273 302 318 340 build

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I think he said the 2nd ring was moly faced. Hard to tell. I mentioned I read about chamfers being opposed on the 2 rings. He said only if 2nd ring is reverse torsional (these arent).
He said when installing expander and rails that joint in expander is in line with pin.
Also steel rail gaps should be offset from expander gap approx 60* each way.
Still find it weird they label the 2nd ring TOP, but I didn't get a part # so no documentation. Be taking a look at them with magnifying glass lol.
You mention 4 gaps? Lol
nm9stheham said:
Do you know to install the rings with the 4 gaps staggered evenly around the piston's circumference? Was there any discussion on moly facings for these rings?

And while it is hard/impossible to do otherwise with that particular style of ring expander, make sure the ends of the expander don't get overlapped.
Click to expand...
 
OK... I have never seen a moly faced ring that was not light grey or silverish in color on the ring face.

4 gaps: 2 on the oil scrpapers and 1 each for the 2nd and top rings.
 
Here's a couple more pics of the rings. Rings on the left in the pics, the light colored ones are the top rings. Rings on right are darker and 2nd groove.
I can't remember to be honest which ones he said were moly. Shoulda wrote it down, but I was more concerned with the proper order.
I asked if they were standard OE specd rings and he said "no, they are high performance"
I'm not familiar with piston rings so if anything doesn't seem or look right to you by all means I'm listening.
Bingo on the 4 gaps! Brainfart here
Thanks again all, much appreciated.
nm9stheham said:
OK... I have never seen a moly faced ring that was not light grey or silverish in color on the ring face.

4 gaps: 2 on the oil scrpapers and 1 each for the 2nd and top rings.
Click to expand...

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AHAH! That looks better! Yes, the ones on the left are the moly faced ones and would be the top ones; the top is where they moly ones normally would go. It's all making sense now with the ring set PN's too!
 
Ok, makes me feel better. I still don't understand their logic in ring markings lol. 1 UP and 2 UP. Seems idiot proof to me. But I'm still learning lol
nm9stheham said:
AHAH! That looks better! Yes, the ones on the left are the moly faced ones and would be the top ones; the top is where they moly ones normally would go. It's all making sense now with the ring set PN's too!
Click to expand...
 
I've seen dots, triangles, squares, painted dots, embossed dots... can't say I have seen the word 'TOP' though. I'm sure there are more markings that have been used.
 
Checking ring end gap. I measured bores with digital verniers. Quite a variance.
#1 4.0620" bore top ring 0.018" 2nd 0.025"
#2 4.0685" bore top ring 0.022 2nd 0.021
#3 4.0615" bore. Top ring 0.018" 2nd 0.025"
#4 4.0690" bore. Top ring 0.022" 2nd 0.021"
#5 4.0620" bore. Top ring 0.018" 2nd 0.025"
#6 4.0705"bore. Top ring 0.022" 2nd 0.020"
#7 4.0620"bore. Top ring 0.018" 2nd 0.025"
#8 4.0715" bore. Top ring 0.022" 2nd 0.020"
General spec sheet with rings says .004 X bore for end gap spec for both top and 2nd ring.
Looks like I'm tight?
****EDIT**** Loose actually, correct?
Perfect circle moly 5/64 top ring.
Cast 5/64 2nd ring.
Gaps were placed facing outside of cylinder. Rings were 1 1/8" deep in the hole when I measured.

Gonna remeasure bores again with telescopics.

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Ok, spoke to Kyle at Mahle Tech Support(they own Perfect Circle) after searching online for end gap specs(with no luck). Kyle had to go to 2 places in his database to get files, I asked he email them to me. Specs are quite wide(IMO) 0.010"- 0.047" for 2 Compression rings, and oil rails are 0.015"-0.055". So compression are good and I will check the oilers.
web link
MAHLE Product Catalog

40787 info.jpg
 
Ok, so Im reading and just realized the 747-16 retainers from Comp are for a double spring?? BUT the 901's are singles?? Their current catalog/pdf recommend retainer #'s 730, 740,743,744,1730 NOT 747...GRRRRRR. They have been running "fine" in 273 for 5 years now.....
Here is a pic I took in 2012 when Badsport shipped to us.

comp cams kit for 273.jpg
 
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P.M Rusty Rat Rob , Steve.... He probably has it available at work , if not at home.
 
Thanks Bomber I spoke to comp tech support. He said they are fine. The 747 land diameter is .010" smaller then the 744 single springs. Tech said it's a non issue.
Only question I have before I install pistons is there is one rod and pin that I can "feel" movement in the pin and bore?? Its very slight but its there. I may need a new bushing installed.
Thanks Bomber
Abodybomber said:
P.M Rusty Rat Rob , Steve.... He probably has it available at work , if not at home.
Click to expand...
 
