Frank Bowman rings
03-04-2014, 05:37 AM
#26
My first engine to use a Bowman ring was a side-exhaust DLE 55. The ring was installed before the engine was run the first time. Prior to installing the new ring the engine could be turned over by rotating the prop hub with moderate resistance. After installing the new ring, but before running for the first time, there was so much compression that the engine could not be turned over by hand at all. I took it to one of the club meetings and even some of the stronger guys in the club could not turn it over.
It bit my finger on the first hand start, but I blame me for that. To this day it is the strongest of my three 55's. There is a video of it pulling my Tarheel Hal on the P-47 thread.
It bit my finger on the first hand start, but I blame me for that. To this day it is the strongest of my three 55's. There is a video of it pulling my Tarheel Hal on the P-47 thread.
03-04-2014, 07:42 AM
#27
My Feedback: (66)
walla in our hobby i find it hard to believe that a ring will break that way. Most cylinders today are very tough and last a long time. maybe much older engines with softer cylinder walss wear that much to cause piston slap but that is the pistons fault not the ring.
For everyone in here dont worry if you have ran your engine already and even if you have run it for a couple of years go ahead and replace the ring.
For everyone in here dont worry if you have ran your engine already and even if you have run it for a couple of years go ahead and replace the ring.
03-04-2014, 09:16 AM
#28
Gene, I just came back from the Perry, GA swapmeet/show and bought two DLE motors the 20 and the 40 twin. I have rings coming for both engines from Frank. I have already trued the reed block in the 20 and ordering a timing kit to make sure the timing is correct and then when they are all back together I will havbe them installed in the planes and crank them up and go fly.
I do wonder if the DLE rings are better now than they used to be. I bought two DLE 30s about 2 years ago and also bought Bowman rings but got lazy and have not put them in yet. These two engines run like tops with the factory rings and I don't notice any lack for power, they start very well, and don't seem to lack any compression at all. Just seems weird even putting the FB rings in now. I know I am sort of an old school advocate of "if it ain't broke don't fix it" mentality sometimes
03-04-2014, 09:19 AM
#29
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In theory, in a ringed engine, the piston should never touch the cylinder wall, thus no wear on the piston at all. And the ring has a gap when it is cold that is calculated so that when the engine reaches optimum operating temperature and the ring has fully expanded, the ends of the ring just barely touch or come to within just a few ten thousandths of touching, thus forming a complete seal for the highest possible compression. Frank's rings do this and actually make an engine run better than most factory rings.
03-04-2014, 09:48 AM
#31
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Did you just buy some rings from Frank? I need a couple more and just emailed him. I have an older new DLE 55 and a new DLE 55 HV model in the box to put on my EF 300 and wanted to put an FB ring in it.
I do wonder if the DLE rings are better now than they used to be. I bought two DLE 30s about 2 years ago and also bought Bowman rings but got lazy and have not put them in yet. These two engines run like tops with the factory rings and I don't notice any lack for power, they start very well, and don't seem to lack any compression at all. Just seems weird even putting the FB rings in now. I know I am sort of an old school advocate of "if it ain't broke don't fix it" mentality sometimes
I do wonder if the DLE rings are better now than they used to be. I bought two DLE 30s about 2 years ago and also bought Bowman rings but got lazy and have not put them in yet. These two engines run like tops with the factory rings and I don't notice any lack for power, they start very well, and don't seem to lack any compression at all. Just seems weird even putting the FB rings in now. I know I am sort of an old school advocate of "if it ain't broke don't fix it" mentality sometimes
03-04-2014, 10:36 AM
#33
My Feedback: (19)
Last year I installed Bowman rings in (2) DLE 30s and a 55. These engines had the original rings and were over 3 years old. The original rings had sealed well and the only reason I opened the engines was to see how they were doing .... curiosity! I did replace the 55 piston as it was showing some wear from open cylinder porting but everything was well otherwise in the engines. I think the Bowman rings improved the engines some but they ran fine before the change. Cranking compression was improved in all cases.
03-04-2014, 12:21 PM
#35
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The Bowman ring will not turn a DLE20 into a DLE30 but you can expect some improvement over the OEM. Better compression and maybe a few more rpm's.
