Lapping piston rings
 

I was sorting thru old Car Craft magazines and I found an article from 1974 about Herman Chapman and a tool he built for lapping rings, using comet cleanser, and a piece of glass , does anyone still do this ?, or do todays rings not need this ?

Re: Lapping piston rings
 

Today, you just pay Total Seal $100.00 each for them to do it. The old way sounds much cheaper.

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Any chance of scanning and posting the article? If not, what issue is it in? The old school tricks for stock eliminator are fascinating.

Rick Thomason
GTOMayhem

Re: Lapping piston rings
 

I remember a Hot Rod magazine article on Dave Boertmans 1969 Chevy Biscayne N/SA 350/255 engine. They went through the motor and how it was built, a very technical article. Quite honestly at that point it was hard for me too understand but it was a start. You don't find technical atricles like that today in car magazines anymore, "just order a crate motor" or call somebody (engine builder) seems to be the norm. Just my 2 cent.

Will Lamprecht 65 Impala I/SA

Re: Lapping piston rings
 

My understanding is that rings are "lapped in" during the manufacturing process. The rings are mounted on a mandrel/fixture and "stroked" through a hardened liner/cylinder.

My experience shows that cylinder wall finish, hone finish, is a vital key to a good seal.

Also, precision piston ring grooves are vital.

Re: Lapping piston rings
 

Herman showed me his lapping setup. It was a piece of aluminum round stock that had a recess machined into it that was .061 deep for 1/16" (0.625) rings. When he ordered the pistons for Super Stock motors (BRC, generally...some Venolias), he spec'd the ring grooves at .061. The ring would go into the aluminum holder and he put some Comet mixed with parts cleaner solvent on a big piece of thick plate glass and rubbed the fixture in a circular pattern, checking the fit of the ring to the groove as he went.He had the same holder for the .043 rings..probably some others as well.

On the Stocker pistons with the 5/64 grooves, he would tighten up the ring lands by lightly dimpling them with a small punch and lap the rings to the now-tighter grooves.

With the advent of CNC equipment, the need for a lot of this is gone.

Anyway, that's how I remember the process.

Re: Lapping piston rings
 

Good point, Will. Many people are so overwhelmed with the technical part of building engines that they believe that the "high tech" referenced in marketing of services and products is the only source of a competitive engine. So the vast majority of racers "buy" the work and the parts, and the expense goes up (again!). Or people get discouraged because of the cost to the point that they do not participate. Then the sources of information go away since demand diminishes and people do not want to jeopardize their livelihood.


If you can change your mindset to be satisfied with "competitive" not "ET killer", that is the first step to having the inspiration to do your own engine work. After a few serious builds and intense striving for information and skill, it is amazing how much you understand. You then have a reference base of knowledge that helps you to glean more information from everything you read, even advertisements.


Another good article to read is the one about Wade Owens 283 engine:http://www.hotrod.com/how-to/engine/...tor-283-chevy/


I personally want to encourage you. I follow your threads and posts and I sense that you are doing so many things right. Keep it up and never be shy to ask questions.


In reference to the lapping of piston rings, there is some benefit to that. Some companies offered the tools for sale if I remember correctly. The additional piece of understand that needs to go with that is that as you lap the rings, you take material off and so the ring gets thinner. Then the clearance increases for the ring land and sealing efficiency sealing suffers. It is the same effect as wear from running the engine. So, you either start with a thicker ring, or you narrow the ring land. In old days, we would press the piston top to compress the top ring land (not too cool) or machine the piston for some items called "ring land restorers" (looked like radial spacers that fit into a specially machined groove at the top or bottom of the ring land and were made of some hard spring steel). Sealed Power/Speed Pro sold the spacers and a specially shaped tool to fit a lathe. It worked okay and was even legal in Stock eliminator with OEM pistons. Today, I might be inclined to order my pistons with thinner ring lands.


Dwight Southerland

Re: Lapping piston rings
 

The article on Scott burton's car in high performance Pontiac is another good one.
I made a couple of chapman's ring tools years ago and still use them. all rings have a torsional twist as they are compressed into the bore. Chapman's lapping process "seated" the bottom of the ring and made it flat.
I used perfect circle's manulathe years ago to save worn piston grooves. A simple device that worked very well. Ron.

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The magazines forget there is a new 16 year old guy "born every minute" . They haven't seen the articles of the 1960's on good engine building or blue printing etc.
A new article would also serve to increase the interest of younger guys as they could actually learn and become more interested in the technology of Drag Racing.
Car Craft, Super Stock Magazines also covered these topics and today there is only one Hot Rod. Unfortunately by popularizing bizarre paint, or factory topics basics is being lost to the general public.

Re: Lapping piston rings
 

Car Craft November 1974, I will try to scan it

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Agreed, any tech articles on stocker engine builds are fascinating. Although some of the methods or parts may be outdated, anyone that can post links to old stocker engine articles ... thanks in advance. I recall a great one on Bobby DeArmonds 427 after he ran a "9".

