Archive for June 2011

XS650: Dry Clutch   Leave a comment


Hartmut, from Dominator Engineering has a passion for British Bikes. Likes to play in the dirt too. Has an ’84 EML Yamaha Sidecross machine.



1 .. sidecross 975cc XS650

sidecross 975cc XS650



Taken out to 975cc. With a high lift long duration cam. Outlandish torque. Pulls from right down deep. Full power beyond 7000 rpm. Often saves gear changes between curves.

Exposed clutch weaknesses. An 8 plate clutch mod and super hard springs was good to 3rd gear. A 10 plate mod with thinner friction plates, ground steels and springs so hard Popeye would have problems was good to 4th.

Luckily he produces clutches for Vincents. Useable wet or dry. And they pass inside the XS650 clutch case. 2 1/2 finger operation. Still going strong at the finish line.

At Schopfheim. Spring. The long straight climb from the start. Over 250m he left the stronger 1000cc machines 30m behind. Bet that felt good.



2 .. Vincent clutch

Vincent clutch



3 .. fits inside the XS650 clutch case ... hub and basket here

fits inside the XS650 clutch case … hub and basket here



4 .. plus plates

plus plates



5 .. and pressure plate

and pressure plate



5 .. and pressure plate

and pressure plate



6 .. pull mechanism

pull mechanism



7 .. Capped



I know much of this appeared here, but I like this product so much it deserves it’s own post.

Should anyone have interest Hartmut can be contacted here. Dont worry about the site being in German. Hartmut has no problems with English.

Posted June 24, 2011 by xscafe in Motor - Clutch

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XS650: Cowboy3669 Dragracer   2 comments

Cowboy3669 … Grand Haven, W Mich, United States.

Yes, I like antique bikes. I race one, lol. Just realized that I have had an XS650 for over 30 yrs. Have my 1st one. Still. …I am the proud owner of a 78 ratbike (trophy winner) and a 650 drag bike.


… cowboy3669 at play


Where to start? After riding a 650 for about 10 years I had a good collection of complete 650s and assorted parts. So when I decided to start racing I figured ‘Might as well race what I got a good supply of parts for’. Cowboy was a nickname I was given over 20 years ago, 3669 is the # on my dragbike…..

.. my toy..


… man and toy … Ness fairing. Picked up at a swap meet years ago. Came without a wind screen. New one cost me more than the fairing did.


The biggest problem with running this engine is the lack of aftermarket parts. With the XS650 not being built since 1984 hi-performance parts are hard to find. Even some stock parts are getting hard to find.


… early version … The tank holds about 2 quarts and I cannot make two 1/4 mile passes on one tank full


There are not many people who drag-race the 650, so I had to figure a lot of things out for myself (lots of broken parts) … the turbo has been an ongoing project for about 6 years.


… turbo and clutch mods…nos bottle too


Started off with a basic bike, built a rigid back half. Ran that for couple of years. Then put nitrous on her.  Ran that for couple more years. About 6 years ago put the turbo on.

The motor is stock bore & stroke (welded crank). Cam of unknown brand. A little more lift & duration. Home designed 3spd Transmission. Turbo off an Isuzu Probe GT diesel. Fogger nitrous injected. I’m using electric over air system. It shifts alright. Now the kill is sorted. 72 in wheelbase. Runs about 10,000 rpm at the finish line. The best has been 10.33 @ 133 mph .. average 10.80 to 11.20 @125mph. … weighs 680lbs with me on it. I weigh in at about 215 in street clothes…seasonally corrected.

Mighty impresive for an old XS

With the gearing (18/37) it is pretty close to the top end.

I have not put the bike on a dyno. Those calulators that input time or mph & weight approx it to be about 125 hp at rear wheel. But I think I’m producing well over 80 hp (10.33@133mph, 690 lbs.w/rider). The only cases I broke was when a gearbox problem pushed the shift drum out. Broke the boss that holds the retaining clip and 2 screws.


5 .. unfortunately more dramatic than it looks ... bad turbo

unfortunately more dramatic than it looks … bad turbo


I think there’s some more left in it. Has been 10.33. Right now I’m fighting wheel spin at launch. Could not get traction at 60°. The 5.5’’ tyre doesn’t hook like a 10’’.

Still gathering parts to try fuel injection. There are a few sources, atv’s, outboards and other bikes…Going to stay with gas. Been looking at automotive parts also. Have plenty to look at, seeing I work in a salvage yard. … Alky would be nice, but have to get this setup figured out first, lol.

