Improved Akron-Hed sanity check

[Kevin Pharis]

This is not the first sanity check for this project... and it won’t be the last. So far every sanity check has proven that sanity has little to do with this project!

The original design;

The concept;

Up close with the rockers;

Just a bit of welding left to do on the cover;

After all the welding is done, there is just a few details to button up and it’s time to start thinking bout swapping out the ‘ol Sherman flathead

[pete eastwood]

I like what I see .
Interesting valve layout, side to side , rather than front to back like all the other overheads ! .
It will be interesting to see how it performs .

[Kevin Pharis]

After a couple hundred hours designing and manufacturing the rocker system... all I can do is hope it’ll perform! So far everything looks promising as the head has many favorable design characteristics... 2 in, 4 out, cross flow, valves in line with the ports, and spark plug near the exhaust valve. The ports are relatively small when compared to other performance heads... but I think they’ll be plenty big enough to produce similar (or better) performance as the other 2 intake port overheads

Too late to give up now... I hope to have the head runnin later this year!!! That is... assuming I survive the pandemic...!?

[perry kete]

That looks great but I don't know why you went to all the trouble when the catalog has them for $67.50!

[Kevin Pharis]

Turns out that they only take silver backed bank notes... and the heads apparently have been discontinued for a few years!?

[John Warren]

Nice Work ! Thanks for sharing

[AndyClary]

I've been watching your progress and I think sanity may have left the room quite some time ago;). Did you figure what the compression would be? While the ports are a little odd shaped, it should certainly flow better than T ports.

Andy

[Kevin Pharis]

The Akron has a typical flat bottom combustion chamber just like all the other pushrod heads... and it measures a cavernous 1-5/16” deep. With a stock crank and pistons, I imagine the compression ratio would be somewhere around 3:1. And with the A crank and .060” overbore probably a staggering 3.1:1!!!

I’ve got a new set of pistons on the to-do list, lookin to maintain the 7.5:1 ratio I currently run with the flathead. Also on the list is a low lift cam to compliment the 1.5:1 rocker ratio. With the 1.750” valves, I’d like to run better than .300” lift at the valve. The plan is to work out a deal with a fella who has a flow bench. Not lookin to alter the head any, just lookin to figure the best lift for the design

[Kevin Pharis]

It’s no “show” polish... but it looks a whoooooole lot better than it did yesterday...!

[civinwt]

Kevin, the (in)-sanity check looks fantastic. It would be a shame to mark up the top of the valve cover in any way, but some sort of marking to indicate who and where this set-up was conceived should be considered. You can now not tell that the cover is a 3 piece affair.

[AndyClary]

7 1/2 is a good number. When you get to a flow bench I know a guy that lives near you with a couple of heads to compare it with. I suspect up to 3000 rpm it will come plenty well.

Andy

[Wayne Sheldon]

"Sanity check"? I think you're crazy! But in a good way.

Aren't we all?

[Kevin Pharis]

With the valve cover done... all that’s left to do is...;

Finalize the push rod dimensions
Drill the last couple mounting bolt holes in the rocker supports
Notch the rocker shafts for the clamp bolts
Drill oil holes in the rockers
Rebuild the head
Machine new keeper grooves in the exhaust valves
Order custom intake valves
Order custom pistons
Design new camshaft
Build new header and exhaust system for the car
Build new intake to fit twin carbs
Build new hood to close up old header clearance and clear new header on opposite side
Freshen up the ‘ol motor so as to make all the magic happen
Paint everything to match
And finally... convince my wife it was all worth it!!!

[Herb Iffrig]

What is next, the exhaust manifold?

[Kevin Pharis]

I have the original exhaust manifold... but my speedster is an outside exhaust kind of car. So planning on building a header flange. Header and tail pipe might get interesting with the steering box, alternator, water pump, and shift/e-brake levers all on that side...

[Kevin Pharis]

Kinda like a “before and after” pic...

[Kevin Pharis]

How bout some header plates...?

Not sure what I’m doin yet... so made em outa stainless just incase

[Kevin Pharis]

Just about have all the other loose ends tied up, so now it’s time to get the pushrods figured out

[Kevin Pharis]

Here’s a couple shots of the new keeper groove machined into the 351c valves that are going in the Akron’s exhaust. Also have custom .875” shorter valves on order that will go in for the intake.

[ModelTSpeedster]

I am still looking for this cover for my Hal Akron head. A similar adaptation would really make yours pop!

[Kevin Pharis]

I considered that logo (specifically the script) design... A LOT!!! And would love to have included some element of its design into my valve cover. But as you can see, ultimately settled on smooth as I wasn’t happy with anything I scribbled down. Besides... I could always carve out another one

[Kevin Pharis]

I am still looking for this cover for my Hal Akron head

That early Hal cover is only about 1-2” deep, and could easily be carved from solid. With that picture and a few well spent design hours, you could have a brand new valve cover before the week is over...