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Dave boertman's article, I believe, showed sealed power's head land top ring (basically a 1/8 inch wide dykes type ring at the top of piston). Ron.

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Dwight,

You are dead on with your response about the early days, most people did most of their own work ... They learned from their mistakes & became better racers for it ... Today, it's all about the $$$$ & the spread between the have's & have-nots is growing wider !!! So, your point about the articles is a great one !!! You should never stop trying & learning ...

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Dwight, posts like this one are the reason that you're one of my (few) heroes!

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I might add that I think "The Net" has caused some of the "Old School" tried and true ways of doing things be discounted by the younger generation. The Gen X,Y and now the Millennials are all so computer literate that is where they go for information. The "Net" has created so many keyboard guru's that have little or no experience with actually squeezing the most out of parts and combinations that those methods are lost. I just think there has been a loss of some information in the information age. The X,Y and Millennials can get information, but they are only getting what is quick and easy. The Net has caused the "Hands On" experience that was handed down in Apprenticeship type situations to go by the wayside.
As an Old Fart that has plenty of both good and bad experience that is just my .02 for free, on "The Net"

Re: Lapping piston rings
 

It seems amazing that 30 years ago, what we had to run to remain legal in Stock Eliminator even worked at all. Those were the days when a run just under the index was something to be proud of. The constant evolution of the sport has been constant,relentless,and outstanding. One of the sure things, there are no more car magazine articles that feature this stuff like there once were. There was a tremendous amount of learning to be had from those years. I got belittled once that"Reimer doesn't know anything but what he reads in car mags". I thought that was a complement. Obviously, that detractor never read many magazines, or he'd know something too.
The evolution of Stock Eliminator into what it is now isn't just motors, but tires,wheels, chassis tweaking,converters,transes, all in all, the cars just aren't the same.I don't know how a new racer could ever do this if it wasn't for the vast herd of experienced racers out there that have a vast pool of useful knowledge. Believe us, it doesn't come easy.

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I remember reading that Chevrolet used cleanser as a field fix for seating rings on the early V-8's.

As far as the just pay someone to do it and the lack of tech articles it's the same in bracket racing. Few if any do the work to their cars. I'm constantly amazed at the people that race that do no work at all on their cars.

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I still have my stuff for that. When I was running my old C/SM car in the mid '70s I was WD for Manley. Their Pistons were stocked with no top ring groove. 2nd was .043", oil ring was 3/16". I bought them that way.

My ring fixture is/was 4.030" on one end, 3 7/8" +.060". (Had a 292" & 306" engine.) Had a sharp machinist friend that made a fixture to hold the Pistons, and a tool to cut them. After lapping both sides flat while compressed I lapped them to .041". We used .0005" vertical, and .001" back clearance, with .040" vertical gas ports. Had a piece of 3/8" steel plate parralell ground to lap them on, laying in my parts washer, with the pump flooding the paper.

I had one end opened up to 4.070" for my present engine. Not as easy to see on these shiney .028" Total Seal rings as the black .043" rings, but they appear to be flat. Layout ink also comes off first swipe on 400 wet or dry paper.

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Good article on Scott's B/SA car, man is that thing fast. Does anyone know what rod bearing to order that is for a crank pin of 2.200'' with a Pontiac rod housing bore of 2.375'' ? I got a neighbor that would love to save his OEM crank.

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So this should still be done if ring manufacture doesn't?

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Bon-Ami was the choice. I got to experience stopping on the way to Amarillo to a point race, unloading the car and running it up and down the highway applying the Bon-Ami to get stainless steel rings to seat.

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lol, I remember aircraft radial engines, had chrome cylinders and cast rings, bon ami was used to get them to quit pumping oil. they could use a lot of oil too . it was a last resort.

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Been there. Used Bon-Ami as well. Stainless Dykes rings in my old '56 Jr Stocker.

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The BonAmi trick was a Pontiac approved fix attempt for oil burning engines. I recall hearing of it and to this day if I hear the name BonAmi that's exactly what I think of. Add some to your oil to get your rings to seat.

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Thanks Dwight, I think I might have bought my Shubeck lifters from you back in 2002 or around then? Anyway your right , you do learn by doing. My 65 Impala is coming out "better" than the 68 Impala I built. This time I was able to do much of the work myself. I will be with Jimmy Vignogna, my engine guy, as we go through the process building the 396 at his Machine Shop.

Another drag racing friend, Pat Hennebery, said the first objective in building a drag car is to just get it down the track. Makes sense.

Hope I don't hijack this thread. ! Sorry

Will Lamprecht Div 1

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He is using a BBC rod, not a stock Pontiac rod. It is NHRA approved for a Pontiac Stocker.

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Thanks, I have already acquired the 68' Car Craft magazine with the "Build the Ultimate Jr Stocker" articles, as well a few others with GTO or other Pontiac builds. The articles are very detailed and seeing the old ads is great.

My son and I are working on our 1967 GTO and plan on building it as a late sixties stock eliminator. We plan on doing almost all the work ourselves, so I am trying to find as much information as I can on all aspects of past and present race car building.