Not sure of the cost. Ongoing project. What is the opportunity cost of fun?


… crank inspection port


Not the recommended way to inspect the crank. Happens when the rod wants to be somewhere else. A bad rod. There was oil in the engine right up to the time the rod made it’s great escape.


… valve contortionist


Two different actions. The valve spring retainer broke resulting in the bent valve.

Left a mark on the piston. But not broken. Broken valve guide. Replaced head, must not have been torqued correctly. Is now.


… carb… drawing thru a 38mm round slide … there is an aux pump that sends additional fuel to the carb under full throttle.



… oops … head gasket heaven


I ran a lot of nitrous at one time. About 70 hp shot. I had more problems keeping pistons in it than I did head gaskets. Now I have a fogger nitrous system. Found it important how much nitrous I was spraying. The nitrous is on for the whole pass. Amount is controlled by changing fogger nozzle jets. For the 133 mph pass I ran a 35 hp shot on each cyl. 14 lbs of boost. Since then I use less nitrous. Backed it down to 15 hp per cyl. Saves parts. And I’m still turning 10.80’s @ 125. Also changed the final drive ratio. Try to run 15-16 lbs boost

Remember seeing one in a Pommy ( English ) mag years ago … the bike he’s talking about is probably Orange Whip. Had NOS on it and to keep the topend on it had made up 2 side engine plates and a big plate over the head with bolts running down to side plates . Even then I thought it was overkill .

I’m running 3 speed.  Stock shafts, gears and forks. Redesigned shift drum. I have the drum cut and welded to use 1st, 3rd and 5th gear. The 5 speed gave a best of 10.40 … The 3 speed so far has a best of 10.33 … 2 less shifts per pass.

It would be nice to have an auto but I have to ride back also. (He’s not talking about automatic activation, but engaging 2 gears at once, the lower gear popping out “automatically”. Like in prostock,  A-street, comp, and mod bikes.)

I’m using electric over air system.  Shifted alright. The kill worked overtime on the 2nd shift. .. I’m pretty sure the old switch was the problem, actually the brass part. The piston inside had gotten dried out before and had gotten stuck. Slow to return. Lube up the piston, problem usually stopped.

Me mate wanted to ditch the mechanical switch. Replace it. Wire directly in place of the old.

He had a few questions:

How do you have the air switch wired in? Is your air shift button supplying a + or – to the solenoid? .. …. the kill is wired in the + side of the coil where it’s been wired since I put a airshifter on the bike

Do you need the same kill time for both shifts? … Didn’t think I needed the same kill for the 2-3 shift.

Any idea what youre using for a kill time? …..  I was using the brass/micro switch so what ever the standard kill time is.

Stock coil and ignition? … Sent him a spare set.

Any idea how much current the coil draws? … ?????????

He was sure he could come up with something reliable. … And he did

There are four wires.

+ Power In – went to the old switch

Ground – needed to add this wire to the battery

+ Coil Out – went to the old switch

+ Trigger In – needed to run a new wire right from the air shift button or solenoid

Do not need a diode in parallel with the solenoid for this unit to work. If there is one, it’s fine.

New timer worked the same. Press button: supply + to the air solenoid and timer. The timer  cuts power to the coil for some length of time. This dead time has nothing to do with how long you hold the button. It cuts power every time you push the button. Very simple, no frills. There’s a diagnostic LED. Turns on when power to the coil is cut. LED wont turn on if the wiring to the coil is bad. Just an easy check.

He said ‘Looks like shit. Cased in heat shrink tube. Filled, so vibration is no problem. Maybe 1″ X 1.5″ X 2″. Easy to find a place for. Or let dangle. Or not.’

He wasn’t sure what I needed for kill time so gave up to 150mS. I had the bike ready for the timer. Met one Saturday we both ran. Brought it with him. And the rain stayed away.

Afterwards he remarked ‘I bet you thought that it would never work!’ LOL. ‘I think you just need to play with it now. Put in a new line and get rid of the T fitting. Toss that old mechanical thing in a box somewhere for later.’

Good to be back in the 10’s….Sweet!!.

Time to fine tune. And remount.

I’m using a IHI off a Probe GT. Carb is a 38mm round slide mikuni. Internal wastegate. 15-16lb’s boost. The oil feed comes out of the right side cover by the outlet from pump. The outlet is connected to a small 12 volt pump that pumps the oil into a fitting that is in place of the neutral light switch.

