piston rings for 1551

[paul j]

I bought new rings and was sold Sealed Power E-647KC and was planning on using E-522KC which is what my research showed was correct for '91. After more research on the difference I come up with E-647KC was used from 5/92 on with 3rd ring chromed carbon steel. The E-522KC ('91) has stainless steel 3rd ring with 1 and 2 staying the same materials. Is there any reason not to go to the newer released E-647KC? The ring measurements are listed as the same. The engine and turbo are stock but I would like to put go 16g if I can find one.

 

[BogusSVO]

The E-647KC rings Has the shallow oil rings, and the E-522KC has the deep oil rings.

That make a difference in the depth of the ring groove.

Since you have the 89-92 pistons (63DT) you need to use the E-522KC rings

If you install the E-647KC rings, you stand a chance of the oil scraper rings not being able to scrape the oil from the cylinder bores properly and ending up with a blue smoke issue.

Also E-647KC = C85434 in EngineTech EngineTech reboxes NPR rings, NPR is/was the OE supplier to Mitsu for pistons and rings.
E-522KC = C85324

BTW EngineTech Reboxes King bearings for the 4g63 /ubbthreads/images/graemlins/grin.gif

 

[paul j]

Great info Bogus.

 

[paul j]

Do you know the width of the rings and how deep the piston groove is? The new E522KC oil scraper is 0.010" (0.025mm) wider than the ones I took off the piston. Is that about normal wear for 175k miles? I need to know if these are the original correct '91 pistons.

 

[BogusSVO]

What is the number cast into the top of the piston?

63DT are 6 bolt, Only 1 part number for rings

63DTF1 are 7 bolt (same casting piston will have 2 different part numbers for rings, depend on year)

.010 sounds like a bit much, most oil scrapers are around 3-4 lbs of outward force.

If you have the F1 pistons, you would have the "Frankenstein" piston swap

2g pistons on 1G rods, means the wrist pin hole was enlarged by 1mm

 

[BogusSVO]

Did you get the rings figured out?

 

[paul j]

Yes we did. The ones you said to use, E522KC are correct. The E647KC oil scrapers are very visibly narrower and would be lost in the deep grove pistons. Very easy to go wrong on this. The parts store gave me wrong ones first. Your info got me the correct ones, machinist looked it up and said they were wrong. He checked some more and said both are the same. Went back to parts store and they checked again and said 522 was correct so we compared them both with measuring and it was obvious.

 

[paul j]

I used a flex hone on my cylinders and the cross hatch pattern looks lower than 45*, more horizontal. How critical is the angle? Also I wiped down with mineral spirits until clean and lightly oiled in order to check pattern. I can re-hone with slower drill speed to increase the angle if necessary. Is it better to clean with soap & water than spirits? Flex hone says that is the way to do it. If I do not re-hone should I now wash with soap and water and re-oil?

 

[BogusSVO]

A flex hone or dingle berry hone really dose not have enough bite to it. It is a glaze breaker and that's about it

Even a ridged 3 stone hone can not apply enough out ward force for a good crosshatch.

The reason for the 45* crosshatch is oil control, less than a 45* holds more oil, steeper than a 45* more oil runs off.

You should use the spirits when honing and keep the cylinder/hone dripping wet.

Then a clean down of the paste/grit with spirits is fine.

But a good soap and wash is needed before assembly.

click

 

[paul j]

What will cut through cylinder glaze other than machine shop boring? Will brake cleaner or carb cleaner do it? It sounds like I need to cut the glaze before using flex hone again.

 

[BogusSVO]

The flex hone is designed to do just that, cut the glaze.

But if you want a solid cross hatch, you need to get a portable hone that runs Sunnen AN stones, they are rare to find.
Or take the block to a machine shop and have them Hone it.



Short of that, you just will not get a good cross hatch.

 

[paul j]

This is a very interesting test report starting on page 10 click What is your take on it?

I was talking to a friend to see if he had a portable Sunnen hone and he says I will regret not removing the block and properly doing work on block. He says top ring will not seal properly since I needed to use a ridge reamer to remove cylinders. I do not buy this.
Am I going to regret not removing engine and boring or honing as needed rather than just re-ringing 1551? Is removing glaze with flex hone going to seat the rings properly? The engine ran fine, no smoke and had lots of power even with cracked turbo housing, crusty impellers, and 175k - out ran a couple Z4's. Head, turbo, and piston assembly is out so how hard is it to remove the block from this stage? I don't have room to put the engine anyplace to work on it except in the driveway or porch. How heavy is it for moving after getting it off of a cherry picker?

 

[EHmotorsports]

Take it to the shop and have the bores measured and honed properly.

 

[BogusSVO]

You used a ridge reamer????? /ubbthreads/images/graemlins/banghead.gif I hate those things, they need to be taken off the market. They cut a hellish taper at the top of the bore.

Yes a mic needs to be dropped in the bore and checked at the top of the bore.

I have had to take blocks to .060 (or sleeve a bore or 3) that would have bored .020-.030 due to the use of a ridge reamer.

Plateau honing is not new, yes it is valid, but not commonly done. It flattens the peaks of the cross hatch.

And the grits they use are just too coarse IMHO. What they were finishing with (AN-200 150 grit) I use to rough in a bore.

When I bore a cylinder, I leave it .003-.005 undersized, then use a 150-200 grit stone to get it just under .0015 then finish with 320-600 grit depending on the ring pack.

I would almost bet that the 120 grit and 180 grit they used would make my cylinder bore finish worse than better.

Weight of an empty 4g block is about 98lbs a short block assembly about 225-240lbs, so you and a buddy can pick it up and carry it.

 

[paul j]

Dale I used my telescoping gauge (Harbor Freight) and set it to 85mm with my digital caliper (HF) and it was a little tight at area where ridge was removed. That area also looks and feels like it matches cylinder below it. I then loosened telescope gauge and let it spring out to cylinder diameter of removed ridge. It measured 84.95mm and felt consistent down to squirters. I may buy a cylinder mic just for the hell of it to get some accuracy. But anyway I am going to remove engine and take it to a machine shop and get everything cleaned and checked. Since it has taken me 10 times longer than what I thought would be a fast job what the hell does it matter.

So guys--

Is it easier to take transaxle out with block or pull trans first?

Also fsm says to unbolt ac compressor from bracket and tie it up. While I was doing that I see the compressor rests on the bracket so if engine is raised it will pull compressor also. But you have to remove the compressor in order to get the bracket off. I ran out of time to pursue the matter so is there a way to get the compressor out of the way of the block while pulling it?

 

[BogusSVO]

84.95mm x .03937 = 3.3444
85mm x .03937 = 3.3464

That is a difference of .0016
So that could be carbon build up in the top of the cylinder, or the tooling was set up tight.

 

[LIV4PSI]

I always remove the transmission with the engine

 

[paul j]

I was checking Engine Tech 2nd ring vs OEM and Sealed Power. OEM and SP have a bevel but in different places. ET has no bevel. Anything to be concerned about?

 

[BogusSVO]

No, none at all.

EngineTech gets the rings from NPR and has them in there boxes.

NPR was/is the OE supplier to Mitsu.

Just make sure the dot/letter is facing up towards the top of the piston.