ultimatejay

Well I got some good news and bad news. The good news is that I tried a thicker spacer and now my end play is ok at .0025.



The bad news is that somewhere during the stacking process I used one of the o-rings for the oil filter housing for the o-ring that goes in the rotor housings( the ones that go in the upper dowel pins). I think I am going to have to tear down the whole stack, unless you think it is not neccessary. The oil filter housing o-ring is a little smaller in diameter but thicker than the rotor housing o-rings. What should I do? $Hit!!!

Lynn E. Hanover

Do the right thing.



There is nothing like the thrill of heading to the door after a long day in the shop with two engines assembled, and lifting up your boot to see what is it that is making that clicking sound.



Why, its a brand new corner piece for an apex seal. There are some long days, and there are some short days. What are the chances that the first engine I disassemble will be short a corner piece?

A math major would say 50%/50%. The correct answere is zero. It is missing from the second engine.



Things go better with lots of light. A clean floor. A big piece of white poster board with a complete set of

parts for one engine laid out in their order of use as the engine goes together. Telephone off. Classical music turned down low. No interuptions. No extra parts for anything on the wall or on the bench where you work.



And of course, super glue the corner pieces to the big piece ahead of time. You are going to rotary school, and getting smarter every day. it needs to become a learned response. One day you will save a kid a bunch of pain when you do a free rebuild on a tailgate at a race. You are a member of one of the smallest clubs on earth. You can assemble a rotary engine. Most of the people at a Mazda dealership can't do that.



I still have to think my way through the oil scraper spring direction thing. My last engine build was in October. An IT race engine. A SCCA class that requires a stock engine. That one was all new parts supplied by the owners and I had that problem with the long rear stationary gear. If I build one Monday I will have to think about the spring direction when I build up the rotors. I just have to do it each time. I draw a direction of rotation arrow on both sides of each rotor to help me with the spring thing. It is a lot easier to fix it now than it will be when that "O" ring starts leaking three months from now.



And look. You get to build another rotary. Lucky dog............



Lynn E. Hanover



I'm on the left. Mike Bashem from Chicago on the right. Crew chief of the red 78 GT-3 (third gen).

Rub20B

I'm doing some things to a Renesis engine to make it more fitable in a first gen..



Now before I had the front pulley pully of I could "feel" a little endplay, now whe have swapped the timing gear and front cover etc.. now everything is assembled again and I can feel no endplay at all.. the engine does turn freely and I checked it plenty of times the needle bearing was not crushed.. its sits at the right place.. I haven't measured the enplay yet with the dial indicator yet but I *think* it feels alot less than before I disassembled it..



https://www.nopistons.com/forums/index.php?...view=getnewpost



Here you can see the progress.. everything is assembled because I havent had the stack apart I didn't think I could have changed anything on it..? Or am I wrong? The timing gear was 0.05mm thicker I think..



What should be the end play range for a renesis?

Lynn E. Hanover

I don't know what is called for in the new engine. However, since the object of the end play is to be sure you are not running the needle races the whole time the engine is running, all you need is a bit of play. If you do not scream the engine, as little as .001" would work. As high as .004" would work as well, in a street engine. The thrust plate, the washers and the needles are as hard as Chinese arithemetic. The race is not a tapered roller race, so there is a geometry problem because each roller has its ends describing a different circle diameter. So since the roller can only turn at one speed, that means that part of the roller is not rolling, but sliding on the thrust face every time it is used.



Should you get the end play short enough to keep the bearings spinning the whole time the engine runs, one or the other bearing will fail. Usually the rear bearing when a conventional clutch is used.

Sooner if a high pressure clutch is used. A good reason to keep the car in neutral rather than hold the clutch pedal in at lights.



For the minimum of .0025" it may be difficult to feel by just shoving the crank fore and aft. For .003" to

.0035" generally you can feel that little clunk as the clearance is used up and stops the crank.



You need to know that there is some clearance, and you need the magnetic base dial indicator for that. The Harbor Fright catalog has a very nice setup for about $15.00. Sometimes on sale.