Some things to think about:

Oil heat- Do you need to put a cooler on the turbo oil feed line ?

Stock oil pump- Can it keep up with the turbo and the rest of the engine? If the stock pump can feed oil coolers ok, can it run a turbo too ?

Oil return-Is it better to put the turbo up above the case oil level so you dont have to run a return pump-gravity return ? What about putting the turbo out front, as low as possible, as close to the center as it will fit ? Keeps a short header for spool purposes.

Blowthrough needs a fuel pump- Can the stock electrical system handle the draw with everything else on?

H20 injection ? – Better than an intercooler ? For shorter intake plumbing and less crap hanging off the bike. Would it mess with the carbs to have water going through there ?

Boost ? – With stock pistons, pump premium, and no intercooler maybe 10psi max?  … Depend on the turbo I suppose.

This guy ( Kev from Oz) is doing some pretty far out stuff as well as the turbo but definitely has some awesome ideas like that AWIC. (air/water intercoolervery nice, but xstra weight)

Here are some pics of the pump I use to transfer the oil from the turbo back to the engine. The pump is a generic fuel pump from Autozone. I think it cost me 25 or 30 dollars.


… pump and plumbing






This where I tapped into the side cover for the feed to the turbo. … haven’t had any problem with the line. Only wrecked one turbo because of lack of oil pressure. The line was plugged.


… oil feed direct from pump…lots of flow


That line is tapped right at the pump outlet. There may not be much pressure but there is a lot of flow.

Not running coolant lines. The feed line for the oil comes off the right cover at the outlet from the filter. The return (drain) from the turbo goes to a small electric fuel pump, and is returned to the engine at a fitting in the cases above the trans – neutral switch. Most of the parts were already in my stash. Not sure on the A/R.

A/R, Aspect Ratio, is the rated volumetric efficiency of a turbos 2 sections


14 .. measuring Aspect Ratio

measuring Aspect Ratio



Picking A/R comes down to spool time vs. top end power band.
You need to decide where you want your power band and plan accordingly from the start.

Not only Power band should decide A/R, but cam selection, heads, intake compression ratio, rear gears ….. there’s a lot to this and no magical method or perfect right or wrong answer.


… no intercooler – dont want a bomb…this long tube is part of the intake


No intercooler. With the draw thru, an intercooler will let the fuel fall out of suspension (turns the intercooler into a bomb). The long tube on my system is just part of the intake tract. I think draw thru systems make just about the same amount of power. They’re just a little less compilcated …. Don’t know if it’s any better to have a long intake but I didn’t have room to put the turbo behind the engine like most draw-thru systems do. So out front it went. Seems to work alright for this set up.

Lag, the problem with using too large of a turbo. That’s why I use nitrous. No problem now.

Lag can be reduced in a number of ways. ( Not to be confused with Boost Threshhold)

  1.      by lowering the rotational inertia of the turbocharger; for example by using lighter, lower radius parts to allow the spool-up to happen more quickly. Ceramic turbines are of benefit in this regard.
  2.     by changing the aspect ratio of the turbine.
  3.     by increasing the upper-deck air pressure (compressor discharge) and improving the wastegate response;  helpful – cost and reliability disadvantages.
  4.     by reducing bearing frictional losses;  using  foil bearings rather than  conventional oil bearings  reduces friction contributing  faster rotational acceleration.
  5.     Variable-nozzle turbochargers greatly reduce lag.
  6.     by decreasing the volume of the upper-deck piping.
  7.     by using multiple turbos, sequentially or in parallel.

The gauge reads about 15-16lbs of boost. I estimate about 100+ hp.

Not sure about what size turbo would be best for the street. My turbo came off a 2200 cc engine. I use nitrous to help spool up. No idea how mine would work on street without the nitrous.

There so few of us putting turbo’s on XS’s. All we can do is fab the systems up and work from there.

Some great turbo related info… rbracing

If you’re gonna go the extreme of installing a turbo, you might as well address the lazy ports on the XS head. Assists the breathing and expelling of burnt gases.

The clutch is a weak spot, especially running nitrous. I had a Suzuki clutch for a couple of years, but the basket broke (big mess). Still needed periodic maintenance due to slippage .


