Blake1101

I recently bought a long block and swapped all my parts over from my other sr my old motor spun a bearing. Long story short got the new motor in the car kept having issues it was acting like a bad Maf got all the bugs sorted out. Drove the car around the neighborhood it would break up a little on the bottom end plugs and one weak injector. But once I got into boost it felt slow and I was getting really bad blow by oil was shooting out of my blow off valve every time I let off the gas. Hooked my catch can up it helped a little checked my pcv valve it was good. So I was lost so I said screw it why not do a compression test 145 on 1-3 but 30 on #4 put a little bit of oil on top of the cylinder and it went up to like 125-130 im assuming rings.

Now here is what I want to know one does that compression restorer stuff that you put in your oil work and would it be harmful to my oil pump and turbo etc.

If I decide to do rings on that one cylinder should I order rings for the stock bore or go oversized and do them all

Looking forward to hearing some opinions thanks

Javi802

you cant do rings for a larger bore on stock pistons. You need the correct rings.

Did you buy your swap from a shop of from somebody?

Blake1101

I bought it from a guy that runs a shop
I was told it had no known issues it was his old motor he was doing a 1jz swap in his clearly I was lied to the guy seemed pretty honest I tried call him and got no answer

Javi802

go to his shop and call his ass out on it. Im assuming he didnt give you a warranty?

If not, then it is technically not his problem, but it doesnt make it right for him to take advantage of a naive person trusting him. I hate that shit, but i do believe in karma, so he'll get his.

Good luck. I recently bought some cams from somebody via online classifieds and turns out one cam is fucked. Which he did not disclose. So now ill be paying more than what a brand new set would have cost me.

zombiewolf513

Youre gonna need to take the engine apart, have the cylinders honed, then replace all of the rings. You cant really just do one cylinder, you dont want to just do one cylinder.

If the guy runs a shop and he took the motor out to install another, chances are he knew it had bunk compression

Kingtal0n

and repeat the compression test one more time to be sure you didn't just get a bad reading.

would sure be a shame to take apart an engine on the whim of a single compression test.

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zombiewolf513

I agree with this

Blake1101

Did a few more compression test yesterday I haven't really had time to mess with with work and all compression numbers were the same did it with the engine cold and warm closed throttle and open throttle same all the way.

I was on Frsport I'm thinking just ordering rings for that one cylinder and a head gasket.
Giving #4 a quick hone this is all depending on how the walls look.
It's only like $75 to do this so I guess what's the harm in trying if it works cool if not.

Plan 2 order oversized Pistons and take it to the machine shop and let them do them all
Then I get a 1 year warranty but I'm looking at like 300-500 depending on which Pistons I get and not sure on what the machine shop will charge we just had a forklift motor rebuilt by them and it was only $500 for them to do the bottom end and check the head but we diddnt supply parts they did

Let me know opinions guys thanks

Blake1101

I know most are going to say do it all but it shouldn't hurt to try out that one

brndck

first things first, go kick the teeth out of whoever sold you an engine with shit compression on one cylinder. I still don't understand why people buy used engines without a compression and leakdown test done before money changes hands.

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Blake1101

I checked the oil pan for shavings and pulled the valve cover before I bought it Super clean I diddnt have my compression test with me a co worker had it motor was clean inside an out and a somewhat reputable guy he deals with a lot of reputable shops out sr specialist in Georgia bought a head from him and some other stuff so i saw no harm super nice older guy if it was some kid I wouldn't have took the chance but yeah I'm pissed it's almost worth the hour and a half drive to give him a nice right hook to the face and tell him he can have the sr back and I'll just take my money back or the 1j

TurboTiger

Have you contacted the guy that sold you the long block?

Blake1101

Called multiple times no answer and a email and its a hour and a half drive I'm not stressing I talked to my buddy today he said I should be fine as long as the walls aren't bad

brndck

Oh well as long as your buddy says it's good . . . . . .

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TurboTiger

Hmmm...

Well, I hope it works out for you. Let us know what happens.

zombiewolf513

Let me tell you why you shouldn't just change the rings in only one cylinder.

You'll have 145ish psi on cylinders 1-3, then 160+psi on cylinder 4. That difference in compression in the cylinders is just as no bueno as bad compression on one cylinder.

Plus, if you already have the engine apart to change the rings and have a whole new set of rings, why would you go through all the trouble to change just one cylinders rings, then have to come back 6 months later to finish the job by having to install the rest?!

Why are you going with oversized pistons again?

slow40sx

yeah, if you're tight on money I would get a full set of stock rings, re-hone each cylinder and it should be fine, assuming the ring lands aren't cracked on cylinder 4 which is probably the case, but then you can just buy a new stock piston as long as the #4 cylinder wall is ok which it probably is

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