Secrets Magazine INDEX

Roof 101 Cyclone OHV

IMPORTANT . . . .Click HERE for more Roof 101 Cyclone OHV images
Click HERE for the specs.
Click HERE for engineering drawings & more
Click HERE for the Dyno Report
Click HERE for original Roof Advertising from 1929 - 1930
Parts are Delivered Unpolished - Repeat, Parts are Not Polished
Our ROOF 101 Cyclone Four Port OHV cylinder head conversion (tm) is a faithful reproduction of the original Robert Roof 1928 ROOF Cyclone. . . With modern improvements to enhance power and reliability. The head project was conceived by Charlie Yapp as a tribute to the original Robert Roof "Cyclone Valve-In-Head"" and newly designed with modern engineering by "Chief Engineer" Jim Roof with help from C. Yapp. The wondrous prints were hand drawn on velum by Jim Roof, grandson of the original Cyclone creator, Robert Roof. Jim's highly detailed 1st generation "blue prints" were converted to CAD-CAM files, from which the casting tooling was CNC machined from over sized blocks of urethane.

VALVES: There is one 1.75" dia. intake valve in the head (larger valves can be fitted by owner if desired) and one exhaust valve in the block per cylinder. Total of 8 valves. Using 1.732" /1.750" diameter exhaust valves (in block) will add power.
This "F" type head (intakes overhead, exhaust in block camshaft in block) has "unheard of volumetric breathing capability" taking the vintage Ford Model A or B to 113 HP (minimum) at 3300 rpm. There are many tricks and much more power if you know the secrets of speed. . . . The head is designed with extra cast iron to make it possible to re-machine the valve seats to install 2" + intakes in the field. . . . the true top end has not been discovered.

ROCKERS: To make this head strong and reliable, an off-the-shelf roller rocker system is used, giving a 1.5:1 ratio at the over-head intakes.

CAMSHAFT: A Model B or touring camshaft will be enough to make some serious power.

FITS: The Roof 101 Cyclone is made to fit the 1928-1934 Model A and B Ford, the German G28T and Burtz-Block engines. We make these historic and popular cylinder heads once every other year. A production run depends on customer's continued demand. Our last run of 12 heads was shipped January, 2017We have sold 90 units since we shipped the first run in 2010. They are dependable, easy to setup and proving to be quite popular.
The ROOF 101 Cyclone cylinder head has 6 castings and about
50 parts total. . . kit shipping weight is 110 pounds.
We look at this as an exciting opportunity and a decent investment for you.
We are happy to work with overseas customers.
Manifold: ROOF (branded) one, two or three carburetor
down-draft intake manifold Included
These parts are not required but do enhance the experience
ROOF aluminum side valve cover.
Timing Cover Ignition System.
Carburetor adapter(s) . . . 1 to 3 needed (2 included)
Crankshaft pulley
Split-Y Header System
Stromberg 81 Carburetors
Stromberg Linkage
High Performance Ignition Systems
Dress up side plates
and much more . . . 
A signed Hold Harmless Release is required.
No Roof Cylinder head can be shipped without the signed release in our files.
To read the Release please click HERE
One of our past buyers called to say that "the release was the best advertising piece that we could put out there". We agree, but it is also important.
Scalded Dog Speed Parts
 A Division of Yapp Studios, Inc.

3860 Cain Run Rd,
Batavia OH 45103.  
Phone (513) 724-9000,  
[email protected]