milano maroon

I am working on my engine rebuild (first time for a rotary) and have been getting my rotors ready. The previous side seal clearance was running pretty loose - around .008 in. So I bought a set of new side seals and have been working with them. But I have a couple of questions which I hope you guys can help me with.



I have used feeler gauges before for stuff like valve lash and spark plugs so I am familar with how they are supposed to "feel" but using them on these side seals is kind of a challenge. It seems like I can get the gap so that a .002 in. gauge barely slides in and is pretty tight and then if I barely sand the end of the side seal (using 400 grit wet or dry paper) all of a sudden the gap kind of gets bigger - goes to .003 in. or so. I have been able to move the seals around so far and I now have most all of them pretty tight - less than .0015 or .002 in. I am getting ready to go through them one more time. I am shooting for .002 or .0025 in.



But here is what I don't get. It seems like the corner seals all have a small clearance, maybe .002 or more. I haven't measured them but I can see them move a little bit when I put pressure on the gap with the feeler gauge. So are there some rules about how to do this? Should all 3 corner seals and side seals be in place when you check clearances. Do they kind of work together? If one side seal is real tight does that one affect the clearances on the other two? Is there a correct sequence of how to do this?



I have been getting the side seals to their basic length but a little tight. Then removing the corner seals and making sure the side seals spring up and down freely. But what I am finding is that once the corner seals are in the side seals sometimes stay down in their groove even though I have .002 or so clearance. The corner seal will move up and down even when the side seal stays in the groove or sometimes it will pull the side seal back out with it. My side seal to groove clearance is OK, usually from .001 to .0015 in. so I don't think that's a problem.



I don't know if I explained my questions very well but I am hoping someone can shed some light on this whole process. Maybe I am doing something wrong. Anyway, any help would be much appreciated.



Thanks,



Jeff

j9fd3s

yeah bascially you need to get them all in the grooves so that they can all move without binding.



my last motor took a lot of time, cause fit each seal to each groove with the other seals IN the groove.



also i bet most of us are not really measuring, but more like the seal is tight without binding, it is hard to get the .002 gauge in there.

milano maroon

Thanks for the reply. So when you push down on the seal to see if it will spring back up, is it OK to hold or push the center of the seal down? It seems that when I do that the seal springs back more easily on the ends. If I just push on the end maybe the edge of the seal is not parallel to the corner seal and it gets bound up a little easier. It seems that in the engine pressure will be applied uniformly across the seal keeping the edges of the ends parallel.



You're right, it is difficult to accurately measure these gaps when you only have a couple of mm. to work with. I guess it is better to err on the loose side but I was hoping to get the most compression possible.



What happens if they are fit too tight?



Thanks again,



Jeff

j9fd3s

if you're a little too tight it'll bind up, might get better as you drive it, the seals get shorter as they wear.



if its way way too tight, they when you try and put it in the groove you'll break the corner seal, i did this. got impatient



also try different seals in different grooves, used rotors move around a little

Lynn E. Hanover

Too tight might be a bit of a problem starting up. But snug or zero is what I set all of mine at. Zero. So long as both side seals and the corner pop back up after being depressed, that is all that is required. Push them all down with a piece of plexiglass and let go. If you just push the ends of the side seals down, then you are making the seal longer, and it will bind up.



The seals wear in very quickly, and good power and easy starting will be yours with zero clearance.



This is for NA engines only. Not nitrus or turbo.



Lynn E. Hanover



There is a rotary in there.

milano maroon

Thanks again for the replies - this is really helpful.



Are the side seals supposed to be able to move up and down independently from the corner seals? Should I expect to be able to push just a side seal down without pushing the corner seal and have it pop back?

djgiantrobot

yes and yes

j9fd3s

turbo goes a little looser, but really sometimes i do it like an na, they run fine.



the caveat is that in this area actually uses about 40hp, so 400hp means you may be able to redline 1st gear

Dave D

Hey Lynn,Could you pm some more pics of your Gt car's front suspension?That looks like an interesting steering setup,or am I just looking from an odd angle?

Dave

Lynn E. Hanover

Not until May. There may be some pics on my machine in Hebron Ohio, or I could take some pics for you.



This machine has few pics to look at. We will be in Zephyrhills Florida until early May.



Most street cars suffer from bad roll steer because of short "A" arms and short control arms. Just cheap is what they are. The minimum. for money reasons. Most race cars are just racing versions of street pieces, made in all shiny metals to attract racers. Most race cars are just hopped up street cars, because most racers have no money.



If you design your own cars, you can have it any way you want. So I have the longest lower "A" arms I can squeze into the chassis. The inner ends at the front pivot on bolts side by side. The "A" arms (latteral links) are just Coleman circle track pieces with 3/4 rose fittings. (Monoballs). The rear link of the "A" arm is a Coleman clevis and 1 1/4" tube running back to the side of the trans. The trans was in the way or I would have the rear pivots side by side as well.

So, there is no measurable roll steer induced by the lower "A's" at all. All roll steer is controlled by the upper links. You do want some roll steer, to help the driver. So we induce a bit at each end. Roll under steer at both ends. So, if you dial up a corner going a bit too fast, you can just let off the power a bit and get some weight transfer to the front end and once you have the apex "made" you go back on the power, straddle the apex, and come out looking like you know what the hell you are doing.



The uprights (knuckles) or the things the spindles are on ar Mustang II. The lower ball joint hole is bored out to 3/4" for a 3/4" bolt to go through the Coleman monoball. A pak of spacer on that bolt can raise or lower the outer pivot point, if you want to maintain angles while changing ride hight.



I sawed off the spindles and welded on quick change axel stub tubes from Speedway Engineering. So all 4 corners use the aluminum rear hubs from a mini quick change. Huge bearings. Inner and outer the same size. So all 4 hubs are the same. the rotor mount plates are the same. the left side rotors are the same and the right side rotors are the same Coleman 72 fin 12" by 1 1/4"



The upper end of the upright is drilled out to 1/2" for a 1/2" bolt many spacers againt to control latteral link angles. Both latteral ant fore and aft links pivot on the same bolt, so no upper "A" arm is required.



Roll steer, caster, camber, and rates are all adjustible. The pieces are cheap and bullet proof.



Both inner ends of the steering links are 2" apart. Adjustible up and down for roll steer and mounted on a tiller bar. A shortened Ford Festiva steering box using just one arm runs the tiller. The Festiva rack at the time were widely available and cheap. A collapsable steering shaft and Borgeson U joints complete the steering. Never a problem with any of the running gear.



PM me after May for more pictures.



Lynn E. Hanover