My Specs. I hope it helps everybody out a little. This specs have proven reliability and performance. For my Naturally aspirated engines I like a very tight fit with every single seal. Since N/A engine depend so much on compression and vacuum to make power I pay close attention to a tight fit. For Turbo, super charged and Nitrous engines I have different clearances. When I clearance an engine with a power added like turbo or nitrous I keep in-mind that this engines is getting artificially increased compression or twice as much more oxygen in comparison to N/A engines. In return I clearance with a bit more GAP then N/A engines. I try to allow more of a leak down from the clearance for turbo charged engines then N/A. With this leak down(from a slightly bigger GAP) for turbo and nitrous engines, I have found some reliability. Imagine if the engine does not have somewhere to leak some compression from a 35lbs boost engine, with out this sligthly bigger GAP, the engine is under some serious pressure on apex seals,corner seals and side seals and the posibility for broken seals are present.



With this explanation Ill give away some of my specs that have worked incrediable for me.

1)N/A engines. I clearance my apex seal to rotor groove to a .002 thousand of an inch. metric measurement is .051mm. Sideseal to rotor groove .0015 thats a thousand and a half, metric measurements is .028mm Sideseal to cornerseal I use, .002 of an inch. Metric is .051mm. Apex seal to rotor housing width I like keeping my apex seals .0015 to .002 smaller then the rotor housing with. This will give a tight fit for N/A engines with some really good vacuum. Pulling about 14 to 15 and sometimes 16 inches of vacuum.



2) turbo,nitrous engines.

Apex seal to rotor groove to .002 of an inch. metric is .051mm. Sideseal to rotor groove is a bit larger then N/A at .002 instead of .0015. Sideseal to Cornerseal I use .003 thousands of an inch .076mm.(DRAGON THE HOLE SECRET HERE IS TO MAKE SURE YOU HAVE .003 OF AN INCH ON EVERY SINGLE SIDESEAL TO CORNERSEAL GAP. THE WAY I DO THIS IS VERY SIMPLE, I MAKE SURE MY .003 OR .076MM FEELER GAUGE RUNS SMOOTH BACK AND FORTH THROUGH MY GAP BUT MY .004 OR METRIC 102MM FEELR GAUGE DOES NOT AND CANNOT PASS THROUGH MY .003 GAP THIS WAY YOUR SURE TO HAVE .003 ON EVERY SINGLE SIDESEAL ON BOTH ROTORS AND GIVING YOU EQUAL COMPRESSION.) it takes time but the benefits are well worth it. Apex seal to rotor housing width I like to stay .0015 to .002 smaller then the rotor housing width. I hope you guys have noticed a slightly bigger gap for turbo and nitrous engines, this has brought me some serious reliability and performance.Just an example I had one engine running 36lbs of boost and a 150nitrous oxide shot all together for 2 hole drag racing seasons and did not take the engine apart. On every single brutal run the engine came back like it was never abused. Fresh and ready for more. I have alot more sucess stories, but you guys get my point.

 

cool.. Thanks, I'll give it a try on my next engine...

 

I was wondering what method (like grinding, cutting, ect) you guys use for clearancing side seals and what tolerances you use.



Thanks,

STEPHEN

 

the dremel sanding bits are about the same diameter as the corner seals



mike

 

Thats a neat trick to know.

 

yeah i thought so too



mike

 

Do then just need to barely touch the corner seal or be pressed into the side of the corner seal?

 

i had this setup where the dremel was in a vice and you could use the desk to keep the seal straight, so you take off a little and check it, and so forth



mike

 

I use that same trick with a dremal in the corner seal hole of an old damaged rotor. It works great. I can't remember what the corner seal/side seal clearance is but it works out that the side seal is just barely loose enough for the spring to push it back up after you push it down.

 

Interesting, what bits do you use with the dremmel? Just a round sand paper bit? What grit is it? Couldnt it potentially make the edge to rough?



STEPHEN