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Micke's Tecumseh Hh120 Build

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#1 MountainMichael OFFLINE  

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Posted November 13, 2014 - 06:38 PM

This began as a question about ideal ring end gaps for a Tecumseh HH120.  Ben kindly provided that info.

 

I then decided to convert the thread into my Tecumseh HH120 build.  I won't be covering every detail; just anything that seems maybe interesting along the way.  The following goes back to the original text:

 

Ok, I've spent some time searching this here and elsewhere.  Most of what I find is centered on how big the ring end gaps might be permitted in a worn bore before reboring is necessary.  Of course, there are other influences for when to rebore besides ring end gap.  But that is not what I'm looking for. 

 

The Tecumseh manual simply says .007" and .020" for ring end gaps.  They don't specify whether that is a range for the top ring or all rings.  Or maybe 20 is for the top, 7 for second ring since it runs a lot cooler?

 

This block has just been bored and honed to .020" over with .003" piston skirt clearance.  I'm looking for the ideal ring end gaps for all 3 rings for when I check and/or file fit as needed. 

 

This engine is for my Sears Super Hydro-Trac 12 and is intended to be my main snow pusher.  However, assembly is going to be delayed until we get out of arctic temps.  No sense trying to heat a garage in zero degree ambient temps.  Although I have 2 artificial hinges and am in danger, I'll just have to use the snow thrower until 'el tractorsaurus' is back together.  

 

The old (automotive water cooled) formula for generic low perf ring end gap is bore size in inches times .004 for the top ring.  So with a 3.5" bore, that would be an ideal top ring end gap of .014".

 

However, that formula is for water cooled engines.  Air cooled engines run a lot hotter, right?

 

The formulae online suggest the 2nd ring should run looser than the top ring.  I really don't get that since the 2nd ring absolutely runs at lower temp than the top ring...

 

Anyway, trying not to overthink this. 

 

Can anyone please provide ideal ring end gaps for top, 2nd and oil rings on an air cooled Tecumseh HH120?

 

Thanks!

 

Micke

 

p.s.:  Valve work ramble:  This is too lengthy so nobody should read it. 

 

After 2 months of whining, I finally had to take the block back from the machine shop after they had only completed the bore and hone... and do the valve work myself. 

 

Even though I provided the Tecumseh reamer for the 1/32" oversize valve stems, you'd have thought I was asking for cold fusion.  Turns out even though this later model reamer was made in India and probably not nearly as good as the earlier spiral flute reamers, hand reaming going slow and careful took 10 minutes on the intake guide, 20 minutes on the exhaust guide.  No huhu.  If there was any challenge, it was this:  Valve guides wear out in a so called "bellmouth" manner.  That is, very loose at top and bottom; little wear in the middle.  The challenge was this:  The reamer's pilot was tight at the top worn out area.  Getting it through the MUCH tighter unworn center area was gummy and scary tight at times.  I twisted/removed the reamer a dozen times to clean out cuttings and to re-oil with ATF.  Although the reamer pilot is fluted, it doesn't cut much.  Nothing like the main cutter flutes cut.  Anyway, it is totally doable and there is no excuse for 2 months of whining.

 

BTW:  The newer Indian reamer lacks a square cut on the end.  The machine shop balked about this.  I spent 10 minutes on a bench grinder and carefully cut flats for a square end.  These turned out better than most squares I've freehanded but in any case worked just fine with a tap handle.  Because of no flats on the drive end, some may assume that it is a "chucking" reamer.  However, my machinist and I agree that making a .030" reamer cut in one pass is an awful lot and must be done SLOWLY by hand.  My suggestion would be:  Please do not chuck this in a drill or mill.  Especially with the binding of the pilot near the center of the valve guide, I suspect using power drive would result in a broken reamer or a badly tapered bore (from heat), etc.    

 

I then used my Dad's left over valve equipment from when he had a machine shop in the 60's and 70's.  Such as:  Sioux and K.O. Lee valve grinding and hard seat equipment and did a fair dinkum 4 (yes four) angle valve job.  Things lapped in super fast and easy so I think everything was probably concentric.  Forced to DIY, I didn't have valve seat runout dial indicator, etc.

 

The exhaust valve from Argentina had an enormous stem underhead.  Close to 1/2 inch in diameter if you can believe that... I couldn't believe it.  It would have choked the poor little engine to death so I undercut both intake and exhaust valve stems back to 5/16" (not in the guide area; only in the port area) and polished them in the portions of the stems that live in the ports.