1. Buy the ring (under $20 including postage).
2. Remove the 4 cylinder bolts and pull head off of piston.
3. Remove old ring.
4. Clean up piston and cylinder if there is excessive carbon buildup. DO NOT HONE CYLINDER.
5. Install new ring.( lite oil on piston sides)
6. Slide piston back into cylinder.
7. Put 4 bolts back in BUT do not tighten.
8. Rotate crank shaft a few turns. This will align the piston and cylinder to each other.
9. Now tighten down the 4 bolts being sure not to move the cylinder head.
10. Go fly.
Mike
1. Buy the ring (under $20 including postage).
2. Remove the 4 cylinder bolts and pull head off of piston.
3. Remove old ring.
4. Clean up piston and cylinder if there is excessive carbon buildup. DO NOT HONE CYLINDER.
5. Install new ring.( lite oil on piston sides)
6. Slide piston back into cylinder.
7. Put 4 bolts back in BUT do not tighten.
8. Rotate crank shaft a few turns. This will align the piston and cylinder to each other.
9. Now tighten down the 4 bolts being sure not to move the cylinder head.
10. Go fly.
Mike
03-04-2014, 12:39 PM
#36
My Feedback: (19)
One major advantage of the Bowman ring is its easier installation. The Bowman ring has less cross section area and less uncompressed diameter than the stock ring. It is much easier to compress for installation in the cylinder. In many cases, it will just slip into the bottom of the cylinder if there is enough taper machined on the bottom of the cylinder. If anyone has installed one of these in something like a DA and compared it to the stock ring you'll know what I'm talking about. By comparison, the DA ring is very difficult to compress. The Bowman ring is really an "amateurs delight" when it comes to rings. Good product.
03-04-2014, 11:06 PM
#41
Senior Member
Basically you want all the mating surfaces flat so there are no air leaks.
Take off the two bolts holding the carb on
Lay some fine emrey paper on a sheet of glass, sand smooth the face of the carb, the rear crankcase and reedblock.
Take the reeds off and sand their seated positions.
Re-assemble, don't overtighten the bolts as you may distort or crack the reed cage.
Take off the two bolts holding the carb on
Lay some fine emrey paper on a sheet of glass, sand smooth the face of the carb, the rear crankcase and reedblock.
Take the reeds off and sand their seated positions.
Re-assemble, don't overtighten the bolts as you may distort or crack the reed cage.
03-05-2014, 03:59 AM
#43
I just asked Frank about installing his rings in a new DLE and check out his response: "I just examined ring in new DLE 61, still bad, I guess some things don't change. DLE is coloring rings black to look like mine, but their rings still not round with too much gap."
DLE seems to be still throwing subpar rings in their engines. I think some of us just get "lucky" when we have one that runs great and doesn't have an issue. As I mentioned before I have two 30s that are running pristine, so for right now, I don't plan to bother with them. I will put a FB ring in after I put some time on them and are in a maintenance window. One thing is not bad to invest 15 bucks in an FB ring - the engine cost is still good with DLE and FB ring.
DLE seems to be still throwing subpar rings in their engines. I think some of us just get "lucky" when we have one that runs great and doesn't have an issue. As I mentioned before I have two 30s that are running pristine, so for right now, I don't plan to bother with them. I will put a FB ring in after I put some time on them and are in a maintenance window. One thing is not bad to invest 15 bucks in an FB ring - the engine cost is still good with DLE and FB ring.
He should take some time off and go fishing.
03-05-2014, 11:14 AM
#49
My Feedback: (34)
Hey guys I have these sweet rings in 2 DLE30 and a DLE55 with notcable benifit.
So my qestion is has anyone ever installed his rings in anything other than the DLE motors?
Im working on ESM B25, Im going to use 2 ASP 1.80 4c that I converted to gas. Both these motors have less than a gallon on them, and I was thinking that these Frank rings may help them not vibrate so hard, and make them a little more dependable.
One think I will say, I have several gas motors, but I was setting one of these motors up, and if I did not look inside the carb with tha flash light to check my throws on the throttle servo, I would not have noticed, what I had my TX at as full power was actuly more like 50% open of the throttle body, (not that it only opened 50% but went past 100% and back over to 50% closed!!!
Mike
So my qestion is has anyone ever installed his rings in anything other than the DLE motors?
Im working on ESM B25, Im going to use 2 ASP 1.80 4c that I converted to gas. Both these motors have less than a gallon on them, and I was thinking that these Frank rings may help them not vibrate so hard, and make them a little more dependable.
One think I will say, I have several gas motors, but I was setting one of these motors up, and if I did not look inside the carb with tha flash light to check my throws on the throttle servo, I would not have noticed, what I had my TX at as full power was actuly more like 50% open of the throttle body, (not that it only opened 50% but went past 100% and back over to 50% closed!!!
Mike
03-05-2014, 12:02 PM
#50
Senior Member
I hope Frank does stick around, it's not just us airplane guys he does rings for, he does chainsaws and all sorts of custom rings.
There will be many concerned people if that business just closed.