MTFCA Forum

Anybody recognize this contraption?

Ball bearing retainer for the valve actuation on an Akron OHV cylinder head - Zoom - Zoom !!!

Well that didn’t take long...

Anybody have a running Akron equipped motor out there?

Saw one of these recently, can't remember where.

Andy

I've never really actually seen one of these Akron heads with the ball bearing filled tubes that supposedly took the place of, or operated in place of rocker arms to actuate the valves, but I don't think their rarity should be surprising, because I remember reading somewhere (a very long time ago) that this set-up, while it seems a rather clever mechanical arrangement, it was not very successful. I believe the problem was that besides a lot of friction from so many ball bearings moving within the tubes, the excessive weight of such a column of ball bearings was such that "inertia" became a problem at a very low speed. In other words, some pretty serious "valve float", at a not very high RPM! FWIW,....harold

The ball filled tubes are neat and all... but was thinking something like this would be more reliable

Back in 1975 as I remember The late Joe Morris, a HCCA club member ran one of those heads in the SCVMTFC annual speedster run. Somewere I have a picture of the car but not of the engine or head. The car was a red, brass era (1914) styled speedster with black fenders and red wood wheels if I'm remembering correctly. Maybe someone else will recall the car.
I know at the time it seemed to run just fine, I don't think Joe ever had any issues with the head. I don't have any idea as to whatever happened to that speedster, it may still be out there somewhere in somebody's garage.

Millzilla will be busy.

Andy

Lloyd Riggs ran an Akron head for many years with the tubes and ball bearings on his speedster. He was from the Danville ,CA area-not sure what happened to the car. I have pictures of the car and head if you want a copy.

For years a guy brought one to the Harvest Swap meet in Canby Oregon. Don't know who the owner was but as rare as they might be?

There's a fellow T enthusiast up in B.C. that is attempting to run one soon.

Those heads fascinate the heck out of me. Can you hear the balls when they run?

Steve you have a good memory. I do still have the head, but little progress has been made. I made a pattern to cast up the tube stands, and had some chrome moly heavier wall tubing bent for the balls. That is as far as I got. The schematic that Kevin shows is very interesting and I think is much simpler than the tube setup. It would be nice to complete this head and install on the 27.

This head came to me assembled and just about complete, including all the valves, keepers, push rod tubes, and exhaust manifold. Only thing missing is the valve spring shields... if they are supposed to be there?

At least 2 of the ball tubes are cracked and have raised dimples where the ball bearings were trying to get out. That’s what started me thinking down alternative methods of valve actuation. I want to put this head on my speedster, but will expect the head to perform as reliably as the flat head on the car now.

These heads are not as tall as the typical OHV conversion, and are similar in profile to a standard flat head. Since the valves are in line with the flow of the ports, the ports are short and direct. The 2 intake ports are squished flat to maintain the low profile, while the 4 exhaust ports make a very quick exit out the opposite side.

I would be curious to know the serial numbers of the known heads. This head is #388... not sure if that is early or late production...?

Here is a couple pics of the port layout for the Akron OHV head. While I’m not too excited about the ports being squished flat, I believe this head will flow enough air to improve upon my slightly modified flat head

Kevin, my head is s/n 249. As mentioned above, I do not have the ball tubes or the spring covers or either manifold. Your concept for the rockers looks very interesting and I would like to discuss this further with you if possible.

So...
If you have #249, and I have #388... than we can conclude with reasonable certainty... that there were at least 2 of these heads made!

While I do have the correct exhaust manifold, this head came with 2 die cut steel straps to clamp an intake manifold to the head. It had a NH and stock T intake manifold clamped to it when found. The head in Speedy Bills collection is displayed in similar fashion

Feel free to contact me directly

Here we have step 1 of the intake rocker done... now to cut the center bushing bore and cut off the handle

I'd love to see the flow characteristics on the "squished" ports... I wonder if it was an attempt to get a flat dispersal of the combustable mixture to improve burning characteristics?

I suspect they were more interested in fitting the car without modifying the firewall.

Ansy

AndyClary wrote: ↑

Tue Dec 10, 2019 3:48 pm

I suspect they were more interested in fitting the car without modifying the firewall.

Ansy

No doubt this was the major motivation for keeping the profile low.

But if they had made a higher compression version... the ports could have been less squished. Or if they had gone the route of the “A” RAJO (4 valve), with its raised bumps to make room for the intake ports.

Either way... all the early heads suffer from oversized ports and poor airflow characteristics anyway... maybe a lil bit of port velocity will do some good...?

Finished an early Christmas present for myself this morning. The first of many steps...

Step two... exhaust rockers!

Start with a big chunk of round bar, then make it a little bit smaller in the lathe Then off to the mill to start sneaking up on it Just can’t be afraid to make a little mess

Fortunately Kevin, unlike the rest of us, thinks in the 4th axis. I'm working my way through two.

Andy

Now back to the lathe for the last bit of work

Kebin, what material are you using and will it require heat treatment?

Andy

Wow Man!

AndyClary wrote: ↑

Fri Dec 27, 2019 12:52 am

Kebin, what material are you using and will it require heat treatment?

Andy

Just so happen to have about 15’ of 3” diameter 4130 normalized steel bar laying around... so what better material to use?!

The plan is to use stock T valve springs, so there won’t be much load on the rockers. I figure they’ll be OK as is... but am considering flame hardening the tips to prevent wear at the valve stems. Others may have a more scientific opinion... but I don’t feel there’s a need to overthink this one

After 4 hours in the mill, time to make some room for the bushings...