 

New valves should always be reground.  In this case, the Argentinian exhaust valve wobbled by 30 thousandths.  Holy cow?!  The NOS Tecumseh intake was "only" out by 8 thousandths.  The legendarily accurate K.O. Lee Valve grinder brought them both to true although the exhaust took quite a long time to get right.  I was shocked.  Glad I took the time, though.  The machinist was going to trust the factory grind.  Yikes. 

 

Since I was forced to DIY on the valve work, I took a couple of decades of porting experience (former speed racer type here) and went after the low hanging fruit.  I studied up on garden tractor puller mods beforehand.  The intake short side radius was a train wreck OEM with a razor sharp 90 degree corner in there.  There were a few other obvious enormous defects.  80% of my time was on intake, 20% on exhaust.  There were some obvious ridiculous defects and I went after mostly just the crazy stuff.  About an hour of porting time between the 2 ports. 

 

I live at 7150 feet elevation, so every engine loses a lot of power up here.  Hoping to get a bit of the high altitude losses back. 

 

The intake seat cut about like normal.  The exhaust seat required white stellite stones and was harder than the hinges of hades.  Although, it was softer over by the combustion area.  Had to diamond dress even stellite stones after every single cut.  Tedious, but ya' know.  I back cut both intake and exhaust valves with a 30 degree cut up within .030" of the lap line.  That's supposedly worth some 10% of 'mousepower' on small flathead type engines just by itself.  Yeah, I know.  "Wish in one hand..."

 

One other rumor I'm afraid I must confirm:  The NOS valves with 1/32" oversize valve stems are LONG.  About .060" long.  As you may or may not know, the butt grinding stone on most valve grinders including my Dad's antique KO Lee are very fine.  It took about an hour each to sneak up on the proper valve lash.  I got them to within about a half a thousandth but it just about cost me my sanity.  Ok, now I'm whining.  mm out

 

Just my experience; your mileage will vary.  

 

edit:  I found the Tecumseh reamer for this PN 670284 in stock at Equipatron.  Although it is the newer Indian reamer, it worked ok with some minor mods and patience as outlined above.  Those guys shipped super fast and were very friendly.  It was roughly 40 clams shipped.   


Edited by MountainMichael, November 14, 2014 - 10:48 PM.

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#2 superaben OFFLINE  

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Posted November 13, 2014 - 08:32 PM

If the quality of work you do is as good as it sounds, you ought to fire back up your father's machine shop and let me send you some work!

 

The ring gap specs are max and min for all the rings.  If it is more than .020, you need new rings.  If it is less than .007, it is too tight and will cause damage when the rings expand.  I usually shoot for .007 or a little bit wider. 

 

Ben W.


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#3 MountainMichael OFFLINE  

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Posted November 13, 2014 - 08:38 PM

If the quality of work you do is as good as it sounds, you ought to fire back up your father's machine shop and let me send you some work!

 

The ring gap specs are max and min for all the rings.  If it is more than .020, you need new rings.  If it is less than .007, it is too tight and will cause damage when the rings expand.  I usually shoot for .007 or a little bit wider. 

 

Ben W.

Hi, Ben.  Thank you for your input. 

 

I will follow that guideline.

 

Thank you for the compliment. 

 

Due to the economy, most of the local machine shops have gone out of business in this area.  It is much of the reason that the machine shop I tried to use delayed things out 2 months - with a non-result at the end.  He is so up to his ears in backlogged work, he has even stopped taking good paying diesel work - mainly due to back injuries from moving the heavy castings.  He was reluctant to take on this job because he has stopped taking anything he considers to be even slightly unusual.    

 

Maybe due to being out of practice and certainly due to having to dig to find everything in my Dad's barn, the reaming, porting and valve work took me about 9 hours.  Although I was admittedly being a bit extravagant, nobody would be willing to pay that for a glorified valve job, ya' know what I mean?

 

I cut my teeth learning machining in my Dad's shop as a kid growing up and I have a definite affinity for it.  However, I live 70 miles (one way) from my Dad's place.  Ya' never know.  Although I early retired in 2004, I might hang out my shingle if some big things change in the economy.

 

Thanks for your input,

 

Micke


Edited by MountainMichael, November 14, 2014 - 08:01 PM.