4spdragtop said:
Thanks Bomber I spoke to comp tech support. He said they are fine. The 747 land diameter is .010" smaller then the 744 single springs. Tech said it's a non issue.
Only question I have before I install pistons is there is one rod and pin that I can "feel" movement in the pin and bore?? Its very slight but its there. I may need a new bushing installed.
Thanks Bomber
Click to expand...
340/ 273 bronze bushed? .....small rod pin end ? I am niteynight..... Post this question I asked , you will get answered... ( screw Brady.. :)
 
Yes 340 small end is bushed. I drilled a 3/32" lube hole in all of them. Wish i could hibernate for a couple months lol. NOT a fan of winter.
Agreed with Brady lol
Abodybomber said:
340/ 273 bronze bushed? .....small rod pin end ? I am niteynight..... Post this question I asked , you will get answered... ( screw Brady.. :)
Click to expand...
 
Dropped by machinist as there was one con rod/piston pin that had an ever so slight wiggle. He measured and its good. So next is piston and con rod install. A couple questions...I've been looking for info on proper ring gap orientation. Seems the net, books are all different.
Machinist says expander joint in line with pin bore, then oil rails 60* off in both directions from expander joint. (See my drawing below).
I forgot to ask proper spacing for on the compression rings. Suggestions?
See pics attached, they all vary lol
Also any special paste/lube for piston skirts?
Thanks all!
nm9stheham said:
OK... I have never seen a moly faced ring that was not light grey or silverish in color on the ring face.

4 gaps: 2 on the oil scrpapers and 1 each for the 2nd and top rings.
Click to expand...

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PISTON_RING_END_GAP_LOCATION.jpg
 
I like the machinists idea , Steve . If it's gonna sit for a while.. never been there. As for dropping in a couple of weeks , a month ..? 30 sae weight on piston skirts , Lucas green break in lube on bearings, and camshaft.
Lucas product 10152...
Autozone stocks it .. Wear gloves its stickier than winter flu flem :)
 
Yeah it will probably sit for a few months. (4-5), before firing. I'll premix my Rotella and Lucas addictive for skirt coating and cylinder walls. I have a couple different brands of bottles of assy lube for rod bearings and for the cam when I get to it.
Suggestions on compression ring gap orientation?
Thanks!
Abodybomber said:
I like the machinists idea , Steve . If it's gonna sit for a while.. never been there. As for dropping in a couple of weeks , a month ..? 30 sae weight on piston skirts , Lucas green break in lube on bearings, and camshaft.
Lucas product 10152...
Autozone stocks it .. Wear gloves its stickier than winter flu flem :)
Click to expand...
 
4spdragtop said:
Yeah it will probably sit for a few months. (4-5), before firing. I'll premix my Rotella and Lucas addictive for skirt coating and cylinder walls. I have a couple different brands of bottles of assy lube for rod bearings and for the cam when I get to it.
Suggestions on compression ring gap orientation?
Thanks!
Click to expand...
First , hand drawn one... He did the work .. he has competence...
 
I just put the gaps at the four 45 degree angle points; never had any issues.

The rings are free to move around anyway, so I don't see the fal-de-rah over exact alignments as long as they start out on different points of the compass; there is nothing to stop the gaps from moving around and lining up for a while at some point in the future. Maybe a serious drag engine that gets torn down every few passes might never see the rings align, but I would not think that to be the case for a street engine driven thousands of miles.

Plain motor oil has worked fine for me for rings/pistons. I make sure some gets in the rings grooves and then rotate each ring around to spread the oil all around the grooves. Any excess oil will drain off in a matter of minutes or an hour at most.
 
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Some progress and more measuring to come lol.
Got to use ring expander and ring compressor. Installed #1 Piston.
Cleaned pin and bore. Installed pin lock (**flat side out**).
Lubed pin up, and aligned rod so numbers face out, and relief valves face in.
WD40 the expander and oil the rails and compression ring
Marked piston top with the ring gap orientation.
Expander(butted not overlapped) parallel to pin.
Each oil rails offset 45* from expander.
Top ring approx 1:30
2nd ring approx 4:30
I will mark the top of the remaining pistons to "speed up" ring install. Nerve wracking putting top 2 rings on lol. For the remaining 7 pistons I will set in a vice for stability.
Wasn't too happy with Lisle piston ring compressor....tight as heck. Hopefully it loosens up a bit.
Not a lotta progress but I can now see where the slug sits...in or outta the hole. Closer to fingering actual compression
Thanks all!

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Are you oiling up your ring compressor?

If you put much more ink on the tops of those pistons it's gonna throw off the engine balance..... just kidding.
 
Lol I'll try to find some light weight markers.
The bottom oil ring is no where near as "loose" as the top 2.
Next ones I will oil/lube more. I know the rails are supposed to keep the expander snug. I thought there would be some slop.
The compressor I coated with WD40. But it's new so it was compressed as heck in the package. It needs to stay expanded a while to loosen up.
Thanks again for checking in.
nm9stheham said:
Are you oiling up your ring compressor?

If you put much more ink on the tops of those pistons it's gonna throw off the engine balance..... just kidding.
Click to expand...
 
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