TONS OF ENGINE TECHNICAL INFO
Under heavy construction
What the hell is going on
????????????
This is what a customer asked me when he purchased top
spring retainers from a unnamed manufacture.
The keepers do not fit very well in the retainers.
Did you purchase the correct retainers ?
Well, they said it fits Honda sohc's and the
package said............Honda 750 thru 78.
Sorry, they are wrong ..................
Consider the page below from an old action four catalog.
They explained some differences between early and later Honda keepers and
retainers.
But, I was told my bike was an early 70's.
That's why I wanted to show you this identification
page. 30 plus years later, many parts have been switched because many
parts interchange.
What is the deal with Titanium vs. steel
and alloy retainers ?
Glad you asked this question.
Honda stamped steel F2 retainers are inadequate, Honda's early keepers and
retainers are fine for most peoples hot street applications.
Other manufactures of steel retainers are super strong ............but heavy.
Titanium ?
Light weight and strong........... but
expensive.
Alloy ?
Well, years ago there were many types and
compositions of alloy retainers ( some good, some not so good )
We have developed a spring kit for early and late Honda's ( F2's also ) that is
the best.
Kit includes:
Lower spring collar.
Best springs available.
Hard anodized light weight alloy top spring retainers.
Yes, hard anodized alloy retainer...............
Tests show:
Hard anodizing top retainers add another 1000 lbs. of strength before
failure.
The following pictures and descriptions
might help you with basic and not-so basic top end procedures.
This will take many hours to do,
so........ stay tuned.
Disclaimer !!!!!!!!!!!!!!!!!!
Some of the following are basic and general procedures.
When it comes to full blown racing applications............ things change a bit.
After
30 plus years some heads are good, some are not.
We will try to help the budget minded and also go into the more extensive procedures.
For the budget minded......... Spray some carburetor cleaner into the intake and
exhaust ports to check the condition of your valves seating.
Valves
and valve springs will need to be removed for basic or extensive work.
Pictured are a couple of valve spring removal tools.
For the budget minded........ the removal tool on the left can be made with a
little effort.
This
is how the homemade spring tool works.
Now
that the head is disassembled...... the valve to valve guide clearance can be
checked.
Refer to your Honda manual for detailed specifications.
Be aware of carbon in the guides when checking for clearances.
For the budget minded........... if your valves are seating properly and your
valve to valve guide clearances are good, lapping the valves is a good idea.
Pictured, are a couple tools for different methods of lapping valves.
Lapping compound and lapping tool can be purchased at any auto store.
You can also use a drill, drill bit and hose as an alternative method.
Most of the time, we replace everything ( valves, guides and springs ) to
modern parts with modern technology.
Springs lead a hard life.
Valves are nitrated for today's fuel.
Guides have major improvements ( will explain later )
So.....
Disassemble the head.
Glass bead the head and ports. Be sure to remove all the carbon from the
guides.
If the carbon is not removed from the guides....... the carbon will scrape, drag
and remove alloy when the guides are pressed out.
On virgin, unmolested heads.......... standard
valve guides are generally fine.
So........ heat the head to approx 250-300 degrees ( in your wife's oven if necessary
)
Put your valve guides in the freezer ( next to your TV dinner works well )
Drift or press the old guides out and install the new guides
while the head is hot. ( drift is $12.00 )
Some manufactures of valve guides need reaming ( not ours )
Pictured is the reaming process. Electric drill, speed reduction unit and reamer
are used because if you stop the ream from turning your ream could get ruined.
Note:
Be aware..... during installation of valve guides, the top of the valve guide
could flare on the inside if you are to aggressive.
Also...... the inside diameter of the valve guide could collapse a bit.
If or when the inside diameter of the valve guide
collapses, we offer a valve guide hone ( $12.00 )
Simply hone the guide as necessary. ( works great )
After honing be sure to remove dirt or dust for an accurate feel or measurement.
A small rag with carburetor cleaner works well.
Of coarse, use this cleaning procedure for final assembly.
Time to do the valve job.
Many people boast about having exotic valve equipment. ( that's cool )
We feel its not the equipment, but the user of the equipment !!!!!!!!!!!
Did you know....... Many people use expensive equipment for valve jobs, but
finish the valve jobs with old fashion stones. (especially with super hard seats
)
Oversize intake valves can provide added power gains.
Certain precautions should be taken with over size intakes.
The intake valves need to be sunken so intake and exhaust valve contact is avoided.
Depending on cam profiles the general rule of thumb is..........
