Topic: Cycle X - 850cc Piston Kit. Advice appreciated

[Zunspec]

Hello,

I have been offered a Cycle X 850cc piston kit from someone who bought one from the USA but really wanted std. pistons.  My apologies for asking but the "search" facility returns zero posts, even if I just put in Honda lol    I guess a glitch there somewhere.

The kit is destined for a std. F1 engine but I am interested in the pro's and con's of the cast 850 pistons vice a forged 836cc kit (Wiseco etc.).  If I do go big bore it would be sensible to add a cam and also flow the head etc.  I don't want to go so far that I need stronger rods but upgrade to valve springs/retainers and barrel studs would be OK.  This is not for racing, a stronger road engine is the goal.

Thank for any insights

Cheers  Geoff

[PeWe]

I did 836 for many years ago when one barrel had got a deep scratch. Then the domino effect with ported head, larger in valves, cam, valve springs, lightened alternator rotor.....
Wiseco 836 is better step since 65mm bore will make sleeves thin enough. 850 (65.5mm) is last repair for worn 836 without new sleevves.
Check Hondamans book about light port job. Cams are many to choose between.

Forum member MRieck can help you with a good kit and well done job. He ships to forum members worldwide.

[Zunspec]

Hi PeWe,

Sound advice about retaining the facility for a re-bore.  I previously thought 836cc was the limit without re-sleeving etc. Of course I can get a good deal on the bought-by-mistake 850 pistons but probably not worth it in the long run.  I recognise the route of being drawn into further upgrades   My engine has only done 9500 odd miles from new so does not really need a re-bore but the valves could do with a re-grind so I might confine my resources to a top end re-fresh, gas flow and possibly a cam that would suit an 836cc conversion at a later date.  Shame to pass on a good deal for the 850 kit but sometimes the head needs to keep the heart in check lol.

Cheers  Geoff

[teebee67]

PM sent Zunspec.

[Zunspec]

Hi Tony,

I replied via PM but don't know if it sent correctly.

Cheers  Geoff

[Cqyqte]

I have a 1975 CB750 F that underwent the 849cc piston transformation by CycleX in 2010.  At that time they called it the Streetfighter package, 

StreetFighter Package :
Parts:

CycleX Super Rods
849cc piston kit
Heavy-duty valve springs
Camshaft
Valve guides (Cycle X)
Super-Flow Exhaust valves
Super-Flow Intake valves
Heavy-duty cylinder studs
Heavy-duty cam chain
All cam chain rollers and slider
Connecting rod bearings
Main crankshaft bearings
Oil seal kit
Primary chains
Heavy-duty clutch plates
Heavy-duty clutch springs (If requested)
Complete gasket set
Late model alternator rotor
Chrome Allen screws (For engine covers)
All of the above-mentioned parts are the highest level in quality.
NOTE:  All motors will include Cycle X MLS Head Gaskets and Cycle X no leak cover gaskets.

Labor:
Completely disassemble the motor for cleaning and inspection.
Remove connecting rods and inspect all crankshaft journals.
Micro polish crankshaft and clean.
Plastic gauge all crankshaft journals and install rod and main bearings as necessary.
Remove cylinder studs.
Surface case cylinder deck and install heavy-duty cylinder studs.
Blast cylinder and inspect.
Surface cylinder deck.
Bore and hone to 849cc.
Disassemble cylinder head for inspection.
Blast cylinder head and surface both sides of the head.
Clean up ports as necessary.
Install Amco 45 valve guides and ream.
Multi-angle valve job.
Reassemble head with Heavy-duty springs.
Inspect transmission and repair if necessary.
Inspect and repair stripped threads as necessary.
Inspect oil pump and address as necessary.
Clean all components and assemble motor with all new gaskets and seals.
Check charging system components.
Set ignition timing.
And of coarse, 30 plus years of experience and secret tricks of the trade.
Install motor on test stand and fire motor.
Re-adjust valves after several start-ups.
Paint motor as per customers request.

If you are considering to do this modification yourself I would strongly suggest you review the list of parts and the work that goes into CycleX's package and be advised that if you short cut on the parts up grade or labour side you maybe creating your own grenade!  I love my Streetfighter and those that have ridden it are surprised at the get up and go performance from it.

[teebee67]

Got your PM thanks Geoff - will be in touch.
Cheers,
Tony

[Zunspec]

Hi Cqyqte,

I have decided to pass on the 850 kit, not least because of the "other" upgrades that naturally follow    I would love to cut'an paste your list into the Cycle X (or others) shopping basket and look forward to a mega engine build but not quite ready for that (yet lol).

Thanks for the feedback though, it's still a learning curve for me with the SOHC.

Cheers  Geoff

[Medyo Bastos]

ive had one in a motor for several years, and have literally beat the piss out of it with no issues

[MRieck]

ive had one in a motor for several years, and have literally beat the piss out of it with no issues

You have to respect anything that can hold urine for several years.

[Bill/BentON Racing]

LMAO,  yes you do!