Lynn E. Hanover



picture is my TDC finder rig.

ultimatejay

Yeah, I am going to tear it down. Good thing is that I am almost positive it's on the rear housing so it will not be that bad. Anyways, I want to take the rear stat. gear out and check the bearing for any binding due to my irons being lapped.



Regarding the oil spring deflection- I would just buy new one's everytime. They're cheap and color coded. But I guess if you have a race engine that you are tearing apart on a daily basis then I would see why you would not buy new one's everytime.



I'll let you know what I find on my partial tear down.

Lynn E. Hanover

I am looking forward to the answer.



I regard looking at the paint dots is actually cheating.



Lynn E. Hanover



Picture is my Camel Lights GTP car.

A rotary of course.

Chris1966

Only one word for Lynn......WOW



You have done everything on these things! Personally I dont lap that much off. I bin the plates when they get that far out of spec. Besides the machining is too costly over here in a small town.



Now, I can easy see how the endplay could be affected by the rear stat gear; but only in extreme cases of grinding larger amounts off the plates (which I didn't think possible). Each amount compounds through the engine stack and shortens the assembly. However, in normal cases it is possible to set the thrust buy just slipping the front stat gear on the eccentric shaft and loading the appropriate parts to make the thrust setup functional while holding it together with a couple of bolts and nuts; and of course the front pulley bolt. I've seen it done this way but wasn't overly impressed with it. The rest of the engine isn't even necessary so generally a lap wont do anything to alter the thrust. Personally I prefer to just dumy (no seals) the engine and check the thrust with everything in alignment. I'm not good enough to eyeball squareness when 0.0035 thrust is required. Put simply, the thrust setting is simply a function of the clearance between the front stat gear and the rest of the loaded components on the eccentric shaft held together by the front pulley bolt.



But I stand corrected by the master himself. Hey, Lynn has helped me out in the past so I don't mind learning more about it all from him. The man should write a book. I'd buy a copy that's for sure.



Glad you got it sorted anyway.



Cheers



Chris.

Lynn E. Hanover

[quote name='Chris1966' date='Dec 31 2007, 03:01 PM' post='891174']

Only one word for Lynn......WOW



You have done everything on these things! Personally I dont lap that much off. I bin the plates when they get that far out of spec. Besides the machining is too costly over here in a small town.



Now, I can easy see how the endplay could be affected by the rear stat gear; but only in extreme cases of grinding larger amounts off the plates (which I didn't think possible). Each amount compounds through the engine stack and shortens the assembly. However, in normal cases it is possible to set the thrust buy just slipping the front stat gear on the eccentric shaft and loading the appropriate parts to make the thrust setup functional while holding it together with a couple of bolts and nuts; and of course the front pulley bolt. I've seen it done this way but wasn't overly impressed with it. The rest of the engine isn't even necessary so generally a lap wont do anything to alter the thrust. Personally I prefer to just dumy (no seals) the engine and check the thrust with everything in alignment. I'm not good enough to eyeball squareness when 0.0035 thrust is required. Put simply, the thrust setting is simply a function of the clearance between the fro

Lynn E. Hanover

Thank you for that.



For a great finish when funds are short, just smear lapping compound onto a plate and slide another plate on that. Hard to do at first, Takes almost nothing off and makes a big mess. The compound can be reused if you can collect it. It dries out but can be thined with oil or water depending on what kind you get. Even valve grinding compound works. Work in about 2" circles for 15 minutes per side. It won't take out all of the wear marks but will generate a quick sealing surface that is a nice flat grey and is very flat. Scrub off with soap and water, then at the car wash. Take the WD-40 with you to keep the rust away.



Lynn E. Hanover



Picture is one of two Riley Chassis my friend Mike Shank will run at Daytona in Janurary. He now has Roush Ford power.

ultimatejay

This is turning out to be a great info thread for sure! I have checked in other forums and haven't found much info on lapping and end play. I hope this helps out others too because it sure has helped me.



Had to work all day today. Boo. Going to take the engine apart tomorrow and post some pics. of what I find.