Some engine rebuilding questions

[stefan]

#1.. Gapping Rings??? I'd never heard about this before seeing it in the haynes manual.. even then i still dont get it.. if i ordered std size rings shouldn't they be the right size? seems a pain to have to file down 16 rings

#2.. Plastigague stuff... also saw this in the haynes manual.. again is this necessary? i got new main&rod bearings

#3 What should i use for "engine assembly lubricant".. the local parts store didnt have anything advertised for this purpose


Sorry, these are prolly silly questions that will make some of you chuckle, but hey..

[packrat427]

Re: Some rebuilding questions

#1.. Gapping Rings??? I'd never heard about this before seeing it in the haynes manual.. even then i still dont get it.. if i ordered std size rings shouldn't they be the right size? seems a pain to have to file down 16 rings

#2.. Plastigague stuff... also saw this in the haynes manual.. again is this necessary? i got new main&rod bearings

#3 What should i use for "engine assembly lubricant".. the local parts store didnt have anything advertised for this purpose


Sorry, these are prolly silly questions that will make some of you chuckle, but hey..

Ring gapping ..
When fitting new piston rings, the end gap is a crucial measurement. In order that a ring may be fitted into the "grooves" of the piston, it is not continuous but is broken at one point on its circumference. The ring gap may be checked by putting the ring into the bore/liner (squared to bore) and measuring with a feeler gauge. End gap should be within recommended limits for size of bore and intended "load" of engine. Metals expand with a rise in temperature, so too small a gap may result in overlapping or bending when used under hot running conditions (racing, heavy loads, towing), and even at normal temperatures, a small ring gap may lead to ring gap closure, ring breakage, bore damage and possible seizure of the piston. Too large a gap may give unacceptable compression and levels of blow-by gasses or oil consumption. When being measured in a used bore it may indicate excessive bore wear or ring wear.(Radial wear on ring face reduces thickness of used/worn ring (face wear in bore) essentially increasing face circumference of ring and thereby increasing size of ring end gap.)

When fitting new rings to a used engine, special "ridge dodger" rings are sometimes used for the top compression ring, to improve compression and oil consumption without reboring the cylinder. These have a small step of iron removed from the top section to avoid making contact with any wear ridge at the top of the cylinder, which could break a conventional ring. Generally, these are not recommended as they are probably not required and may give inferior oil consumption. A more acceptable method is to remove the wear ridge with a "ridge reamer" tool before lightly honing bore to accept new rings.





Plastic gauge..

Bearings have to withstand brutal punishment, from buildup of engine-oil crud to extreme heat and pressure. Not surprisingly, a bearing will fail when it's been subjected to enough of these naturally occurring problems, as well as human-induced ones such as an improper install or a false reading in your measurements. It only makes sense to pay close attention to your bearings, and the extent to which you take into account rod-bearing clearances will dramatically affect the longevity of your engine.

You see, an engine bearing's main job is to support the film of oil between the bearing itself and the friction surface. It's crucial not to overlook this; it is this typeof carelessness that could induce catastrophic engine failure and, yes, shouting words your mother wouldn't approve of. Taking it a step further, proper rod preparation also involves the marriage between the rod, the pin, and the piston, which all require proper lubrication and setting of the retaining rings. Do it right and you'll keep friction to a minimum and prevent your pin from binding up-which ultimately means mo' power.

When measuring for rod-bearing clearances, you have your choice of using a bore gauge, an inside micrometer, or a snap gauge. Obviously, the most accurate method-but not always the most affordable-is with a properly calibrated bore gauge. However, depending on feel, an inside micrometer or a snap gauge can also be perfectly acceptable for a budget build. A plastic gauge, on the other hand, is not recommended for measuring rod-bearing clearances-or anything else.

Assembly lube ..

Designed to be used a lubricant to apply to potential wear surfaces before assembly in order to prevent metal contact upon startup before adequate lubrication is supplied. Provides three times greater film strength than conventional black Molybdenum Disulfide greases and will not clog oil filters. This product clings to all surfaces and is an excellent rust inhibitor, allowing the storage of parts for years. A thin film of protection is all that is required on mating parts. Red Line Assembly Lube will mix with our motor oil and can be used on all lubricated parts such as cams, followers, pistons, and bearings, and bolt threads. Use only a small amount on bearing and piston surfaces - too much can make it difficult to turn over the engine. Red Line Assembly Lube is an excellent corrosion inhibitor and can be used on machined surfaces to provide long-term corrosion protection. Do not use on exhaust bolts or other high temperature bolts which require an anti-seize.

