Ring Gap Question: 1988 225 HP V6 Looper

[Greg_E]

I'm in the process of rebuilding the power head on one of my engines.
Following the instructions, I installed each ring in the particular cylinder bore that it will be installed in, squared it up with one of the pistons and measured the end gap.
All of the rings with the square profile are within the spec. .019" - .031" and are all in the mid-range of the spec.
Only two of the rings with the angled profile are in spec. I've rechecked them in the bores that had the ring sets where both rings measured good, and they still measured out of spec. The four that measure out of spec. are all at.037" -.041" gap. Is it possible that they were ground incorrectly when they were made or am I missing something?

Assuming I can get past this problem, I have another question. What is the preferred method of installing the rod caps if you don't have the OMC special alignment tool?

 

[Faztbullet]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Did you measure your bore to see if worn at taper? I rarely see a block of this age that is not worn. Are you over the .004 wear limit of bore

 

[Greg_E]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Hello again Faztbullet. You have replied to some of my previous threads regarding this rebuild. Just to refresh your memory, this is a low budget rebuild to use as a spare in case one of my engines on the boat fails.
A couple of the bores are just at the .004 limit, and a couple are at the limit for taper in one axis but OK in the other. I had them measure in line with the connecting rod and at 90*.

The thing that puzzles me is that all the square rings read in spec between .020" and .026", while only two of the angled rings do.

I put one of the angled rings into a cylinder that had a different ring set where both checked good, and it still was out of spec. This would lead me to believe that it is the ring, not the cylinder bore. Your Thoughts?
The date code of the four bad ones is the same. . The rings are .006" -.010" out of spec, and I have no cylinders that are that oversize, out of round, or tapered.

While I have your attention, what is the best technique to install the rod caps if you don't have the special tool?

Thanks for your help and Happy New Year!

 

[kodibass]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Greg
Not to make you feel worse but I just got a set of rings for a old 25 bigtwin rude, the end gaps all is in spec, the cylinders have been honed to a nice crosshatch, I put the rings on the piston and install as I have done on many old motors, the pistons are so tight that it takes a rubber mallet to move them up&down in the cylinders.. I look at the rings that came out they look small to me in thickness compared to the new rings, but the the place I ordered them from swear they are the correct rings.

 

[Faztbullet]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Where did yo get rings Greg? Are they OEM or aftermarket? Measure all the keystones in the same cylinder to verify your measurements and if all are within .001 its the cylinder and if defective it should show your previous readings. On the cap alignment make sure caps are matched correctly and threads clean, take a old rod bolt and cut several slots down the side to make you a "chase" bolt to clean threads. Rods should be clean and dry, install cap and oil new rod bolt threads(no loctite) and torque cap to 15 ft lbs, take a brass drift and lightly tap and inspect parting lines, when not visible or felt with a tip of lead pencil,rotate and torque to next set of 30ftlbs and rotate and install final toque of 44 ftlbs.

 

[Greg_E]

Re: Ring Gap Question: 1988 225 HP V6 Looper

They are Sierra rings. VIP is stamped on each ring. I assume that is the actual manufacturer and Sierra markets them.
They were all in sealed packages but they have an old date code on the boxes. 08062006.
I will recheck each one and probably get back to you this weekend. I didn't have time today.
As always, your help and knowledge is greatly appreciated.

 

[Greg_E]

Re: Ring Gap Question: 1988 225 HP V6 Looper

OK. Here Is what I've done.
I labeled the ring sets 1-6
I took one of the best cylinders (#3) to make the comparison of the ring end gap for all rings and cleaned the oil out of it.
Each ring was inserted into that cylinder and squared up with a piston 1" in from the top of the block. (approx.)
The ring gap was always placed in what I will arbitrarily call the three o'clock position. That would be in line with the connecting rod facing out from the center line of the block.
Each ring was measured and recorded.
Once again, all of the square rings are within the spec. There is some variation in measurements but they all passed. Four of the angled rings are out of spec by a substantial margin. .006"-.010" oversize.
I made an error in my original post. The two rings sets that read good for both rings are from the same date code, and the four that have oversize ring gaps all have a different date code (all four the same date). I will go back and correct my original post to avoid any confusion in the future.
So assuming they ground too much off the ends of the rings, what will that effect. Returning the rings is not an option at this point.

