After checking my deck height, I'm ready to mount my cylinders and heads.
In my baggie with the lifters are these 4 springs...
Are they specific to the Keith Black Pistons, meant to be an alternative to the final C-clip?
Does anyone use these?
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Assembly time!
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Squaw Valley? I've skied every part of that mountain. It's my favorite resort, but the food at Northstar was better.

I'm in California's Squaw Valley, Fresno County, Sierra Foothills.
Hotter than Hades in the Summer.
(recently renamed Yokuts Valley to honor the Yokut Indians who live here)

Never seen them in a stock motor.

springs hold the piston pins in place in the pistons (full float)

Agree wrist pin keepers

I guess I really don't know how they are installed then.
The diameter is greater than the wrist pin.
thoughts?
I'm thinking I can do without and just use the C-clips to hold the pin in, the groove is there and I have already confirmed that the C-clips hold firm...

914werke parts looking good!
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Those are "spirolox" wrist pin retaining devices...

I'd hit FULL STOP on that job right now!

Those are damaged! They shouldn't be re-used!

I'd want to know where those came from.

I'd make damn sure of my wrist pin retaining circlip.

Even on the normal clips these should usually be considered a single time use item and replaced during any tear down.

Spirolox are a PIA to work with, but they tend to be less likely to come out than a normal cir-clip.

If the pistons are designed for spirolox retention I would NOT change it up and use normal clips...

I've never had Spirolox just show up in a job. Sometimes pistons are designed to use two of them on each side and you end up with 4 times the number of sprilox versus pistons. On a 4 cylinder you will always have either 8 or 16 of these and it looks like you just have 4...

That would set my "squirrel-o-meter" off like nothing else!

A different form of piston pin lock and not enough of them to do the whole engine...

How to install
https://www.youtube.com/watch?v=NB2t3b29beE

Great info, thank you!
Starting to make sense...
The other 4 are in one side of each piston already and look very good.
I will need to order 4 more for the distressed ones.
But now this means I most likely have to mount the pistons before the cylinders because of the installation process which looks like a solid PIA

So, the other missing 4 Spirolox were installed in the pistons...

Makes more sense now. I'd expect eight of those in your engine.

Order extras as you may damage a couple before you get the "hang of it".

You will BLEED and curse a lot; Spirolox are sharp!

Practice does help but you're going to HATE Spirolox at first...

The guy who removed those mangled them pretty well.

Check the entrance to the pin bores under magnification for damage.

You can carefully dress damage with a jewelry file or ultra fine emery cloth.

I'd make sure the grooves the clips fit in were clean and not mangled.

The pin should slide in easily. It's tight but it is NOT an interference fit.

I'm guessing you didn't remove these...

You would have remembered it!

Lol, I hate them already!
I'm going to measure stock pistons for the C-clip tolerence and compare.
When I snapped in an old C-clip for checking the deck, they were as snug as any other piston I've worked on before.
I really would like to have the pistons in the cylinders for mounting.
Just can't be an idiot and make any mistakes this far in...
So thank you all for the "Wake Up" call!

The Pins and surrounding areas look great, they also slide in and out nicely

I've never encountered anyone intentionally replacing Spirolox with a standard clip.

We all just put up with the bull shit...

Might work fine!

Might blow up in your face!

I'm too much of a chicken-shit to make a change like that just to make installation easier.

Spirolox were a specific design to improve wrist pin retainment at high RPM.

Besides being an absolute PIA to deal with they are considered a performance upgrade.

I don't remember a Spirolox that was properly installed causing a failure.

I've seen a couple of improperly installed ones create havoc.

Pups have to be "all the way" in.

Yah, I get it...
They make perfect sense from an engineering standpoint
Fail safe for expanding pistons/heat
These Keith Black pistons should have minimal expansion.
Under extreme heat I could see the C-clips distorting
It should all come down to whether the groove/slot is the same size vs stock

Here are the little butt heads. I have not had them in engines I have built before and they where a bitch to get out till you found just the right tool. This is a RAT 2270 bult Engen with 170HP or so and has all the good parts. Ck out the RAT windage tray. Jake has a way of opening these boys up.

