rebuild whole motor or not??
07-04-07, 10:16 PM
#1
mmm doritos
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rebuild whole motor or not??
ok so i have a 87 TII that ran i put an atkins rebuild in and it ran great last summer i parked it for the winter and for the install of a microtech and T04R so the engine only has like 5k on it... now i took it to get tuned and the guy did a comp test and the front rotor has awesome compression but the rear rotor is crap..he said he could just pull the back plate off and redo the rear rotor since the front is good or he could redo the whole thing...what would you do? keep in mind this motor only has like 5k on it
07-04-07, 10:40 PM
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Did he test the compression before or after the tune? I'm pretty sure atkins has a warranty. Return the engine.. have them fix it? not sure what all that would entail for you...
07-04-07, 10:56 PM
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well i never botherd too send in the warranty info so thats kinda out of the question...and he did the test before he tuned it cause it was runnig kinda shitty during idle and what not
07-05-07, 12:25 AM
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As long as all of the ATF burned off, I'd say just re-do the rear rotor... no reason to buy more than you have to... But, if you WANT.... its not much harder to do the whole thing.. Just more money. Probably not much prep work or cleaning involved at 5k.
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07-05-07, 02:17 AM
#9
It could just be sticky seals from sitting. You might try some atf, 2 cycle, etc. in the chamber to see if it frees up after a few days. Heck, try some penetrating oil, it won't hurt anything.
The problem with just pulling the rear iron off is that the pieces all tend to stick together. When you pull up on the iron, the housing and the stuff in front of it often tends to break apart too. Coolant seals are pretty much a one-time-use thing. Even though you drain the block of coolant, there is a little residual coolant in the passages, so when you lift the plates apart, some of that coolant will get on the seals. Same for motor oil that is still on the irons and in the rotors.
So...what happens if one of the housings toward the front of the engine come apart and the seal shifts out of place, or coolant or oil gets on it? Well, it's kinda like a kiddie swimming pool with a hole in the bottom. You can dry it off clean and put tape on the hole, and the tape will stay sealed even once water is applied. But, if you lift the tape up and let water underneath it, the tape will never seal the hole again. That's the way coolant seals are.
Also, coolant seals compress when the stack is first tensioned down, and seat themselves to a particular place on the adjacent housings. When you untension the block, the seals don't really expand back out like new, and so it's more likely you'll get a weak seal that way, too.
For this reason, I don't like the idea of doing it this way, because it's possible you could induce a coolant seal leak by trying to save yourself a few hours and a hundred bucks in coolant seals. Then you will be doing it all over again, again.
I have done it this way before, however, and have had pretty decent luck at it the few times I have tried. What I do is come up with a way to keep tension on the rear rotorhousing and the rest of the stack...usually involving some rope or wire tied onto the rear rotorhousing exhaust studs, wrapped around the front iron, and then onto the rear rotorhousing sparkplugs. You still have to be really careful, and if you think you have shifted or violated one of the 3 frontward sealing surfaces, you may as well just unstack the whole thing and clean it back to bare metal, and reseal it with new seals.
The problem with just pulling the rear iron off is that the pieces all tend to stick together. When you pull up on the iron, the housing and the stuff in front of it often tends to break apart too. Coolant seals are pretty much a one-time-use thing. Even though you drain the block of coolant, there is a little residual coolant in the passages, so when you lift the plates apart, some of that coolant will get on the seals. Same for motor oil that is still on the irons and in the rotors.
So...what happens if one of the housings toward the front of the engine come apart and the seal shifts out of place, or coolant or oil gets on it? Well, it's kinda like a kiddie swimming pool with a hole in the bottom. You can dry it off clean and put tape on the hole, and the tape will stay sealed even once water is applied. But, if you lift the tape up and let water underneath it, the tape will never seal the hole again. That's the way coolant seals are.
Also, coolant seals compress when the stack is first tensioned down, and seat themselves to a particular place on the adjacent housings. When you untension the block, the seals don't really expand back out like new, and so it's more likely you'll get a weak seal that way, too.
For this reason, I don't like the idea of doing it this way, because it's possible you could induce a coolant seal leak by trying to save yourself a few hours and a hundred bucks in coolant seals. Then you will be doing it all over again, again.