 

[Faztbullet]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Piston/cylinder pressure will be the same as a cylinder with worn out rings, where are you located??? Too bad yours is not a 86-87 small bore cause I would make you a heck of a deal on a fresh reman....

 

[Greg_E]

Re: Ring Gap Question: 1988 225 HP V6 Looper

I'm in central CT. If I take the two good sets of rings and check the end gap in all the cylinders and they are all in spec couldn't the four defective sets be replaced? I know that defective ring sets would be rather unusual, but I have no other explanation for the fact that all the square rings are in spec. and the four angled rings with the same manufacturing date are out of spec. when measured in the same cylinder.

 

[Faztbullet]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Call WSM in New York 1-800-222-3375 and see if they have any outboard parts in stock as most are in FL. Get some of their RIK rings, if they transfer you to FL ask for Anthony...

 

[Greg_E]

Re: Ring Gap Question: 1988 225 HP V6 Looper

I will check all the cylinders with the two good ring sets just to verify all the cylinders are within spec. If they are, I will give WSM a call.
I downloaded the pdf from their site and came up with part number 200-135 for the RIK rings for 1988-1992 225 HP looper.

BTW I ordered the fitting for the vent mod and drilled the casting. I'm hoping that will help the idle. The engines sit so low in the water on the Gil bracket that they don't idle very well. Apparently my local dealer didn't know about that mod when the engines were rebuilt.

Just out of curiosity, have you ever had rings that were bad out of the box? I assume there is some reason you like the RIK rings vs OEM or other manufacturers.

 

[Faztbullet]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Just out of curiosity, have you ever had rings that were bad out of the box?

Yes but not to the spec's /excess you posted.....

I assume there is some reason you like the RIK rings vs OEM or other manufacturers.

The RIK's will fit a OEM piston and they come with the WSM pistons. They also have a different sound if dropped compared to a OEM ring as the "ting" is different and I have a lot of engines out there running these combos and with no problems...

 

[Greg_E]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Faztbullet: I cannot buy from WSM. I called and they said dealers only. I'll be sending you a PM.

Before I ordered another set of rings I wanted to be sure the ones I have are defective. This time I used a depth gauge to be absolutely sure that the rings were squared up in the bore, and that each ring was in the same spot in the bore when measured. The depth gauge was set to 13/16" which is a spot on the cylinder wall just below the bottom ring when the piston is near the top of its travel. My thinking is that this spot would have the most wear, so it would be worst case scenario when checking the ring gap.
I measured all of the bad angled rings in their respective cylinders, and they are all .035" or more gap.
I then took one of the good sets of rings and checked both rings in each of the six cylinders. I did two measurements for each ring. One with the gap at 12 o'clock and one at 3 o'clock (stbd. side), 9 o'clock (port side).
The best cylinder(#2) read .020" / .021" for the square ring and .023" /.023" for the angled ring.
The worst cylinder (#5) read .025" / .025" for the square ring and .026" /.025" for the angled ring.
Most measurements were in the .023-.026" range which is about the midpoint of the .019-.031 spec.
I had the time today, so I was very meticulous while doing these checks.

Below are two pictures. One is a good angled ring in cylinder 3 and the other picture is one of the defective angled rings in the same cylinder. .025" vs .037" You don't need a feeler gauge to tell which one is bad.

To anyone considering rebuilding their engine: This is why you can't take shortcuts or assume the new parts are good.

 

[bird33]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Faztbullet,

I may interested in that powerhead if still available. I have a J200TXCUC that is having a few issues.
Not trying to hijack this thread but FB's PM was full.

Thanks

 

[Faztbullet]

Re: Ring Gap Question: 1988 225 HP V6 Looper

Hey Bird check your PM....

 

[Greg_E]

Re: Ring Gap Question: 1988 225 HP V6 Looper

OK. I got my new RIK ring sets and checked each set in the cylinder it will be installed in. All of the measurements are within the spec. of
.019"- .031". Most measurements were in the .025" -.026" range and there was no wide variations between the two types of rings in a particular cylinder. They were all .001" difference or the same. The worst cylinder was #5 at .028". Not great, but still in spec. This is the 2nd rebuild on a stock bore, so I knew going into this that the readings would be on the higher side. I'm OK with that.
Faztbullet. Thanks for all your help.