engine tear down and put back together
10-18-11, 01:46 AM
#1
Rotary Enthusiast
Thread Starter
engine tear down and put back together
what "HAS" to be replaced after tearing down an engine to replace just the apex seals? i bought a block a while ago and i suspect two stuck seals on the rear rotor so if i cant untick them....
10-18-11, 02:49 AM
#2
The coolant seals, the little washer like main bolt seals. Usually the front cover gasket tears, usually intake gaskets tear. Exhaust gaskets can sometimes be reused...But why waste the labor and gaskets when you already went through all the work of opening it up. Truthfully, the best thing to do will be to rebuild it while it's out.
Personally, I wouldn't place all your hopes in stuck apex seals since you can tap them with a brass punch, LIGHTLY through the exhaust ports to unstick them in extreme out of options cases. I've only had to do that a few times as a last resort before tearing down an engine with a presumed apex seal problem or carbon sticking. I used to push on them with my finger through the exhaust port after assembling an engine with the old 3 piece seals to make sure they have the spring action because I would cheat and dab a tiny dot gasket cement between the apex parts to make the apex seal one complete piece to ease installation. that seal would seperate into 3 upon initial startup. But I'd make sure it would still spring in and out of the rotor before firing the engine since it is possible for the cement to glue the seal to the rotor as well. Sure it would unstick it self after a few minutes of running, but I'd rather have it fire on all sides when first start came around.
If you have the engine out, then it will be easy to test the spring'y ness off the seal, just by pushing right on the tip via the exhaust ports. Better yet, you get a good look at the seal it self. It might not be stuck, but toast.
Personally, I wouldn't place all your hopes in stuck apex seals since you can tap them with a brass punch, LIGHTLY through the exhaust ports to unstick them in extreme out of options cases. I've only had to do that a few times as a last resort before tearing down an engine with a presumed apex seal problem or carbon sticking. I used to push on them with my finger through the exhaust port after assembling an engine with the old 3 piece seals to make sure they have the spring action because I would cheat and dab a tiny dot gasket cement between the apex parts to make the apex seal one complete piece to ease installation. that seal would seperate into 3 upon initial startup. But I'd make sure it would still spring in and out of the rotor before firing the engine since it is possible for the cement to glue the seal to the rotor as well. Sure it would unstick it self after a few minutes of running, but I'd rather have it fire on all sides when first start came around.
If you have the engine out, then it will be easy to test the spring'y ness off the seal, just by pushing right on the tip via the exhaust ports. Better yet, you get a good look at the seal it self. It might not be stuck, but toast.
10-18-11, 03:01 AM
#3
Rotary Enthusiast
Thread Starter
it was rebuilt by some random. i was just concerned because when i turn it over by hand after oiling it it chugs strong on all 3 faces of the front rotor, but only strong chug on the rear with two slight sshhhh on the other two faces but i wonder if once fired up itll free up and be fine. may just be the vasiline etc holding it all in and not sealing properly yet???
10-18-11, 03:30 AM
#4
This is my social media.
iTrader: (22)
Join Date: Jan 2006
Location: WA
Posts: 2,744
Likes: 0
Received 0 Likes
on
0 Posts
You haven't taken it apart yet? If that's the case...
This is tough. Because you don't want to install the manifolds, plugs, wires, fuel rails, fluids, etc. to find out that it isn't going to run properly... But on the other hand, you don't want to tear it down in case you're able to "unstick" the apex seals by other means, and then have to spend more money for a soft seal kit.
This is tough. Because you don't want to install the manifolds, plugs, wires, fuel rails, fluids, etc. to find out that it isn't going to run properly... But on the other hand, you don't want to tear it down in case you're able to "unstick" the apex seals by other means, and then have to spend more money for a soft seal kit.