.030" recess per every millimeter of oversize ( general rule of thumb)
Speaking of oversize valves and performance cams...........
Pictured above is a big cam in the cam towers. Check clearances between the
lobes and portions of the towers.
Also, for large cams some things to pay attention to...................
Starting at the top of the engine, check rocker to top retainer clearance (
.040" min ) through one complete revolution.
Stop at maximum lift and check top retainer to valve guide seal clearance (
.020" min )
Stop at overlap position ( both inlet and exhaust valves open ) and check
clearance between inlet and exhaust valves (.040" min)
Check piston to cylinder head and head gasket clearance (.030" min) especially
with big bores.
Check piston to inlet and exhaust valve clearance (.030" min) important with high
compression pistons, high lift cams and oversize valves.
Pictured on the left is a early Honda cam tower. ( right
photo is a later version )
We like to use the later version. For some reason we have seen the rocker shaft
break in the center with the early towers.
Here is what we notice from time to time.
30 plus years later........... Honda heads have been interchanged, milled and
altered in many ways.
The above photo shows matt measuring cylinders and heads for alterations.
Sometimes, it can be hard to notice changes with the naked eye.
Of coarse, compression ratio's and valve to piston clearances can be affected.
Cylinder measures...... 84.92mm
Head measures.............73.27mm
Base gaskets ................0.50mm OEM style ( uncompressed )
Head gaskets ...............1.26mm OEM style ( uncompressed )
Speaking of compression ratio's .
Early combustion chamber heads ( thru 1976 ) have a lot of humps and bumps in
the chamber ( technical talk).
Later combustion chamber heads are a bit smoother in the chamber. ( we like
those better )
77-78 super-duper sports ( F-2 ) have bigger chamber. ( we will talk about them
later )
Note:
The following figures are approximate because their are so many variables. (
cams, head modifications and gaskets for example)
Early heads:
We have checked some 10.5 comp pistons on early heads ( un-modified ) and the
comp ratio was more like 10.8 to 1.
Notice the 836cc head gasket on a stock early head, also the difference or
ridge in the chamber with the bigger bore.
Many engine builders will lay a gasket on the head and scribe a line
........then massage, flow and make the combustion chamber less interrupted.
We feel this procedure makes for a happier motor and will not affect the
compression ratio much.
So........... for example.
Early head, slightly modified chamber and 2 base gaskets will be approx. 10.2 to
1
1 base gasket a bit more compression.( once again, general figures )
Speaking of modified combustion chambers,
Some builders will smooth the chambers until all the humps and bumps are
removed.
We feel and tests show that some interruptions are a good thing ( in the right
places, of coarse )
The above photo shows our favorite chamber modification.
Some of the valve cover bolt holes and cam tower holes in the
head are "through holes." These threaded holes pass completely
through the head to atmosphere. On the threads of the bolts of these holes
we like to use Gasgacinch. This product no only acts as a thread lock, but
also as a sealant to prevent oil seepage along the threads. This is a
great precautionary measure to avoid later headaches.
Heavy
duty cylinder studs are important, but..............................
When installing new studs, connecting rods, etc................certain
procedures should be followed.
People like ARP, Falicon and A1 technologies have detailed articles about
proper tightening sequences when new fasteners are used. ( go read them ) The
slang term used by mechanics is "burnishing of the threads."
For example:
Years ago,
Chevrolet had a problem with connecting rod caps falling off.
Apparently they forgot to "burnish" the threads. ( we were told ) and
this problem appeared.
They fixed the problem by changing the assembly procedure.
The same thing can happen with new cylinder studs, they can loosen up somewhat.
So........ Lets jump ahead and talk about assembling the top end.
If you bore the cylinder ( especially big bores ) you will need to bevel
the bottom sleeves a bit.
Taking time to bevel the sleeves will help the rings slip into the bore during
assembly.
Machinist have the tools to do beveling ..... but porting tools, small grinders,
or even a file, followed up with emery cloth works.
We have special tools from the olden days to compress rings for assembly. You
may not have fancy tools, so beveling will help with whatever means you select.
Generally no sealer on the base gasket is needed, unless you were to aggressive
with your gasket scraper.
Install pistons and rings.
Coat the skirts of the pistons with oil ..........but, very little oil on your
cylinder bore and rings ( what ?)
This procedure will allow your rings to seat immediately, even before you go for
your first ride.
Hopefully, you installed new cam chain rollers, slider and "O" rings.
Depending which head gasket you selected will determine what procedure to follow.
Racers like copper head gaskets because they can use them over and over.