… banshee centrifugal assist…makes a difference


This is the clutch in the dragbike. Now. A stock 650 clutch pack. And lockup. From a Banshee. The centrifugal assist was made for the banshee. Had to modify the holes to the spacing of the xs bolt centers, approx  0.030 out. I also had to make spacers for the springs and to get the lock-up head in the right position. And redo the side cover.


… 3669



… .and again … go yamaha.. the fuel tank part is actually the result of using a stock tank as a mold.I cut the tank at the seam, laid up fiberglass inside. then molded to the body I made .


Some other interesting dragxsters…


orange whip … burnt out, the proverbial phoenix – rose from the ashes to become Whiplash .. see the plates and external bolts – to hold the head on



… Whiplash, the next generation


More pics here.


kenny d … Back in the ‘day’, safety was not paramount (nice gloves & boots!) … not an XS but I liked the pic



sprint … limeyland



… supercharged



… from the late 70s. It was run on alcohol. Air shifter, total loss MSD ignition.



… re-phased  crank and cam,  transmission cut off the extra cases,  frame stretched fifteen inches … Dyna ignition set up with a Suzuki advancer for the rear motor, both motors lit with dual output coils.



… 70′s Twin-Engine Yamaha Drag Bike.  This twin-engine top fuel drag racer was built in the early 70′s , recently only used as a static display. These bikes were started on a set of rollers using a car as power. Pull in the clutch, get the rear tire spinning on the rollers, and fire the bike. These were high gear only affairs, and ran in the 170 mph range.  One throttle operates all four carbs, and one clutch lever on the handle bar operates rear motor clutch and trans. The motors are connected using a Gates-Gilmer type belt… A new M+H Racemaster slick is mounted out back with a new smooth hard rubber race only tire on the front…nicely designed and constructed… It is scary to think about how much power is accessible via that little chrome clutch lever. The front suspension design is interesting on its own, and the long frame and engine placement means no wheelie-bar.



another twin



… from Dutch Trash Choppers



… Check out this wild XS650 drag bike project. The cylinderhead is turned around backwards. The front wheel is from a Puch Maxi moped.


For a run down on reverse heads check out Terry’s site. Scroll down.


… reverse head



a little closer



halco 840 out for the day



ready for action



…drag day .. street


Or this, found out in the wops,


… supercharged 4lb boost

XS650: Tracy Bodies   3 comments

Jay asked me some time ago if I knew anything about Tracy Bodies.  Ya’ein… Produced back in the 70’s. Monocoque. Sleek. Tank and seat. Fiberglass. But not much more. Had never seen one in the flesh … so, off I went. To see what I could find.


… … Jim Phillips sketch


I found myself quite an interesting story. Several really. Multilingual. Spanning the Atlantic. Success. Failure. Survival.


… 50 T’bird 650



… 60 T’bird


One thread starts with a Triumph Thunderbird. Don Browns’ first bike.


first triple … P1 triple prototype…63x80mm-3 times…The Rocket3/Trident, Triumph Motorcycles’ step away from the basic vertical twin. The plan was to give the US market 750 cc power  without vibration


Another with Doug Heele and Bert Hopwood. Early 60’s.  Triumph Triple Development Squad. From that to this…


68 ‘Ogle’ Rocket 3



Slippery Sam … BSA/Triumph. 68-75  Rocket 3 and Trident attempting to head off the rising sun.


BSA/Triumph. 68-75  Rocket 3 and Trident attempting to head off the rising sun.


7 .. Windjammer a la Craig Vetter

Windjammer a la Craig Vetter


About this time  Craig Vetter   graduated from University of Illinois Design School. Turned a passion into a life. A search for handling, comfort and fuel economy became industrial fairing production. By the late 60’s 5 moulds were producing for various models. Desiring for a ‘one fits all’ he ended up mating the generic upper section to a CB750 lower, including a headlight carrier. The ‘Windjammer’ was born 70/71 and he cashed in proper from the Goldwing crowd.