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#4 MountainMichael OFFLINE  

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Posted November 13, 2014 - 11:29 PM

Free valve guide reamer to GT goodguys:

 

This Tecumseh service tool reamer is for the Tecumseh NOS service valves with valve stems that are 1/32" oversize.  It bores from approximately 5/16 to 11/32. 

 

These things can be a son of a gun to find in stock and can sometimes be overpriced.  I could easily sell this in ebay but choose to offer this instead: 

 

Anyone wants this hand modified reamer pn 670284, post "dibs" in this thread and pm me your address.  I'll mail it to ya' gratis - lower 48 only, of course.  Might be a few days of delays since we're gettin' snowed in up on the mountain. 

 

The only cost:  After you're done with it, offer it up to the next GT good guy shipped free gratis.  I'm guessing with proper technique, the thing should be able to cut about 10 pairs of guides before it gets sketchy.  Maybe more.  Just remember:  It's always turned clockwise even when withdrawing it.  Never counterclockwise due to the angle of the cutting flutes.  Counterclockwise and metal cuttings will jam behind the flutes causing galling and/or breakage. 

 

I followed by honing with 120, 180 and 320 flex hones but I suspect that isn't necessary.  In any case, this reamer leaves a bore that is a bit loose at first nod.  I suspect that is appropriate due to high temps in air cooled engines.  I found that an 11/32" plus .004" pilot would not begin to fit in the reamed guides, so it mustn't be terribly loose... 

 

There are no guarantees, of course, with hand machining.  One sneeze or just bad luck and the thing could break off in the middle of yer guide!  It'd be best if you're conversant with making heavy cuts with a reamer - or if your machinist is willing to take on the job.

 

Again, my machinist said he was willing to do the job but after delaying it out for 2 months, I gave up and did it myself. 


Edited by MountainMichael, November 14, 2014 - 12:51 AM.

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#5 boyscout862 ONLINE  

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Posted November 14, 2014 - 09:28 AM

Sounds like you really know what you are doing.  It was nice of you to offer the tool but, I've learned that as soon as you part with a tool you will need it again and I really hate kicking myself.

 

I've aquired most of a machine shop and am trying to find the adapters to grind a crank on my Southbend. Most shops have closed and I don't trust the remaining. I have a couple dozen engines to rebuild from a 1 1/2 hp B&S to a 350 SB Chevy. I'm slowly trying to get the shop area cleanned and set up.

 

A friend where I used to live, started a business 20+ years ago, where he pours babbit bearings for old engines. He works a regular job and works in his shop on his time off. He had a 6 month back log last time I talked to him.

 

You skills and tools can be an opportunity to make an income based on WHAT YOU WANT TO DO. I am retired also and feel that retirement just means doing what you choose. I enjoyed your descriptions of the work and hope that you will share more with us. Good Luck, Rick


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#6 MountainMichael OFFLINE  

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Posted November 14, 2014 - 01:41 PM

Hi, Rick.  Thank you for your input.  I hear ya'; seems as soon as I get rid of anything I soon need it again.  Still, I'll leave the offer there in case anyone has difficulty finding one.  It's an odd cut and not a stocked reamer I could find from any other maker.


Edited by MountainMichael, November 15, 2014 - 10:59 PM.

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#7 MountainMichael OFFLINE  

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Posted November 14, 2014 - 07:34 PM

Nothing unusual to report.  After chasing packratted tools around for awhile as usual, I spent a few hours on detail work like a radius on the cylinder edge on the valve side to remove another air flow problem, scrubbing the block a few times in solvent and other cleaning bases, side cover and other parts.  Valves/springs/retainers are in with impinged tungsten disulfide powder on the valve stems along with some zddp augmented assembly oil.  L side cover - new Timken race and seal are in, etc. 

 

A couple of valve pics.  Nothing perfect here, but time was limited and it's not exactly a race engine.  I went a bit wide on seats and margins due to being air cooled.  I went a bit long on the undercut on the intake valve.  That's what I get for doing the undercut with a die grinder and a drill press.  ha ha. 

 

The old valves are in the pic for stem comparison.

 

It's a hobby so when when the heater couldn't keep up and I started getting cold, it wasn't fun anymore.  Time to call it quits for the day especially since I'm nursing a flu bug. 