For example:
If a used copper head gasket is being applied, the following annealing process
will need to be done !!!!!!
Use an oxygen/acetylene torch with a rosebud tip. Hang the gasket with a wire.
Evenly heat the gasket and watch for changing colors.
First blue, second green, third is orange. Drop the head gasket in cold
water.
Your gasket is now annealed.
Clean the gasket with Scotch-brite or equivalent and as necessary.
Many people recommend Gasgacinch or copper coat as a head gasket sealant.
Install the head....... but, make sure you have Honda's tightening sequence
available.
Use high pressure lube on the head nut washers and head nut threads. ( for accurate
torque spec's)
If new cylinder studs are used .. "burnishing " the threads is recommended
. ( mentioned previously )
We usually wait 24 hours and double check the torque ... and let the sealer do
its thing.
Basically, the same procedure is followed with conventional head gaskets (
except annealing of coarse )
So......
Ready to assemble ?
Remember to seal the through bolts ( mentioned previously )
Check the cam towers for flatness ( they never seen to be flat ) surface
them on glass with emery cloth as needed.
Check cam lobes for contact with towers ( bigger cams )
Install cam as your Honda manual describes or degree cam ( we will take some
photos and give degree procedures soon )
Set your valve lash ( clearance) as needed.
Note:
Long duration cams with make more peak horsepower, but sacrifice a bit of low
end performance.
Tests show......... buy setting your valve lash looser, you can lessen duration
and gain more lower end.
For example:
Every .001 ( plus or minus) of valve lash equates to 1.5 degrees duration ( plus
or minus )
Of coarse, cam timing maybe manipulated to active different goals.
Valve cover sealing can be a problem.
Most covers are not flat anymore.
Gasket scraping marks.
Chroming process generally has a dripping effect on gasket surfaces.
We are working on a new valve cover gasket that will help with these problems (
similar to a head gasket)
Also,
Gaskets generally should be re-torqued. After a bunch of warm-ups side covers
should checked.
What about the head gaskets ?
This can be a pain because the valve cover, cam, cam towers will need to be
removed to check head torque.
Even worse..... motor will need to be removed on stock framed Honda's.
High-performance coated rocker
arms and shafts Rocker arms and shafts are etch prepped and coated with a Flora-Polymer that can withstand over 150 thousand PSI of load. Greatly reduced friction will increase horsepower and reduce heat. Flora-Polymer coatings will also retain oils for better lubrication. Note: Minor scuffing to rocker arm surfaces which were normally not acceptable are now usable with this process. $ 99.00 for complete valve train ( 4 shafts and 8 rocker arms ) exchange. Speaking of coatings !!!!!!!!!!!! Our piston skirt coatings will almost eliminate friction. Our piston top heat barrier will reduce your cylinder head temperature up to 65 degrees. Note: During the testing process a Harley V-twin front piston was uncoated and the rear piston was coated. Heat sensors showed a heat reduction of 65 degrees. $ 129.00 for set of 4 pistons ( cast or forged ) Speaking of heat coatings !!!!!!!!!!! Cylinder combustion chambers will benefit greatly. |
Gasket Installation:
Here is what we notice...
When we are reconditioning Honda motors we notice very few cylinders, heads, covers, etc... are true or flat. Actually, The top side of the head ( cam side) is more inconsistent than the bottom. Valve covers can be inconsistent also. Chroming the valve cover can leave a untrue surface, because the chroming process can at times, leave a dripping texture on the gasket surface.
Previous gasket replacements can and have left scraping marks, which can cause problems. We are also not fond of the factory cylinder studs and re-torquing head gaskets can be time consuming. ( Heavy Duty studs are torqued to 20-22 foot pounds vs the factory 13.7 – 15.2 pounds with stock studs.) And they resist stretching under running conditions. You MUST follow recommended factory tightening sequences.
Because of the above mentioned conditions, certain precautions and preparations are followed.
NOTE: Some automobile manufacturers do not even use gaskets because of close tolerances. ( They use fancy sealers or nothing.)
Here is what do:
When we install gaskets on HD's, Triumphs, Honda's, Kawasaki's the gasket surfaces must be true and not abused. Threebond #1104, Gasgacinch, Yamaha bond or Honda bond is applied to the gasket surface. This sealer is used for three reasons.
First: To help the gasket overcome any flaws or chrome on the surface.
Second: (Equally as important.) To manipulate and hold the gasket perfectly in place.
Third: Threebond will not fall off ( Like silicone) and cause blockage in critical areas.
Most engine builders use aerosol copper coat on head gaskets. ( 4-5 thin coats.)