I have done it this way before, however, and have had pretty decent luck at it the few times I have tried. What I do is come up with a way to keep tension on the rear rotorhousing and the rest of the stack...usually involving some rope or wire tied onto the rear rotorhousing exhaust studs, wrapped around the front iron, and then onto the rear rotorhousing sparkplugs. You still have to be really careful, and if you think you have shifted or violated one of the 3 frontward sealing surfaces, you may as well just unstack the whole thing and clean it back to bare metal, and reseal it with new seals.
07-05-07, 05:10 PM
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thats some good info to know thanks....i think he has given up on the atf treatment he has tried it and it didnt help...he said that what he uses to keep the other housings from separating is those long slider clamps that wood shops use to clamp wood together while the glue dry's...and he said that he has done it many time's and has been succesful....i think the atf treatment was just a last ditch effort thing for him to do....and as for the rotor housing its brand new so it has to be a bad seal
07-05-07, 05:53 PM
#11
I see this a couple ways.
One being fix whats bad, save some money.
One being you've rebuilt the engine and put zilch for miles on it. The rebuild went bad. Its only bad on ONE rotor........but the actual engine experienced a full on premature failure. Sure only one rotor has decent compression....but maybe the other one is 5K behind the other for pre-mature failure? Might get even closer after shimmying it around to do 1/2 a rebuild.....
In the long run to do the whole thing is not much more money.....but infinitely more peace of mind. You decide.
One being fix whats bad, save some money.
One being you've rebuilt the engine and put zilch for miles on it. The rebuild went bad. Its only bad on ONE rotor........but the actual engine experienced a full on premature failure. Sure only one rotor has decent compression....but maybe the other one is 5K behind the other for pre-mature failure? Might get even closer after shimmying it around to do 1/2 a rebuild.....
In the long run to do the whole thing is not much more money.....but infinitely more peace of mind. You decide.
07-05-07, 06:32 PM
#12
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well im pretty confident that the engine went bad from sitting or from detonation on startup after the microtech and new turbo instalation...so my engine builder said since the front rotor had such good compression that he would like to try and just remove the rear rotor and have a look at what went wrong and to be able to tell if it was a shitty build or what not...then determine wheather to just do the rear or do the whole thing..he quoted me like 500$ to just do the rear rotor if i bring the short block to him...do u think thats a good price and how much would it be to do the whole thing on average?
07-05-07, 06:44 PM
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well im pretty confident that the engine went bad from sitting or from detonation on startup after the microtech and new turbo instalation...so my engine builder said since the front rotor had such good compression that he would like to try and just remove the rear rotor and have a look at what went wrong and to be able to tell if it was a shitty build or what not...then determine wheather to just do the rear or do the whole thing..he quoted me like 500$ to just do the rear rotor if i bring the short block to him...do u think thats a good price and how much would it be to do the whole thing on average?
If you are one of those people that needs the piece of mind, then I suppose 500 bucks is worth it. I suspect 200-250 of that is labor though.
07-05-07, 06:54 PM
#14
mmm doritos
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i dont think i have the proper tools and i dont even know what exactly im supposed to "clearance" so that probaly means i should keep my hands off right? lol and i have no idea how to install an apex seal
07-05-07, 07:00 PM
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However, if you aren't confident, don't do it.. You'll hate yourself if you do it wrong, this way.. you have a finger to point and somebody to fix it.
07-06-07, 03:15 PM
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I'm going with the seals just maybe "stuck" from sitting. Try tow starting it. It worked for my 2 JSPEC motor swaps. They both had 0 or near 0 compression in the rear rotor, but after the tow start and some persuasion they both have strong compression on both rotors. I'm not saying it'll work for you, but it's cheaper than a rebuild if it works.
07-07-07, 09:56 AM
#21
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yes i have gotten it running up around 4k and the motor seems to smoth out when you take it up to higher rpm's...what do u mean when you say other issues?
07-07-07, 04:12 PM
#23
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ok well i got the motor pulled today and i examined the seals thru the exhaust ports and i think there fucked...on the front rotor all the seals feel great and you can hear good compression just turning the motor by hand...on the rear rotor one seal the one side of it feels good and springy and the other side just pushes right in and dosent spring back the the next seal dosent even stick out like its compleatly stuck in the rotor or brokin off?? then the next seal you can push it in and it kinda just falls back down but it dosent really spring back it just falls back out and makes a tick sound when it does....so what do you guys think?
07-07-07, 05:07 PM
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the car did run low 13 second quarters on a stock hybrid already and used to run damn good so doubt that someone left the springs out lol but what would cause a warped spring? i just hope now that there is no damage to the rotor or my BRAND NEW HOUSING!!!