Some use STP additive to assemble parts also ..

TORCO
MPZ is a non-melting concentrate of oil soluble molybdenum, phosphorous and zinc fortified with polymers to increase its adhesive strength. Engine Assembly Lube is designed as a prelube for cylinders, pistons, wrist pins, cams, plain bearings, ball bearings, roller bearings, journals, and gear sets. Cam Lube is a gelled version of assembly lube designed for anti-scuff protection of cam lobes, lifters and other highly stressed valvetrain components.

[packrat427]

http://chucker54.stores.yahoo.net/platas.html

This one is good ..

http://mahleclevite.com/techbulletins/CL77-1-205R.pdf

[stefan]

wow. excellent reading, thanks!

also, another question, How do I install the valve seals? The book mentions some kind of ford tool

[jglutz]

1st : Packrat...that is the most awesome post!
I would say the biggest diff between assembly lube and moly is $$$. After an hour or so of running a rebuild I change oil and filter. Most importantly don't assemble dry...Parts soaked in motor oil during re-assembly is adequate, more messy, but just as good.
When measuring ring end gap, the rings can be squared in the cyl bore by pushing them in to the bore with a piston.
Prior to mounting the head...I fill the block with oil and crank it with a BF drill motor until oil flys out the top of the block and repeat after the head is mounted...I always fell better if the lube circuit is primed. That way i do not have to wait for any valve train noise to go away...always a nerver racking time...worry if it will go away or if i did something wrong.

Stefan...do the plasti-gage...if you miss something...buy the time you find out it will be to late...not only does it insure that the gaps/tolerances are right but also all of the bearings are propely placed...you can only get a good reading if all is perfect..

Stefan...inserting valve stem seals. Take a seal and find your smallest deep wall socket that the exposed part of the rubber fits into and the face of the socket contacts the metal top of the seal. With both the seal and stem wet with motor oil, lightly tap the stem in place using the socket, you will feel the difference in tapping when the seal is fully seated. (go ahead Jim, let me have it)

[stefan]

Ok, according to the 323 haynes manual the main bearing oil clearence is supposed to be 0.0007 - 0.0014"
And the rod bearings are supposed to be 0.0011 - 0.0026"

But one finest plastigauge i could find was the green type, which only measures 0.001 - 0.003"

[jglutz]

^^That sounds right.
The green plastigage is correct for the range you specify. It is really 0.0010 to 0.0030;
0.0010 < 0.0011 - 0.0026 < 0.0030

[stefan]

ok, ill try it out.

another question... the origina bearings, only the one that sits in the block had an oil grove and hole, and the one that sat in the cap was smooth.\
My new bearings are all the same, all 10 have an oil grove and hole. is this a problem/normal?

[jglutz]

^^Just make sure you get the oil holes lined up and the tabs on the caps also allign...I've seen after-markets like that.
Also the face of the caps should go flush with very little effort...always keep an eye on that hen tightening.

[stefan]

ok, the reading i got was 0.002



but the oil clearance specs are supposed to be 0.0007-0.0014"

im out of that range

but it says the service limit is 0.0040

whats the diffrence between the service limit and the specified range... shouldn't the the upper limit of the specified range be the service limit?

but more importantally, am i ok with 0.002

[sasquatch]

looks like you got a good motor

[stefan]

what? you mean that is a good reading? its out of the range...

im confused

[sasquatch]

oops i read it wrong. ops:

[jglutz]

Stefan, A couple points about your last pict.

The face/mating surface in the block around the tapped holes does not look clean....this is very important to insure a good reading.

Do the new beaaring widths match the old? Looking closely, I see a clean gap betewwen the left side of the bearing and the brown oil stain on the journal from the previous bearing.

Those oil grooves in the new bearing are preety big. I do not remember mine being so big or if I even had any. The instructions for using plasti-gage say to read at the widest spot...The problem is...where the widest spot would typically be, the middle, you have and oil groove.

Did you put the correct cap and turned the right way for this pict?

LEt me know and I'll post picts of my old bearings.

[FB71]

spec = new or freshly machined

service limit = used or normal wear