8 .. In 1968,

In 1968, three years out of design school, I was known for my fairing designs. But I wanted to do an entire motorcycle. At the same time Don Brown was pondering how to somehow “Americanize” the BSA Rocket 3, I was designing a special ‘zoomy’ seat – tank for my new Suzuki 500. It held 6 gallons of fuel and 1 gallon of two-stroke oil! I rode it everywhere and in the summer of 1969 regularly raced it at the Indianapolis 1/8 mile drag strip. It was there that I realized that the long, ‘zoomy’ shape, as beautiful as it was,- forced a viewer’s eye right off onto something else – anything else. My next motorcycle design, I decided, would somehow keep a viewer’s attention right there. .. n March of 1969 I brought my Suzuki to Daytona and pestered every motorcycle company executive I could locate. “Look at this,” I said, “You need me to design a bike for you. That’s when Harry Chaplin took my card. .. Don continues: The telephone number was in Rantoul Illinois. On April 21, 1969, I called Craig to discuss a project he might be interested in. That set the stage for lunch on June 3, 1969, which proved to be interesting indeed. Craig remembers: Don’s offer was to fly to Nutley and meet. If he liked me, he would give me the keys to a BSA Rocket 3 and I could drive it home to Illinois. I bought a one-way ticket…Craig Vetter



9 .. BSA Rocket 3 ... Ogle designed Rocket 3 Trident ... had the power but why give someone who knows nothing about motorcycles the job of designing one ... beats me

BSA Rocket 3 … Ogle designed Rocket 3/Trident…had the power but why give someone who knows nothing about motorcycles the job of designing one? … beats me



69 CB750K … the before and after benchmark


BSA/Triumph presented their ‘Ogle’ designed Rocket 3-Trident to their US Dealers and Distributers in 68. Disappointment. Boxy and Bone-Ugly. Kickstart. 4 speed. A Sales and Marketing non-event against the coming CB750/4.


11 .. speed and distance ... no looks

speed and distance … no looks


Don Brown, BSA’s US VP and Director, funded the setting of various Speed and Distance records by Du Hamel, Mann and Hempstead  late 68, Daytona. The gods at Bonneville Flats smiled . Wasn’t Enough.


… Craig Vetter was approached. April 69.

  • ‘Redesign the Rocket 3’
  • ‘Don’t Tell a soul’
  • ’I’ll see you right-
  • – do a deal-from petty cash’
  • ‘Slim.’
  • ’Thunderbird sleek’
  • ‘1 to 1.5 person.’


Over a handshake the keys to a Rocket 3 slipped into his possession (E.N: KC-00197 A75R … reportedly one of the Daytona Rocket 3’s  speed and long-distance record setters).


13 .. summer of 69

summer of 69


His Summer of ’69.  The prototype was shipped to England Oct 69. Cycle World got to write about it in ’70.


Cycle World – Sept 70


In ‘71 it was displayed at Houston. Then BSA turned up its toes.


15 .. BSA




16 .. Vetter Rocket

Vetter Rocket


Vetter’s final prototype Rocket 3 featured

  • an innovative monocoque seat and tank unit tarted up with gold Scotchlite reflective tape
  • a simple chrome headlight
  • Borrani aluminum rims
  • polished stainless steel fenders and
  • a 3-into-3 megaphone exhaust, supplied by Brown who also sent
  •  a set of extended Ceriani road racing forks
  • Vetters’ suggestion to extend the cylinder head fins so the engine appears more powerful, was  carried out on = production bikes



… Triumph X75 Hurricane


So Triumph rebranded her. As the X75 Hurricane. Allocated 1183 engines. Production ran ’72 through ’73  = 1172.


Hurricanes, 2005, Duxford


Classic. Iconic


Hurricane lines … sleek


Tracy Nelson. Board-Glasser, O’Neills. Late 60’s, moonlighting with his tanks.

The Fiberglas Works.


… 72 Superstars Catalogue … 2 piece


Fiberglas Works in Santa Cruz had spotted the action. By 74 their ‘Californian’ Café/Street Racer Bodies were fixed program. Having spent the last 7 years clawing their way to the top of the custom fiberglas world, they wanted some of this. How’s that?  US $169.95 with an extra $70 for custom paint.


… regular magazine ad … 74



… Fiberglas Works 72 Superstars Catalogue …from a fine blog… Damned to be Free


Damned to be Free … Flowing like Glass, Jim Phillips Poster


Tracy body … more hungry mantis than cuddly seal



… cool ebay find


Artwork from Jim Phillips featured in many of their catalogues and ads.


… Jim Phillips


Fiberglas Works and later Tracy’s Fiberglas Works or Tracy’s and Friends must have been a stammkunde from way back. Jim went on to make a name for himself in the Band Poster, Surf and Skateboard worlds.


… Jim Phillips artwork … catalogue



27 .. 71 poster ... Jim Phillips

71 poster … Jim Phillips




… Samoto 400F



… Samoto Honda


Also in the action were Samoto(Rome). Honda Dealer. Playing with the big 4’s. In 73 they produced 15 88bhp CB750/4’s and 2 CB1000/4’s.