[Dan McEachern]

Kevin- there is a real straight forward tool in SW to transfer a picture image into a sketch. Happy to share if you want it. Dan

[Kevin Pharis]

That sure sounds a bunch easier than my usual way... but pics typically have some sort of distortion and can’t (shouldn’t) be trusted. I have “vectorized” pics in the past, then imported as a sketch only to create a geometrically sound version using the “vectorized” sketch as a guide

I know this is technically the old fashioned way... but from what I have experienced, I feel yeilds the best (and most time consuming) results. I am curious to see how SW handles this feature and look forward to checking it out

[Kevin Pharis]

Building push rods this evening... got an ‘ol stock cam and a couple solid lifters stuck in a block as a baseline. Pushrods are made from high tensile steel rod stock, with pressed on hardened chromoly cups. The 1/4” pushrods run in bushings that pass thru the intake ports and upper water jacket of the head. These bushings prevent the pushrods from following the swing of the rocker arms. So I have devised an upper pushrod link with ball cups at both ends that will allow the upper end of the pushrod to follow the swing of the rocker arm.

Got the intake side all set up and we are looking promising! The exhaust side is soon to follow...

[Dan McEachern]

Some 16 Valve Roof heads used a similar arrangement on the pushrods although not that elegant.

[Kevin Pharis]

I know that the Roof 16 used a short link to connect the rockers to the valve tips... but just found these patent drawings showing the 2 piece pushrod design used on the A version of the Roof 16 heads

The bummer about this design, is that the pushrod needs to be a tight fit in the guide to prevent vacuum leaks at the guide... but this prevents the pushrod from swinging with the arc of the rocker arm. I imagine the A version Roof 16 valve train must have been problematic at higher speeds, and all the vacuum leaks must have been a pain at idle.

The Akron has a similar design system with the pushrod exposed to the intake port... except that the Akron didn’t use a “rocker”, and so the pushrod didn’t need to swing during operation. It does have a tube installed that passes thru the intake port to pilot the pushrod, but this tube is ultimately open to the port at the bottom. I intend to fill the bottom of the port with enough epoxy to seal off this tube and eliminate the associated vacuum leaks

[Scott_Conger]

What am I missing here? All T's have leaks at the pushrod and valve guides. You are probably aware, but others may not be, that excess clearance/wear at the guides is the primary reason that some Model Ts smoke so profusely at idle after a good run, but do not appear to smoke when out on the road. It is usually misdiagnosed as bad rings with lots of time and money thrown at the engine with no positive remediation of the original problem of smoking and may in fact make it smoke worse at idle.

[Les Schubert]

Kevin
I have a Roof 8 (Laurel model 40) and the pushrods are essentially similar to your posting. The bottom of the pushrod essentially resembles a valve stem with a hole drilled into the top about a 1/2”. The rest of the pushrod is about 3/16” diameter and then the “cup tip” is at the top. I remade the lower stem parts (Years ago) and had to make one of the top halfs. Made that in 2 pieces and welded it together. LOTS of miles on it.
One other thing. The rocker arms are REALLY hard and long lasting material. The shafts are mild steel and are essentially a “consumable”.
I hope this helps

[Scott_Conger]

rereading again about the rocker requiring the rod to swing is exactly what I didn't understand. DOH! Reading comprehension 101...

my last post is pretty much pointless in the discussion...sorry about that.

[Kevin Pharis]

After 6 months of obsessing over this darn Akron-Hed... I’ve finally finished the rocker arm conversion!!!

Now to start rebuilding the head. Next stop... hard seats, guides, and surfacing. Then I will spot face all the head bolt pads so the adapter plate has a good surface to sit on. And that should be the extent of the work on the head. I was really careful while designing the adapter not to require any head modifications... just incase all this nonsense didn’t work, I didn’t want to become one of those guys who destroyed a hens tooth because of a so called... “good idea”

This winter I’ll pull the motor and start the freshen up. New custom dome pistons, fresh babbit, and a good look over for the transmission are on the list of to-do’s. Also will have my old cam mapped, and a new cam ground to match the old profile while accounting for the 1.4:1 rockers

[Kevin Pharis]

The machine shop told me 2 weeks to complete... that was 3+ months ago...

And so as I wait ever more impatiently for the machine shop to finish the guides, seats, and surface, I have found a fella to flow the head (should it ever be ready...). I have no intentions of “porting” the head, just simply want to design and size the cam appropriately to make best use of the original port design.

I now resume impatiently waiting...

[Susanne]

Have they even started it? Unless they can't get the guides, the seats are commonly available and decking a head takes about... 20 minutes. 30 if they take 2 passes. Seats X8 - maybe a couple hours, unless there's some major issue with the head.

3+ MONTHS is crazy long time.

[Mark Gregush]

I went with the two piece push rod on my 28 Chevrolet conversion. The first go round I had the Chevrolet ball socket on the bottom push rod and a modified recessed cap screw on the rocker. Next go round I will be going back to the ball on the rocker and ball sockets on tops of both sections of the two push rods.

[Kevin Pharis]

So after a dozen unanswered messages over the last 4 months, I went to the machine shop today... and had every intention of kicking the door in and taking my head back!!!

The door was already open... so I had to accept that the theatrics of kicking in the door in wasn’t going to play out as planned. Then just as I walked thru the door... I was caught off guard with a “Hey! How are ya...? Let me show you the progress”. Couldn’t they have returned at least one of my calls...?! Regardless, they had installed guides and 7 seats in my Akron-Hed, and what they had done so far looked as good as one could expect.

The 8th seat however... due to a core shift, the seat bore had broken thru the bottom side of the thin cantilevered base material, and created the very predicament I expected on every exhaust seat. For this seat we are following thru with the original plan of a stepped diameter seat to create the mechanical stop to seat the insert.

Supposedly the plan is to have the head ready to go next week... I’m at the edge of my seat...!