6/22/2026
NEWS
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NEWS
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CYLINDER HEADS
JUNE 22, 2026
SOME HEADS ARE CAST WITH MORE TO COME.
SOME HEADS ARE CAST WITH MORE TO COME.
NEWS: JUNE 10, 2026
CASTING HAS BEGUN IN EARNST.
HERE ARE PHOTOS OF THE BEGINNING PROCESS OF THE COPE
AND DRAG AND FITTING THE CORES.
CASTING HAS BEGUN IN EARNST.
HERE ARE PHOTOS OF THE BEGINNING PROCESS OF THE COPE
AND DRAG AND FITTING THE CORES.
NEWS May/29/2026
Contacted the foundry this morning.
We are next.
The molds have been adjusted,
mold sand shipment has arrived, and casting should begin in a few days.
I will post some images as soon as I get them.
Timing can't be determined until they know how many
per day they can cast. We will begin to see progress soon.
I talked with machine shop, and they are eagerly waiting too.
NEWS 4/20/2026
Some of the Rocket-428-cylinder head sand cores have been delivered to the foundry.
The balance of the cores should be done in 3 to 4 weeks (mid May-ish).
Actual casting will vary as materials come in.
Contacted the foundry this morning.
We are next.
The molds have been adjusted,
mold sand shipment has arrived, and casting should begin in a few days.
I will post some images as soon as I get them.
Timing can't be determined until they know how many
per day they can cast. We will begin to see progress soon.
I talked with machine shop, and they are eagerly waiting too.
NEWS 4/20/2026
Some of the Rocket-428-cylinder head sand cores have been delivered to the foundry.
The balance of the cores should be done in 3 to 4 weeks (mid May-ish).
Actual casting will vary as materials come in.
NEWS 4/8/2026
WE ARE COMPLETELY SOLD OUT OF ROCKET-428 HEADS
HOW ABOUT THAT!!!
Will there be more?
It depends on many hard things.
Right now, today, I will have to say a firm NO,
but I will take names of serious buyers for now.
SEND ME AN EMAIL TO BE ADDED TO A ROCKET LIST.
SEND NO MONEY!
EMAIL: [email protected]
----------------------------------------------------
The Rocket-428 water-jacket cores have moved along, and that company has 5 cores left to
cast up. When completed, these fragile core castings will be moved to the foundry.
Everything is moving along as expected.
Additional castings
of our Ignition -Front-Cover and the Equalizer-Intake-Manifold are in the works.
_______________________________
NEWS 3/16/2026
BY THE END OF THE FIRST WEEK OF FEBURARY -
The Rocket-428 core-box was delivered and the cores were started.
The Cope and Drag patterns were picked up by the foundry at my place.
The foundry must wait for the cores to be finished
then casting can be put into the que.
The machine shop has been informed and is ready to get started.
time frame is too loose to spec yet.
Deposit invoices have been mailed or emailed
to each person on the list.
March 6th The foundry picked up the cope and drag pattern boxes
and the "Front Cover Ignition Plate".
WE ARE COMPLETELY SOLD OUT OF ROCKET-428 HEADS
HOW ABOUT THAT!!!
Will there be more?
It depends on many hard things.
Right now, today, I will have to say a firm NO,
but I will take names of serious buyers for now.
SEND ME AN EMAIL TO BE ADDED TO A ROCKET LIST.
SEND NO MONEY!
EMAIL: [email protected]
----------------------------------------------------
The Rocket-428 water-jacket cores have moved along, and that company has 5 cores left to
cast up. When completed, these fragile core castings will be moved to the foundry.
Everything is moving along as expected.
Additional castings
of our Ignition -Front-Cover and the Equalizer-Intake-Manifold are in the works.
_______________________________
NEWS 3/16/2026
BY THE END OF THE FIRST WEEK OF FEBURARY -
The Rocket-428 core-box was delivered and the cores were started.
The Cope and Drag patterns were picked up by the foundry at my place.
The foundry must wait for the cores to be finished
then casting can be put into the que.
The machine shop has been informed and is ready to get started.
time frame is too loose to spec yet.
Deposit invoices have been mailed or emailed
to each person on the list.
March 6th The foundry picked up the cope and drag pattern boxes
and the "Front Cover Ignition Plate".
The Rocket-428 High Compression Cylinder head
Cast Aluminum 356-T6,
7:1 Compression Ratio (140-cc)
All Heads Are Dual Plug.
Cast Aluminum 356-T6,
7:1 Compression Ratio (140-cc)
All Heads Are Dual Plug.
This head wins hill climbs!
Casting and machining time is usually about 4-5 months.
SOLD OUT - SOLD OUT
$xxxxxx
IF PAID BY CHECK
All costs and time suggestions are approximate
and could change as we move forward.
ESTIMATED DELIVERY IS JUNE-ISH (+-)
YAPP STUDIOS INC.
3860 Cain Run Rd
Batavia OH 45103
513-724-9000
[email protected]
SOLD OUT - SOLD OUT
$xxxxxx
IF PAID BY CHECK
All costs and time suggestions are approximate
and could change as we move forward.
ESTIMATED DELIVERY IS JUNE-ISH (+-)
YAPP STUDIOS INC.
3860 Cain Run Rd
Batavia OH 45103
513-724-9000
[email protected]
ROCKET-428 CYLINDER HEAD
356-T6 Aluminum, 7:1 CR
all castings are 8 Spark plugs
FOR THOSE NEEDING A FOUR (4) PLUG HEAD
WE HAVE OPTIONAL
"PLUG-SEALS"
The Rocket's combustion chambers are a match of our very successful
Lion Speed Head III & IV.
The extra thick walls hold heat steady for even firing and extra metal is available to those that want to reshape to their own designs. The spark plug positions are designed for maximum flame front and have proven power on the dyno.
Plugs on the driver's side have more power.
All of Charlie Yapp's cylinder heads are custom tested designs.
Lion Speed Head III & IV.
The extra thick walls hold heat steady for even firing and extra metal is available to those that want to reshape to their own designs. The spark plug positions are designed for maximum flame front and have proven power on the dyno.
Plugs on the driver's side have more power.
All of Charlie Yapp's cylinder heads are custom tested designs.
The foundry and machine shop helping me produce this 2026 production run are the same who have done our Rocket-428 in the last run. They know my need for precision and have proven to me that they will do a fantastic Made-In-USA-job.
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It will reopen at shipping time.
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