… Samoto 1000


Quite a heritage. And we’re only scratching the surface.


… Fiberglas Works  card molded into gas tank



… Tracy and friends logo



… Tracy logo



… Tracy body … the more common variant – parallel seat, upper shock mount cutaway



… underside … 14lb … 2.75/3 gallons



… Tracy body … parallel seat, upper shock mount cutaway



… less commonly found … cobra tapered seat, flared upper shock bulge






… cobra style



… custom



… Don Castros’ Triumph 750



Tracy hardly



… XS Tracy



… coming at ya



… ready to go



Steve from RedMaxSpeedShop bought Jays’ bike. With the Tracy body. Is thinking about doing a replica. If anyone is interested the link is above.



… redmax



These bodies are now up to 40 years old. There are reports of owners facing problems with cracking and leaking. Originals not likely to be ethanol compatible. Less likely to affect Triumph X75 Hurricane owners. These have metal canisters hidden inside the fiberglass molding.

74 Tracy catalogue pp 1-32

74 Tracy catalogue pp 33-65


… tracy body on SR400 … Kobe Bandits


 Kobe Bandits

Interesting thread over at Honda CB750s.

Note: Apparently the original finish is in the epoxy. The outermost layer tinted to replicate candy finishes. Any metal flake would be added before the next layer of epoxy and mat was applied. I always thought my H1 body’s original color was fire engine red but at Tracy’s prompting I stripped it back to the epoxy and found rainbow flake over black gelcoat. Talk about durability. Some people in prepping will mistake this base color for paint and actually sand the top layer of epoxy off. Makes them brittle. {[Geeto67 @]}

XS650: XS1 Heads   Leave a comment

Kind of strange how you can do a job dozens of times and one day discover you’ve been missing the art. Blindly bypassing the finer details not directly pertinent to what you’re doing.

I pulled an old NOS XS1 head out of the mothballs the other day. Pretty clean. Next to it sat a used XS1 head. Well used. Started to clean it down. Slowly I became aware of differences. Mostly minor. But functional.


1 .. S650-0148## on the left ... NOS to the left

S650-0148## on the left … NOS to the left


I found 8 or so differences on the outside alone.

  • thicker, differently formed and more cleanly cast mounts and supports, front and rear on the used head
  • thicker tappet adjustment cover mounting face flange on the used head
  • artful blitz moulded into the unused head where the oil feed pipe passes
  • round cam sprocket tunnel on the used head, blocky cast on the unused head


2 .. inside the rocker cover

inside the rocker cover


Multiple casting marks on the unused cover. Rougher casting quality too. What are the other differences?

  • cast ridge inside each tappet adjustment cover opening, used head
  • cast ridge between the bearing supports and the oil inlet cast, directly over the cam, used head
  • round brace for each of the inner stud holes on the used head are replaced on the unused head

They appear inside the cover only. Later models have a thicker wedge shaped form sitting over the cam. I assume these are for better splashed oil control. Seems the ridges above the adjustment openings would reduce oil draining onto the inside of the adjustment cover,lower leak risk. Those above the cam would allow oil to concentate and drip directly onto the cam/rocker mating surfaces.

I’ve seen the blitz on some early models and the blocky sprocket tunnel cast is standard so I assume the unused head is early but later than the used head. Why they were experimenting with lighter top mounts and relaxed oil control I have no idea.


3 .. XS1 head

XS1 head


Later models differ too.


4 .. a later head

a later head


  • Thick wedge above the cam
  • oil inlet node different
  • adjustment opening ridges intact
  • this later head has the 4 bolt front left cover


5 .. and outside

and outside


  • no blitz, but definite casting mark
  • adjustment cover flange thicker than the unused head
  • has the rectangular casting on the cam sprocket tunnel and the heavier front/rear mounts-cant see here

All the heads have the walling before the inlet valves-presumably to pool oil to the front so it has to drain past the exhaust valves into the cam chain tunnel. As they all have the feed channel to the exhaust valves. The bleeding holes from the breather box are also the same.

I guess there are other differences and other heads.

Apart from these differences the unused head seems to be useable. Wonder how critical those ridges are. Guess if the covers leak and I mark cam lobe surfaces I’ll know.

Posted June 3, 2011 by xscafe in Motor - Head, Motor - Oil

Tagged with , ,