Howell v-2

[Gordon]

I started celebrating too soon. I ran the engine twice for about two minutes just before I quit on Saturday night and it ran well. I tried starting it again Monday morning and it will not run. Low compression on cylinder one. #1 has always been OK but #2 has been the problem. Now #2 is good and #1 has low compression. I have relapped the valves, checked the spark plug taped hole which was the problem with #2, checked and replaced the head gasket but still no luck. There is good compression in the cylinders with the head off when I put my hand over the top so it is someplace in the head. I am starting to think that this engine is jinked.

 

[kadora]

I have absolutely the same problem with one of my single cylinders.
I did everything but no compression so i think head casting is cracked.

 

[gus]

Gordon & Kadora.

Jinx. You are correct. From day one when I covered with hand,the compression seems not as good as all other engines built.One last resort is to use Viton O-Rings.With other engines with O/head on,I could feel the bump at TDC. Not this engine.
Good news.
My sister flew in from Sydney to help out visiting/caring for stroke sister.
Hall Device arriving tomorrow.Will crimp on to harness cable end.
Visiting hours is 12noon and it means I can juggle my time. Hopefully the sputter and false starts will lead to a full run.

 

[Gordon]

This whole situation has me baffled. It seems like I cannot get compression in both cylinder at the same time. For some reason it changes from day to day. First #1 is fine and #2 is low compression. The next day #2 is fine and #1 is low compression. I certainly cannot find a pattern or an explanation. Last week it was running well on #2 cylinder and marginal on #1. Yesterday it was running well on #1 and marginal on #2.

Oh well. I am off for eight days on a trip to Norway. It is one of those group tour things where all the people with the yellow hats line up here. Not really my thing either but it cannot be any more frustrating than building engines.

 

[Cogsy]

If your compression is changing randomly like that, it suggests it's likely a valve issue. I guess the good news is that if you're getting compression and firing some of the time, they may well seat themselves in fully (eventually) and your comporession worries will go away. Fingers crossed for you!

 

[crankshafter]

Hello Gordon.
welcome to Norway.
CS

 

[Gordon]

Well I am back to the V-2 and it is now running again. I ended up making another valve seat cutter and reworking the valves and now it seems to be starting and running pretty consistently. Now after reassembling everything Like all internal combustion engines good compression is the key. I am now chasing oil leaks. Most of the sealing is with O rings and they seem to require more precision than I am capable of. The biggest leak is in the elbow which feeds the oil pump from the bottom of the crankcase and things must be dissembled to get at it. There is an O ring against the bottom of the oil pump and in spite of actually using a clamp to assure some compression of the ring it still is leaking. The elbow is held in place by a 2-56 set screw which does not lend itself to a firm grip on the elbow. I will have to see what other option I can come up with.

Still lots of finishing work and details to go.

 

[Gordon]

Finally have the V2 running. I need some work on the carburetor to keep the throttle in position and it still needs some adjustments. Hopefully the video works. I have not done it before.


[ame]https://www.youtube.com/watch?v=Sw0iUDqemOw[/ame]

 

[Brian Rupnow]

Gordon--Congratulations!! You have completed what seems to be a very difficult engine, based on the results of others on this forum who have tried to make it. Be Proud!!---Brian

 

[Cogsy]

Very nice indeed. Sounds great.

For your youtube link, you need to post the one where youtube is not split (not youtu.be) and with the 'watch' in it, then it will display in thread like this:
[ame]https://www.youtube.com/watch?v=Sw0iUDqemOw&feature=youtu.be[/ame]

 

[Gordon]

Thanks Cogsy. I fixed it. What I really need is someone else to hold my Kindle so I can actually get to the engine while making the video.

 

[Johnvankoeveringe]

This has a theoretical compression ratio of 5:1. The valves seem to be sealing well and I am not getting a good bounce back even when I plug the intake and exhaust ports. It kind of fires but just does not really run. I have been avoiding remaking the valve seats because the originals are in with loctite but that may be the next step. I can get it to fire a time or two with starting fluid but only for a couple of pops. The valves certainly seal as well as the other engines which I have built. Off to an old engine show tomorrow so I will just forget it for at least a day.

 

[Johnvankoeveringe]

This has a theoretical compression ratio of 5:1. The valves seem to be sealing well and I am not getting a good bounce back even when I plug the intake and exhaust ports. It kind of fires but just does not really run. I have been avoiding remaking the valve seats because the originals are in with loctite but that may be the next step. I can get it to fire a time or two with starting fluid but only for a couple of pops. The valves certainly seal as well as the other engines which I have built. Off to an old engine show tomorrow so I will just forget it for at least a day.

 

[Johnvankoeveringe]

Hello Gordon!!
I'm also ready to run my Howell V2, I've been working on for the last 12 years.
my problems are somewhat different but along the same lines.
I have great compression on both cylinders and good hot spark on both plugs at or slightly BTDC.
Also all valves are opening and closing at the proper times as per JH drawings all within a degree or so.
however, it refuses to fire at all , electric start motor turns engine over at a good speed.
I have a fair bit of experience with gas engines but this one baffles me.
Hopefully some other people may read this and may have some insight into this mistery.

I am getting to the end of my build of the Howell v twin. I am having a problem with compression. I have plenty of compression when I take the head off and put my hand over the open cylinder. I have made a gasket between the head and the cylinder in spite of the fact that Jerry Howell said that it was not necessary. When I put the head on and turn it over I get a lot of pressure and/or suction at the ports without the valves being open. This is even when turning it over slowly by hand. I have lapped the valves using compound down to 400 grit but I still get the poor seal. Since the valves are in a separate cage loctited into the head I even put shellac around the edge of the cage to see if it was possibly leaking between the cage and the head. Still not working. The valves seem to be sealing when I suck or blow through the ports with my lungs. I am running out of ideas.

Some folks have mentioned a tool made by George Brittnell (sp?). Any link to that?

I am still confused as to how the carburetor and the crankcase vent work together but that is a problem for once I get the compression solved.

Gordon

Gordon--I had to do a lot of hunting to find this, but if you look at posts #257 and #260 in this built thread, you will see one of the famous George Britnell valve seat cutting tools. I made this one for the Atkinson engine I built years ago, and built a second one for all the rest of my engines which have 1/8" diameter valve stems and 5/16" diameter valve heads. The results with valve seats when using a tool like this are nothing short of amazing. I never did really figure out a good way (short of hand filing) to put a back relief on the cutting edges, but the tool seems to work perfectly well cutting brass valve seats without any back relief. I do not cut my valve seats in the lathe. I finish everything else on the brass valve cages, (concentricity really, really counts, so drill/ream the valve stem hole and the clearance above it all in one set-up). then I Loctite the valve cage into place, and then I slide the small diameter of the tool down into the valve stem hole and when the cutting edges of the tool touch the area in the valve cage which is to be cut, I turn it two or 3 full revolutions by hand using only medium pressure. the valve seat should only be about .015" x 45 degrees. NOT MORE. I machine my valves to have a 92 degree included angle, and lap them into the newly cut seats using first 400 grit, then 600 grit carborundum paste. Lap them by hand, and for gosh sakes don't lap them too much.---Brian
http://www.homemodelenginemachinist.com/showthread.php?t=18313&highlight=britnell+tool&page=26