 

Micke

 

Undercut and back cut valves.jpg Tecumseh Indian Reamer.jpg


Edited by MountainMichael, November 15, 2014 - 11:01 PM.

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#8 MountainMichael OFFLINE  

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Posted November 15, 2014 - 12:59 PM

Takin' a breakski to print a couple of pages from the Tecumseh technician's manual.  Brief update:

 

Yesterday, I had cleaned the block a few different ways.  Also scrubbed the bore with dawn, water, scrub brush, then followed with another scrubbing with solvent.  Repeated scrub with red brake cleaner.  At this point, I usually tell myself that all the honing abrasives are out of the crosshatch but that never proves true.  Like so:

 

Today before trying ring fit, I spent about a half hour scrubbing the bore again with Dex 6 ATF.  I tried the coffee filters so called trick but I didn't see that getting any abrasive or iron out.  Instead, Scott Rags In A Box (durable paper towels in a box) worked best.  Somewhere around 30 minutes of scrubbing today with Dex 6 and various changes of paper towels and I no longer saw grey accumulating on the paper towels and the bore looked much cleaner.  I now feel somewhat confident the bore is clean enough.  As such, maybe the piston and rings will have a fairly long life.

 

(aside:  This engine only had 3 years [very HD] usage on it with proper periodic maintenance but everything was pretty much shot.  Reason:  It was sucking dirt (abrasives) through 5 or 6 significant leaks that were sadly not corrected when the NOS crate motor HH120 was installed to replace the original engine.  I have repaired the leaks so that maybe the short life thing doesn't repeat this time around)

 

Ring end gaps were as follows using the following parameters:  .020" oversize piston fitted at .003" skirt clearance.  Using .020" oversize NOS Tecumseh rings, out of the box the top ring end gap was .014", 2nd ring was .008.  Oil ring was at .006".  I filed and deburred the very rough ends of the oil ring to get the gap wider and into lower end of range.

 

'k, I'm burnin' propane so back to El Garagienda to clean the crank assembly (again) and resume final assembly.  I'm takin' my time goin' slow so it is fun and I make less earlyheimers mistakes.  


Edited by MountainMichael, November 15, 2014 - 01:10 PM.

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#9 MountainMichael OFFLINE  

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Posted November 15, 2014 - 06:40 PM

How to Hotrod Big Block Tecumseh... jk

 

This is a typically long ramble by me so it shouldn't be read by anyone.  ha ha.  ?

 

Short block assembly is done - no huhu.  It turns over nicely with just hand torque on the PTO shaft.

 

Extrapolated rod clearance is right at half a thousandth.  Seems tight to an auto guy but I suppose it has to be tight because the aluminum rod expands a lot at running temp.

 

Goodguy Joe - a shameless plug:

 

Original crank was way out of spec all eaten up by all the dirt this poor engine was eating.  Sure was glad to have a super nice cherry crank with beautiful as new bearings thanks to Joe's Outdoor Power.  His mic reading in the ad was spot on correct, crankpin was round and no taper.  I'm a multi-return customer and (governator accent) "...I'll be back...".

 

PTO Side Cover Gasket - let's go ahead and chuck the OEM, eh?:

 

I've been underwhelmed with how Tecumseh paper PTO side gaskets hold up.  On disassembly, 2 of my HH120's were leaking badly from the gaskets and the gaskets were so brittle they came off in about 100 pieces each even though there was no adhesive and near zero adhesion.  So this time, I decided to try omitting the paper gaskets trying something less shrinkage prone and much more flexible.  Controversial; go ahead and tell me how dumb this is; it very well could be.  What I did:  I've had some very good results way back when in tough leakage prone apps - when I was a pro master mech with this stuff depending upon care taken in assembly... I prepped both surfaces repeatedly with brake cleaner and used 'The Right Stuff' being very careful to remove a lot of excess prior to final assembly ~ and carefully 'finger bevel' the goop very thin towards the inner area in order to control internal extrusion problems.  It will have plenty of drying time making me think it will be just dandy.  Of course saying that is like saying:  "Hey Murphy, here I am!"  Therefore - Murphy's law and all... if it flops, I'll let ya' know straight away.  It'll probably take something like HE or an F5 tornado to get the PTO cover off next time.  If you've never used it before, 'The Right Stuff' really sticks like a sonofagun.  I believe it is a modified hybrid RTV/Urethane mix like used to be used on windshields.  Windshield apps require massive adhesion.  Anyway, we'll see if it holds tight or sluces oil like before.