10-18-11, 03:55 AM
#5
Rotary Enthusiast
Thread Starter
I think option a might have to be the go just hope for the best and if necessary then remove and rebuild unless anyone else has a recomendation. cheers
10-18-11, 10:48 AM
#6
recommended replacement:
apex seals(since yours are unknown)
apex seal springs(don't install used springs on new seals, the springs usually are etched and worn from carbon deposits within several thousand miles)
oil seal o-rings(the OEM seals aren't reusable even with a few hundred miles on them even if they look like new still, they WILL leak)
corner seal springs if yours are the original wire type, spend the few dollars to upgrade these
corner seal plugs, they're rubber and get deformed easily
coolant seals, inner and outer
dowel pin o-rings for the upper dowel pins
tension bolt washers
front and rear main oil seals(just spend the $15 to avoid leaks and hours of headache replacing them later)
front cover gasket and oil galley o-ring
that is the necessities, unfortunately it is also close to a typical basic rebuild kit... in all you're looking at about $500-650 for parts.
some coolant seals and oil seal o-rings are reusable(OEMs for these 2 circumstances are 100% not reusable after a VERY short time). i rebuild engines with more durable seals than OEM produces which are reusable to a certain extent which helps with the rare warranty claim and for those who race and tear down their engines regularly.
apex seals(since yours are unknown)
apex seal springs(don't install used springs on new seals, the springs usually are etched and worn from carbon deposits within several thousand miles)
oil seal o-rings(the OEM seals aren't reusable even with a few hundred miles on them even if they look like new still, they WILL leak)
corner seal springs if yours are the original wire type, spend the few dollars to upgrade these
corner seal plugs, they're rubber and get deformed easily
coolant seals, inner and outer
dowel pin o-rings for the upper dowel pins
tension bolt washers
front and rear main oil seals(just spend the $15 to avoid leaks and hours of headache replacing them later)
front cover gasket and oil galley o-ring
that is the necessities, unfortunately it is also close to a typical basic rebuild kit... in all you're looking at about $500-650 for parts.
some coolant seals and oil seal o-rings are reusable(OEMs for these 2 circumstances are 100% not reusable after a VERY short time). i rebuild engines with more durable seals than OEM produces which are reusable to a certain extent which helps with the rare warranty claim and for those who race and tear down their engines regularly.
Last edited by RotaryEvolution; 10-18-11 at 10:54 AM.
10-19-11, 04:06 AM
#7
It's a newly rebuilt engine that's never been fired? Tough call then. Try pushing on the rear rotor's seals a few times each apex seal and turn the engine over.
Double edged sword really. It may free up by pressing on them or firing the engine, or it may not and you'd be wasting some gaskets.
I'd say fire it and see what happens. It's only about 40 dollars in gaskets that go on the outside of the engine. If those seals don't free up, then you're only out about 40 dollars and a couple hours of labor. Just opening up the engine will cost you a lot more, and would be a bummer if you found out it really has been all rebuilt and never ran, only needing that initial start. The builder may have done what I sometimes do and used a tiny dab of glue to make the 2/3 piece apex seals one solid seal to ease installation, and some extra glue could be wedging it into the rotor tip. But of course, maybe it's completely opposite. Tough call man.
Also, spray some oil in the cylinders, turn the engine over a few times and let it sit over night.
Double edged sword really. It may free up by pressing on them or firing the engine, or it may not and you'd be wasting some gaskets.
I'd say fire it and see what happens. It's only about 40 dollars in gaskets that go on the outside of the engine. If those seals don't free up, then you're only out about 40 dollars and a couple hours of labor. Just opening up the engine will cost you a lot more, and would be a bummer if you found out it really has been all rebuilt and never ran, only needing that initial start. The builder may have done what I sometimes do and used a tiny dab of glue to make the 2/3 piece apex seals one solid seal to ease installation, and some extra glue could be wedging it into the rotor tip. But of course, maybe it's completely opposite. Tough call man.
Also, spray some oil in the cylinders, turn the engine over a few times and let it sit over night.
Trending Topics
Thread
Thread Starter
Forum
Replies
Last Post
ncds_fc
New Member RX-7 Technical
1
08-15-15 10:06 AM
