both the engine and the car? For a non turbo rotary, you absolutely cannot go wrong with the Mazda OEM 2 piece 2mm apex seals. Any of the unbreakable seals are meant to save engine components under detonation from, you guessed it, a turbo application. They also will not be as kind to rotor housings as stock apex seals, I have yet to see this disproved.
Your rotor apex grooves should not be loose enough that oversized seals will help you..... I'd bet that if you clearance the setup with new OEM seals you'll have a nice two thousandths, which is perfect. If you're concerned with compression and a nice tight motor turn your attention to the side seal to corner seal clearance.
My two cents, best of luck with the build
10-02-13, 10:46 PM
#35
Based on the pics I'm not sure I'd send those housings out to be resurfaced..... if there isn't grooving or irregularities it won't make a big difference IMO. Now the chrome flaking I don't like the looks of. Ideally you'd use rotor housings with zero flaking, but that gets expensive in a hurry with a three rotor.
Re: apex seals, for an N/A engine it's a bit silly to use any 'unbreakable' seals IMO. I've owned two shops over the last decade and have built quite a few engines. You have to ask yourself, what are your goals and application for both the engine and the car? For a non turbo rotary, you absolutely cannot go wrong with the Mazda OEM 2 piece 2mm apex seals. Any of the unbreakable seals are meant to save engine components under detonation from, you guessed it, a turbo application. They also will not be as kind to rotor housings as stock apex seals, I have yet to see this disproved.
Your rotor apex grooves should not be loose enough that oversized seals will help you..... I'd bet that if you clearance the setup with new OEM seals you'll have a nice two thousandths, which is perfect. If you're concerned with compression and a nice tight motor turn your attention to the side seal to corner seal clearance.
Goopy Performance Apex Seals
Thank you for the input, I am really new to this and am really at the mercy of what I find online. There is a guy in Tucson (RXforyour7) who has been racing rotaries for over 30 years, he said if I paid him $150 I could burn up an hour of his time with questions and answers. But he hasn't ever seen a 20B, and has been pretty difficult via email.
10-03-13, 11:15 AM
#36
i run the oem apex seals in my motor, they have flex armour fortifacation on them. It is a new process that pettit racing does. He rebuilt my motor and did it. It is a 2 rotor with a full street port and ported turbos, and a 4" exhaust. I track my car a lot and i have had no issues what so ever with my motor.