 

Sandwich bag trick in lieu of (NLA) crankshaft sleeve seal installation tool:

 

The well greased sandwich bag trick (sounds like a blue vid but it's not) from YouTube seemed to work very well in lieu of a seal installation protection sleeve on the crankshaft.  After the seal was over the step in the crank, it was easier to slide the oiled bag out of there than it looked in the video.  In this location, I used the ultra slimy/slippery Permatex assembly lube.  I usually only use that on camshaft lobes, but it sure makes the plastic bag slide well.  Please do remember to remove the Ziploc portions in advance as they absolutely won't slide past the seal lip, obviously!  ;-)

 

Heck, I even remembered to put in the alignment pins before gluing the cover on.  I believe it is kinda' amazing I remembered that since I'm fighting a losing battle with the flu.  My lungs sound like a broken Accordion.  Kinda' takes some of the fun out of it.  OTOH, it may (or may not) be better than sitting around moping about it.  Was pretty light headed a few times.  Yeah, I know.  Whining.

 

Timken Main Bearing Side Preload: 

 

(repeatedly carefully seated and triple checked) Timken main bearing side preload with the replacement crank and NOS Timken bearing races was at .006" on a spec of .001" to .007".  I'm not comfortable with asking a mundane no-tech casting like this to hold that much preload and wanted something closer to the median.  So I used a lapping plate on the inner seat of the mag bearing plate and gradually brought it to where the preload is .004".  Just as the Tecu manual says, it is essential to have a table with a hole in it so that the engine can be laid down with the PTO shaft thru the hole.  This lets gravity keep the lower Timken bearing well seated - if you actually ever get it seated.  More about that in the para below.  If any Q's, see the technician's manual and all will be clear.

 

Pro/amateur tip:  If you're wondering if you've really got the lower Timken seated fully... there is a very good chance you haven't.  Or at least, I didn't.  Although the block is cast iron, there is a lot of elasticity or SPRING in it.  Tapping the crank makes the crank bounce.  There are few exceptions.  IF your side preload is somewhere in range like mine was, you can assure full seating of that lower Timken this way:  Go ahead and bolt down the mag side bearing plate.  Then tap the crank with a deadblow hammer a few times.  Because the mag bearing plate is already holding things tight, there is little chance that the crank will bounce when the plate is bolted down.  I was only then fully confident that the lower Timken was fully seated.  Before I used this trick, the crank was bouncing and I was getting some discouraging scatter on the feeler gauge measurements.  But not after this.  Once it was fully seated with no bounce, measurements and therefore lapping progressed in a nicely linear manner thereafter.

 

If your side cover is not in range and you want to seat the crank without question, I speculate that you might pull the mag bearing plate down snug with the screws; please don't get crazy with torque or you might wreck your block or bearing plate.  When snug, tap the end of the crank with a dead blow hammer.  The snug tension on the bolts should reduce the maddening bounce of the crank.

 

Why a dead blow hammer?  The Tecu manual just says a mallet.  But whenever something wants to bounce this badly, a dead blow hammer (a plastic mallet filled with lead shot) can at least try to reduce some of the bouncing.

 

Wish I didn't have to belabor this as in the above, but if you get your side preload wrong (no preload OR actual end play OR excessive preload), you have some serious problems on the way.

 

Bass Ackwards Seal OEM - flippin' that pup?  Sure, why not:  

 

The only other little mod:  I've been thinking about this awhile and wondered if it would work or would it just crush the seal body?:  I noted that the seal in the mag side bearing cover plate when OEM on HH120's is installed with the seal lip and garter spring pointing out which is against automotive wisdom for resisting leaks - in fact, that botch is known to cause a lot of leakage... - and it is the reverse of how it is on the PTO side.  The two HH120's I have were leaking like a sieve from the mag bearing plate seal, so I tried pressing the seal in backward (using Permatex Super 300 as an installation lubricant and sealer between the sheet metal seal shell and the bearing plate - an old guy favorite for this sort of thing) so that the seal lip and garter spring would be facing in instead of out.  With some care, this pressed together just fine without crushing the seal shell and the seal lip now runs on a portion of the crank that I had earlier cleaned and mirror polished during prep to #600.  If the wear line on your crank is rough, this might be a fix worth trying since it will run the seal lip over 1/16" away from the original seal wear line.  Just a thought on that part.  

