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-   -   engine binding???? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/engine-binding-724342/)

mightymite Jan 25, 2008 10:05 AM

engine binding????
 
just got the engine together. before i went over all the bolts to tightn down to spec.. i turned over the engine by hand on the flywheel. now here is where im not sure every 2.5-3 rotations, the engine feels like its binding. it happens when i turn either direction.

i got to thinkn maybe its the comprestion stroke and im just fighting against compressing air but i dont think that is the cause i have nothing bolted to the engine oil and fuel injectors spark plugs and what not


what would cause this? do i need to split the engine again?

Aaron Cake Jan 25, 2008 10:34 AM

Did you do any porting? There may be a flash of metal left at a port edge.

Are there any clicking noises? If so, then something bad is going on.

Personally I never rotate an engine until the tension bolts are down. The apex seal corner pieces have a habit of getting where you could never imagine they can be.

pfsantos Jan 25, 2008 10:38 AM

Are the spark plugs in? That would be the only way the engine would bind due to compression.

Did you jam/drop the torrington bearing at the front? Other than that looks like post above.

mightymite Jan 25, 2008 10:50 AM


Originally Posted by Aaron Cake (Post 7783194)
Did you do any porting? There may be a flash of metal left at a port edge.

Are there any clicking noises? If so, then something bad is going on.

Personally I never rotate an engine until the tension bolts are down. The apex seal corner pieces have a habit of getting where you could never imagine they can be.

i did no port work

there are no clickn sounds or snag feeling its just gets tight then lose after for maybe a .25 of a rotation every 2.5 to 3 times i turn it over

i have all the bolts in there snug but not toqued

QUOTE=pfsantos;7783202]Are the spark plugs in? That would be the only way the engine would bind due to compression.

Did you jam/drop the torrington bearing at the front? Other than that looks like post above.[/QUOTE]

nope the bearings are fine

speakn of bearings

im thinkn the eshaft may be out of wack or a rotor is..... i got to thinking i had 2 engines i biult this one from, one of the engines the eshaft bearings was shot had alot of uneven wear on one side of the rear bearings if the eshaft is out of round it looks like it would cause this kinda wear... so could it be shaft if i put a slighty out of round in it? i thought i grabed the good eshaft =/

Tofuball Jan 25, 2008 10:53 AM


Originally Posted by Aaron Cake (Post 7783194)
Personally I never rotate an engine until the tension bolts are down. The apex seal corner pieces have a habit of getting where you could never imagine they can be.


I've done that before. ONCE.

I didn't know till after I heard the crunch :P

K-Tune Jan 25, 2008 11:19 AM

yep i didnt even try to turn my motor till everything was torqued down properly.

mightymite Jan 25, 2008 11:25 AM

well im still thinkn its the eshaft. ill have to check it after i get everything tightned right..... i have one main worry can i split the engine if need be. i have oem seals and i know after u lets the engine go through a heat cycle or two u cant reuse the seals.... so can i reuse the seals??

micah Jan 25, 2008 01:20 PM

When I built my 12A, I clamped it together the first time... and it wouldn't turn over smoothly... bearings were in check, etc... Couldn't figure it out... took it all apart, put it all back together.. and it spun freely.. never figured it out. At first I thought I had pinched a seal.. but.. that wasn't the case.

Aaron Cake Jan 25, 2008 02:18 PM

It is possible there is a seal binding due to improper cleaning, or you have a high spot on one of your bearings. If it was my engine I'd just eat the price of a new set of coolant o-rings and pull it apart again. Then inspect seals, groves, bearings, etc. for any signs of problems.

mightymite Jan 25, 2008 06:34 PM

y shouldnt or y couldnt i reuse the coolent seals.. i dont see any reason y i couldnt i dont have tention bolts tightnd all the way and i never started the engine.....

