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New pistons for a 1928 standard, maybe Jeep


unimogjohn

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Hi all, a while back (and now I cannot find it) there was a discussion about using Jeep amuminum pistons in a 1928 standard engine.  Do any of you recall the conversation?

 

My current engine has several cracks in the water jacket.  They have been fixed by using JBWeld.  Now I have another crack.  I am thinking I should just bite the bullet and replace the block.  I have a good block that I bought a few years ago from Dave G. in Maryland.  But I am sure that it might need an oversized piston once it is cleaned up.  I have no idea what size is in the current engine and I do know that it has been opened up at some point, so it could have either steel or aluminum pistons.  

 

Does anyone have any knowledge of this subject? I know that Egge will make me some, but at a significant cost, like $2000.  Any help or advice would be appreciated.

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Look for a piston specifications list or book. That will give you diameters, wristpin diameter compression height (distance from pin centerline to top of piston) and other specs.

i used 2 sets of Jeep pistons in my '31 Buick. The compression height was off a touch so I compensated for that by milling the head and block slightly.

 

My '18 Buick has a set of Corvair pistons in it. I had to modify the rods a bit for that.

 

 

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John,

If you want to go with original Buick cast iron pistons, I have dozens and dozens of new old stock ones from an old Buick dealership in Sherman, Texas that sold out in 1969. They are not identified, but if you give me the width and height of what you want, I think I can find a set of six matching ones. Have many different sizes.  $10 each plus postage.
Pete Phillips, BCA #7338

Leonard, TX

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John,

The Buick pistons specs are: (All dimensions given in inches)

3.125 diameter with a flat top

3 rings

2.1875 Compression height

.750 piston pin diameter

 

Jeep specs:

3.125 diameter flat top

3 rings

2.167 compression height

,8120 pin diameter

 

As you can see the if you use the jeep pistons you will drop the top of the piston .0205 and the compression ratio too. However, the small end of the connecting rod would have to be bored to take the jeep piston pin. If the machine shop bored the hole and offset it .062 to the top (the difference in pin diameter) you could raise the the top of the piston .031 (about 1/32") and the compression too. I think I did the math right, but if I didn't someone else will catch it. Personally I would go with the jeep pistons and make the changes to the connecting rods. A 10% increase in horse power is a nice dividend and it will cost way less than new pistons.

 

If you want to stay with cast iron pistons i think the 26 standard piston had a 2.25 compression height (according to the book I have anyway). That would raise the piston at the top of the stroke 1/16 inch and the compression too. I think you have the clearance to the valves.

 

Anyway it's fun to think about.

 

Cheers,

Dave

 

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Hi Leif,

The jeep pistons are for the years 1941-71 for the 134 ci/2.2L in line 4 cylinder engine, both flat head and the F head that was used in the cj series jeeps in those years. I found the pistons at United Engine & Machine Co uempistons.com

They are in the Silv-o-lite catalog part #2606. They come standard size and over size starting at .010 through .080. I didn't see a price.

Cheers,

Dave

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http://www.mahle-aftermarket.com/media/local-media-north-america/pdfs/pi-20-09.pdf

 

If you go to the Mahle link, you can find pistons that might fit, kind of a backwards search, method so stick with me.  Good machine shops have even better look-up tools than this.

 

The specs start on page 247.  Search for your bore (or close and a bit over if you plan to bore any way), then compression height, then pin diameter.

 

You will find your jeep piston as a 224-2756

 

Then you can go to page 238 for more info to find out what the heck a 224-2756 fits.

 

I addition to my Buick, I happen to own a 1960 CJ5 and have done a good bit of business with Walcks Jeep Parts in Ohio

 

http://walcks4wd.com/walcks-willysjeepparts/    first rate folks to work with, they don't carry any junk.

 

Here are the pistons at $45.95 each.  They carry standard, 0.020, 0.040 0.060 inch up to 0.080 oversize.

 

http://walcks4wd.com/engine/piston-rings.html?p=2

 

Hope this helps some.

 

The 6 cylinder Buicks (like my '23) have a 3.375 bore, similar compression height and 0.750 pin diameter.  You can practice looking up a modern piston that is close for me.

 

 

Edited by Brian_Heil
Typo (see edit history)
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Brian, Dave B, Pete and Leif; thank you all for the research and information.  I know now that I can go ahead and rebuild the engine if I need to.

 

Right now I am JBWelding the water jacket cracks up.  They had been done previously so this obviously is nothing new.  I thought I have them all plugged, but found two more small cracks this morning when I filled the radiator with water.  So they now have been plastered over and will let it harden for at least 24 hours.  

 

My plan is to see if I can make this engine water proof again.  I think it was JBWelded sometime in the early 80s, so it has held up pretty well, no reason it should not hold water now.  Or at least we will see.  I think that the cracks just keep expanding and contracting over time and gradually worked themselves beyond the original repair area.  