 

IF this 'better idea' leaks like a sieve anyhow, I'll let you know promptly.  ;-)  "Hey Murphy!  Try not to get hit by a bus or anything."

 

Cold Weather Whining:

 

Ok, I lived in San Diego for 5 years and S. Texas for another 5.  I'm saying that is why I'm so whiny about cold temps.  If that won't cut it, consider that I have a flu (world's smallest violin and it's playin' just for me) as my final excuse.  Nobody wants to go around freezing when they are sick, right? 

 

We're slated for snow and/or bitter cold weather in my area until Wednesday of next week.  So I brought the engine inside to prep, mask and paint the block to match or coordinate with the paint work I've done on all the tins and such (while I was waiting for nothing from the machinist) and to get the (scrupulously prepped and polished & thread chased) NOS cylinder head on it.  I lucked out and found an NOS Tecumseh set of "belleville washers" for the head.  The old ones were pretty flat.  My understanding is that the cup shaped belleville washers are intended to buy time between gasket settling and re-torque.   

 

Head Gasket Sealer??:

 

For what it is worth, the guy who runs the garden tractor puller website insists that all performance GT's should use Permatex aerosol high temp ultra copper sealer on head gaskets.  It's old school stuff that has been used since long before I was a young pup to seal low tech head gaskets.

 

IMPORTANT NOTE:  The very generous (with info) and cool guy's GT puller website says that ultra copper RTV might also be used instead of the aerosol.  However, other reading indicates that ultra copper RTV is ABSOLUTELY UNSUITABLE for head gaskets.  I'm not trying to throw rocks at the guy.  He has a great website.  Nobody is right all the time.  I personally believe that the RTV product is NOT for head gaskets.  Permatex says their ultra copper RTV sealer is NOT for head gaskets.  It simply lacks the adhesion and temp range of the aerosol product.  Permatex says only the aerosol high temp head gasket sealer is for head gaskets. 

 

The HH120 Tecu head gasket is about as low tech as they get.  My previous HH120 was destroyed due to repetitively failing head gaskets that finally veed out about 1/2 inch from the top of the block.  I don't want that to happen  with this motor.   

 

Since HH120's have a fairly significant history of some head gasket problems (some of which I've addressed above), I'm going to give the Permatex copper aerosol a try for the first time in 37 years.  (redneck speak):  "These right chere ain't no permatorque gaskets!"  Of course, way back when I was a kid, it was just high copper content paint... but it worked.  Usually.  

 

Paint Eyewash:

 

About the paint:  I'm using Pontiac Blue metallic engine paint from the 1960's contrasted by some aesthetically strategic parts in "arrest me red" Krylon Fusion.  The Pontiac Blue isn't nearly a match with Sears Suburban metalic blue.  However, I'm kinda' nostalgic for it since I built/owned some knuckle dragging Pontiacs awhile ago.  And, it is a color I like and is somewhat close to a supercharged 2006 Mustang GT I own in Windveil Blue.  I've used red accents to bring the stang to life, so I'm doing the same for El Tractorsaurus.  None of the colors are original at all, but I like 'em ok and it was cheapo paint I could find without a lot of huhu.  The Duplicolor engine paint has poor adhesion (IMO) so I use an adhesion promoter to hopefully help it stick at least a little bit.  Ceramic?  Why don't they can the ceramic nonsense and focus on making the dern paint stick??  End rant.  For now. 

 

Was the valve lash really ok or was I just 'imaginifying' due to high fever?? 

 

After final assembly, I double checked the valve lash at TDC.  The engine was about 20 degrees cooler now than when I set the lash.  With it this cold, it shows almost .021 and .011 on a spec of .020 and .010.  Close enough.  Thankfully, Murphy stayed the bleep out of that.  It would have been a tough screwup to fix.  I have to admit I lucked out and nailed it since I set that lash heading into the dark/cold/flu/arthritis-pain hours.