Bob B

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Place a rag under the piston so nothing will fall inside the case. Seems silly but I shoot one clip across the room each time I install them. One did fall into the case and went fishing with a magnet

Hah, exact same thing happened to me. Thank God the magnet found it.

You don't need to lock the wrist pins when you are checking height. Just slide em in.

Yup! I had one jump in the case.
Sounded like it went to the bottom...
Rolled the case over and it fell out, got real lucky.
Good advice, Thank You!

Here is what Mark S and I did today:
just going to cut the plastic bag after the wrist pin and rings are installed.

Bob B. 2270 RAT rebuild

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That's a very good idea!

I'll be doing mine "under wraps" as well.

Thanks Bob!

I recall seeing Teflon buttons or Delfin ..
Seemed like another idea that might work.
They are flush with the outside of the piston so they don’t fall out

<snerk> They are piston return springs. You are supposed to put them on top of the pistons to make the transition from top dead center easier. That way the engine produces more horsepower <snerk>

Good to know, I thought they went on top of the exhaust lifters, help make that Brap Brap sound!

How to properly install Spiral Locks

These things are a bitch to install but we got it now. It takes a certain technique. If you don't have. One of these, very hard to install it. There are tools to help install it. Some are made by Stromberg, Anyways Pelican sells one for 95 bucks. Looked at Utube videos on it and it ended up being technique. And practice. And then it was very simple.

By the way. This RAT 2270 Engen Mark Sonners and I are rebuilding is very old like early 2000 and we thought that the pin in the bottom oiling control groove may have been a RAT design. Went back to George the machinist and he called Keith Black or whomever owns them and that was the standard piston used for Harley Davidson engine rebuilds back then.

Mark Howard thought that the piston needed some sort of a bridge that went in the ends. Where the rod Pins go. To support the bottom oil ring because it was a stroker piston. Here is like 5 degrees open. In the piston. Where the rod goes. On both sides. And the idea is. That this bridge kind of thing supports the rings on the bottom.

Picture of piston, bottom grove and the pin. The spiral locks are made from spring stainless steel.

Best Bob B


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Stroker SBCs have used "pin bore intercepting oil control ring groove" forever.

Every time I've seen this it has had a separate "bridge" ring than goes below the normal oil control ring to bridge the gaps on both sides.

The oil control groove is made wider to accommodate this ring.

On one installation this bridge ring looked a lot like a giant Spiro-lok and had to be wound onto the piton.

I've never encountered this set up WITHOUT the extra bridge ring...

I've never encountered this on a foreign engine...

I think you've inadvertently posted a picture that I needed.

I've heard about the "roll pin" mod done to stroker pistons by Jake.

I think that picture show the placement of the roll pin and the depth it gets installed too.

That roll pin will locate both the bridge ring and the lower scraper ring of the oil control ring pack.

Without that roll pin ring damage is more likely from what I've read.
I would expect terrible oil consumption without the helper ring. Maybe that roll pin takes the duty of the "bridge" ring.

Is the oil control groove in the piston wider than the oil control stacked ring assembly?

If so, you need the bridge ring.

If not, the roll pin simple locates the lower scrapper for strength.



Awesome picture!

Thanks for posting!

We had to increase the gap on the lower scraper ring to fit the pin. Each time we ran it past the machinist George at EMW on Prairie in the Los Angeles area http://www.europeanmotorworks.com/ George redid Ian Karrs Engen as far as fixing up the line bore and I believe he does the Engines that PMB has built for them. He has gilded us with all our questions.
I have always said the good machinist is your best friend when rebuilding your Engen. It really helps that he is 12 minutes from my shop.

Best regards,

Bob B

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I have watched the video where a guy was building a 2270 in 912E with LN Nickie’s (very pretty) and there is no roll pin.

Bob B
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Did your set up include the helper ring or is it "roll pin only" locating the lower scraper ring?

Please provide a link to that video.

Hard to tell from the picture but those pistons may not intercept the oil control ring groove...

Will blend in with the red fasteners. Fashion is so important!

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As Betty always says.. It's not a good job until you bleed on it and cuss at it.