 

Dave B sold me a great block, no cracks.  There are no ridges in the cylinders and nor scoring of the cylinder walls that I can see.  I am going to look for a gauge to see if it is still standard or oversized.  I have no idea what size pistons are in the current engine, but it would be great to just be able to hone the bores to clean them up, put in new rings and reuse the old pistons in the Dave B block.  But I will not know until this engine fails and I take out the engine and rebuild the Dave B block.

 

I may take the Dave B block to a local machine shop and have the eight broken bolts taken out and the bores cleaned up.  At least then I will have a serviceable block and will know what size piston I will need.  

 

Olson's Gaskets in WA, has all the gaskets for a rebuild at a good price of $400.  And they will sell gaskets by the piece also.  

 

Here is a pic of the Dave B block before and after all cleaned up, and a couple of shots of the JBWeld repair.  The pic of the bore looks bad, but it is really not, just gunk for the most part, I just did not want to start grinding it for fear of making thing worse.

 

Will update this in a couple of days.

 

 

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Edited by unimogjohn (see edit history)
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Final report for now. 

 

I have the block all sealed up with JBWeld and am running the engine.  No leaks and is running great.  Going to take the new block to the machine to see what the condition of the block is in and the size of the bore.  Oh, that is oil flowing down the block in the pic, not water.  And I changed the oil and filter to get rid of the moca tinted oil.  

 

I made new cork seals for the side covers too.

 

Final question, where would I look for the 17 inch long bolts that go into it to attach the head.  Pete, you have any of those?  TX

 

Pic of the put back together engine.

 

 

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Wow John! Now I can understand what I will be going thru on my 1925. I have the "Buick Technical Tips" Book. Copyright 1993. The compilation of articles sent into the Bugle. On page 90 Frank Bergoyne. BCA#5721 sent in an article about his "1925-25 Piston swap tip" and the Jeep pistons. Also about replacing the valves with ones from a IHC Farmall model H. On page 91 of the same book there are articles on "1928 Standard 6 exhaust valves", Submitted by  Bill ColsonBCA # 1928 and one on "1928-1931 Piston Slap and Offset Wrist Pins". Submitted by Al Barany BCA # 37 Reprinted from "RAMCO Motor overhaul Service Manual Bulletin #146". Long dissertation continued on pg. 92. I am to understand that the Buick Pistons of this period had the wrist pin bores offset to the centerline of the piston. I know many are switching to the aluminum Jeep pistons. What about this offset?

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The pics are not of a 1923 block.  I now see looking at the first post you are running a 1928 engine.  Boy was I confused.  Ha.

 

A reminder to all that most of our old engines have a ring of accumulated 'goo' at the bottom of each cylinder's water jacket.  Draining the block still leaves this ring of water soaked goo that can still freeze even though you thought your block was dry.  Always store and run with 50/50 coolant and if you do drain, the goo is still 50/50 soaked and won't freeze.  Note that John's cracks are right in this area and the previous owner never read this post.

 

 

 

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Everyone, this will be my last post on the topic.

 

I visited the machine shop and two of the machinists came out to the truck to look at the block.  They gave it a good visual inspection, and said that it would not be worth it to attempt to remove the eight broken studs, unless the engine was the only one left in the world.  They said that the cost to remove each stud would be at least $30 each, and more than likely would be more like $100 or more.  They looked at the threads left in the block of the remaining studs and they were all shot too, they would never hold a new bolt.  So bottom line, the cost just to repair the studs where the head would bolt on would be in the $1,200 to $1,500 range.  I have seen complete engines for much less than that so will just keep my eye out for one.  

 

Right now my JBWeld repairs are holding up fine and I am going to put in the crack sealer product tomorrow.  Hopefully, that will give me many more years of service.  Thanks again for all the help.  I know the information you provided me will help others down the road.  Nice to have the old 28 back on the road again.  

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  • 1 year later...
On ‎19‎.‎9‎.‎2016 at 12:48 AM, Pete Phillips said:

John,

If you want to go with original Buick cast iron pistons, I have dozens and dozens of new old stock ones from an old Buick dealership in Sherman, Texas that sold out in 1969. They are not identified, but if you give me the width and height of what you want, I think I can find a set of six matching ones. Have many different sizes.  $10 each plus postage.
Pete Phillips, BCA #7338

Leonard, TX

Dear Pete,

I'm looking for cast iron pistons that fit 3.375" bore. I am restoring an old 2-cyl LeRoi motor and one of the pistons has a crack in the skirt. The piston has 3 rings, its height is appr. 3.2", the compression height 1.5" and the wrist pin diameter is 0.9" (see attachment). I have, so far, been unable to locate an original replacement and I'm wondering whether some of your old cast iron Buick pistons might be adaptable. I would really appreciate your comments and advice.

DSCN1749.JPG

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9 hours ago, Pete Phillips said:

I found a couple that are close, but you would have to grind off some of the skirt, I think. I am not familiar with the term "compression height"

Thank you very much, Pete. Compression height is the distance from the center of the wrist pin, to the top of the piston. From your photos it seems that this may be a little more than 1.5'' on the Buick pistons, but can I ask you to measure it for me?

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