Very Very Nice Work Kevin, Thank You for sharing. Some can not understand what it really takes to make these parts, time, equipment, and knowledge.

All the Best,

Hank

I do have to admit that a more modern mill could have done the same work in half the time or less... but that requires the one thing that didn’t make your list... MONEY!!!

Am far enough along now to mock up the first sanity check...

Then got to thinkin... sanity’s got nothin to do with this project!!!

Wow...Nice engineering on the rockers.

Which car program ate you using and does it give you a mirror image for the even number cylinders?

Andy

AndyClary wrote: ↑

Sat Dec 28, 2019 2:50 pm

Which car program ate you using and does it give you a mirror image for the even number cylinders?

Andy

I have been designing in SolidWorks, and programming with FeatureCAM. I expect that all CAD/CAM softwares have the ability to mirror the design/model at the push of a button... but generating the machine code is a bit more complicated job. All CAM softwares I’ve ever used will force the recalculation of the toolpath after the model has been mirrored, translated, etc... This recalculation is rarely perfect, so I always give it a good look over. The good news... is that the setup and machining operations typically are not lost, and detailed review and edits are all that are required to get the “other side” programmed

Thanks Kevin. I'm going to give Fusion360 a try, they give classes at a local maker's space. They are more into 3d printing but I should get a handle on the CAD.

Andy

I’m just starting out with FeatureCAM... it’s my first experience with AutoDesk products. It’s been a bit of culture shock! I have looked over Fision360 some, and it is similar to FeatureCAM as they are both AutoDesk products... but COMPLETELY different workflows! Fusion360 is a somewhat conventional user interactive software, it should be a good fit for someone cutting their teeth in the CAD/CAM world... and it’s free too!

Don’t know if I’ll get to it this weekend... but here’s a before photo

You might need a new broom by the time you’re done.

Andy

Hell with the broom!! I’m gettin me a snow shovel!!

Starting with a flathead?

Do you have a 4x8x20 block to mill the valve cover?

Andy

AndyClary wrote: ↑

Sat Jan 04, 2020 6:27 pm

Do you have a 4x8x20 block to mill the valve cover?

Andy

Don’t be ridiculous!! Would only need to be 4x8x19!!


Actually, was thinking about milling the bottom edge out of 1/4” or 3/8” sheet, then forming a cover from aluminum sheet. Don’t really want a folded and welded street rod looking valve cover, but think I could form the sheet to give a better “drawn” look. I still have to work out the spark plug adapters too, as this cover will need to have “Hemi” style spark plug wire tubes.

Here is a shot of the latest design revision to the adapter plate... was hoping to make the plate appear a bit less “billet”

Another fit check... so far so good!

Lookin better yet?

It looks like a piece of art ! I wish I was that talented.

Been “plugging” away at the spark plug adapters. Found these 10mm thread spark plugs with over 1” of reach. Needed the long reach to be able to extend the electrode down into the combustion chamber, rather than being recessed up in a hole. The extra threaded section is for a spark plug tube that reaches thru the top of the valve cover. The spark plug tubes also double as the valve cover hold downs

Nicely done! The spark plugs adapters you spoke to me about look great.

The top panel of the valve cover is done... is it starting to look like the picture yet??
The top panel has 1/8” of crown in it to combat the “billet” look. I should have made a vacuum plate to suck the cover down and prevent vibration during machining... but I didn’t! Oh well! So there a few grooves and gouges but once they are blended out and polished they will simply be waves in the finish and will actually help the cover look less “billet”

The valve cover will be a welded 3 piece assembly when finished. The top panel, a machined base ring to blend the top and bottom profiles, and the current plan is to bend a 2” wide strap to connect the 2 pieces. I considered a casting, but it would have been almost just as much effort to build the required pattern. All this effort to only yield 2 pieces... not worth it!

I'm surprised it's not see through so the masses can appreciate your rocker arms.

Andy

I considered the see thru option at first... but got derailed once I realized how complex the wiper mechanism would need to be...

Rain-X?

Andy

Hmmmmm... in the light of new options... maybe I’ll reconsider

The materials for the rest of the valve cover are ready for pick up... and I’m sitting at the airport not to return till the end of the week...!!! This is gonna drive me nuts!!!!!!!!

Back in town now... and found this waiting for me

Is that a coating or heat treatment? They look really good.

Andy

They were flame hardened at the tips, and then bead blasted. I think what you are seeing is a thin layer of oil (likely hone oil) that makes em glisten in the pic

You can tell I’m loosin my mind not having the rest of the materials for the valve cover yet...

I am going to be really curious to hear how the Akron head performs with the rocker arm conversion. They really never had a chance with the silly beads and tubes system. (Yeah I know they used ball bearings)

Of course I am expecting nothing short of NASCAR performance... But am willing to settle for comparable performance and reliability to my current heavily modified flathead... only without the detonation and heating issues!

I relate the heating issues to the Sherman flat head not circulating water to the rear cylinders well, and the detonation most likely is a result of excessive dynamic compression (about 170 psi)

This head will get swapped in place of the Sherman, along with a new cam to account for the 1.5:1 rockers, and new pistons to maintain the 7.5:1 static compression ratio.

Found some time today to make the base ring for the valve cover assembly. The base ring is cut from aluminum plate in a single operation.

Now all that is left to do is bend up a strip of 3/16” x 2” aluminum to match the outer profile. And after a couple hours of welding should yield something that looks like a valve cover. And after a few more hours of grinding and polishing... should be able to comb my hair in it

Kevin. Doesn't look quite right, I have a needle scaler you can borrow to blend it to the head.

Andy