 

Let's beat that dead horse some more; grit in the crosshatch -- aka, 'Catcher in the Rye'??:

 

edit:  Wouldn't you know it, but after all that bore cleaning, you guessed it:  When I wiped down the bore with my home brew final assembly lube (Pennz Platinum 5w30 GTL (gas to liquid) synth oil spiked with ZDDP plus at the proper ratio)... the Pennz started removing more grey residue from honing iron and abrasives.  I mean, it wasn't huge but it was clearly visible.  Go figure!  I'd have sworn it was clean Clean CLEAN.  But ya' know.  Better to find it, I suppose.  I'm guessing that the aggressive cleaning package in the Pennz Platinum freed up some more residues.  Other opinons welcomed.  This ought to be a darn clean bore, IMHO.  Since Pennz Platinum has massive cleaning elements and TBN, I think maybe next time I'll just scrub the bore with that and not bother with the other dozen scrubs...??  Or does it take various alternating cleaning bases to get the grit out of a new hone crosshatch?  I've long thought it sure is stubborn.

 

Flexhone vice plateau brush?

 

Aside:  I hope this is true, but I read that running a Flexhone in a newly bored and honed cylinder is sufficiently equivalent to running a plateau brush.  I hope so, because that is what I did back in my Dad's barn when doing the valve work.  The machinist had left the hone finish looking/feeling too rough to my Dad and me (we are reasonably certain it never saw a plateau brush), so hence the Flexhone work.  It smoothed up nicely and I took the crosshatch up from 30 degrees (why did he do that??) to 45 degrees as is pretty much SOP. 

 

My beer is getting low, so end ramble.  I hope this is of use to someone someday.  I'm pretty good about posting back if problems develop, so if something above flops, I'll tell ya' in short order.

 

Micke


Edited by MountainMichael, November 16, 2014 - 04:58 PM.

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#10 MH81 ONLINE  

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Posted November 16, 2014 - 07:30 AM

Mickey, thanks for the detailed thread.
It will help he next guy, I'm sure.
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#11 MountainMichael OFFLINE  

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Posted November 17, 2014 - 06:18 PM

Thanks, MH81.  I appreciate it.

 

This was originally a replacement engine so it was white in color when I brought the tractor home.  The white paint had turned to a kinda' sickly "yellowed teeth" color with plenty of the usual flaws. 

 

This post is just a pic after prep and re-paint.  Just basic scuff, clean, mask, Bulldog adhesion promoter and then Dupli-Color Pontiac blue metallic engine paint.  I could've masked a bit better around the exhaust port but figured paint will burn off there anyway.

 

In the pic, there is a haze over by the exhaust valve that looks kinda' like masking leakage.  It doesn't look that way in person but I'll wipe down the surface with lacquer thinner before installing the head just in case. 

 

Nothin' fancy.  Since I'd already prepped and painted the sheet metal, thought I should cover up the "yellow teeth" color.  

 

It's sittin' in a warm room to help cure sealers and paint until the weather warms up.  Outdoors, it made it to 34 here briefly today.  Bitter cold outdoors once again now.  Hence why I'm drying the paint and sealers INDOORS!

 

It is too heavy for me.  Will have to use a hand truck to get it back to the garage.

 

Micke

 

HH120 in blue.jpg

 

edit:

 

I guess being shut in by cold weather caused my sometimes pedantic nature to make those masking flubs irritating.  Brush touched a few of 'em and new pic below.  It'll probably still burn off from this area but at least now it can do it honest-like vs my assumptions.

 

In the below, you may also notice that I cleaned up the exhaust port threads with a 1" x 11-1/2 (thread pitch) pipe tap (a tap that was rated for iron - although I believe most in this large size range will be rated as such) back during the valve work at my Dad's barn.  This took a lot of rust out and evened up an uneven area in the threads. 

 

Even after soaking for a week with Aerokroil, the old muffler was a real peach to get out - NOT.  Back in real life, it was a brass plated obscenity.  Later, I'd read in here there can be thread failures in the future - especially with the added leverage of typical stack type muffler hardware. 

 

Hence the tap work as a hopefully preventative measure.  Re-tapping appears to help the new muffler hardware to thread in by an added thread or two for arguably better strength with a Cub muffler.  Before that, a typical hardware store 1" nipple didn't really seem to thread in far enough.  Probably worrying about nothing here, I don't know.

 

Since I have it on the shelf for my 'stang, I'm thinking maybe Permatex hi-temp nickel anti-seize on the pipe threads so that the pipe threaded hardware can hopefully be removed again someday without ruining the block?  ~ Custodianship and all that. 