Everyone on this site is great and have been exceedingly helpful. That has been a pleasure for a neophyte like myself. As I have told others on here (Mark Yacavone) I will quietly observe, ask a few questions and try not to be bothersome.

Thanks Again Everyone,

Rick Thomason
GTOMayhem

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The same bearing that the big block Chryslers are using. Your new 6.1 will use the small block chevy bearing. Moma mopar already took care of that for you.

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how did that ever happen

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Because no manufacturer made a rod for that engine.

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It's a BBC rod, but built .500 longer. Not a big deal.

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[QUOTE=Monte Howard;493093]It's a BBC rod, but built .500 longer. Not a big deal.[/QUOTE

It's only .010 longer.Instead of 6.625 is 6.635 The standard Chev bearing is the same size as a .050 under Pontiac journal. Easy to get bearings, that's the big advantage. The BBC rod is 50 grams heavier as well.
No great injustice here so relax.

Re: Lapping piston rings
 

Back in 68 no one was using MM ring packs like what are available today.

Mahle now offers a 1MM 1MM 2MM ring pack and Mahle rings from what I have seen seal up good on start up.

To achieve good ring seal plate honing is a must which was not used way back when.

A good hone is a must with the proper abrasives.

No matter what you use for a ring its not going to seal if the cylinders are not round once the head is bolted on or the proper finish is not used for the final honing.

Richard Maskins has a good view on honing.
https://video.search.yahoo.com/video...t=mozilla&tt=b

Here are some pics of cylinders that were not plate honed and I don't care who's ring are used in these engine that are not going to seal. Look at the blowby under the top rings.

http://i1086.photobucket.com/albums/...psea76f04c.jpg
http://i1086.photobucket.com/albums/...pse2194c56.jpg

http://i7.photobucket.com/albums/y27...CKS/glazed.jpg

Shadows under every bolt hole when the torque plate bolted on.

http://i7.photobucket.com/albums/y27...ps8fc31bac.jpg

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[QUOTE=Dwight Southerland;493003]If you can change your mindset to be satisfied with "competitive" not "ET killer", that is the first step to having the inspiration to do your own engine work. After a few serious builds and intense striving for information and skill, it is amazing how much you understand. You then have a reference base of knowledge that helps you to glean more information from everything you read, even advertisements.

That is outstanding advice for anyone that doesn't have a "bottomless pit for a budget".

Re: Lapping piston rings
 

[quote=Todd Hoven;493117]
Todd, pretty sure he meant it is 0.500" longer than the stock big block Chevy rod, which is 6.135" long.

The FE Ford was also allowed to use an aftermarket big block Chevy connecting rod before the aftermarket made rods specifically for them.



On the original subject, these days most of us try to get our piston company representative together with our ring company representative, and make sure the ring grooves and rings are well matched. I've found that my friends at JE and CP have no problems talking to Keith at Total Seal, and making my pistons match my rings really well. I do not do much to my rings or ring grooves when I get my parts.

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Alan
Who do you talk to at JE. I need to get 2 pistons to replace 2 that were damaged

Thanks,

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Just a quickee................

It doesn't go in the oil!!!!!!!!!!!!!!!!!!!!!

Remove the spark plugs and put the BonAmi directly into the cylinders and crank her over....Use air to blow out whatever you can from the cylinders.....Start it up....Let it run for a bit....Change oil and filter...See what you got....Sometimes better...Sometimes not...It's just a bandaid..

GM also had TSB's about helping ring seal and oil consumption by using GM Top Engine Cleaner in Gas & Diesels.....Gas it went down the carb and diesels it went in thru the glow plug holes...

Just a crutch...

Bob

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We called this "flinting" an engine when we did it to 6v53detroits. They would idle so long they would gum up and when you stepped on it there was a cloud you could see for a mile plus it had no power for a while. Once it got real bad we'd pull the air filter and at a fast idle throw a handful of scouring powder in. Couple rev's and see how much it smoked, maybe do it again.

Worse case scenario, we sent the engine to second line for rebuild.

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The NHRA approved rod list for the Pontiac 350, 389, 400,421,428, 455, it looks like all the OEM rods were the same size. 13 rods are listed on the approved list with only two rods as super stock only. Of the remaining 11 rods, nine are listed as the OEM size. Crower makes two, Oliver has three, Eagle has one, Childs and Albert has one, and Carrillo makes two.


It looks to me a lot of venders make a rod for that engine. It ok to grind the crank .049'' under (NHRA allows -.070'') to 2.200'' crank pin size but nobody makes a rod bearing -.049'' under that fits into a 2.375'' housing bore. If I read the rules correctly spacers are not allowed in stock.


So if good bearings are not available just ask NHRA for a new rod, AKA the FE ford rule.

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Mopar ask for the same thing for the dragpaks. At least the Pontiac uses a corporate bearing size.

So if good bearings are not available just ask NHRA for a new rod, AKA the FE ford rule.[/QUOTE]