Lifer

My Feedback: (1)

I have bought 2 rings from Frank and at this point all my new engines will be so equipped. You can feel the difference from the start. Better compression, quicker break-in, etc. The cost is minimal.

SkidMan

My Feedback: (17)

Exactly the same for me.

Replacing rings is about the easiest job a person can do with the guts of a 2-stroke.

Paul

Ernie Misner

Make sure you stuff a clean rag around the rod in the crank case after you pull the jug off. You don't want anything falling down into the crank case. After installing the new ring on the piston, align it with the pin, put some oil around it, squeeze it tightly onto the piston, and carefully slide the jug back down onto the piston and ring. Oh, take the rag out. If you are finicky (and there is any slop in the cylinder bolts), there is a cylinder alignment procedure you can do before tightening the cylinder retaining bolts.

Donairplane

My Feedback: (3)

I have two DL 50 . First one ran like realpoor. Hard starting, poor idle and low compression.
Checked ring had .017 ring gap. Installed Frank's ring. Picked up 100 rpm first run. What
an improvement, starts easy now. Great compression. Frank's rings from now on!!

Don

captinjohn

This Brown trout was well over 30 inches. When the guy took the photo he did not wait untill I had the fish so you could see the other 1/2 of the fish. I released the fish over the small dam so she could go spawn! Got home & after looking atthe pic.....Iwished I had a good photo. Its weight felt like about 16 pounds. Capt,n P.S. She sure put up a fun battle, I will always remember !

3136

It looks like you are doing something indecent to that poor fish[X(]

captinjohn

Hi there Down Under....is it warm there at least? Pretty cold & windy here in Michigan. Capt,n

3136

Hey Capt'n, sorry to hear about all the bad wheather you guys are having.
It was 34c/94f yesterday and 30c /86f the day before but today is pouring rain and 18c /64f.
Nice fish, Ive tried many a time but never caught a thing, only in the sea did I have any luck

sopwith

I have been using old string trimmer and chain saw engines for my planes (store bought engines are too pricey for my budget), and have had problems installing new rings. The rings generally never break in properly never giving me proper compression. How long should it take for the rings to break in? I have been using factory rings, and the pistons and cylinders are always in good condition. Any help from you experiences guys? I haven't tried a FB ring yet, I need to sort out the break in problem first. I use a ball deglosser, in some cases hand sanding, as I can't find a ball or straight deglosser to fit. As a side note, the FB rings generally seem cost the same or less than the original manufacturer rings!

w8ye

My Feedback: (16)

I would not put a ball job in a cylinder. You do not need to bust the glaze to get the ring to seat. You are probably doing more harm than good? The balls bounce around in and out of the ports and actually make a mess. If the cylinder has some galled alluminum in it, you can use Muriatic acid on a Q-tip and some 320 Crocus cloth to try to remove the aluminum. Don't get any acid on the aluminum part of the cylinder itself or the acid will eat it away.

Chinese rings are very hard and you are unlikely to seat in a Chinese ring in a year's use.

Bowman's rings should seat within a few tank fulls of gas. I think the Bowman rings are Ductile Mehinite

Ernie Misner

Have you tried using old school oil for break in before going to the synthetic to see if it makes a dfference?

BadAzzMaxx

I have a couple JC 120 engines that would hardly do 56-5700 RPM's on a 27-10 prop, Installed Frank's rings and now can get 62-6300 on a 28-10 prop.

So there is something to using Frank's rings.

Milton

sopwith

I think the problem is likely the cheap, hard rings. In the old days of full scale radial cylinder engines, the rings were broken in on the bench by coating the cylinder with fine grit lapping compound and manually running the piston in and out for awhile. The mess was cleaned up and the rings were broken in. I am tempted to give it a try just to see what happens. It is not like I am using expensive engines, most of them I buy at garage sales for under $5. Next time I go to town I will try to pick up some lapping compound and give it a try. Half the hobby is trying new things, and sometime the new things are a disaster!

sopwith

P.S What is the typical compression test reading on these small engines? I just modified a compression tester to work and tryed a few tests. The string trimmers, 25-31cc seem to all test out at 85-95 psi. The ones that feel they have good compression are only slightly better than the ones that feel to have poor compression. These cheap lawn care motors rarely have 2 rings, the ones I checked were all one ring engines. I looked at chain saw repair videos on line, and they seem to all consider 150psi to be a good test, but these are all multi ring engines. I am tempted to try adding another ring using my small lathe, but I suspect the vibration will be a problem.

yak-54

A very Good article Very conclusive
I liked what i reed Thank you Mr Bowmen
Do you recommend to Change the Ring when the Engine is New or can itbe Changed Later?
Ilan

Ernie Misner

Frank told me either way. Install when new or when broken in with the stock ring is okay too.

acerc

Got the ring's from FB Thursday. Installed the one's in the CRRC55 and the DLE55. I will run them tomorrow for at least two tank's with some standard oil to break in a little. But just from the feel of turning the prop I believe there is a difference. The resistance ,feel of the compression, when turning the prop is a little stronger. Which tend's to make me believe the compression is better before I even fire it up.

karolh

Instead of using some 'standard oil' for breaking in your new ring, why not just use the oil you are planning on running the engine with from the very start. It might take a bit longer but your engine will thank you for it.

Karol

acerc

I measured the ring gap of the stock ring before removal and the FB prior to install. The FB was much closer and fit the pin much better.
I normally use a synthetic @ 40-1 from the start. But it takes so long to break in. Would like to get there a little sooner to compare the two CRRC's and two DLE's. Am really interested what the difference will be.

rcguy59

My Feedback: (8)

Would someone please post the particulars as to ordering from Mr. Bowman?

w8ye

My Feedback: (16)

Just keep using your synthetic at 40: 1. The Frank Bowman ring will break in faster all on its own.


Bowman’s Rings

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Bowman's Rings Model Airplane

rcguy59

My Feedback: (8)

Thanks!

BadAzzMaxx

I do not know if what I do is the right way or not but this is what I got

Hand flipping as hard as I could 8 times

Stock ring about 65 PSI
Bowman ring 85 PSI

Turning engine with a electric starter

Stock rings 95 PSI
Bowman rings 120 PSI

As for the post about pre breaking in rings, There is a little more to Bowman rings than breaking in, They have a better ring gap and with stock ring they will even have a bigger gap after they are broken in.

Milton

acerc

Milton if I'm not mistaken when taking a compression test it is the accumulative preesure of numerous consecutive strokes, not the single stroke.

w8ye

My Feedback: (16)

The automotive type compression tester has a Schrader type valve that accumulates the highest pressure. When done, you press the button and it releases the pressure.

As said earlier, To take a chainsaw and pull it through with the cord five or six times or until the pressure doesn't rise any more generally gets up to around 150 lbs.

A chainsaw with close to 100 lbs will be harder to start and be weak in the power department.