Ring end gaps. If you've built your own engine post up!
 

So here's the deal. I started putting the bottom end of my ZC back together sunday night. I go to set the end gaps for the rings and am a little worried about the clearances.

Starting from the bottom. The oil control rails had a gap of 0.030" out of the box so I didn't touch them. All four of the 2nd compression rings had a end gap of 0.015" so I didn't touch those either. The top compression rings, for the most part, had a gap of 0.018" out of the box. One or two of the top compression rings were slightly tighter (0.016" - 0.017") so I did file those to 0.018". I was, and still am, worried about that end gap but I thought it may be better to keep it consistent.

Are the end gaps ok? I have been told not to worry about the oil control rails as you offset the gaps anyway. The 2nd compression ring is dead on but the top compression ring just seems too loose. I have asked around and have been told everything from "order new top compression rings" to "don't worry about it".

DOHC ZC block bored .5mm over. The rings are also .5mm over. If I do order new top rings should I get them 1mm over?

Any help would be great. Thanks.

Re: Ring end gaps. If you've built your own engine post up!
 

http://thezcr.com/assets/images/zcbook/2a-2.jpg

Re: Ring end gaps. If you've built your own engine post up!
 

I know the OEM specs. Thanks anyway.

Re: Ring end gaps. If you've built your own engine post up!
 

if it's at OEM spec then you shouldn't have any problem. did you check the side gaps too?

Re: Ring end gaps. If you've built your own engine post up!
 

No I haven't check the side gap yet. For a FI application the end gaps need to be looser than OEM spec but I don't want to be too loose. OEM spec for the top ring is VERY tight.

edit: Here are the minimum end gaps per JE.

http://www.jepistons.com/pdf/piston_instrc4032.pdf

I just need to know if I'm within the recomended spec and / or what others have succesfully run in the past. I called JE but the tech wasn't in so I had to leave a message.

Re: Ring end gaps. If you've built your own engine post up!
 

according to their chart your pretty loose.... id think youd want it to be in the .015. i think you already know what you should do but dont want to so you want someone to tell you it will be ok. im not gonna tell ya either, im just gonna tell ya im sure it will run fine the way it is but its obviously out of spec.

Re: Ring end gaps. If you've built your own engine post up!
 

That's not it at all. I'm not looking for reinforcing any premonition I have. This is the first time I have built an engine so I am looking for some feedback. The specs on JE's site (I think the street / strip or whatever category it is) states a minimum of 0.015" but doesn't give a range like OEM specs. I honestly do feel that the top ring is too loose but since I have never built an engine before in my life I want to make sure that my feeling is correct since I have no experience to base it off of.

Me getting my opinion reinforced is pointless. All I want is someone with some experience to give me some feedback.

Re: Ring end gaps. If you've built your own engine post up!
 

all rig gaps i have seen for a honda have mic'ed out perfect and required no filing, i recomend factorey spec rings (std. or o/s).

Re: Ring end gaps. If you've built your own engine post up!
 

I just got off the phone with JE and the tech said that the acceptable range was 0.015"-0.020".

Re: Ring end gaps. If you've built your own engine post up!
 

mindless you still hangin around lynchburg?

Re: Ring end gaps. If you've built your own engine post up!
 

Yeah. Just trying to get this damn thing together. The majot stuff I still need are : adjustable cam gears, wideband, and clutch.

Re: Ring end gaps. If you've built your own engine post up!
 

so far i have done 2 zc's and the 1st one lasted me a long time with boost. i rebuilt the thing over 2 years ago and it finally gave out after some time on a basemap. i didnt really measre the ring gaps :P

You will be fine :y :8

Re: Ring end gaps. If you've built your own engine post up!
 

This isn't no chevy v8 or anything. Just line them up the right way and toss them in. No problems yet.

Re: Ring end gaps. If you've built your own engine post up!
 

you can hear engine building bullshit from everyone... when it comes down to the meat and potatoes, its totally not as complicated as people make it seem. ring gap isnt excessive unless its more than .030" stagger the gaps, 180 out of eachother, and inline with the wrist pin.

Re: Ring end gaps. If you've built your own engine post up!
 

I built my Y8 (twice :-X) both times using .017 for the top compression ring. You're good with .018. The reason why the motor was trashed in the first place was 19psi on an afc with 3 degrees retard and no other timing control. lol. The pistons melted, but the rings were still fine. We rebuilt it with the same specs and it's been running in Cray91's car for a couple months, with no real torture being applied as of yet.

You're good.

Re: Ring end gaps. If you've built your own engine post up!
 

I've never really touched the oil control set...from everything i've learned you're never really supposed to file em down anyway because of how thin and fragile they are. Usually though for the upper sets of rings i either (A). Follow the stock recomendations if the stock pistons are being retained with no overboring, or (B). Follow the piston manufacturer's specs if aftermarket pistons are being used, or has been overbored with oem type replacements. Just make sure to align the rings the right way after that and you shouldn't have any problems. Good luck! :)

Re: Ring end gaps. If you've built your own engine post up!
 

Thanks guys. I'm glad I didn't go out and buy a new set of rings now.

I got another ring compressor and am going to try and get the pistons in the block tonight.

Re: Ring end gaps. If you've built your own engine post up!
 

good luck man when you get it al done we'll have to meet up so i can check your ride out

Re: Ring end gaps. If you've built your own engine post up!
 

Sounds good. I might end up calling you before that if I run into problems though. :8

Got the pistons in last night. Everything went smooth thank god.

edit: Before I put the pistons in and torqued the con rods to spec I could turn the crankshaft by hand and now I can't. I haven't tried turning it with a wrench or anything yet but I could move it a little by pushing on the crank. Is this normal for a "fresh" engine?

Re: Ring end gaps. If you've built your own engine post up!
 

sure man call me if you need help o btw make sure that thins lubed up before you go turning it over

Re: Ring end gaps. If you've built your own engine post up!
 

yeah I lubed all the bearings while assembling it.

Re: Ring end gaps. If you've built your own engine post up!
 

Did you plastigauge all the journal surfaces? Remember...Honda motors don't have the same journal size for every journal...each one is a different size. If the head is off the motor you should still be able to turn it by hand with a socket and ratchet, just might be a little tight cause of the rings. If you can't turn it at all, you got some probs with your bearings...yank em all and check em. :P

Re: Ring end gaps. If you've built your own engine post up!
 

Yes, all clearances are fine.