the bigger the seal the better, right?
#1
Full Member
Thread Starter
Join Date: Jun 2002
Location: New York
Posts: 217
Likes: 0
Received 0 Likes
on
0 Posts
the bigger the seal the better, right?
I guess there is some contraversy over bigger apex seals, but I dont see the problem, if the seals are bigger, they can withstand more, allowing for more boost, resulting in greater power. Am I right, or wrong?
#2
um.. more seal = more surface contact
surface contact = more friction/drag
friction/drag = more heat
more heat = needs more cooling
ALso, there is more drag, so it takes more power to turn over the rotors.. well if you're upping the boost then i guess taht's not a problem.
Look the Mazda engineers spent a SHITLOAD of time researching the perfect inbetween size. 2-3mm is good enough for wahtever you need IMO.
surface contact = more friction/drag
friction/drag = more heat
more heat = needs more cooling
ALso, there is more drag, so it takes more power to turn over the rotors.. well if you're upping the boost then i guess taht's not a problem.
Look the Mazda engineers spent a SHITLOAD of time researching the perfect inbetween size. 2-3mm is good enough for wahtever you need IMO.
#4
What Subscription?
Join Date: Apr 2001
Location: Aiken SC USA
Posts: 5,926
Likes: 0
Received 0 Likes
on
0 Posts
From Pineapple:
First of all, 2mm seals are perfectly fine for extremely high boost levels. Many people sucessfully run 20+ psi on stock 2mm seals with no reported problems. However, 3mm seals are much more durable and not all of us have (1) great tuning skills and (2) the financial resources to shrug off a small tuning mistake that requires a full rebuild. One hard ping and a 2mm seal will likely break. 3mm seals generally take much more tuning abuse (multiple, hard pings), which is often enough margin to back off and save the motor. Also, we use a special 2-piece 3mm seal that, when it does fail, tends not to cause subsequent damage to rotors and housings. While getting the rotors machined out for 3mm seals and purchasing the seals themselves costs a bit more, it does not begin to compare to that of a second rebuild. For this reason, we recommend 3mm seals to customers who plan to exceed stock power levels and/or go with aftermarket fuel injection systems. Again, it's not mandatory if you have advanced tuning skills or are willing to risk a second rebuild, but 3mm seals are relatively cheap insurance.
First of all, 2mm seals are perfectly fine for extremely high boost levels. Many people sucessfully run 20+ psi on stock 2mm seals with no reported problems. However, 3mm seals are much more durable and not all of us have (1) great tuning skills and (2) the financial resources to shrug off a small tuning mistake that requires a full rebuild. One hard ping and a 2mm seal will likely break. 3mm seals generally take much more tuning abuse (multiple, hard pings), which is often enough margin to back off and save the motor. Also, we use a special 2-piece 3mm seal that, when it does fail, tends not to cause subsequent damage to rotors and housings. While getting the rotors machined out for 3mm seals and purchasing the seals themselves costs a bit more, it does not begin to compare to that of a second rebuild. For this reason, we recommend 3mm seals to customers who plan to exceed stock power levels and/or go with aftermarket fuel injection systems. Again, it's not mandatory if you have advanced tuning skills or are willing to risk a second rebuild, but 3mm seals are relatively cheap insurance.
#5
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,826
Received 2,594 Likes
on
1,842 Posts
#7
Lives on the Forum
Re: the bigger the seal the better, right?
Originally posted by red xeven
I guess there is some contraversy over bigger apex seals, but I dont see the problem, if the seals are bigger, they can withstand more, allowing for more boost, resulting in greater power. Am I right, or wrong?
I guess there is some contraversy over bigger apex seals, but I dont see the problem, if the seals are bigger, they can withstand more, allowing for more boost, resulting in greater power. Am I right, or wrong?
Also, there is no "protection" of the apex seal against damaging detonation.  Due to the dynamics of the combustion chamber, the force of the detonation is actually "funneled" against the apex seal, which is one of the big reason the rotary engine tolerates very little detonation.  A piston engine with either blow head gaskets (relatively "easy" job to replace and fix) or the damaging force needs to blow by the piston land before it hits the piston rings.  Piston tolerances are TIGHT, and rings can be really far down the piston skirt - all of which help to protect the rings against blow-out from detonation.
-Ted
Thread
Thread Starter
Forum
Replies
Last Post
Jeff20B
1st Generation Specific (1979-1985)
73
09-16-18 07:16 PM
Snook
Single Turbo RX-7's
18
10-08-15 10:09 PM