Aaron Cake Jan 26, 2008 10:46 AM

If the engine was not tightened, you should be able to reuse the seals.

hypntyz7 Jan 26, 2008 11:10 AM

Most likely, either you didnt clean all the carbon out from under the apex seals in the rotor grooves, OR you're using glued-together 2pc seals and the glue hasnt broken on one or 2 of them yet. Sometimes the glued seals don't break apart until you have the starter on the engine.

mightymite Jan 26, 2008 11:55 AM


Originally Posted by Aaron Cake (Post 7786821)
If the engine was not tightened, you should be able to reuse the seals.

so what your sayn is the rubber seals seat and dont expand once there compressed regaurdless of heat

hypntyz7 Jan 26, 2008 03:34 PM

IF they've been wet, it's possible to reuse them but you have to be meticulous in wiping them bone dry with towels. If they havent been wet, then you can reuse them, even if you used hylomar, vaseline, etc. to hold them into the irons. If you put a drying RTV sealant on them, it will be harder to get them clean to reuse.

sevensix Jan 26, 2008 08:10 PM

glad i found this topic. i just torqued down my rebuild.. how easy should it be to turn it?? i can't turn it just grabbing onto the eshaft but if i attach the front counterweight its turnable, but takes force

hypntyz7 Jan 26, 2008 11:39 PM

You should be able to use 2 or 3 fingers and spin a 1/2" drive ratchet on the front bolt. Or turn the flywheel by hand half a turn at a time. Assuming you lubricated the bearings and shaft during assembly, and assuming there is a little lube in the chambers, with no sparkplugs.

On engines with glued together 2pc seals, it is normal for the engine to "click" or "pop" internally the first few rotations, or for that matter while you are tensioning it down. This is when the glue breaks and the seals come apart. Sometimes the glue doesnt break until you turn it several times, sometimes not even until you hit it with the starter to spin really fast.

It is not uncommon for one of these glued seals to cause the engine to have a tight spot during hand rotation, until it breaks free. Sometimes I will be turning a block by hand and it will have a couple of tight spots, but after 5 or 10 rotations it pops free and spins much easier in those spots.

mightymite Jan 27, 2008 09:25 AM

well my seals arent glued but thanks for the info on that......

can anyone else tell me if i can reuse my coolent seals?

mightymite Jan 27, 2008 11:28 PM

id like to thank everyone for there help and bump.....

Captain Jean-Luc Picard Jan 28, 2008 04:13 AM

Uhm, I think you have been given a more than adequate answer by more than one person thus far about the reuseability of the seals...what more do you want?

mightymite Jan 28, 2008 06:29 AM


Originally Posted by Captain Jean-Luc Picard (Post 7793790)
Uhm, I think you have been given a more than adequate answer by more than one person thus far about the reuseability of the seals...what more do you want?

well i would like more answers bcs right now 1 person siad yes and another said no so how do i know if ill be ok if i reuse my coolent seals... id like some more first hand in put

pfsantos Jan 28, 2008 09:49 AM

The water seals are reusable if you haven't started and heat cycled them yet.

Once they stick to the housings and come apart and stretch when you remove them, you know they're done.

This would be a good time to double check that the water seal seam is in the right location as per FSM. If in doubt, ask.

In regards to the apex seal side piece, you're supposed to cut off excess glue that sticks out (if any).

mightymite Jan 31, 2008 12:46 AM


Originally Posted by pfsantos (Post 7794321)
The water seals are reusable if you haven't started and heat cycled them yet.

Once they stick to the housings and come apart and stretch when you remove them, you know they're done.

This would be a good time to double check that the water seal seam is in the right location as per FSM. If in doubt, ask.

In regards to the apex seal side piece, you're supposed to cut off excess glue that sticks out (if any).

thanks....

update i got the engine split i took the front housing offf and turned it over and it still feels the same a lil less do to the slop but now im 100% sure the problem is on the back half of the engine....so im going to swap out the rotor and eshaft ill post a update for those who care after i put it back together over a cup of coffee in the morning

im going to glue the seals this time i didnt last time but it was a slight pain getn the seals right...mazda never glued there apex seals did they?

oh one more thing the corner seals "the tiny triangle shaped apex seals" on both the front and rear rotors face the rear iron right?

hypntyz7 Jan 31, 2008 02:53 AM

mazda apex seals come glued together (short end piece). Aftermarket seals do not, however for ease of install it is possible to do it yourself. Just take an iron, wipe off both mating surfaces of the apex seal, put a drop of glue, and lay the pieces on the iron and slide them together. Within a couple of seconds, slide the entire seal around slightly to keep it from drying to the iron face, then remove it. Lay it aside on a towel or something. Use a razor to scrape the glue off the iron, and repeat. When they are all dry, use the razor to gently scrape the glue off the sides of the seals...this is very important.

mightymite Jan 31, 2008 01:35 PM

ok after splitn the engine i looked at the eshaft and i in fact did use the better of the 2 i had....so i didnt replace it or the rear rotor. i put it back together the way it was and some how no binding.. i still dont know what caused it but its fixd now


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