It sounds funny (To some people) that copper coat is used on conventional gaskets rather than copper gaskets. ( It works great) And once again you MUST follow recommended factory tightening sequences.
The head gaskets are checked to make sure the dowel pins and head gasket holes are perfect before copper coat is applied. Dowel pins and head gaskets are checked because they are accurately positioned and manipulating the head gasket is not an option. Minor attention to head gasket dowel pin holes is common from time to time.
Example:
We had received a chrome valve cover (Yesterday) from a customer to install on his motor. Because we are aware of age, warping, chrome dripping and scrape marks, we checked the gasket surface.
This cover was so bad, even NASA space shuttle gaskets and sealer would not have helped.
Finally:
After the motor has been started and ran a few times, we will recheck torque spec's on all the covers. Most of the time they need to be re-torqued.
Most people re-torque head gaskets after a thousand miles or so. Especially if stock cylinder studs are used.
These procedures are what we do, and should be considered when installing any brand of gaskets.
Speaking of warm-ups:
We feel the initial warm-ups are very important when trying to make the head
gasket happy.
We feel head gaskets get uncomfortable and are prone to failure when revved up
and stuff during initial start-up.
Here is what we do................
Start and allow the motor to get hot to the touch ( about 2 to 3 thousand RPM,s
)
Turn off and let cool.
Repeat these heat and cool down cycles about 8 to 10 times ( gradually raising
RPM,s )
If you follow the above mentioned procedures you will be fine. ( results may
vary, needed to say that)
Their are many opinions about start-ups and break-in procedures. ( no need to
debate, do what you feel is best)
We have been working on a Honda drag bike for a few years.
We will show pictures of the bike in progress.
Cycle X big
block cylinder.
Cycle
X rods.
Cycle X lock-up clutch.
Cycle X mock-up
Could this be the future fastest normally aspirated
Honda sohc drag bike ?
Our soon to be un-retired Honda drag bike will be getting a our full attention.
More to come
More to come
More to come
By the way............
If you have a question, we will post the question and answer it (anonymously
) in a FAQ section.
FAQ section (frequently
asked questions)
Question:
What is the purpose of those 8 rubbers around the studs between 1&2 and
3&4 cylinders ?
Do we need them, because we found an early cylinder in great condition?
Well, we would suspect Honda thought they
needed those rubbers to help with potential webpage in the head gasket area.
Personally, we feel heavy duty studs should have been used from the beginning (
like many other makes and models )
Maybe Honda felt HD studs were not cost effective during production.
But, early and later cylinders are interchangeable and if you follow the above
mentioned procedures.......... you will be fine with-out them.
Thanks
TESTING, TESTING,
TESTING....
After motors are modified or rebuilt we test them on our engine stand.
The test stand can check charging systems, oil systems etc. Valves and cam
chains are reset after running so everything is perfect.
The test stand has a special feature. We have a separate oil tank that is pressurized
with air which forces oil into the important oil cavities for initial start up.
After the motor develops its own oil pressure this pressurized tank is shut off.
(cool hey?) This feature is very important because of obvious reasons.
HONDA SOHC MOTOR WORK
This section will show you step by step
how to build your motor. We will have two versions of a
rebuild : Full mod - but streetable, and stock - but more aggressive.
This section is long over due
but worth the wait! Ken will be working on this for the rest of the week, so check
back.
Performance
gains can be made with out complete motor tear down and without some
expensive reinforcement of motor components.
Because we like the power potential of Honda SOHC's and we like to drive fast so
we
will start this motor section with our recommended high performance upgrades.
Before we go any further, Some motors we have seen have led a hard life. If you
have a motor that has never had a oil change and has been abused for 30 plus
years find a new one. If your crank journals are worn or scuffed and every gear
and bearing is unusable, things can get to expensive.
Crankshafts
are lightened, Balanced,
micro polished and fluted for oil flow. This procedure will give you very
noticeable acceleration and rev potential. Any loss of flywheel effect will be compensated
by your big bore kit. (balanced for sustained 14,000 rpm)
Pistons
are balanced perfect. (We will talk about pistons later)
Nearly every high performance builder or catalog from the 70's talks
about heavy duty connecting rods.
Rod
bearings
and main bearings need be checked
for proper clearance. This is done with Plastigage.
Honda factory manuals are best for this procedure.
After bearings are checked and addressed as necessary, clean thoroughly. Cleanliness is next to
godliness.
Notice the new primary chains and heavy duty cam chain.