 

That reminds me... need to do some port work on the pipe nipple I'll be using.  ;-)  Every 'mousepower' counts when ya' live on Mars (very high altitude - not much air).  Multi-angle cone shaped on the inlet; semi-step anti-reversion on the outlet..?  Suggestions appreciated!

 

HH120 Masking Flubs Corrected.jpg


Edited by MountainMichael, November 17, 2014 - 11:05 PM.

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Posted November 18, 2014 - 09:11 PM

Added steps for a formerly massive oil leaker?

 

Because this HH120 in its last incarnation was the worst leaker I've ever witnessed, I decided that every bolt going in the block anywhere near oil should have the threads sealed.  One at a time, I removed the PTO side cover and mag side bearing cover bolts, thoroughly sealed the threads with Loctite 592 and retorqued.  These will need plenty of time to cure up (aka, to go anaerobic) since these are not pipe threads.  They'll get that time since some things are getting in the way of finishing this project right now. 

 

Although looking at the block from the inside made me previously believe that most of these were blind bolt holes, what I saw just now makes me think about half of them are (possibly unintentionally) wet.

 

Someone had mounting bolts holding this engine down that were too long meaning possible damage to those blind bolt holes, so even those threads will be sealed.  Just in case.  This replacement HH120 block was probably later model than the original and the oil sump design in the block had been widened for increased oil capacity; hence blind mounting bolt holes versus through bolts on open flanges on the original 1968 block.

 

mm


Edited by MountainMichael, November 18, 2014 - 09:20 PM.

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Posted November 18, 2014 - 09:46 PM

The old girl looks much better!
Sounds like you're taking all the precautions. Nothing worse than a leaky restore.
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#14 MountainMichael OFFLINE  

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Posted November 19, 2014 - 04:58 PM

Thanks for that.  I appreciate it! 

 

I needed to kill some time while the Permatex head gasket sealer dries so I thought I'd come in and post a few pics.

 

About the Permatex Hi Temp Copper aerosol head gasket sealer:  I can't verify if this is accurate, but I was taught years ago that it is important to let the solvents get out of the sprayed coating before installation or solvents could be trapped that could boil or blister on startup.  It's a difficult thing to judge:  I've never personally seen this coating approach anything near dry.  Stays sticky right up until the engine cooks it during warm up.  My radiant heater is only holding the garage at 60, so I thought I'd give it an hour of "flash time".  Can't really call it drying time.

 

I don't leave it dry overnight anymore due to a lot of wind and dust where I live.  The Perma-Sticky ;-) surface collects too much garbage overnight. 

 

Pics attached of prep for head installation.  Alignment pins made just because; valve clearance checked due to all the replacement parts (valves, head, valve job, etc).  Pics captioned where necessary.

 

I see the dust in the pics.  I'll be cleaning one more time right before placing the head and gasket in place. 

 

Play Doh Setup.jpg

 

Valve Clearance.jpg

 

Coated head gasket.jpg

 

In the below, I'm not a big fan of polished combustion chambers.  However, the NOS head had an awful finish; like razor sharp fish scales.  It would literally rip off skin on light contact.  I figured it would cause detonation and carbon accumulation problems so I cleaned it up a bit. 

 

The spark plug was badly shrouded so I worked a radius there for better mixture access to the plug.  I stopped at the end of the spark plug body. 

 

The valve pockets were really bad.  "...the horror..."  I'll call my work there:  "...deshrouding the valves...".  ha ha ?

 

Seriously, if I still had a bead blaster cabinet, I probably would have followed the sanding with that. 

 

Combustion chamber.jpg

 

Below is the hi-temp anti-seize I plan to use on the head bolts.  Regular old motor oil is usually specced but I've read of these engines breaking a lot of head bolts during re-torque, hence this step acknowledging that bolt stretch at specced torque isn't going to be spot on accurate.

 

Before cleaning and machine work, I chased various bolt holes with taps.  Head bolt holes were included in that, naturally.  They were really rough with rust.  Time well spent, IMHO. 

 

Hi Temp Nickel Anti-Seize.jpg

 

Ok, it's been an hour.  Back to Garage Mahal. 


Edited by MountainMichael, November 19, 2014 - 05:33 PM.

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Posted November 19, 2014 - 09:42 PM

You've posted some great details.  If the rebuild doesn't work out, I know it won't be your fault!

 

Ben W.


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