TIP: Soak chains in oil overnight so the oil penetrates the links (They last
longer).
Get an accurate torque wrench and proceed to assemble your bullet proof
crankshaft.
Transmission
is now inspected
thoroughly. (Gears, forks, shift drum)
The only problem experienced with the Honda transmission is they will jump out
of third gear.
Modified Honda motors must have the third and forth gears removed and
undercut. This undercut procedure will insure the trans will lock in gear with
no chance of jumping out of gear.
TIP: During inspection of the trans, blued shift forks are a obvious sign there
is a problem. Keep in mind that the shift forks move gears, not hold
gears in place.
CLUTCH Plates
are soaked in oil with the chains.
CYLINDER studs
(heavy duty) are installed. We install these heavy duty studs
on all motors (even stock motors).
SEALS are installed.
GASKET SEALER. We only use ThreeBond 1104 sealer for case halves. Please do not
use silicone sealer.
CAMSHAFTS:
Stock motors can benefit from a mild
camshaft, power increases will be noticeable and you will not need to be concerned
about piston to valve intersection. Springs will also not be needed. We like a mild road-race cam used on small tracks. Call
for specifies cam profile. Hotter cams will need valve relief (piston's)
heavy duty springs, etc.
Cams, can and should be chosen for specific styles of riding. High RPM cams have
more duration.
More duration will generally give you more top end power but you might
loose some power at low RPM. Choose your cam accordingly.
Camshafts are a touchy subject and should be selected by someone with
experience.
OK, here's your tech tip:
Degree-ing your new camshaft can mean up to a half a second on the drag strip.
Just like your rear chain, cam chains stretch. This means that if you install
your camshaft with a stretched chain and do not degree properly, you have just
wasted your time.
Some people years ago would even grind their stock camshaft sprocket (oblong the
mounting holes) and bump the cam back to stock spec's to compensate for cam
chain stretch. (noticeable difference)
For really aggressive profiles, welded then reground camshafts are more durable
than billet shafts.
When we install a full race camshaft in this motor, we will show you how to degree
a cam.
HONDA SOHC HEADWORK
Pricing.
#1
Parts:
Cycle X super flow intake valves (
standard size )
Cycle X super flow exhaust valves ( standard size )
Cycle X valve guides.
Cycle X springs and hard anodized top retainers.
Disassemble to inspect.
Glass bead.
Remove guides.
Surface as needed.
Install guides and ream to fit new valves.
Install standard intake and exhaust valves.
Port head ( yosh style ) for hot street.
Valve job ( multi angle )
Chamber work ( for big bore ) if needed.
Install heli coils as needed.
Clean and ultrasonic clean head for assembly
Assemble head.
Parts and labor:
# 2
Parts:
Cycle X super flow over size intake valves (33.5)
Cycle X super flow exhaust valves ( standard size )
Cycle X valve guides.
Cycle X spring and retainer kit. (the best )
Labor:
Disassemble to inspect.
Glass bead.
Remove guides.
Surface as needed.
Install guides and ream to fit new valves.
Install oversize intake valves (33.5) and standard exhaust valves.
Machine intake seats for oversize 33.5 intake valves.
Contour intake ports for oversize intake valves and port head for hot street.
Valve job ( multi angle )
Chamber work ( for big bore )
Install heli coils as needed.
Clean and ultrasonic clean head for assembly
Assemble head.
#3
Parts:
Cycle X super flow oversize intake valves (33.5)
Cycle X super flow oversize exhaust valves ( 28.5)
Cycle X valve guides.
Cycle X spring and retainer kit. (the best )
Labor:
Disassemble to inspect.
Glass bead.
Remove guides.
Surface as needed.
Install guides and ream to fit new valves.
Install oversize intake valves (33.5)
Install oversize exhaust valves (28.5)
Machine intake seats for oversize intake valves.
Machine exhaust seats for oversize exhaust valves,
Contour intake and exhaust ports for oversize valves.
Port head for 80cfm.
This head configuration will require information like........ type of
carburetion, intake rubbers and cam selection.
Valve job ( multi angle )
Chamber work ( for big bore )
Install heli coils as needed.
Clean and ultrasonic clean head for assembly
Assemble head.
#4
Drag race head:
Machine valves seats for oversize, install bronze or steel seats.
Machine intake valve blank to oversize ( generally 37mm )
Machine exhaust valve blank to oversize ( generally 31mm )
Machine seats and port head ( 100 plus cfm )
Additional work:
Weld intake ports for straight and down draft style porting and big carbs. (
generally 38mm carburetors)
